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Letteratura scientifica selezionata sul tema "Ditopic ligand"

Autore: Grafiati

Pubblicato: 21 dicembre 2024

Ultima modifica: 22 giugno 2025

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Articoli di riviste sul tema "Ditopic ligand"

1

Jouvenot, Damien, Edith C. Glazer, and Yitzhak Tor. "Photodimerizable Ditopic Ligand." Organic Letters 8, no. 10 (2006): 1987–90. http://dx.doi.org/10.1021/ol060253i.

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2

Bonanno, N. M., A. J. Lough, K. E. Prosser, C. J. Walsby, P. K. Poddutoori, and M. T. Lemaire. "A stable open-shell redox active ditopic ligand." Dalton Transactions 45, no. 13 (2016): 5460–63. http://dx.doi.org/10.1039/c5dt04061b.

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3

Kariuki, Benson M., James A. Platts, and Paul D. Newman. "A hybrid bipy–NHC ligand for the construction of group 11 mixed-metal bimetallic complexes." RSC Advances 11, no. 54 (2021): 34170–73. http://dx.doi.org/10.1039/d1ra06581e.

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4

Duerrbeck, Andre, Sergey Gorelik, Jonathan Hobley, Ji'En Wu, Andy Hor, and Nicholas Long. "Highly emissive, solution-processable and dynamic Eu(iii)-containing coordination polymers." Chemical Communications 51, no. 41 (2015): 8656–59. http://dx.doi.org/10.1039/c5cc01793a.

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5

Hayvali, Zeliha, Necla Gündüz, Zeynel Kilic, and Edwin Weber. "Synthesis, Complex Formation and Spectral Investigation of New Tritopic Bis(Crown Ether) Compounds Containing Recognition Sites for Sodium and Nickel Guest Cations*." Zeitschrift für Naturforschung B 55, no. 10 (2000): 975–81. http://dx.doi.org/10.1515/znb-2000-1015.

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AbstractNew bis(crown ether) ligands (1 - 3) of Schiff base type containing recognition sites for sodium and nickel guest cations have been synthesized by the condensation of two equivalents of 4′-formyl-5′-hydroxy(benzo-15-crown-5)with 1,5-diamino-3-azapentane, 1,8-diamino-3,6- diazaoctane or 1,8-diamino-3,6-dioxaoctane. Homonuclear ditopic crystalline 2:1 (Na+:ligand) complexes (1a - 3a) of the ligands with NaClO4 have been prepared. Heteronuclear tritopic crystalline 2:1:1 (Na⊕ : Ni2⊕ : ligand) complexes (2b and 3b) have also been synthesized from the reactions of the ditopic complexes (2a and 3a) with Ni(CH3COO)2 · 6H2O. The UV-VIS spectra of 1 - 3, their sodium complexes 1a - 3a and sodium-nickel complexes 2b and 3b have been recorded in polar and non-polar solvents as well as in acidic and basic media. In polar solvents and basic solutions, tautomeric equilibria (phenol-imine and keto-amine forms, O-H···N⇌O···H-N ) are present, depending on the hydrogen bonding. The results indicate that the concentrations of the keto forms of the compounds generally increase as the polarity of the solvent increases

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6

Soldevila-Sanmartín, Joan, Teresa Calvet, Merce Font-Bardia, Concepción Domingo, José A. Ayllón, and Josefina Pons. "Modulatingp-hydroxycinnamate behavior as a ditopic linker or photoacid in copper(ii) complexes with an auxiliary pyridine ligand." Dalton Transactions 47, no. 18 (2018): 6479–93. http://dx.doi.org/10.1039/c8dt00645h.

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7

Bonanno, Nico M., Zackery Watts, Cole Mauws, et al. "Valence tautomerism in a [2 × 2] Co4 grid complex containing a ditopic arylazo ligand." Chemical Communications 57, no. 50 (2021): 6213–16. http://dx.doi.org/10.1039/d1cc01991k.

