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Auteur : Grafiati
Publié le 7 juillet 2024
Mis à jour le 7 juillet 2024

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1

Klein, Hans-Friedrich, Goetz Lull, Birgit Rodenhäuser, Gerhard Cordier et Helmut Paulus. « Monoolefincobalt(0)-Komplexe / Monoolefincobalt(0) Complexes ». Zeitschrift für Naturforschung B 43, no 10 (1 octobre 1988) : 1256–62. http://dx.doi.org/10.1515/znb-1988-1008.

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Mononuclear cobalt(o) complexes containing olefin and trimethylphosphane ligands Co(olefin)(PMe3)3 (olefin = C2H4 (1), C3H6 (2), cyclopentene (3), trans-1,2-diphenylethene (4), tetrafluorobenzo-bicyclo-(2.2.2)-octadiene (5)), are obtained from CoCl2 by reaction with magnesium in the presence of the ligands or by substitution of 3 with olefin. X-ray crystal structure determinations of 4 and 5 show a distorted tetrahedral arrangement of ligands around the cobalt atom. Chemical and spectroscopic properties are consistent with a paramagnetic valence state of the compounds in solution. By reaction with carbon monoxide a dicobalt complex is formed, while azobenzene gives paramagnetic Co(N2Ph2)(PMe3)2.
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2

Zhao, Lili, Chaoqun Chai, Wolfgang Petz et Gernot Frenking. « Carbones and Carbon Atom as Ligands in Transition Metal Complexes ». Molecules 25, no 21 (26 octobre 2020) : 4943. http://dx.doi.org/10.3390/molecules25214943.

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This review summarizes experimental and theoretical studies of transition metal complexes with two types of novel metal-carbon bonds. One type features complexes with carbones CL2 as ligands, where the carbon(0) atom has two electron lone pairs which engage in double (σ and π) donation to the metal atom [M]⇇CL2. The second part of this review reports complexes which have a neutral carbon atom C as ligand. Carbido complexes with naked carbon atoms may be considered as endpoint of the series [M]-CR3 → [M]-CR2 → [M]-CR → [M]-C. This review includes some work on uranium and cerium complexes, but it does not present a complete coverage of actinide and lanthanide complexes with carbone or carbide ligands.
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3

Frenking, Gernot, et Ralf Tonner. « Divalent carbon(0) compounds ». Pure and Applied Chemistry 81, no 4 (1 janvier 2009) : 597–614. http://dx.doi.org/10.1351/pac-con-08-11-03.

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Quantum chemical studies show that there is a class of carbon compounds with the general formular CL2 where the carbon atom retains its four valence electrons as two lone pairs. The C-L bonds come from L → C donor-acceptor interactions where L is a strong σ-donor. Divalent C(0) compounds (carbones) are conceptually different from divalent C(II) compounds (carbenes) and tetravalent carbon compounds, but the bonding situation in a real molecule may be intermediate between the three archetypes. There are molecules like tetraaminoallenes which may be described in terms of two double bonds (R2N)2C=C=C(NR2)2 where the extraordinary donor strength of the dicoordinated carbon atom comes only to the fore through the interactions with protons and Lewis acids. They may be considered as "hidden divalent C(0) compounds". The donor strength of divalent C(0) molecules has been investigated by calculations of the binding energies with protons and with main-group Lewis acids and the bond dissociation energies (BDEs) of transition-metal complexes.
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4

Mour, İzzet A., Saim Ozkar et Cornelius G. Kreiter. « Synthesis and Spectroscopic Studies of Pentacarbonylfumaronitrile-chromium(0), -molybdenum(0), and -tungsten(0) ». Zeitschrift für Naturforschung B 49, no 8 (1 août 1994) : 1059–62. http://dx.doi.org/10.1515/znb-1994-0808.

