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Dissertations / Theses on the topic 'Half-sandwich'

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Published: 1 April 2023

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1

McCamley, Andrew. "Photochemistry of half-sandwich complexes in matrices." Thesis, University of York, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238716.

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2

Puntambekar, Shakher Gajanan. "Half-sandwich arene iron complexes : synthesis and reactivity." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329900.

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3

Coles, Stuart Raymond. "Half-sandwich group 4 complexes in alkene polymerisation." Thesis, University of Warwick, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439647.

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4

Billah, Syed Abul Muzaddad Mustafij. "Half-sandwich indenyl and related compounds of ruthenium(II)." Thesis, University of Salford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262619.

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5

Hollandsworth, Carl B. "Full and half sandwich compounds of dimolybdenum and ditungsten." The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1095455882.

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6

Bătinaş, Aurora Alexandra. "The chemistry of half-sandwich vanadium imido-amido complexes." [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2009. http://irs.ub/rug.nl/ppn/318.

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7

Hollandsworth, Carl Burton. "Full and half sandwich compounds of dimolybdenum and ditungsten." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1095455882.

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Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xxi, 215 p.; also includes graphics (some col.). Includes bibliographical references (p. 209-215).
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8

Svačina, Zdeněk. "Příprava syndiotaktického polystyrenu pomocí monocyklopentadienylových komplexů titanu." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2008. http://www.nusl.cz/ntk/nusl-216371.

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A series of four novel halosilylsubstitued monocyclopentadienyl titanium complexes; [Si(CH3)2FCp]TiCl3 – FSiTTC, [Si(CH3)F2Cp]TiCl3 F2SiTTC, [Si(CH3)Cl2Cp]TiCl3 - Cl2SiTTC, [Si(CH3)2ClCp]TiCl3 - ClSiTTC was tested as catalytic precursors for polymerization of styrene in toluene. The maximum polymerization activity was achieved after polymerization period of 20 minutes. Activity decreased in order FSiTTC/MAO > F2SiTTC/MAO > Cl2SiTTC/MAO > ClSiTTC /MAO. Prepared polystyrenes were characterized using 13C NMR spectroscopy and DSC analysis. Syndiotacticity index of obtained PSs was determined by means of Soxhlet extraction with butan-2-one as solvent. Syndiotacticity indexes of PSs obtained by investigated catalysts possessed higher values then those obtained by standard catalysts (CpTiCl3 a Cp*TiCl3) at comparable polymerization conditions.
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9

Maddox, Tania Patricia. "Thermal and photochemical reactions of half sandwich transition metal complexes." Thesis, University of York, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284128.

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10

Capper, Glen. "Half-sandwich organoruthenium and organorhodium complexes of biologically relevant ligands." Thesis, University of Leicester, 1995. http://hdl.handle.net/2381/34044.

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This thesis describes some chemistry of [(mes)RuC12]2, [(Cp)RuCl(CO)2] and [(Cp*)RhCl2]2 complexes and in particular, the reactions with biologically relevant ligands. Chapter one introduces the general chemistry of arene-ruthenium and pentamethylcyclopentadienyl-rhodium from early work described by Winkhaus and Singer in the preparation of half-sandwich arene-rathenium complex [(C6H6)RuCl2(PPh3)] and the contributions on the reactions of [(Cp*)RhCl2]2 reported by Maitlis and co-workers. The second half of the introduction discusses the introduction and uses of inorganic complexes as anti-tumour agents. Chapter two describes the reactions of amino acids with potentially coordinating side chains with [(mes)RuCl2]2 and the characterisation of the amino acidate complexes formed. The crystal structure of the complex [(mes)RuCl(phgly)] has been determined and a high temperature 1H n.m.r. spectrum has been obtained. Chapter three describes the preparation and characterisation of a number of pyranato and pyridinato complexes of arene-ruthenium and Cp*-rhodium. A low temperature 1H n.m.r. spectrum was obtained for the complex [(Cp*)RhCl(etmalt)] and conductivity experiments were obtained which indicate that the complexes exist in water as a mixture of water or chloride co-ordinated species. Chapter four describes the reactions of a number of half-sandwich complexes of ruthenium and rhodium with nucleobases to determine the binding site(s) involved in co-ordination. A set of competition reactions were undertaken to determine any preference of the complex [(mes)RuCl(phgly)] for the various nucleobases. We have found that for this ruthenium complex, guanosine forms the most stable complexes with thymidine and uridine forming the least stable.
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11

James, J. Thomas. "Half-sandwich hydrazido and alkoxylimido complexes of the early transition metals." Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320162.

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12

Mistry, Neetisha Shantilal. "Mechanistic studies into the catalytic activity of half-sandwich ruthenium complexes." Thesis, University of York, 2013. http://etheses.whiterose.ac.uk/5282/.

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A mechanistic investigation into the catalytic activity of half-sandwich ruthenium complexes, [Ru(η5-C5H5)(L)3]+ (where L = phosphorus- or nitrogen- donating ligands ) for the alkenylation of pyridine is reported. Mechanistic studies have demonstrated that [Ru(η5-C5H5)(PPh3)(NC5H5)2][PF6] is an important intermediate in the formation of E-2-styrylpyridine derivatives. Collaboration between the reported experimental and additional theoretical studies (conducted by David Johnson) has allowed for a catalytic cycle for the alkenylation of pyridine to be proposed, highlighting the role of vinylidene and pyridylidene ligands. A general synthetic procedure for a range of [Ru(η5-C5H5)(PR3)(L)2][PF6] complexes from [Ru(η5-C5H5)(NCMe)3][PF6] was performed, where R = Ph, Me, iPr, OPh; and L = pyridine, 3-methylpyridine, 4-methylpyridine, 4-dimethylaminopyridine, 1-methylimidazole, t-butylimidazole. The properties of these complexes have been investigated. The reactivity of [Ru(η5-C5H5)(PPh3)(NC5H5)2][PF6] with terminal alkynes was investigated in two different reaction media (dichloromethane and pyridine). The stoichiometric reaction of [Ru(η5-C5H5)(PPh3)(NC5H5)2][PF6] with phenylacetylene in a dichloromethane solution generated a vinylidene-containing intermediate [Ru(η5-C5H5) (PPh3)(NC5H5)(=C=CHPh)][PF6]. This reacts further to produce a pyridylidene-containing complex [Ru(η5-C5H5)(PPh3)(κ3-C3-C5H4NCH=CHPh)][PF6]. Upon the addition of excess pyridine a 1-ruthanaindolizine species is generated. Similar observations have been made with alkynes HC≡CR (where R = 4-F-C6H4, 4-CF3-C6H4) and [Ru(η5-C5H5)(PPh3)(L)2][PF6] (where L = 3-methylpyridine, 4-methylpyridine, 4-dimethylaminopyridine) and the substituent effects and properties of the pyridylidene-containing complexes are compared to the literature. The addition of phenylacetylene or 4-ethynyl-α,α,α-trifluorotoluene to [Ru(η5-C5H5) (PPh3)(NC5H5)2][PF6] in a pyridine solution at 50 °C produces 2-substituted E-styrylpyridine derivatives in a 100 % atom efficient manner. The formation of the 1-ruthanaindolizine complex results in catalyst deactivation. A range of reaction conditions have been investigated to identify the optimum catalyst performance.
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13

Da, Lio Sebastiano <1988&gt. "HALF-SANDWICH COMPLESSI DI RUTENIO: PREPARAZIONE E REATTIVITÀ DI DERIVATI ORGANOSTANNILICI." Master's Degree Thesis, Università Ca' Foscari Venezia, 2012. http://hdl.handle.net/10579/1975.