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8

Hossain, Sayed Muktar, Avinash Lakma, Rabindra Nath Pradhan, Serhiy Demeshko, and Akhilesh Kumar Singh. "Valence directed binding mode of [2 × 2] iron grids of an unsymmetrical picolinic hydrazone based ligand." Dalton Transactions 46, no. 37 (2017): 12612–18. http://dx.doi.org/10.1039/c7dt02433a.

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9

Renard, Nicolas, Eric Brenner, Dominique Matt, and Christophe Gourlaouen. "Adaptive Behavior of a Ditopic Phosphine Ligand." European Journal of Inorganic Chemistry 2019, no. 25 (2019): 2996–3004. http://dx.doi.org/10.1002/ejic.201900571.

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10

Blanco-Gómez, Arturo, Tamara Rama, Olaya Domarco, et al. "Amplification of a metallacyclic receptor out of a dynamic combinatorial library." Dalton Transactions 46, no. 45 (2017): 15671–75. http://dx.doi.org/10.1039/c7dt03379f.

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We present herein the Pt(ii)-directed self-assembly in water of a new conformationally flexible N-monoalkyl-4,4-bipyridinium-based ditopic ligand into a library of six different metallacyclic structures.

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Tesi sul tema "Ditopic ligand"

1

ALBISETTI, A. FIGINI. "Structural and Thermodiffractometric Studies of Coordination Polymers Containing Ditopic Exobidentate Nitrogen Ligand." Doctoral thesis, Università degli Studi di Milano, 2008. http://hdl.handle.net/2434/57743.

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2

Rahm, Fredrik. "Chiral Pyridine-Containing Ligands for Asymmetric Catalysis. Synthesis and Applications." Doctoral thesis, KTH, Chemistry, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3564.

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<p>This thesis deals with the design and syntheses of chiral,enantiopure pyridinecontaining ligands and their applicationsin asymmetric catalyis.</p><p>Chiral pyridyl pyrrolidine ligands and pyridyl oxazolineligands were synthesized and employed in thepalladium-catalysed allylic alkylation of 1,3-diphenyl-2-propenyl acetate with dimethyl malonate. Theinfluence of the steric properties of the ligands wereinvestigated.</p><p>Ditopic ligands, containing crown ether units as structuralelements, were synthesized and some of the ligands were used asligands in the palladiumcatalysed allylic alkylation of1,3-diphenyl-2-propenyl acetate with dimethyl malonate. A smallrate enhancement was observed, compared with analogous ligandslacking the crown ether unit, when these ditopic ligands wereused in dilute systems.</p><p>A modular approach was used to synthesize chiralenantiomerically pure pyridyl alcohols and C2-symmetric2,2-bipyridines, with the chirality originating from thechiral pool. Electronic and steric properties of the compoundswere varied and they were used as ligands in theenantioselective addition of diethylzinc to benzaldehyde. Thesense of asymmetric induction was found to be determined by theabsolute configuration of the carbinol carbon atom. Theelectronic properties of the ligands had a minor influence onthe levels of enantioselectivity induced by the ligands.</p><p>Chiral pyridyl phosphinite ligands and pyridyl phosphiteligands were synthesized from the pyridyl alcohols andevaluated as ligands in palladiumcatalysed allylic alkylations.With the phosphinite ligands, the sense of chiral induction wasfound to be determined by the absolute configuration of theformer carbinol carbon atom. A kinetic resolution of theracemic starting material was observed with one of thephosphite ligands. Moderate enantioselectivities wereachieved.</p><p><b>Kewords:</b>asymmetric catalysis, chiral ligand, chiralpool, oxazoline, crownether, ditopic receptor, bipyridine,pyridyl alcohol, modular approach, P,Nligand, diethylzinc,allylic alkylation.</p>

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3

Turner, Thomas P. W. "Bifunctional unsymmetrical ditopic ligands for alkene methoxycarbonylation." Thesis, University of Bristol, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658207.