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Photolysis of hexacarbonyl-chromium(0), -molybdenum(0), and -tungsten(0) in presence of fumaronitrile yields at room temperature pentacarbonyl-fumaronitrile-chromium(0) (1), - molybdenum(0) (2), and -tungsten(0) (3). The complexes were purified by crystallization and characterized by IR and 13C-NMR spectroscopy. The fumaronitrile ligand is bonded to the M(CO)5 moiety by one nitrile nitrogen atom rather than by the carbon-carbon double bond. In toluene 2 dissociates into fumaronitrile and pentacarbonyl-molybdenum(0), which is stabi­lized by the solvent. Fumaronitrile and solvated pentacarbonyl-molybdenum(0) exist in solu­tion together with 2 in an equilibrium which lies in favour of the former species.
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5

Bohanna, Cristina, Miguel A. Esteruelas, Fernando J. Lahoz, Enrique Onate, Luis A. Oro et Eduardo Sola. « Synthesis of Butadiene-Osmium(0) and -Ruthenium(0) Complexes by Reductive Carbon-Carbon Coupling of Two Alkenyl Fragments ». Organometallics 14, no 10 (octobre 1995) : 4825–31. http://dx.doi.org/10.1021/om00010a051.

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6

Morkan, İ. Amour, et A. Uztetik-Morkan. « Photochemical Synthesis and Identification of Tetracarbonyl-bis(olefin)metal(0) Complexes of Group VI B Elements ». Zeitschrift für Naturforschung B 55, no 12 (1 décembre 2000) : 1153–56. http://dx.doi.org/10.1515/znb-2000-1208.

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Photolysis of hexacarbonyl metal(0) or tetracarbonyl-bis(1,3-butadiene)metal(0) (metal: chromium, molybdenum, tungsten) in the presence of tetracyanoethylene, TCNE, or fumaronitrile , FN, at room temperature yields fram-bis(μ2-tetracyano-ethylene)tetracarbonyl-chromium(0) (1), -molybdenum(0) (2), -tungsten(0) (3) and trans-bis(fumaronitrile)tetracarbonylchromium(0) (4), -tungsten(0) (5) complexes. The complexes were purified by chromatography and recrystallization and characterized by IR , 1H, 13C NMR and mass spectroscopies. It is shown that two tetracyanoethylene ligands are symmetrically bonded to the M(CO)4 moiety through their carbon-carbon double bond in the form of μ2 -TCNE . The two fumaronitrile ligands are bonded to the central atom through their nitrogen atoms. The spectral data are discussed in terms of metal → ligand π - interaction.
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7

Mour, İzzet A., et Saim Özkar. « Synthesis and Spectroscopic Study of Pentacarbonyl(η2-tetracyanoethylene) Metal(0) Complexes of the Group 6 B Elements ». Zeitschrift für Naturforschung B 49, no 5 (1 mai 1994) : 717–20. http://dx.doi.org/10.1515/znb-1994-0525.

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Pentacarbonyl(η2-tetracyanoethylene) metal(0) complexes of chromium, molybdenum and tung­sten have been synthesized by the photochemical reaction of hexacarbonyl metal(o) with tetra- cyanoethylene in toluene at room temperature. The complexes were purified by chromatography and recrystallization, and characterized by UV- visible, IR and 13C NMR spectroscopy. Tetra- cyanoethylene is symmetrically bonded to the M(CO)5 unit through its carbon-carbon double bond as an η2-ligand. The spectral data are dis­cussed in terms of the metal → ligand π inter­action.
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8

Alcock, Nathaniel W., Graham A. Pike, Christopher J. Richards et Susan E. Thomas. « Generation of homochiral quaternary carbon centres from (vinylketenimine)tricarbonyliron(0) complexes ». Tetrahedron : Asymmetry 1, no 8 (janvier 1990) : 531–34. http://dx.doi.org/10.1016/s0957-4166(00)80542-x.

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9

Raubenheimer, Helgard G., Simon Lotz, Gert J. Kruger, Antonie van A. Lombard et Joey C. Viljoen. « Reactions of deprotonated sulphur-donor complexes of pentacarbonylchromium(0) with carbon disulphide or carbon diselenide ». Journal of Organometallic Chemistry 336, no 3 (décembre 1987) : 349–60. http://dx.doi.org/10.1016/0022-328x(87)85194-x.