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Sono stati sintetizzati nuovi complessi half-sandwich di rutenio del tipo [Ru]Cp, [Ru]Tp, [Ru](indene), che contengono come legante il gruppo triclorostannilico [Ru]-SnCl3 e triidrurostannilico [Ru]-SnH3. Lo studio della reattività di questi complessi con vari reagenti quali, alchini terminali, eteroalleni, acetiluri e reattivo di Grignard, hanno portato alla sintesi di nuovi complessi. In particolare, la reazione tra etilisotiocianato e [Ru]-SnH3 porta alla formazione di un nuovo complesso contenente un tiostannil come legante. Infine, si sono sintetizzati nuovi complessi stannilici Cp[Ru]-SnCl3 e Cp[Ru]-SnH3, contenenti due trimetossifosfina.
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14

Gasparato, Dario <1987&gt. "HALF-SANDWICH COMPLESSI DI OSMIO: PREPARAZIONE E REATTIVITÀ DI NUOVI DERIVATI." Master's Degree Thesis, Università Ca' Foscari Venezia, 2012. http://hdl.handle.net/10579/2027.

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Sono stati sintetizzati nuovi complessi half-sandwich di osmio del tipo [Os]Cp e [Os]Tp che contengono come legante un gruppo tricloro stannilico [Os]-SnCl3 e triidruro stannilico [Os]-SnH3. Lo studio della reattività di questi complessi con vari reagenti quali alchini terminali, etero alleni, acetiluri e reattivo di Grignard, hanno portato alla sintesi di nuovi derivati. In particolare la reazione tra etilisotiocianato con il frammento metallico [Os]-SnH3, porta alla formazione di un nuovo complesso contenente un tio-stannil come legante. Infine lo studio di complessi paracimenici di osmio permette la sintesi di nuovi diazo-alcano complessi.
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15

Capponi, Marco <1979&gt. "Preparazione e reattività di "half-sandwich" complessi con azine come leganti." Master's Degree Thesis, Università Ca' Foscari Venezia, 2016. http://hdl.handle.net/10579/7562.

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In questo lavoro di tesi è stata realizzata la sintesi dei primi complessi azinici di rutenio stabilizzati da frammenti "half sandwich" derivati da ciclopentadiene, pentametilciclopentadiene, indene, p-cimene, fosfine, fosfiti e bipiridile. Lo studio della reattività verso reazioni di sostituzione, ciclizzazione e riduzione è stato condotto sui complessi preparati. La caratterizzazione spettroscopica (IR, NMR multinucleare) ha completato il lavoro.
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16

Johnson, Tony Richard. "Vinylidene and cyclic carbene chemistry of iron and manganese half-sandwich complexes." Thesis, University of Sheffield, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340247.

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17

Scapinello, Maria Federica <1986&gt. "Preparazione e reattività di "half-sandwich" complessi di rutenio con legante indenilico." Master's Degree Thesis, Università Ca' Foscari Venezia, 2012. http://hdl.handle.net/10579/1749.

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18

Trevisan, Mauro <1989&gt. "Preparazione e reattività di "half-sandwich" carbeni complessi stabilizzati da leganti bipiridilici." Master's Degree Thesis, Università Ca' Foscari Venezia, 2016. http://hdl.handle.net/10579/9260.

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Carbeni complessi di rutenio del tipo [Ru(η5-C5Me5)(=CAr1Ar2)bpy]BPh4 1 (Ar1= Ar2= Ph a; Ar1= Ph, Ar2= p-tolyl, b; bpy= 2,2’-bipiridile) sono stati preparati trattando il cloro complesso [RuCl(μ-Cl)( η5-C5Me5)]2 prima con una quantità stechiometrica di dipiridile in presenza di zinco metallico in THF e successivamente con un eccesso dell’appropriato diazoalcano Ar1Ar2CN2usando come solvente una miscela di etanolo e diclorometano (1:1). Lo studio della reattività dei complessi 1 ha dimostrato che questi reagiscono con fosfiti per dare i prodotti di sostituzione [Ru(η5-C5Me5)(P(OEt)3)bpy]BPh4 10. Carbeni complessi di rutenio del tipo [Ru(η5-C5Me5)(=CAr1Ar2)4,4’(CH3)2bpy]BPh4 2 (, Ar1= Ar2= Ph a; Ar1= Ph, Ar2= p-tolyl, b; byp= 4,4’-dimetilbipiridile) sono stati preparati trattando il cloro complesso [RuCl(μ-Cl)( η5-C5Me5)]2 prima con una quantità stechiometrica di 4,4’-dimetilbipiridile in presenza di zinco metallico in THF e successivamente con un eccesso dell’appropriato diazoalcano Ar1Ar2CN2usando come solvente una miscela di etanolo e diclorometano (1:1). Tutti i complessi sono stati caratterizzati spettroscopicamente attraverso l’utilizzo di IR e NMR. Il carbene complesso [Ru(η5-C5Me5)(=C(Ph)p-tolyl)bpy]BPh4 1b è stato analizzato anche mediante diffrazione dei raggi X, determinando così la struttura cristallina.
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19

Brunker, Timothy J. "Studies of half-sandwich tris(pyrazolyl)borate complexes of first row transition metals." Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393565.

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20

Walters, Stephen John. "Acyl(oxy) carbene and vinylidene chemistry of iron and ruthenium half-sandwich complexes." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245691.

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21

Rovida, Giulio <1992&gt. "Preparazione e reattività di complessi half-sandwich di rutenio e un legante allilfosfinitico." Master's Degree Thesis, Università Ca' Foscari Venezia, 2019. http://hdl.handle.net/10579/14816.

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In letteratura sono presenti solo pochi esempi di reazione di cross coupling C-C [2+2] tra alchini e doppi legami direttamente legati al metallo. I prodotti ottenibili facendo reagire un complesso metallico come RuCl(η5C5H5)(PPh3)2 con un nucleofilo allil-fosfinito, come PPh2(OCH2CH=CH2) in presenza di un sale coordinante come NaPF6 sono il fulcro di questa ricerca. In questo elaborato è presentata la sintesi di complessi half-sandwich di Rutenio (II) ciclopentadienilici coordinati a leganti allilfosfinici mediante reazioni di sostituzione termica nucleofila del legante trifenilfosfina. La reattività del complesso RuCl(η5-C5H5)(PPh3)2 con allil-difenil-fosfinito, PPh2(OCH2CH=CH2), ha permesso la definizione di efficienti metodi di sintesi dei tre prodotti derivanti dal precursore catalitico in questione. La caratterizzazione dei prodotti ottenuti è stata determinata tramite tecniche IR, NMR e SC-XRD. Sono state eseguite prove di reattività sui composti ottenuti con nucleofili di differente natura: alcoli-propargilici, fosfine e diazolcani con analisi della potenziale regioselettività della via sintetica. L’analisi degli spettri NMR 1H,31P,13C ha permesso il monitoraggio delle reazioni e la caratterizzazione di ciascun prodotto. L’ottenimento di monocristalli dei prodotti ha permesso l’analisi tramite “software di refining” dei dati ottenuti dal reticolo cristallino dei prodotti ottenuti e ha permesso di conseguire una completa caratterizzazione tramite diffrazione di Raggi X. La stabilità del legame π tra il centro metallico e il doppio legame allilico ha vincolato fortemente la reattività dei complessi con la maggior parte dei nucleofili utilizzati. Solo il prodotto RuCl(η5-C5H5)(κ1-(P)-η2-PPh2OCH2CHCH2) ha permesso la sintesi di complessi metallocenici ciclici che presentano un legante di tipo κ1-(P)-η4-dienilfosfinito. Il comportamento reattivo di RuCl(η5-C5H5)(κ1-(P)-η2-PPh2OCH2CHCH2) con nucleofili alchinolinici chirali ha permesso di verificare anche una possibile diastereoselettività della via sintetica e sintetizzare i diastereoisomeri corrispondenti.
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22

Chan, Michael. "Stoichiometric and catalytic reactivity of half-sandwich imido complexes of the group 5 metals." Thesis, Durham University, 1995. http://etheses.dur.ac.uk/5209/.