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A series of unsymmetrical xylenyl-backboned diphosphine ligands are reported: o-C6H4(CH2ptSU2)(CH2PRR'), R = Ph, R' = 2-Py (L1) and O-C6H4(CH2ptSU2)(CH2PR2), R = 2-Py (L2), R = 2-(3-Me-Py) (L3), R = 2-(4- Me-Py) (L4), R = 2-(6-Me-Py) (Ls) and R = 2-Pyrim (Ls). The ligands have all been characterised by 31p, 1H and 13C NMR spectroscopy and high resolution mass spectrometry. Studies of [PtCI(CH3)(L)] and [PdCI(CH3)(L)] (L = L1-LS) have shown that the favoured isomers have the more strongly a-donating CH3 ligand trans to the bulkier ptSU2 donor. Studies with [PdCI2(L)], [PtCI2(L)] and [Pt(CH3h(L)] (L = L1-LS) show that the donor strength of the two phosphorus centres is not averaged in these complexes, in contrast to the related complexes of o-C6H4(CH2ptSu2)(CH2PPh2) (TP). These complexes have been characterised by a combination of NMR spectroscopy, high resolution mass spectrometry, elemental analysis and X-ray crystallography. The coordination chemistry of PR3, R = 2-(3-Me-Py), R = 2-(4-Me-Py), R = 2-(6-Me-Py), with LiCI and LiSr is also reported. Tripodal coordination to lithium by the three pyridyl nitrogen donors is detected for each ligand. These [LiX(PR3)] complexes have been characterised by 31p, 1H and 13C NMR spectroscopy and X-ray crystallography. Protonation studies with [PdCI2(L)] and [PtCh(L)] (L = L1-LS) suggest that the pendant pyridyl and pyrimidyl groups of L1-LS are protonated in methanolic solutions when treated with acids such as HSF 4, CH3S03H (MSA) and CF3C02H (TFA). The evidence for protonation came from 31p NMR spectroscopy and X-ray crystallography. Protonation studies with [Pt(CH3h(L2)] have shown that tridentate coordination of platinum by L2 (through both P donors and one pyridyl N donor) occurs. Catalysts derived from the new ligands were tested in the palladiumcatalysed methoxycarbonylation of ethene. The systems based upon L1, L2, L4 and Ls are shown to be active and selective for the production of methyl propionate (MeP) over polyketone (PK). Those derived from L2 and Ls are comparable in activity to the best reported system (which is based upon o-C6H4(CH2ptSU2h, dtbpx) when promoted by the strong acid MSA. The L2 and Ls systems are more active than dtbpx with the weaker acids TFA and PA. Complexes derived from L3 and Ls are inactive in methoxycarbonylation catalysis. Catalysts derived from L1-LS are also shown to be active in palladium-catalysed styrene methoxycarbonylation. Mechanistic studies suggest that catalysts derived from L2 produce MeP following the hydride mechanism. Competition between the coordination of palladium by the nitrogen donor of a pendant pyridyl group and acid anions was observed under catalytically relevant conditions. Complexes derived from L3 appear to be inactive in MeP catalysis due to persistent tridentate coordination of palladium (via the two P donors and one pyridyl N donor) blocking substrate coordination. Complexes derived from Ls may be inactive in MeP catalysis due to the electron deficient nature of the PPyrim2 donor. Carbonylation studies with isotopically labelled 13CO support the conclusion that MeP preference is a balance between kinetic and thermodynamic influences - the minor palladium-ethyl complex isomer may react faster to generate the more stable palladium-acyl isomer.

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4

Smith, Kate Jennifer. "Ditopic ligands for the extraction of divalent metal salts." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/12982.