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10

PAGANELLI, S., U. MATTEOLI, A. SCRIVANTI et C. BOTTEGHI. « ChemInform Abstract : Pt(0) Complexes as Catalyst Precursors for Homogeneous Carbon-Carbon and Carbon-Oxygen Double Bond Hydrogenation. » ChemInform 22, no 6 (23 août 2010) : no. http://dx.doi.org/10.1002/chin.199106053.

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11

Iqbal, Pervez, et Kiran Aftab. « Study of Complexation Behaviour of Lignite Extracted Humic Acid with Some Divalent Cations ». Engineering Science Letter 2, no 03 (9 octobre 2023) : 99–104. http://dx.doi.org/10.56741/esl.v2i03.431.

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In biogeochemical cycles, humic substances are natural electron shuttles in transforming nutrients and environmental pollutants. Humic acid complexes with macro and micronutrient metals are eco-friendly organo-mineral fertilisers. This study prepared and characterised lignite-extracted humic acid-metal (Fe, Mg, Zn) complexes. The proximate analysis exhibited the moisture, volatile matter, ash and fixed carbon contents of extracted humic acid of 02.61%, 17.31%, 57.18% and 22.90%, respectively. The percentage of metal ions in humic acid complexes ranges from 3.5-7.25%. The FTIR analysis of coal-extracted humic acids-metal complexes showed Zn, Mg and Fe ions complexed in a bidentate manner predominantly with the carboxylic acid moiety of humic acid. Thermal gravimetric analysis indicated a higher value of humic acid decomposition than their metal complexes. The thermal stability observed order is HA- Zn >HA-Fe>HA- Mg. The X-ray diffraction pattern pointed toward the noncrystalline nature of humic acid and their respective complexes due to having few intense and small diffuse peaks in the 2θ range from 0 to 80°. Hence, the humic acid-metals complexes increase the soil humic content and the availability of essential nutrients that enhance the loam's biotic action.
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12

Bennett, Martin A., Christopher J. Cobley, David C. R. Hockless et Thomas Klettke. « Mononuclear and Binuclear Complexes of Platinum(0) Containing (Alkynyl)phenylsilanes ». Australian Journal of Chemistry 52, no 1 (1999) : 51. http://dx.doi.org/10.1071/c98135.

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Reaction of bis(cycloocta-1,5-diene)platinum(0) with the (alkynyl)phenylsilanes Ph3SiC2But, Ph2Si(C2But)2 and PhSi(C2But)3 gives, respectively, [Pt (Ph3SiC2But)2] (1b), [Pt {Ph2Si(C2But)}]2 (2b), and [Pt {PhSi(C2But)3}]2 (4b), which contain zerovalent platinum atoms coordinated by two alkyne units. Spectroscopic data indicate that (2b) and (4b) contain two PtC4 and two SiC4 tetrahedra joined at the corners. X-Ray crystallography shows that complex (4b) is isostructural and isomorphous with the known nickel analogue, two of the alkyne units being uncoordinated; the central eight-membered ring comprising two silicon, four alkyne carbon and two platinum atoms has an approximate chair conformation. In contrast, the monomer (1b) is isostructural but not isomorphous with the analogous nickel compound (1a); in the crystal there is evidence for a weak intramolecular phenyl-phenyl interaction.
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13

Müller, Christian, Carl N. Iverson, Rene J. Lachicotte et William D. Jones. « Carbon−Carbon Bond Activation in Pt(0)−Diphenylacetylene Complexes Bearing Chelating P,N- and P,P-Ligands ». Journal of the American Chemical Society 123, no 39 (octobre 2001) : 9718–19. http://dx.doi.org/10.1021/ja016675z.

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14

Kégl, Tímea R., Rui M. B. Carrilho et Tamás Kégl. « Theoretical insights into the electronic structure of nickel(0)-diphosphine-carbon dioxide complexes ». Journal of Organometallic Chemistry 924 (octobre 2020) : 121462. http://dx.doi.org/10.1016/j.jorganchem.2020.121462.

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15

Bruce, Michael I. « Some complexes of all-carbon ligands and related chemistry ». Coordination Chemistry Reviews 166 (novembre 1997) : 91–119. http://dx.doi.org/10.1016/s0010-8545(97)00004-0.