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This thesis describes investigations into the chemistry of half-sandwich imido complexes of the Group 5 metals, with particular emphasis on the development of complexes which can be applied to catalytic processes. Chapter 1 provides an introduction to the imido ligand and highlights aspects of the reactivity of half-sandwich transition metal imido and related complexes. The isolobal analogy between Group 4 bent me'tallocene. Group 5 half-sandwich imido and Group 6 bis(imido) metal fragments is outlined. In Chapter 2, reactions of CpV(NR)Cl(_2) (R=2,6-(^i)Pr(_2)C(_6)H(_3), 2,6-Me(_2)C(_6)H(_3)) with alkylating agents are described, yielding a number of highly unusual products. The novel structures of [CpV(N-2,6-(^i)Pr(_2)C(_6)H(_3))(|i-Me)2]2(l^-Mg) and [CpV(fx-N-2,6-iPr2C6H3)]2(|i-Me), featuring bridging methyl and imido substituents, have been determined. The former also possesses the first crystallograghically characterised V-Mg bond and multiple agostic interactions. The aim of Chapter 3 was to evaluate the steric and electronic influence of the imido substituent in half-sandwich imido complexes of niobium. For the [CpNb(N-2-(^t)BuC(_6)H(_4))] system, the successful isolation of a number of previously unstable species has been reported. The orientations of the diphenylacetylene and the ethylene ligands in CpNb(N-2-(^t)BuC(_6)H(_4))(PhC=CPh)(PMe(_3)) and CpNb(N-2,6-Cl(_2)C(_6)H(_3))(C(_2)H(_4))(PMe(_3)) respectively have been established through crystal structures and lend support to the isolobal relationship between the [Cp(_2)Zr] and [CpNb(NR)] fragments. In Chapter 4, the tantalum dialkyl complexes Cp*Ta(N(^t)Bu)(CH(_2)R)(_2) R=Ph, CMe(_2)Ph, CMe(_3)] are described and the molecular structure of Cp*Ta(NtBu)(CH(_2)CMe(_3))') reveals multiple agostic interactions. Reactions of Cp*Ta(N(^t)Bu)(CH(_2)R)(_2) with excess C(_6)F(_5)OH yield a number of crystallographically characterised pentafluorophenoxide and oxo-bridged products, namely [Cp*Ta(CH(_2)Ph)(0C(_6)F(_5))(µ-O)](_2), Cp*Ta(OC(_6)F(_5))(_4) and [Cp*Ta(OC(_6)F(_5))(_2)(µ-0)](_2). Chapter 5 discusses attempts to develop and explore the oxidative coupling chemistry at the half-sandwich tantalum imido fragment. Hence, a number of new tantalacyclopentane complexes and related species have been prepared, including Cp*Ta(N-2,6-(^i)Pr(_2)C(_6)H(_3))(σ-l,4-(2-Et)C(_4)H(_7)) and Cp*Ta(N- 2,6-(^i)Pr(_2)C(_6)H(_3))[a-l,6-C(0)(3-Et)C(_4)H(_7)C(0)].Chapter 6 contains the experimental details for Chapter 2-5.
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23

Geddes, Keira M. "The synthesis of novel planar chiral ansa-half-sandwich metallocenes containing a ferrocene linker." Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.415022.

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24

Gasparetto, Giulia <1991&gt. "Preparazione e reattività di half-sandwich complessi di rutenio e iridio con leganti idrazinici." Master's Degree Thesis, Università Ca' Foscari Venezia, 2017. http://hdl.handle.net/10579/9759.

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Complessi idrazinici di rutenio del tipo [Ru(η5-C5(CH3)5)(H2N-N(H)R)(P(OMe)3)2]BPh4 (1, 2, 3) con R = H, CH3 , Ph sono stati preparati trattando il cloro complesso [RuCl(μ-Cl)(η5-C5(CH3)5 ]2 con un eccesso di fosfito in THF e in presenza di zinco metallico. Successivamente alla soluzione è stato aggiunto un eccesso dell'appropriata idrazina. Lo studio delle reazioni di ossidazione dei complessi 1- 3 ha dimostrato che questi reagiscono a bassa temperatura con Pb(OAc)4 per dare i rispettivi diazeni derivati del tipo [Ru(η5-C5(CH3)5)(HN=NR)(P(OMe)3)2]BPh4 (4, 5, 6). Il medesimo studio è stato applicato a complessi di iridio del tipo [IrCl2(η5-C5(CH3)5)(P(OR)3)] con R= CH3, CH2CH3. Tutti i complessi sono stati caratterizzati spettroscopicamente attraverso l’utilizzo di IR e NMR.
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25

Karpin, George W. "Synthesis and Antimicrobial Activity of Half-Sandwich Ir(III), Rh(III), and Co(III) Complexes." Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/79414.

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This dissertation describes the synthesis and antimicrobial use of a series of half-sandwich Ir(III), Rh(III), Co(III) amino acid and ethylenediamine complexes. This investigation focuses on the formulation (ηn-arene)M(L)X, (L = ethylenediamine or α-amino carboxylate), (M= Ir, Rh, Ru, Co). Arene, Ligand and metal center variations were designed to tailor antimicrobial activity specific for each organism studied (Staphylococcus aureus or Mycobacteria). Each of the D/L-amino acids formed a diasteromeric complex with chiral centers on both the metal center and amino acid ligand. The unique chirality of each center elicits different antimicrobial activity against the Mycobacteria studied. The metal center (M), arene ligand (ηn-arene), and amino acid (aa), were changed independently and studied for the antimicrobial activity. In a similar fashion, each of the complexes modified with ethylenediamine and diamine derivatives were studied for their antimicrobial activity against S.aureus. All complexes were synthesized,characterized by nuclear magnetic resonance (NMR), high-resolution mass spectroscopy (HRMS), single-crystal X-ray diffraction, and elemental analysis. During the course of this work it was found that the amino acid complexes with all metal centers were specific for antimicrobial activity against all types of Mycobacteria, while the diamine derivatives were active against different strains of S.aureus. Acitvity was measured to be as low as 2 ug/mL respectively depending on the complex used. A structure activity relationship was developed to determine what combinations of ligand, metal and arene were necessary to achieve the highest antimicrobial activity. The optimal arene R-chain length for CpR was determined to be R=hexyl for all complexes studied. The most active amino acidcomplex was determined to be that of L-phenylglycine for Mycobacteria, the cis-1,2-diaminocyclohexane complex is the most active ligand against S.aureus. Each metal center had similar activity levels. Toxicological studies were performed to test their viablity to be used in mammalian systems. The complexes with the highest activity were studied against several mammailan cell lines and revealed that mammailan cells were undergoing normal cellular processes at up to 40 times the minimal inhibitory concentration (MIC). A study of the MOA or mechanism of action revealed the ability of the amino acid complexes to affect the peptidyl transferase region on the 23s ribosomal subunit of M.smegmatis. This was accomplished by isolating resistant strains of M.smegmatis towards the most effective complex (Cp*hexyl)Ir(L-phenylglycine)-Cl. Cross drug resistance of these mutants was shown with clarithromycin. The DNA of the 23s ribosomal subunit was sequenced revealing a deletion/insertion mutation within domain V (bases 2057-2058).
Ph. D.
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26

Assoua, Mebi Charles. "Half-sandwich ruthenium (II) complexes of 1,3,5-triaza-7-phosphaadamantane syntheses, reactivity, and catalytic application /." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3258845.

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27

Poole, Andrew D. "Half-sandwich imido and related complexes of niobium and tantalum : relatives of the Zirconocene family." Thesis, Durham University, 1992. http://etheses.dur.ac.uk/5809/.