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This thesis extends earlier work at the University of Edinburgh aimed at opening up new flowsheets for the hydrometallurgical recovery of base metals using tetradentate ligands which are capable of transporting metal salts {both a metal cation and its attendant anion(s)}. Prototypes were based on salicylaldimine derivatives of diamines, “salen” ligands in which coordination of a metal dication releases the two phenolic protons which are captured by pendant secondary amine groups generating a preorganised dicationic binding site for the anion(s). The thesis initially deals with the design, synthesis and evaluation of ligands to improve the strength, selectivity and speed of binding of nickel(II) sulfate by incorporating two additional donors in the salen unit to generate N<sub>2</sub>X<sub>2</sub>O<sub>2</sub><sup>2-</sup> binding sites for the nickel yielding pseudo octahedral complexes. The ligands N,N or O,O or S,S <i>o</i>-aminophenyl-substituted 1,2-diaminoethane, 1,2-dioxaethane, 1,3-dioxapropane or 1,2-diethioethane were also used in a screening study with some other divalent metal salts (calcium, cobalt, copper, magnesium, manganese and zinc) commonly found in the feed solutions in commercial processes. Chapter two deals with the nickel(II) coordination chemistry of a series of sexadentate (N<sub>2</sub>X<sub>2</sub>O<sub>2</sub><sup>2-</sup>) ligands. Nickel-ligand-anion complexes have been synthesised for sulfate, nitrate and chloride salts and neutral nickel-ligand complexes have been made. Crystal structures of complexes all contain the same isomer which has a planar<i> mer</i> arrangement of the salicylaldimato XNO<sup>-</sup> units. A “nickel only” complex for an X<sub>2</sub>N<sub>2</sub>O<sub>2</sub><sup>2-</sup> ligand with pendent piperidine groups shows that these could provide a cavity to encapsulate a single sulfate anion. All the ligands were found to be very weak extractants and showed slow complexation kinetics and phase transfer of nickel sulfate. The synthesis and characterisation of a series of tridentate ligands related to the sexadentate ligands, with NXO<sup>-</sup> binding sites, are reported in chapter three. In theory these could form complexes with a ligand: nickel ratio of 2:1, with a more nearly “ideal” octahedral donor set. Solid state structures of the ligands show them to be pre-organised with an approximately 90° X˙˙˙N˙˙˙O angle. Nickel complexes have been synthesised for sulfate, chloride and acetate salts. Analysis indicates that complexes with ligand: nickel: dianion ratios of 2:1:1 were formed. The tridentate ligands were found to be very weak extractants for nickel sulfate. Chapter four describes the screening of the potentially sexadentate N<sub>2</sub>X<sub>2</sub>O<sub>2</sub><sup>2-</sup>, tridentate NXO<sup>-</sup> and the tetradentate “salen” ligands N<sub>2</sub>O<sub>2</sub><sup>2-</sup> in which the complexation and phase transfer of calcium(II), cobalt(II), copper(II), magnesium(II), manganese(II), nickel(II) and zinc(II) sulfates and chlorides were studied.

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5

Dussart, Caitlyn. "Chiral self-recognition study of metallic complexes : towards coordination polymers." Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAE006.

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Les assemblages polymériques métallo-supramoléculaires constituent une nouvelle classe de matériaux apparue au cours des dernières décennies. Ces matériaux présentent un large éventail de propriétés qui dépendent de la nature des métaux et des ligands ditopiques utilisés. La réversibilité des liaisons de coordination offre également un caractère dynamique au système qui peut répondre à un stimulus externe. En introduisant de la chiralité dans ces systèmes moléculaires, nous pouvons étudier la capacité de ces structures moléculaires à s’associer ou à se désolidariser pour former des espèces homochirales ou hétérochirales. Ce manuscrit se concentre sur la synthèse et la chimie de coordination de ligands chiraux avec une symétrie C2, tels que les bisoxazolines, les bisimidazolines et les dérivés du 1,2-diaminocyclohexane. La complexation de deux ligands sur un métal de transition donne formation à des complexes homoleptiques ML2 dans lesquels la chiralité des ligands et la géométrie de coordination sont des paramètres importants pour observer une auto-association ou une hétéro-association des ligands. Tous ces complexes ont été étudiés et caractérisés à l’état solide ou en solution et l’impact des groupements chiraux sur les ligands a également été analysée. Afin de convertir ces complexes en assemblages polymériques, des ligands ditopiques chiraux ont également été conçus, synthétisés et étudiés<br>Metallo-supramolecular polymeric assemblies are a new class of materials that have emerged in recent decades. These materials exhibit a wide range of properties depending on the nature of the metals and the ditopic ligands used. The reversibility of the coordination bonds also gives the system a dynamic character that can response to an external stimulus. By introducing chirality into these molecular systems, we can study the ability of these molecular structures to associate or disassociate to form homochiral or heterochiral species.This manuscript focuses on the synthesis and coordination chemistry of chiral ligands with C2-symmetry, i.e. bisoxazolines, bisimidazolines and derivates of 1,2-diamonocyclohexane. The complexation of two ligands to a transition metal gives rise to homoleptic ML2 complexes, in which the chirality of the ligands and the coordination geometry are important parameters for observing self-association or hetero-association of the ligands. All these complexes have been studied and characterized in the solid state or in solution and the influence of the chiral groups of the ligands has also been analysed. In order to convert these complexes into polymeric assemblies, chiral ditopic ligands have also been designed, synthesized and studied