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16

Müller, Christian, Rene J. Lachicotte et William D. Jones. « Thermal and Photochemical Silicon−Carbon Bond Activation in Donor-Stabilized Platinum(0)−Alkyne Complexes ». Organometallics 21, no 6 (mars 2002) : 1190–96. http://dx.doi.org/10.1021/om010984g.

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17

Schulze, W., et K. Seppelt. « Transition metal complexes with fluorinated and SF5-substituted carbon ligands ». Journal of Fluorine Chemistry 29, no 1-2 (août 1985) : 47. http://dx.doi.org/10.1016/s0022-1139(00)83282-0.

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18

Klein, Hans-Friedrich, Michael Helwig, Michael Karnop, Herbert König, Birgit Hammerschmitt, Gerhard Cordier, Ulrich Flörke et Hans-Jürgen Haupt. « Tris(trimethylphosphine)cobalt(0) Compounds Containing Azaolefinic Ligands — Syntheses and Structures of Benzo[c]cinnoline and Phenylisocyanate Complexes ». Zeitschrift für Naturforschung B 48, no 6 (1 juin 1993) : 785–93. http://dx.doi.org/10.1515/znb-1993-0613.

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Mononuclear cobalt(0) complexes Co(η2-azaolefin)(PMe3)3 (azaolefin = benzo[c]cinnoline (1), p-dimethylamino-phenyl(phenyl)diazene (2), 1/2 diazobenzene (3), bis(p-tolyl)diazene (4), bis(p-fluorphenyl)diazene (5), bis(p-trifluoromethyl-phenyl)diazene (6), phenylisocyanate (7)) are obtained from Co(cyclo-C5H8)(PMe3)3 by substitution of the olefin. X-ray crystal structure determinations of 1 and 7 show tetrahedral arrangements of ligands around the cobalt atom. By reaction with carbon monoxide carbonyl(phosphine)cobalt(0) complexes are formed. 7 catalyses the cyclotrimerization of phenylisocyanate, while with CoCl(PMe3)3 as a catalyst the cyclic dimer of phenylisocyanate is selectively formed. A convenient synthesis for CoCl(PMe3)3 is described.
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19

Stübner, Ronald, Vladimir Kolkovsky, Jörg Weber et N. V. Abrosimov. « Carbon-Hydrogen Complexes in n- and p-Type SiGe-Alloys Studied by Laplace Deep Level Transient Spectroscopy ». Solid State Phenomena 242 (octobre 2015) : 184–89. http://dx.doi.org/10.4028/www.scientific.net/ssp.242.184.

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A deep level transient spectroscopy (DLTS) study on n- and p-type diluted Si1-xGex alloys (x=0, 0.011, 0.026, 0.046, and 0.070) is presented. Defect levels of several carbon-hydrogen (CH) complexes are observed. The high-resolution Laplace-DLTS technique allows us to detect configurations of defects which contain different numbers of Ge atoms in the first and second-nearest neighbourhood of the CH complexes. The electrical properties of the defects will be analysed and their origin will be discussed.
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20

Moreno-Mañas, Marcial, Roser Pleixats, Rosa M. Sebastián, Adelina Vallribera et Anna Roglans. « Organometallic chemistry of 15-membered tri-olefinic macrocycles : catalysis by palladium(0) complexes in carbon–carbon bond-forming reactions ». Journal of Organometallic Chemistry 689, no 23 (novembre 2004) : 3669–84. http://dx.doi.org/10.1016/j.jorganchem.2004.05.024.

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21

Dieck, Heindirk tom, et Ingo Kleinwächter. « Rutheniumkomplexe mit Diazadienen, VI [1] η6-Cycloheptatrien-und η4 -Norbornadien-diazadien-ruthenium(0)-Komplexe / Ruthenium Complexes with Diazadienes, VI [1] η6-Cycloheptatriene-and η4-Norbornadiene-diazadiene-ruthenium(0) Complexes ». Zeitschrift für Naturforschung B 42, no 1 (1 janvier 1987) : 71–76. http://dx.doi.org/10.1515/znb-1987-0114.