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This thesis describes studies directed towards the preparation of half- sandwich niobium and tantalirai compounds containing imido and phosphino-carbene ligands, with particular emphasis on the relationship of such species with bent metallocene complexes of the Group 4 triad. Chapter 1 highlights areas of transition metal chemistry of relevance to the general theme of this thesis, including reviews of metal imido and zirconocene chemistry. Chapter 2 describes the use of silylated anilines for convenient solution syntheses of half-sandwich imido complexes of niobium and tantalum of the type Cp'M(N-2,6-(^i)Pr(_2)-C(_6)H(_3))Cl(_2)(Cp' = Cp, Cp*). In addition, the syntheses and reactivities of mono- and bis-alkyl derivatives (methyl, neopentyl, and benzyl) are presented. The bis-neopentyl complexes CpNb(NR)(CH(_2)CMe(_3))(_2) (R = CMe(_3); 2,6-(^i)Pr(_2)-C(_6)H(_3)), reveal multiple a-agostic interactions which have been primarily studied via an X-ray crystal structure determination and NMR spectroscopy. Thermolysis of Cp*Nb(N-2,6-(^i)Pr(_2)-C(_6)H(_3))(CH(_2)Ph)(_2) in die presence of PMe(_3) affords die benzylidene complex Cp*Nb(N-2,6-(^i)Pr(_2)-C(_6)H(_3))(η(^1)-CHPh)(PMe3) whose X-ray crystal structure has been determined. Chapter 3 describes the preparation of the niobium and tantalum imido complexes Cp'M(N-2,6-(^i)Pr(_2)-C(_6)H(_3))(L)(PMe(_3)) (M = Nb, L = C(_2)H(_4), C(_3)H(_6), CO, Me(_2)C(_2). Ph(_2)C(_2), C(_6)H(_4), PMe(_3); M = Ta, L = C(_2)H(_4), C(_3)H(_6), CO). Single crystal structure determinations on CpNb(N-2,6-(^i)Pr(_2)-C(_6)H(_3))(η(^2)-C(_3)H(_6))(PMe(_3)) and CpNb(N-2,6-(^i)Pr(_2)-C(_6)H(_3))(η(_2)-C(_6)H(_4))(PMe(_3)) have been undertaken and their relationship to Group 4 metallocenes noted. Treatment of Cp*Ta(N-2,6-(^i)Pr(_2)-C(_6)H(_3))(L)(PMe(_3)) (L = C(_2)H(_4),C(_3)H(_6)) with a-olefins was found to lead to displacement of PMe(_3) and the generation of tantallacycle containing species. Chapter 4 compares the reactivity of tantalum imido and phosphino-carbenederivatives of the form Cp*Ta(E)(H)(X)(PMe(_3)) (E = N-2,6-(^i)Pr2-C(_6)H(_3), η(^2)-CHPMe(_2); X = H, I) with a number of a-olefins. Investigations into die mechanism of catalytic oligomerisation of a-olefins by Cp*Ta(η(^2)-CHPMe(_2))(H)(_2)(PMe(_3)) reveal that pathways involving metallacycle intermediates are most probable, whereas Cp*Ta(N-2,6-(^i);Pr(_2)-C(_6)H(_3))(H)(_2)(PMe(_3)) reacts with a-olefins to afford stable tantallacycle complexes. The reactivity of die dihydrido species has been moderated by the preparation of mono- iodide derivatives and their reactivity towards a-olefins studied. Cp*Ta(η(^2)-CHPMe(_2))(H)(I)(PMe(_3)) dimerises ediylene selectively to but-1-ene, while Cp*Ta(N-2,6-(^i)Pr(_2)-C(_6)H(_3))(H)(I)(PMe(_3)) reacts with ethylene to form die stable ethyl species Cp*Ta(N-2,6-(^i)Pr(_2)-C(_6)H(_3))(Et)(I). Furtherrmore, studies investigating a variety of niobium and tantalum imido species as possible catalysts for die oligomerisation and polymerisation of a-olefins under industrially relevant conditions have been undertaken in collaboration with B.P. Chemicals Ltd.. Chapter 5 gives experimental details for chapter 2-4.
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28

Alharis, Raed Awad Aubed. "Electronic effect on C-H activation at half sandwich complexes of Ir, Rh and Ru." Thesis, University of Leicester, 2018. http://hdl.handle.net/2381/41219.

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A range of cyclometallated half-sandwich complexes have been synthesised in good yields by reactions of [MCl2Cp*]2 (M = Ir, Rh) or [RuCl2(p-cymene)]2 with different para-, meta- (NMe2, OMe, Me, F, CF3 and NO2) and ortho- ( R= Me and NO2) substituted 1-phenylpyrazole ligands in the presence of NaOAc. All complexes were characterised by using 1H, 13C, 2 D NMR spectroscopy, ESI-MS and several compounds have been structurally characterised by X-ray crystallography. DFT calculations (carried out by the group of Prof. S. A. Macgregor, Heriot-Watt University) are also discussed. Chapter one gives an overview of the mechanisms of C-H activation including AMLA and CMD and the synthesis of cyclometallated complexes, in particular of Ir, Rh and Ru. Catalytic C-H functionalisation by AMLA/CMD C-H activation is introduced. Chapter two describes the synthesis and characterisation of half-sandwich cyclometallated Ir(III), Rh(III) and Ru(II) complexes from different para- and ortho-substituted 1-phenylpyrazoles. Chapter three provides an introduction to the regioselectivity of acetate assisted cyclometallation in the literature and the synthesis and characterisation of a range of half-sandwich Ir(III), Rh(III) and Ru(II) cyclometallated complexes with different meta-substituted 1-phenylpyrazoles. NMR spectroscopy was used to determine isomer ratios and deuteration experiments and computational studies were used to evaluate whether the selectivity is kinetic or thermodynamic in origin. Chapter four gives a brief introduction on the use of Hammett plots to investigate reaction mechanisms. Competition reactions between different para- and meta- substituted 1-phenylpyrazoles were used to study the electronic effects of the substituents on the cyclometallation. The results show that ligands with electron donating groups react faster whilst those with electron withdrawing groups give more thermodynamically stable products. The experimental results agree well with those from DFT calculations. Chapter five includes all the experimental work and characterisation data of discussed in Ch.2, Ch.3 and Ch.4.
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29

Melis, Diana. "Quinoline-triazole half-sandwich iridium(III) complexes: Synthesis, antiplasmodial activity and preliminary transfer hydrogenation studies." Master's thesis, Faculty of Science, 2020. http://hdl.handle.net/11427/32414.

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Malaria is a devastating and pervasive infectious disease and continues to be a major global health issue, with over half the world's population being at risk of transmission. In the absence of a suitable vaccine, efforts to eradicate the disease rely heavily on clinically available drugs. Plasmodium falciparum, the deadliest species of malaria, has however become resistant to most conventional antimalarial treatments, resulting in the worldwide search for new, effective drugs. Amongst other requirements, these drugs should target resistant parasitic strains in an attempt to curb the escalation of the disease. In this regard, the incorporation of a metal into the organic framework of a biologically active compound has become an increasingly popular method of enhancing antiplasmodial activity in the drug-resistant parasite strains. Two series of 7-chloroquinoline-1,2,3-triazole ligands, one with the direct attachment of the triazole to the quinoline and one where the two entities are separated by an aminopropyl linker, were synthesised. Coordination of selected ligands with [IrCl(μ-Cl)(Cp*)]₂ yielded six neutral, cyclometallated and two cationic,N,N-chelated iridium complexes. Computational analysis revealed that metal coordination to the quinoline nitrogen occurs first, forming an unstable kinetic product that, upon heating over time, forms the stable, cyclometallated, thermodynamic product. All of the compounds were fully characterised using an array of spectroscopic (¹H, ¹³C{¹H}, ¹⁹F{¹H}, ³¹P{¹H} NMR and FT-IR spectroscopy) and analytical (mass spectrometry and melting point analysis) techniques. Single crystal X-ray diffraction confirmed the proposed molecular structure and a pseudo-tetrahedral geometry around the metal centre for the cyclometallated and monodentate, quinoline nitrogen-coordinated complexes. The ligand series containing the propyl chain linker displayed superior in vitro antiplasmodial activity against the chloroquine-sensitive NF54 strain of P. falciparum in comparison with the series having thetriazole directly attached to the quinoline moiety. Upon complexation with iridium, the activity of selected ligands is significantly enhanced (0.247< IC₅₀ (μM)< 2.34), with some complexes being over one hundred times more active than their respective ligands. For most of these compounds, their antiplasmodial activity is lower in the chloroquine-resistant K1 strain, however, their calculated RI values suggest that they likely only experience mild cross-resistance, not to the same extent of chloroquine. Selected complexes were tested against the healthy, mammalian Chinese Hamster Ovarian (CHO) cell line and were found not to be cytotoxic. They were also determined to be more selective towards the parasite than healthy cells. An “IC₅₀ speed assay” using the three most active complexes against the chloroquine-sensitive NF54 strain found the two neutral, cyclometallated complexes to be fast-acting compounds which reach their lowest IC₅₀ values within 24 hours, while the active cationic complex was determined to be slow-acting, only reaching its lowest IC₅₀ value after 48 hours. To gain insight into the possible mechanisms of action of these compounds, selected ligands and complexes were tested for their ability to inhibit the formation β-haematin(the synthetic form of haemozoin), sinceone of the mechanisms of 7-chloroquinoline-containing compounds is the inhibition of haemozo information. All five of the tested compounds were found to inhibit β-haematin formation to some extent but were, in general, less effective β-haematin inhibitors than chloroquine itself. Interestingly, the aminopropyl-containing cationic complex which displayed the lowest antiplasmodial activity exhibited far greater β-haematin inhibitory activity (IC₅₀ 9.65 μM) than chloroquine(IC₅₀ 65.3 μM).Finally, three of the most active complexes were evaluated for their ability to facilitate transfer hydrogenation, by reducing β-nicotinamide adenine dinucleotide (NAD+) to NADH in the presence of hydrogen source, sodium formate. Through preliminary qualitative and quantitative cell-free experiments, it was found that the two most active neutral, cyclometallated complexes tested may be capable of acting as transfer hydrogenation catalysts while the active, cationic complex tested did not indicate reduction of NAD+ to NADH over 4 hours.
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30