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6

Santillan, Guillermo A. "Coordination polymers and building blocks based on ditopic heteroscorpionate ligands." Diss., [La Jolla] : [San Diego] : University of California, San Diego ; San Diego State University, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3379543.

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Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 2009.<br>Title from first page of PDF file (viewed November 17, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

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7

Galbraith, Stuart G. "Ditopic ligands for the selective solvent extraction of transition metal sulfates." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/10911.

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The thesis considers the development of new reagents which could transport transition metal <i>salts</i> in extractive hydrometallurgy and addresses the ligand design features which are needed to control the strength and selectivity of binding of both a particular metal cation and its attendant anions(s). Extractive metallurgy of base metals is surveyed in chapter 1 and suggests that more efficient recovery processes are needed. One new approach, which could lead to much better materials balances in many cases, is to use hydrometallurgical techniques which involve co-extraction and transport of metal cations and their attendant anion(s). The problems in obtaining the selective extraction of anions makes the development of such a process very challenging, especially for hydrophilic anions such as sulphate which would be present in many pregnant solutions generated in processing sulfides ores. The rapidly emerging field of anion coordination chemistry and approaches to the development of selective ligands are discussed. Chapter 2 focuses on the pH dependence of sulfate-loading from an aqueous solution into chloroform solutions of a selection of zwitterionic ditopic ligands containing two 3-dialkylaminomethylsalicylaldimine units. These “salen-type2 ligands have quadridentate N<sub>2</sub>O<sub>2</sub><sup>2-</sup> binding sites for divalent metal cations and the <i>cis</i>-coordination of the phenolate aligns the pendant protonated 3-dialkylaminomethyl groups to bind to a sulfate dianion. Studies of the pH dependence of sulfate-loading confirm that sulfate binding is enhanced significantly by the incorporation of a divalent cation such as Cu<sup>2+</sup> in the salen N<sub>2</sub>O<sub>2</sub><sup>2-</sup> site. Metal dication loading is very dependent on the nature of the bridging group between the two imines in the “salen” unit; Cu<sup>2+</sup> loading follows the order <i>ortho</i>-phenylene > 1,2-ethane > 2,2’-biphenyl. The ethane-bridged ligand, 4,4’-di-<i>tert</i>-butyl-6,6’-bis(dihexylaminomethyl)-2,2’-(ethylenedinitrilodimethylidyne) diphenol, was found to have a nearly ideal loading profile for CuSo<sub>4</sub>. Stability to hydrolysis and oxidation is a key requirement for commercial metal solvent extractants. The stability of the imine bond in the “salen-type” extractants investigated in chapter 2 was tested in a two phase chloroform: water systems under conditions likely to be used for loading or stripping of metal <i>salts.</i> Stability is dependent on the nature of the bridging unit between the two imines varying in this order 2,2’-biphenyl > <i>ortho</i>-phenylene > 1,2-ethane. Two new ligands, 4,4’-di-<i>tert</i>-butyl-6,6’-bis(dihexylaminomethyl)-2,2’-(ethylenedinitrilo-1,1’-phenyldimethylidyne) diphenol and <i>N,N’-</i>dimethyl-<i>N,N’</i>-bis(2-hydroxy-3-[(E)-phenyliminomethyl]-5-<i>tert</i>-butylbenzyl)hexane-1,6-diamine, which exhibit improved stabilities at low pH are also discussed.