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Abstract Reduction of [(cyclo-C7H8)RuCl2]2 in the presence of a diazadiene RN=CH−CH=NR (DAD; R = i-C3H7) gives red, airsensitive, sublimable (η6-C7H8)Ru(DAD) (5). A rigid structure on the basis of the 1H NMR spectrum is excluded. On the other hand pentacoordinate complexes [η4-nor-C7H8)Ru(DAD)P(C6H5)3] (8) or [(η4-nor-C7H8)Ru(DAD)CO] (9) have rigid, Cs-symmetric, square-pyramidal structures. They are obtained by chemical or irreversible electro-chemical reduction of [(η4-nor-C7H8)Ru(DAD)Cl2] to [η4-nor-C7H8)Ru(DAD)(solv)] (7) (solv = tetrahydrofuran or acetonitrile) and addition of phosphine or carbon monoxide. 7, in non-coor-dinating solvents, is a stereospecific catalyst for the 1-alkene → trans-2,... -alkene isomerization.
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22

Aga, Hirohide, Akiko Aramata et Yoshio Hisaeda. « The electroreduction of carbon dioxide by macrocyclic cobalt complexes chemically modified on a glassy carbon electrode ». Journal of Electroanalytical Chemistry 437, no 1-2 (novembre 1997) : 111–18. http://dx.doi.org/10.1016/s0022-0728(97)00386-0.

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23

Eisch, John J., Andrzej M. Piotrowski, Kyoung I. Han, Carl Kruger et Y. H. Tsay. « Organic chemistry of subvalent transition complexes. 9. Oxidative addition of nickel(0) complexes to carbon-carbon bonds in biphenylene : formation of nickelole and 1,2-dinickelecin intermediates ». Organometallics 4, no 2 (février 1985) : 224–31. http://dx.doi.org/10.1021/om00121a003.

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24

Koptseva, Tatyana S., Vladimir G. Sokolov, Sergey Yu Ketkov, Elena A. Rychagova, Anton V. Cherkasov, Alexandra A. Skatova et Igor L. Fedushkin. « Reversible Addition of Carbon Dioxide to Main Group Metal Complexes at Temperatures about 0 °C ». Chemistry – A European Journal 27, no 18 (mars 2021) : 5745–53. http://dx.doi.org/10.1002/chem.202004991.

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25

Li, Juan, Guochen Jia et Zhenyang Lin. « Theoretical Studies on Coupling Reactions of Carbon Dioxide with Alkynes Mediated by Nickel(0) Complexes ». Organometallics 27, no 15 (août 2008) : 3892–900. http://dx.doi.org/10.1021/om8002224.

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26

Ryndin, Yu A., O. S. Alekseev, P. A. Simonov et V. A. Likholobov. « Supported metallic catalysts obtained by anchoring metal complexes on carbon supports ». Journal of Molecular Catalysis 55, no 1 (novembre 1989) : 109–25. http://dx.doi.org/10.1016/0304-5102(89)80247-0.

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27

Weber, Jaques, E. Peter Kundig, Annick Goursot et Edouard Penigault. « The electronic structures of bis(η6-benzene)- and bis(η6-naphthalene)chromium(0) ». Canadian Journal of Chemistry 63, no 7 (1 juillet 1985) : 1734–40. http://dx.doi.org/10.1139/v85-291.

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SCF MS Xα molecular orbital calculations are reported for the bis(η6-benzene)- and bis(η6-naphthalene)chromium(0) complexes. The bonding may be essentially discussed in terms of the covalent interactions between the metal 3d and ligand π and π* orbitals. The different charges on chromium atom in the two systems are explained by the different balances between ligand-to-metal (bonding) and metal-to-ligand (back-bonding) electron donations. Some resemblances are found between the electronic structures of the two compounds and it is possible to correlate to a large extent the energy levels of their molecular orbitals. However, a shift towards lower values is predicted for the energy levels of the naphthalene complex, together with a large disruption of all the virtual π* and 3d* levels. This would undoubtedly favor nucleophilic attack followed by metal–ring or carbon–carbon bond cleavage, in agreement with the extreme lability of the coordinated arene rings observed in this complex.
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28

Bennett, Martin A., Mark Bown et David C. R. Hockless. « Tris(dimethylphenylphosphine)ruthenium(0) Complexes of n4-Coordinated Polycyclic Aromatic Hydrocarbons ». Australian Journal of Chemistry 53, no 6 (2000) : 507. http://dx.doi.org/10.1071/ch00068.