Lev, Daniel Abraham. "Group 8 and 9 half sandwich complexes of N-heterocyclic phosphines : synthesis, reactivity, and catalysis /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3158465.

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31

Čubrilo, Jadranka. "Contributions to the chemistry of arene ruthenium half sandwich complexes complexes bearing labile chalcogen ligands and alkynol coupling reactions /." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-33824.

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32

Wang, Min [Verfasser], and Michael [Akademischer Betreuer] Buchmeiser. "Synthesis of half-sandwich group 4 transition metal catalysts for tandem ring-opening metathesis/vinyl insertion polymerization / Min Wang ; Betreuer: Michael Buchmeiser." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://d-nb.info/1118369459/34.

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33

Roberts, Hannah Nike. "The use of molecular design to fine-tune the redox properties and electronic structure of half-sandwich group 6 metal acetylide complexes." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/the-use-of-molecular-design-to-finetune-the-redox-properties-and-electronic-structure-of-halfsandwich-group-6-metal-acetylide-complexes(622ea5ae-2d9c-4523-ace3-165e51e93be5).html.

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Chapter One introduces the chemistry of organometallic acetylide complexes, with a particular focus on complexes containing redox active half sandwich end-capping groups. Carbon chain complexes containing these auxiliaries are of particular interest for the development of molecular materials with: electronic, magnetic, luminescence and optical properties. An overview of the research undertaken in these areas and the spectroscopic analysis has been explored. Chapter Two describes the synthesis of the cycloheptatrienyl tungsten complexes: [W(C=CHR)(dppe)(η-C7H7)]+ and [W(C≡CR)(dppe)(η-C7H7)]. In common with the molybdenum counterparts, the structural and spectroscopic properties of these systems are controlled by the electronic structure of the W(dppe)(η-C7H7) auxiliary which has a frontier orbital with dz2 character. Chapter Three compares two series of cyclopentadienyl molybdenum alkynyl complexes, cis-[Mo(C≡CR)(CO)(dppe)Cp'] and trans-[Mo(C≡CR)(CO)(PMe3)2Cp'] (Cp' = Cp or Cp*). The change in molecular geometry leads to enhanced alkynyl character in the HOMO of the cis derivatives when compared to the mainly metal-centred HOMO of the trans complexes. This work indicates the potential for a switchable redox response, via perturbation in electronic structure controlled by changes in molecular geometry. Chapter Four assesses the effect of elongation of the all-carbon chain on the redox chemistry and electronic structure. The synthesis, spectroscopy and electronic structure of the cycloheptatrienyl Group 6 metal complexes, [M{(C≡C)n-SiMe3)(L2)(η-C7H7)] (M = W, n = 2, L2 = bpy; M = Mo, n = 3, L2 = bpy or dppe) has been investigated. In the dppe series, chain extension serves to increase the carbon chain character of the HOMO. Chapter Five explores general conclusions derived from this thesis and the potential future work.
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34

Hu, Wanning [Verfasser], and Ulrich [Akademischer Betreuer] Schatzschneider. "Organometal half-sandwich complexes and their bioconjugates: Biological activity on cancer cells and potential applications in biolabelling / Wanning Hu. Betreuer: Ulrich Schatzschneider." Würzburg : Universität Würzburg, 2013. http://d-nb.info/1109770944/34.

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35

Morris, David. "Design and Modification of Half-Sandwich Ir(III), Rh(III), and Ru(II) Amino Acid Complexes for Application in Asymmetric Transfer Hydrogenation Reactions." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/71819.

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This dissertation describes the design and synthesis of a series of half-sandwich amino acid complexes of the form), (aa = α-amino carboxylate), and their utility as asymmetric transfer hydrogenation catalysts of ketones. Variation of the metal center, the n-ring, and the aa was used to tune these systems for specific sets of ketones. Upon reaction with homochiral]s, the ligand environment in all of these complexes is pseudotetrahedral, leading to stereogenic metal ions (SM, RM). The addition of another stereogenic center from the amino acid ligand (the carbon, RC or SC;glycine) gives rise to two pairs of diastereomeric complexes.
Ph. D.
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36

Yu, Yan [Verfasser], and Peter [Akademischer Betreuer] Burger. "Synthetic, Structural, Spectroscopic and Electrochemical Studies of Dinuclear bis μ-Oxo-Bridged Molybdenum(IV) and Tungsten(IV) Half-Sandwich Complexes / Yan Yu. Betreuer: Peter Burger." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2014. http://d-nb.info/1052996701/34.

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37

Henrion, Mickaël. "Synthesis and homogeneous catalytic applications of nickel(II)-N-heterocyclic carbene complexes." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAF057/document.

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Une étude détaillée a été effectuée sur des composés organométalliques de carbènes N-hétérocycliques (NHC) de nickel(II), et plus particulièrement sur des complexes demi-sandwich nickel(II)−NHC. Ces complexes ont montré des activités sans précédent en catalyse homogène, notamment en α-arylation de cétones acycliques, où des charges en pré-catalyseur de seulement 1 mol% ont pu être utilisées. L' étude mécanistique de cette réaction tend à montrer l'implication d'intermédiaires radicalaires. De plus, ces complexes demi-sandwich se sont révélés être des pré-catalyseurs performants en hydrosilylation de dérivés carbonylés et d'imines. Les méthodologies qui en découlent fournissent de façon efficace et sélective les produits de réduction correspondants, dans des conditions réactionnelles douces. Un intermédiaire réactionnel demi-sandwich de type nickel−hydrure, agissant probablement comme le véritable précurseur catalytique, a en outre pu être isolé. D'autre part, la synthèse de nouveaux complexes Ni−NHC a remarquablement mené à une nouvelle méthodologie de substitution du ligand cyclopentadienyl dans des dérivés demi-sandwich alkyl,NHC−Ni. Enfin, l'utilisation de NHCs moins classiques, comme les NHCs possédant un squelette malonate, ou encore les carbènes (alkyl)(amine) cycliques, a mené à l'isolement de nouveaux complexes carbéniques de nickel(II), dont les premiers résultats catalytiques sont encourageants
A detailed study has been conducted on organometallic compounds of N-heterocyclic carbenes (NHC) of nickel(II), in particular on half-sandwich nickel(II)−NHC complexes. These complexes showed unprecedented catalytic activity in homogeneous catalysis, especially in the α-arylation of acyclic ketones, where catalyst loadings as low as 1 mol% could be used. Mechanistic experiments suggest that radicals are implied. Furthermore, these half-sandwich complexes proved to be efficient pre-catalysts in the hydrosilylation of carbonyl compounds and imines, allowing the reduction processes to proceed under mild reaction conditions. During the course of these studies, a half-sandwich nickel−hydride intermediate that probably acts as the true pre-catalyst was isolated. Remarkably, the synthesis of new Ni−NHC complexes led to a methodology for cyclopentadienyl ligand substitution in stable 18-electron alkyl,NHC−Ni derivatives. Finally, the use of less common NHC ligands, such as NHCs possessing a malonate backbone, or else, the use of cyclic (alkyl)(amino) carbenes, led to the isolation of new nickel−carbene complexes, which gave encouraging preliminary catalytic results
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38

Assim, Khaybar. "Synthese und Charakterisierung von Übergangsmetallkomplexen zur Herstellung von nanostrukturierten Materialien." Doctoral thesis, Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-224679.