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8

Bokolinis, Georgios. "The synthesis of novel ditopic ligands for supramolecular chemistry and sensor applications." Thesis, University of Huddersfield, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430296.

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9

Gordon, Ross John. "Improved mass transport efficiency in copper solvent extraction." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/5673.

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This thesis considers methods which can be employed to increase the mass of copper transferred into and out of the organic phase during the load and strip stages of commercial solvent extraction processes. Conventional 5-alkylsalicylaldoxime reagents transfer 1 mol of divalent copper per 2 mol of ligand in a neutral complex of the type [Cu(L-H)2] via a pH-swing process. New triacidic ligands have been designed which triple the molar transport of copper to form [Cu3(L-3H)2]. Until recently copper recovery by solvent extraction has been confined to oxidic ores which are leached with sulfuric acid. New leaching technologies generate high tenor copper sulfate feed streams from sulfidic ores. The conventional 5- alkylsalicylaldoxime reagents do not work effectively in conjunction with these leach processes as they do not consume the acid which is generated on loading the oxime. To address this problem ditopic zwitterionic ligands have been designed which can transfer both metal cation and attendant anion. These new metal salt reagents are diacidic, therefore not only transfer metal salts but also increase the molar transport relative to the conventional reagents. Equilibrium-modifiers are often added to improve the mass transport efficiency of conventional solvent extraction processes. The nature of their interaction with the species in solution is poorly understood. This thesis investigates their interaction with the free ligands and copper complexes to gain an understanding of their mode of action in order to rationalise the design of future modifiers to optimise recovery efficiencies. Increased molar transport is addressed in Chapter 2. The diacidic ligand 5- methylsalicylaldehyde-pivaloylhydrazide (L2) and its dinuclear copper complex [Cu2(L2-2H)2] were synthesised and characterised to gain an understanding of their speciation in solution. X-ray structural analysis of [Cu2(L2-2H)2] confirmed that the phenolate oxygen atoms bridge the copper centres rather than the amidato oxygen atoms of the hydrazone. Variable temperature magnetic susceptibility data confirm that the copper centres are antiferromagnetically coupled as expected for the Cu-OCu angle (99.6(2)°). An understanding of the coordination geometry of the dinuclear systems lead to design of triacidic ligands. A series of 3-hydrazono- and 3- hydroxyanil- 5-alkylsalicylic acids were synthesised. The prototype ligand 5-methyl 3-octanoylhydrazonosalicylic acid (L6) was demonstrated to triple molar transport and increase mass transport by 2.5 fold. Solvent extraction results indicate that copper is sequentially loaded as pH is increased. The plateaux observed in loading curves suggest formation of stable mono-, di-, and tri-nuclear copper complexes within the pH-ranges 1.75 - 2.75, 3.25 - 4.0 and > 4.25 respectively. The triacidic ligands were also demonstrated to double the molar transport of the conventional salicylaldoximes when used in 1:1 blends by formation of a ternary complex. Chapter 3 describes the incorporation of two tertiary amine groups into diacidic salicylaldehydehydrazone ligands to form dinucleating metal salt extractants. Piperidinomethyl, piperazinomethyl and dihexylamino groups were incorporated into various positions of the ligand including 3- and/or 5- positions of the salicylaldehyde or incorporated into the hydrazone. Solvent extraction results obtained for 3,5- bis((dihexylamino)methyl)salicylaldehyde-octanoic hydrazone (L20) are consistent with transfer of 1 mol of copper sulfate per mol of ligand in the organic phase between pH 2.0 and 2.5. This result is indicative of the formation of [Cu2(L20)2(SO4)2]. Conventional salicylaldoximes are “strong” copper extractants which require concentrated acid electrolyte to efficiently strip the copper from the organic phase. However, as the use of concentrated acid affects the quality of the copper cathodes, oxygen-containing equilibrium modifiers are often added. These facilitate copper stripping without adversely affecting the loading. The affect of 2-ethylhexanol (2- EH) and trioctylphosphine oxide (TOPO) on the extractive ability of 5-toctylsalicylaldoxime (19) in n-heptane is reported. Both are found to decrease copper extraction more under stripping conditions than loading conditions. 2-EH shows little affect at pH greater than 2.5. TOPO does not significantly affect copper loading at pH greater than 3.0. Evidence for the formation of the adduct [Cu(19-H)2)(TOPO)] was obtained from UV/Vis, IR, EPR and sonic spray mass spectrometry.