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From the reaction of [Ru2Cl3(PMe2Ph)6] Cl with the appropriate radical anions, yellow complexes of general formula [Ru(PMe2Ph)3(η4-arene)] [arene = naphthalene (C10H8) (1), anthracene (C14H10) (2), and triphenylene (C18H12) (3)] have been isolated in poor yield and characterized by elemental analysis, n.m.r. (1H, 13C, 31P) spectroscopy and single-crystal X-ray diffraction. Crystal data: (1), monoclinic, C2/c, a 31.096(8), b 12.012(4), c 17.078(8) Å, β 104.41(3)˚, V 6178(4) Å3, ? 8, refined to final R value of 0.032 with use of 3641 reflections [I > 3σ(I)]; (2), monoclinic, C2/c, a 55.909(4), b 14.348(5), c 17.573(5) Å, β 105.41(1)˚, V 13590(6) Å3, Z 16 (two molecules per asymmetric unit), refined to final R value of 0.049 with use of 7770 reflections [I > 3σ(I)]; (3), mono-clinic, Pn, a 9.377(3), b 12.229(3), c 15.975(3) Å, β 103.51(2)˚, V 1781.2 (7) Å3, Z 2, refined to final R value of 0.026 with use of 2830 reflections [I > 3σ(I)]. In each case, coordination of the zerovalent metal fragment Ru(PMe2Ph)3 to the diene section of one of the terminal rings causes the aromatic molecule to be folded by c. 40˚ at the outer carbon atoms of the diene. The coordination geometry about ruthenium is approximately square pyramidal, with the diene and two tertiary phosphines in the equatorial plane and the remaining tertiary phosphine in the axial site.
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Kubo, Kazuyuki, Hiroyuki Okitsu, Hiroto Miwa, Shoko Kume, Ronald G. Cavell et Tsutomu Mizuta. « Carbon(0)-Bridged Pt/Ag Dinuclear and Tetranuclear Complexes Based on a Cyclometalated Pincer Carbodiphosphorane Platform ». Organometallics 36, no 2 (3 janvier 2017) : 266–74. http://dx.doi.org/10.1021/acs.organomet.6b00700.

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30

Yang, Yong, Fang Xie, Jiahui Chen, Si Qiu, Na Qiang, Ming Lu, Zhongli Peng, Jing Yang et Guocong Liu. « Electrocatalytic Reduction of CO2 to CO by Molecular Cobalt–Polypyridine Diamine Complexes ». Molecules 29, no 8 (9 avril 2024) : 1694. http://dx.doi.org/10.3390/molecules29081694.

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Cobalt complexes have previously been reported to exhibit high faradaic efficiency in reducing CO2 to CO. Herein, we synthesized capsule-like cobalt–polypyridine diamine complexes [Co(L1)](BF4)2 (1) and [Co(L2) (CH3CN)](BF4)2 (2) as catalysts for the electrocatalytic reduction of CO2. Under catalytic conditions, complexes 1 and 2 demonstrated the electrocatalytic reduction of CO2 to CO in the presence or absence of CH3OH as a proton source. Experimental and computational studies revealed that complexes 1 and 2 undergo two consecutive reversible one-electron reductions on the cobalt core, followed by the addition of CO2 to form a metallocarboxylate intermediate [CoII(L)–CO22−]0. This crucial reaction intermediate, which governs the catalytic cycle, was successfully detected using high resolution mass spectrometry (HRMS). In situ Fourier-transform infrared spectrometer (FTIR) analysis showed that methanol can enhance the rate of carbon–oxygen bond cleavage of the metallocarboxylate intermediate. DFT studies on [CoII(L)–CO22−]0 have suggested that the doubly reduced species attacks CO2 on the C atom through the dz2 orbital, while the interaction with CO2 is further stabilized by the π interaction between the metal dxz or dxz orbital with p orbitals on the O atoms. Further reductions generate a metal carbonyl intermediate [CoI(L)–CO]+, which ultimately releases CO.
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31