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Die vorliegende Dissertation beschäftigt sich mit der Synthese und Charakterisierung von Übergangsmetallkomplexen und deren Anwendungen in der MOCVD (= metal-organic chemical vapor deposition), sowie als Precursoren zur Darstellung von Nanopartikeln und Nanokompositen. Ein Schwerpunkt dieser wissenschaftlichen Arbeit liegt dabei in der Entwicklung von Me-, tBu- und SiMe3-substituierten Manganhalbsandwichkomplexen für die Generierung dünner Mangan-basierter Schichten mittels MOCVD-Technik. Die gezielte strukturelle Veränderung des Cyclopentadienyl-Liganden beeinflusst die physikalischen und chemischen Eigenschaften dieser Verbindungen, welche systematisch untersucht werden. Ein weiteres zentrales Thema dieser Arbeit ist die Entwicklung von Bis(β-diketonato)- und Allyl-(β-diketonato)-palladium(II) Verbindungen als MOCVD-Precursoren. Hierbei dienen asymmetrische β-Diketonate des Typs CH3COCCO(CH2)n (n = 3, 4) als Liganden. Zudem wird durch Substitutionsreaktionen mit Me- und tBu-Gruppen am η3-Allyl-Liganden Einfluss auf die Stabilität der Verbindungen genommen. Die Abscheidung dieser Precursoren führt, in Abhängigkeit des verwendeten Reaktivgases, zur Bildung von Palladium- bzw. Palladiumoxid-Schichten. Zudem wird die Synthese und Charakterisierung von Co(II)-Carboxylaten des Typs [Co(CO2CRR´(OC2H4)nOMe)2] (n = 1, 2; R = H, R´ = Me; R = H, R´ = Ph) beschrieben. Stellvertretend wird eine Verbindung als Single-Source Precursor zur Darstellung von Co3O4-Nanopartikeln eingesetzt. Darüber hinaus wird die Inkorporation von Co3O4-Nanopartikel in organisch-anorganische Hybridmaterialien mittels Zwillingspolymerisation vorgestellt.
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39

Ahmad, Shah Masood. "Filling the Structure-Reactivity Gap: in silico approaches to rationalize the design of molecular catalysts." Doctoral thesis, Università degli studi di Padova, 2019. http://hdl.handle.net/11577/3422346.

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The design of molecular catalysts is an ambitious task implying the fundamental issue of relating the molecular structure to the reactivity, i.e., to the catalytic activity. The rationalization of the experimental data is often not straightforward and mechanistic schemes are not transferrable when the conditions of the process are changed or the catalyst is modified even slightly. Computer-aided investigations proved to be a more and more valid support in the last decade, but in most of the cases the aim is limited to investigate in detail the catalytic mechanism of a specific reaction and no general conclusions are drawn that can be used as a guide for designing novel catalysts for the same or analogous processes. In this Project, a computational approach has been set up to investigate the family of organometallic complexes displaying catalytic activity toward [2+2+2] cycloadditions of unsaturated molecules. In a recent book (Transition-metal-mediated aromatic ring construction, John Wiley & Sons, 2013, Chapter 4), Ken Tanaka describes Rhodium mediated [2+2+2] cycloadditions and writes ‘…Although mechanistic aspects of these reactions attract interest, only a few studies have been reported in specific catalysts and substrates…’. Thus this project, abbreviated with the acronym of STREGA (Filling the Structure-Reactivity Gap: in silico approaches to rationalize the design of molecular catalysts), aims at filling the gap between the goldmine of experimental data on this class of very important reactions and their mechanistic rationalization with the purpose of outlining the essential electronic and structural features of the catalyst leading to optimal performance, selectivity, and product yield. In particular, the roles of different metal, different ancillary ligands, different aromatic ligands, and substrates have been accurately investigated; existing data from the literature were also employed for this analysis. Larger polycyclic ligands can in principle host more than a metal center; for example, Cr can be coordinated to the benzene moiety of a rhodium indenyl complex. This might lead to interesting inter metal cooperative effects which might enhance or inhibit the catalytic activity; thus bimetallic catalysts have been considered. The effect of different cooperative metal nuclei was explored changing from Cr to Mo and W, which all belong to Group 6. Finally, the role of the polycyclic aromatic ligand was investigated and found that indeed it is an important factor since it influences rhodium hapticity and consequently its reactivity. All these results allowed to establish a solid structure-activity relationship which is of general validity for rhodium half-sandwich catalysts towards alkyne [2+2+2] cycloadditions and likely is transferrable to analogous Co, Ru, and Ir based fragments.
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40

Jing-Chang, Kuo, and 郭憬忠. "Preparation and Application of Half-Sandwich Metallocene." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/82917229361865706501.

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碩士
國立中正大學
化學工程研究所
89
In this work, our research has been focused on the following two topics, which involve using the half-sandwich metallocene complexes as the polymerization catalysts. 1.To develop new catalyst composition for the syndiospecific polymerization of styrene. 2.To study the cyclo-copolymerization of 1,5-headiene with norbornene for the preparation of a novel cyclic polymer. In the first part of our studies, we have used the Group II and Group III cyclopentadienyl complexes as one of the catalyst component to combine titanium alkoxide and MAO for in situ generating the active catalyst for syndiospecific polymerization of styrene. Experimental results clearly indicate the reaction between Group II and Group III cyclopentadienyl complexes and titanium alkoxide lead to the formation of a cyclopentadienyl containing titanium complex (a half-sandwich metallocene catalyst), which is responsible for the high reactivity in the current catalyst system. In the second part of our work, the preparation of a new cyclopolymer is accomplished by using a half-sandwich metallocene catalyst to undergo the cyclo-copolymerization of 1,5-hexadiene and norbornene. Experimental results show that the new cyclic copolymer has a higher glass transition temperature comparing with the polymer prepared from the homo-cyclopolymerization of 1,5-hexadiene. Structural analyses by 1H 13C NMR clearly indicate the incorporation of norbornene as comonomer in the resulting copolymer.
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41

"Synthesis and structural characterization of half- and full-sandwich group 4 metallacarboranes." 2002. http://library.cuhk.edu.hk/record=b5891274.

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Kwong Wai-chuen.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2002.
Includes bibliographical references (leaves 98-102).
Abstracts in English and Chinese.
Acknowledgement --- p.I
Abstract (in English) --- p.II
Abstract (in Chinese) --- p.III
Abbreviation --- p.V
List of Compounds --- p.VI
Contents --- p.VII
Chapter Chapter 1. --- Introduction
Chapter 1.1 --- Metallacarboranes of the C2B4 Systems --- p.1
Chapter 1.1.1 --- Group 1 Metallacarboranes of the C2B4 Systems --- p.3
Chapter 1.1.2 --- Group 4 Metallacarboranes of the C2B4 Systems --- p.6
Chapter 1.2 --- Group 4 Metallacarboranes of the C2B9 Systems --- p.17
Chapter 1.3 --- Group 4 Metallacarboranes of the C2B10 Systems --- p.35
Chapter 1.4 --- Applications of Group 4 Metallacarboranes --- p.44
Chapter 1.5 --- Research Objectives --- p.47
Chapter Chapter 2. --- Synthesis and Structural Characterization of Group4 Metallacarboranes of the C2B9 Systems
Chapter 2.1 --- Synthesis and Structural Characterization of {{466}4:η2-[(C6H5CH2)2C2B9H9]2ZrCl(THF)} {Na(THF)3} --- p.48
Chapter 2.2 --- Synthesis and Structural Characterization of [η4:η2- {(C6H5CH2)2C2B9H9} 2ZrCl(THF)] [Li(THF)4] --- p.54
Chapter 2.3 --- Synthesis and Structural Characterization of ZrCl[N(SiMe3)2]3 --- p.57
Chapter 2.4 --- "Synthesis and Structural Characterization of η2-(C6H5CH2)2C2B9H9]M(NEt2)2(NHEt2HCH2Cl2) (M = Ti, Zr)" --- p.62
Chapter 2.5 --- "Synthesis and Structural Characterization of [μ-{ o-C6H4(CH2)2 }C2B9H9]2M(THF)2 (M = Zr, Hf)" --- p.68
Chapter 2.6 --- Conclusion --- p.71
Chapter Chapter 3. --- Synthesis and Structural Characterization of Group4 Metallacarboranes of the C2B10 Systems
Chapter 3.1 --- "Synthesis and Structural Characterization of {{471}-l,，2-(o-C6H4(CH2)2)- 1,2-C2B 10H10]2Zr} {Na(THF)3}2 and {[μ-l，2-(o-C6H4(CH2)2)-l,2- C2B10H10]2ZrCl2} {Na(THF)3}2(THF)" --- p.72
Chapter 3.2 --- Conclusion --- p.78
Chapter Chapter4. --- Summary --- p.79
Chapter Chapter5. --- Experimental Section --- p.81
References --- p.98
Appendix
Chapter I. --- Crystal Data and Summary of Data Collection and Refinement --- p.103
Chapter II. --- Atomic Coordinates and Thermal Parameters --- p.109
Chapter III. --- Bond Distances and Angles --- p.117
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42