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Zanardi, Alessandro. "N-heterocyclic-carbene-based Ditopic and Hemicleaveable ligands for the design of improved catalysts." Doctoral thesis, Universitat Jaume I, 2010. http://hdl.handle.net/10803/669141.

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La presente memoria ha profundizado en el diseño de nuevos catalizadores al utilizar dos nuevos tipos de ligandos diferenciados: triazolil-di-ilideno y bis-alquenil-NHCs. El uso del ligando trimetiltriazolil-di-ilideno, ha permitido obtener series de compuestos de tipo homo- y hetero-bimetálicos, estableciéndose criterios claros de coordinación que garantizan que el mismo ligando se puede utilizar de manera amplia en su coordinación a prácticamente cualquier par de fragmentos metálicos. La preparación y la caracterización de los compuestos heterobimetálicos establece un gran avance en el diseño de catalizadores tándem que permitan catalizar secuencias catalíticas formadas por reacciones muy diferentes. La utilización de los ligandos de tipo bis-alquenil-NHC, ha permitido diseñar de forma sistemática compuestos en los que el ligando actúa como mono-, bi- y tri-dentado. Los compuestos derivados de la coordinación de los ligandos bis-alquenil-NHC han sido probados como catalizadores en reacciones de hidrosililación de alquinos, observándose que la actividad catalítica depende del grado de coordinación del ligando NHC. De este modo, los complejos monocoordinados y bisquelatos han mostrado las mejores actividades, junto a una elevada selectividad hacia los isomeros Z.

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Capitoli di libri sul tema "Ditopic ligand"

1

Pardasani, R. T., and P. Pardasani. "Magnetic properties of tetranuclear cobalt(II) complex with ditopic ligand." In Magnetic Properties of Paramagnetic Compounds, Magnetic Susceptibility Data, Volume 5. Springer Berlin Heidelberg, 2022. http://dx.doi.org/10.1007/978-3-662-65098-1_259.

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2

Walczak, Rafał, Iga Zuba, Wojciech Starosta, and Jianwei Ren. "Post-synthetic modification of zirconium terephthalate sorbents and their application for sorption of selected toxic elements from water." In Waste PET-MOF-Cleanwater: Waste PET-Derived Metal-Organic Framework (MOFs) as Cost-Effective Adsorbents for Removal of Hazardous Elements from Polluted Water. UJ Press, 2022. http://dx.doi.org/10.36615/9781776419463-08.

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Abstract (sommario):

Metal-organic Framework (MOF) porous materials have been a subject of interest for about two decades. The discovered recipe for their synthesis consisting of a combination of highly tunable metal nodes and ditopic or multitopic ligands resulted in the exponential growth of new structures. At present, a wealth of material on synthesis, structural, and functional properties have been accumulated. It shows a potentially wide range of applications in the field of gas storage, separation of gaseous mixtures, catalysis, drug delivery, energy, and environment protection. The unique features of MOFs, such as large specific surface area, diversity of possible structures, and theoretical possibility of a design structure for specific applications make them suitable for industrial applications [1]. However, extensive application research is required before a potentially beneficial solution can be put into practice. The issue of economic efficiency and technical suitability should be resolved first.

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Atti di convegni sul tema "Ditopic ligand"

1

Sanmartín-Matalobos, Jesús, Ana García-Deibe, Martín Amoza, et al. "Computational and Experimental Studies Into the Conformations of a Triptycene-Based Ditopic Ligand." In The 18th International Electronic Conference on Synthetic Organic Chemistry. MDPI, 2014. http://dx.doi.org/10.3390/ecsoc-18-e007.

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