Nagel, Yvonne, et Wolfgang Beck. « Metallkomplexe mit biologisch wichtigen Liganden, XLI [1]. Platin(II)- und Cobalt(III)-Komplexe von Monosaccharid-Derivaten mit Metall-Schwefel- und Metall-Kohlenstoff-Bindungen / Metal Complexes with Biologically Important Ligands, XLI [1]. Platinum(II) and Cobalt(III) Complexes of Monosaccharide Derivatives with Metal-Sulfur and Metal-Carbon Bonds ». Zeitschrift für Naturforschung B 40, no 9 (1 septembre 1985) : 1181–87. http://dx.doi.org/10.1515/znb-1985-0915.

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The reaction of bis(2,3,4,6-tetra-0-acetyl-β-D-glucopyranosyl)disulfide with (Ph3P)2Pt(C2H4) gives cis-di(2,3,4,6-tetra-0-acetyl-l-mercapto-β-D-glucopyranosid)bis(triphenylphosphane)platinum (II). A dithiocarbimato complex (Ph3P)2Pt(S2CNR) has been isolated from cis-(Ph3P)2PtCl2, CS2 and 1-0-Methyl-2-amino-2-deoxy-4,6-benzyliden-α,β-D-glucopyranoside. Metal complexes with metal-carbon bonds have been prepared by oxidative addition of monosaccharide halides to (Ph3P)2Pt(C2H4) or to cobalt(I) cobaloxime, respectively. From the reaction of (Ph3P)2Pt(C2H4) with 2,3,4,6 -Tetra-O-acetyl-α-D-glucopyranosyl-bromide the anomers trans-(α- and β-glucopyranosyl) Pt(PPh3)2Br have been obtained. This indicates a radical reaction.
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32

Bennett, Martin A. « Aryne Complexes of Zerovalent Metals of the Nickel Triad ». Australian Journal of Chemistry 63, no 7 (2010) : 1066. http://dx.doi.org/10.1071/ch10198.

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The chemistry of dihapto-aryne complexes of the zerovalent Group 10 metals of general formula [M(η2-aryne)L2] (M = Ni, Pd, Pt; L = various tertiary phosphines) is reviewed, with emphasis on the highly reactive nickel(0) compounds (aryne = benzyne, C6H4; 4,5-difluorobenzyne, 4,5-C6H2F2; 2,3-naphthalyne, 2,3-C10H6; L2 = 2 PEt3, 2 PiPr3, 2 PCy3, dcpe). These can be generated by alkali metal reduction of the appropriate (2-halogenoaryl)nickel(ii) halide precursors, such as [NiX(2-XC6H4)L2], which in turn are accessible by oxidative addition of the 1,2-dihaloarene to nickel(0) precursors such as [Ni(1,5-COD)2]. The X-ray structure of [Ni(η2-C6H4)(dcpe)] shows that this compound is a typical 16-electron Ni(0) (3d10) species in which benzyne acts as a 2π-electron donor. Several unusual organonickel compounds derived from [Ni(η2-4,5-C6H2F2)(PEt3)2] have been isolated recently, including [Ni2(μ-η2:η2-4,5-C6H2F2)(PEt3)4], in which a 4π-electron donor 4,5-difluorobenzyne is located at right-angles to a pair of nickel atoms. Free benzyne can be intercepted by both [Ni(η2-C2H4)(dcpe)] and [Pt(η2-C2H4)(PPh3)2], but the resulting benzyne complexes rapidly insert benzyne to give the appropriate η1:η1-2,2′-biphenylyl complexes. [Pt(η2-C6H4)(PPh3)2] also undergoes rapid ortho-metallation to give [PtPh(2-C6H4PPh2)(PPh3)]. However, a trapping reaction has been used to make the first 1,4-benzdiyne complex, [{Ni(dcpe)2}2(μ-η2:η2-1,4-C6H2)] by treatment of the 4-fluorobenzyne complex [Ni(η2-4-FC6H3)(dcpe)] with LiTMP. The use of alkali metals in the preparation of the η2-benzyne complexes is avoided in a more recently developed procedure, which starts from (2-bromophenyl)boronic acid, and is based on Suzuki–Miyaura coupling. This procedure has made accessible for the first time an aryne complex of palladium(0), [Pd(η2-C6H4)(PCy3)2], and the labile nickel(0) complex [Ni(η2-C6H4)(PPh3)2]. The aryne-nickel(0) complexes Ni(η2-aryne)L2 (L2 = 2 PEt3, dcpe) undergo sequential insertions into the aryne-metal bond with unsaturated molecules, such as CO, C2F4, substituted alkynes, substituted diynes, alkynylphosphines, and alkynyl thioethers, often with considerable regioselectivity. After the reductive elimination of two nickel-carbon σ-bonds, a variety of interesting polycyclic compounds can be obtained.
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33