Paciello, Rocco Angelo. "Synthesis and Reactivity of Electron-Rich Ruthenium and Iron Half-Sandwich Complexes." Thesis, 1987. https://thesis.library.caltech.edu/11846/2/Paciello_RA_1987.pdf.

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Late transition metal organometallic complexes, Cp*(PR3)2MX (Cp* = η5-C5Me5), with highly electron donating ligand sets have been synthesized and their reactivity studied. Synthetic routes which allow systematic variation of metal (Ru, Fe), phosphines (PMe3, PEt3, PnBu3, PMe2Ph, DMPE), and sigma-bonded ligands (halide, hydride, alkyl, heteroatom) have been developed.

Thermally and photochemically induced ligand loss from these complexes has been studied. Trapping and C-H bond activation chemistry have been observed for the transient [Cp*(PR3)MX] complexes produced upon ligand loss. The reactivity of analogous ruthenium and iron complexes is compared and discussed.

The Ru(IV) complex, Cp*(PMe3)RuH3, has been prepared and isolated. This complex is found to catalyze H-D exchange, and hydrogenations of unsaturated organic species. The analogous Fe(IV) complex, Cp*(PMe3)FeH3, has been prepared and observed spectroscopically. Hydrogen bonding modes in these polyhydrides are discussed. Highly fluxional Cp*(PMe3)FeH3 is proposed to be in equilibrium with Cp*(PMe3)Fe(η2-H2)H.

An equilibrium method for the determination of relative Ru-X and Ru-Y bond strengths in Cp*(PMe3)2RuX has been developed. A linear correlation of Ru-X to H-X bond strengths has been found over a wide range of ligands, X. The relationship is found to be general for a number of metal centers.

A study of the kinetics of phosphine exchange for Cp*(PMe3)2RuX has been undertaken. The rate of phosphine loss can be abstracted from a treatment of the kinetics of approach to equilibrium. Lone pairs on X are found to promote ligand dissociation. Dative bond dissociation enthalpies are obtained if small, and constant, barriers for ligand recombination are assumed. The functional group approximation used in solution thermochemical studies is found to break down when large changes are made in the steric constraint at the metal center.

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Pitto-Barry, Anaïs, A. South, A. Rodger, and Nicolas P. E. Barry. "The synthesis and unexpected solution chemistry of thermochromic carborane-containing osmium half-sandwich complexes." 2015. http://hdl.handle.net/10454/11260.

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Yes
The functionalisation of the 16-electron complex [Os(η6-p-cymene)(1,2-dicarba-closo-dodecarborane- 1,2-dithiolato)] (1) with a series of Lewis bases to give the 18-electron complexes of general formula [Os(η6-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)(L)] (L = pyridine (2), 4-dimethylaminopyridine (3), 4-cyanopyridine (4), 4-methoxypyridine (5), pyrazine (6), pyridazine (7), 4,4’-bipyridine (8) and triphenylphosphine (9)) is reported. All 18-electron complexes are in equilibrium in solution with the 16-electron precursor, and thermochromic properties are observed in some cases (2, 3, 5, 8, and 9). The binding constants and Gibbs free energies of the equilibria are determined using UV-visible titrations and their stabilities investigated. Synthetic routes for forcing the formation of the 18-electron species are proposed, and analytical methods to characterise the equilibria are described.
We thank the Leverhulme Trust (Early Career Fellowship No. ECF-2013-414 to NPEB), and the University of Warwick (Grant No. RD14102 to NPEB).
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44

Yang, Jin. "The study of ruthenium(II) half-sandwich phosphido complexes containing pentamethylcyclopentadienyl (Cp*) ligand." Thesis, 2016. http://hdl.handle.net/1828/7678.

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Previous work in the Rosenberg group showed that the half-sandwich complexes Ru(η5-indenyl)Cl(PR2H)(PPh3) (2i), where R = cyclohexyl (Cy), isopropyl (Pri), phenyl (Ph), para-tolyl (Tolp), react with the strong, bulky base KOBut to give highly reactive complexes Ru(η5-indenyl)(PR2)(PPh3) (6i) containing a ruthenium-phosphorus double bond, Ru=PR2. The reactions of these phosphido complexes 6i with some reagents, such as alkenes, carbon monoxide and dihydrogen, illustrate their rich and varied reactivity. To better understand the mechanisms of these reactions (whether the indenyl effect is necessary), synthesis of analogous secondary phosphine complexes containing the pentamethylcyclopentadienyl (Cp*) ligand, Ru(η5-Cp*)Cl(PPh3)(PR2H) (2) were prepared via ligand substitution at Ru(η5-Cp*)Cl(PPh3)2 (1). Cp* phosphido complexes Ru(η5-Cp*)(PR2)(PPh3) (6) were generated in situ and their reactivity was investigated to see if they behaved similarly to the indenyl complexes. Experimental evidence in this thesis suggests that variable hapticity is not necessary in our indenyl system. In addition, these experimental evidence highlights enhanced lability of ligand at the bulky Cp*Ru fragment and higher Bronsted basicity of the phosphido ligand (PR2-) in Cp* phosphido 6 relative to the indenyl analogues 6i.
Graduate
2017-12-11
0488
yangjin@uvic.ca
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45

"Half-sandwich group 4 metallacarborane monoamides and their application in synthesis of 2-aminoimidazoles." 2012. http://library.cuhk.edu.hk/record=b5894909.

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Wang, Yang.
"October 2011."
Thesis (M.Phil.)--Chinese University of Hong Kong, 2012.
Includes bibliographical references (leaves 87-92).
Abstracts in English and Chinese.
Acknowledgement --- p.I
Abstract (in English) --- p.III
Abstract (in Chinese) --- p.IV
Abbreviation --- p.V
List of Compounds --- p.VI
List of Figures --- p.IX
Contents --- p.X
Chapter Chapter 1 --- Introduction --- p.1
Chapter 1.1 --- Synthesis and Structure of Half-Sandwich Group 4 Metallocarboranes Containing the Dicarbollyl Ligand --- p.2
Chapter 1.2 --- Half-Sandwich Group 4 Metallacarboranes Catalyzed Reactions --- p.20
Chapter 1.2.1 --- Polymerization of Olefins --- p.20
Chapter 1.2.2 --- Catalytic Dimerization and Hydrogenation of Alkynes --- p.22
Chapter 1.2.3 --- Catalytic Addition of Amines to Carbodiimides --- p.23
Chapter 1.2.4 --- Catalytic Transamination of Guanidines --- p.24
Chapter 1.2.5 --- Catalytic Synthesis of A^-Heterocycles --- p.25
Chapter 1.3 --- Research Objectives of This Thesis --- p.26
Chapter Chapter 2 --- Half-Sandwich Group 4 Metallacarborane Monoamindes --- p.27
Chapter 2.1 --- Introduction --- p.27
Chapter 2.2 --- Synthesis of Dicarbollyl Ligands Bearing Functional Side Arms --- p.27
Chapter 2.3 --- Synthesis and Characterization of Half-Sandwich Group 4 Metallacarborane Monoamindes --- p.33
Chapter 2.4 --- Summary --- p.43
Chapter Chapter 3 --- Synthesis of 2-Aminoimidazoles Catalyzed by Half-Sandwich Titanacarborane Monoamide --- p.44
Chapter 3.1 --- Introduction --- p.45
Chapter 3.2 --- Known Methods for the Synthesis of 2-Aminoimidazole --- p.44
Chapter 3.2.1 --- Condensations Methods --- p.44
Chapter 3.2.2 --- Direct Introduction of N at C2 Position --- p.46
Chapter 3.2.3 --- Heterocyclic Exchange Reactions --- p.47
Chapter 3.2.4 --- Transition Metal Catalyzed Reactions --- p.48
Chapter 3.3 --- Results and Discussion --- p.49
Chapter 3.3.1 --- Synthesis of Propargy 1 Amines --- p.49
Chapter 3.3.2 --- Synthesis and Characterization of 2-Aminoimidazoles --- p.50
Chapter 3.3.3 --- Proposed Reaction Mechanism --- p.55
Chapter 3.4 --- Summary --- p.57
Chapter Chapter 4 --- Conclusion --- p.59
Chapter Chapter 5 --- Experimental Section --- p.61
References --- p.87
Appendix
Chapter I. --- Publication Based on the Research Findings --- p.93
Chapter II. --- Crystal Data and Summary of Data Collection and Refinement --- p.94
Chapter III. --- X-ray crystallographic data in CIF (electronic form)
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46

Soldevila-Barreda, Joan J., K. B. Fawibe, Maria Azmanova, Laia Rafols, Anaïs Pitto-Barry, U. B. Eke, and Nicolas P. E. Barry. "Synthesis, characterisation, and in vitro anticancer activity of catalytically active indole-based half-sandwich complexes." 2020. http://hdl.handle.net/10454/18070.

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Yes
The synthesis, characterisation and evaluation of the in vitro cytotoxicity of four indole-based half-sandwich metal complexes towards two ovarian cancer cell lines (A2780 and A2780cisR) and one normal prostate cell line (PNT2) are presented herein. Although capable of inducing catalytic oxidation of NADH and able to reduce NAD+ with high turnover frequencies, in cells and in the presence of sodium formate, these complexes also strongly interact with biomolecules such as glutathione. This work highlights that efficient out-of-cells catalytic activity might lead to higher reactivity towards biomolecules, thus inhibiting the in-cells catalytic processes.
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47

Pitto-Barry, Anaïs, A. Lupan, Markus Zegke, Thomas Swift, A. A. A. Attia, Rianne M. Lord, and Nicolas P. E. Barry. "Pseudo electron-deficient organometallics: limited reactivity towards electron-donating ligands." 2017. http://hdl.handle.net/10454/13140.

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Yes
Half-sandwich metal complexes are of considerable interest in medicine, material, and nanomaterial chemistry. The design of libraries of such complexes with particular reactivity and properties is therefore a major quest. Here, we report the unique and peculiar reactivity of eight apparently 16-electron half-sandwich metal (ruthenium, osmium, rhodium, and iridium) complexes based on benzene-1,2-dithiolato and 3,6-dichlorobenzene-1,2-dithiolato chelating ligands. These electron-deficient complexes do not react with electron-donor pyridine derivatives, even with the strong σ-donor 4-dimethylaminopyridine (DMAP) ligand. The Ru, Rh, and Ir complexes accept electrons from the triphenylphosphine ligand (σ-donor, π-acceptor), whilst the Os complexes were found to be the first examples of non-electron-acceptor electron-deficient metal complexes. We rationalized these unique properties by a combination of experimental techniques and DFT/TDFT calculations. The synthetic versatility offered by this family of complexes, the low reactivity at the metal center, and the facile functionalization of the non-innocent benzene ligands is expected to allow the synthesis of libraries of pseudo electron-deficient half-sandwich complexes with unusual properties for a large range of applications.
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48

Hu, Wanning. "Organometal half-sandwich complexes and their bioconjugates: Biological activity on cancer cells and potential applications in biolabelling." Doctoral thesis, 2012. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-87899.

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In summary, structure-activity relationships in peptide and dendrimer carriers modified with different organometal complexes were studied on a human breast cancer cell line. Variation of the organometal cargo and carrier can significantly influence their biological properties and might open the way to new approaches in chemotherapy. Furthermore, the incorporation of complexes with different C≡O vibrational signatures in a model peptide was explored to examine information encoding in biomolecules in a barcoding strategy for potential imaging applications. In particular for the latter, additional stable metal-carbonyl markers need to be prepared in future work to expand the pool of vibrational labels available
In der vorliegenden Arbeit konnten also Struktur-Wirkungs-Beziehungen für Organometall-Peptid- und Dendrimer-Konjugate mit unterschiedlichen funktionellen Gruppen an einer humanen Brustkrebs-Zelllinie untersucht werden. Die Variation der Organometall-Gruppen und des Trägermoleküls führen zu signifikanten Unterschieden in ihrer biologischen Aktivität. Zusätzlich wurden Modell-Peptide mit verschiedenen Metallcarbonyl-basierten IR-Markern versehen um diese in einer Barcoding-Strategie zu labeln. In Zukunft soll das Spektrum der verfügbaren, nicht-überlappenden Schwingungsmarker noch deutlich erweitert werden
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49

Habas, Khaled S. A., Barreda Joan J. Soldevila, Maria Azmanova, Laia Rafols, Anaïs Pitto-Barry, Diana Anderson, and Nicolas P. E. Barry. "Evaluation of the toxicity of two electron-deficient half-sandwich complexes against human lymphocytes from healthy individuals." 2020. http://hdl.handle.net/10454/18162.

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Yes
Electron‐deficient half‐sandwich complexes are a class of under‐studied organometallics with demonstrated potential as metallodrug candidates. The present study investigates the effect of two 16‐electron organoruthenium complexes ([( p‐ cym)Ru(benzene‐1,2‐dithiolato)] ( 1 ) and [( p ‐cym)Ru(maleonitriledithiolate)] ( 2 )) on the cell viability of non‐immortalised human lymphocytes from healthy individuals. The genotoxic effects of 1 and 2 in lymphocytes using the Comet and cytokinesis‐block micronucleus assays is also investigated. Gene expression studies were carried out on a panel of genes involved in apoptosis and DNA damage repair response. Results show that the two 16‐electron complexes do not have significant effect on the cell viability of human lymphocytes from healthy individuals. However, an increase in DNA damage is induced by both compounds, presumably through oxidative stress production.
This project was supported by the Royal Society (University Research Fellowship No. UF150295 to NPEB), the University of Bradford (RDF Award), and by the Academy of Medical Sciences/the Wellcome Trust/ the Government Department of Business, Energy and Industrial Strategy/ the British Heart Foundation Springboard Award [SBF003\1170 to NPEB].
The full-text of this article will be released for public view at the end of the publisher embargo on 30 Oct 2021.
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50

Lee, Bo-ting, and 李柏庭. "Syntheses and Polymerization Studies of Half-Sandwich Metallocene Complexes Prepared by The Selective Cyclopentadienyl Ligand Transfer Reactions." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/47131877068965914066.

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碩士
國立中正大學
化學工程所
95
A novel synthetic route for the preparation of monocyclopentadienyl group(ⅣB) metal complexs via cyclopentadienyl ligand transfer reaction was disclosed in this study.The cyclopentadienyl ligand transfer reactions are conducted by using transition metal alkoxides (titanium, zirconium, hafnium，alkoxides) as the Cp-ligand acceptors to react with group (II) Cp-containing complexes (Cp2Mg、Cp*2Mg and nPrCp2Mg), which act as the Cp-ligand donors.The new synthetic methods lead to the successful generation of monocyclopentadienyl complexs of Titanium、Zirconium and Hafnium.The polymerizations of vinyl monomers using these catalysts have been investigated. This new synthetic route offers the preparation of novel mono-cyclopentadienyl complexs of Zirconium and Hafnium,which are difficult to preparated by other methods.
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