Rakowski^DuBois, M. « Carbon-chalcogen bond cleavage reactions characterized for dinuclear sulfur-bridged cyclopentadienyl molybdenum complexes ». Polyhedron 16, no 18 (janvier 1997) : 3089–98. http://dx.doi.org/10.1016/s0277-5387(96)00522-0.

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Valente, A., A. M. Botelho do Rego, M. J. Reis, I. F. Silva, A. M. Ramos et J. Vital. « Oxidation of pinane using transition metal acetylacetonate complexes immobilised on modified activated carbon ». Applied Catalysis A : General 207, no 1-2 (février 2001) : 221–28. http://dx.doi.org/10.1016/s0926-860x(00)00622-0.

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35

Schaub, Thomas, Marc Backes et Udo Radius. « Nickel(0) Complexes of N-Alkyl-Substituted N-Heterocyclic Carbenes and Their Use in the Catalytic Carbon−Carbon Bond Activation of Biphenylene ». Organometallics 25, no 17 (août 2006) : 4196–206. http://dx.doi.org/10.1021/om0604223.

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36

Sano, Kenji, Takakazu Yamamoto et Akio Yamamoto. « Preparation and Reactions of η3 -Allylcarboxylatoruthenium ». Zeitschrift für Naturforschung B 40, no 2 (1 février 1985) : 210–14. http://dx.doi.org/10.1515/znb-1985-0211.

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AbstractReactions of (1,5-cyclooctadiene)(1,3,5-cyclooctatriene)ruthenium(0) with 3-butenoic acid in the presence of tertiary phosphines, PR3 , afford η3 -allylcarboxylatoruthenium(II) complexes formulated as (PR3)2[xxx](1 (PR3 = PPh3), 2 (PR3 = P(C6H4-p-OCH3)3). The reaction of 1 with carbon monoxide gives the complex (PPh3)2(CO)[xxx] while reaction with Br 2 or I 2 leads to ring closure of the organic ligand to afford 2-butenolide.
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37

Mastrorilli, Pietro, Giovanni Moro, Cosimo Francesco Nobile et Mario Latronico. « Carbon dioxide-transition metal complexes. IV. New Ni(0)CO2 complexes with chelating diphosphines : influence of PNiP angle on complex stabilities ». Inorganica Chimica Acta 192, no 2 (février 1992) : 189–93. http://dx.doi.org/10.1016/s0020-1693(00)80758-6.

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38

Atkin, Anthony J., Sophie Williams, Philip Sawle, Roberto Motterlini, Jason M. Lynam et Ian J. S. Fairlamb. « μ2-Alkyne dicobalt(0)hexacarbonyl complexes as carbon monoxide-releasing molecules (CO-RMs) : probing the release mechanism ». Dalton Transactions, no 19 (2009) : 3653. http://dx.doi.org/10.1039/b904627p.

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39

Tonner, Ralf, et Gernot Frenking. « Divalent Carbon(0) Chemistry, Part 2 : Protonation and Complexes with Main Group and Transition Metal Lewis Acids ». Chemistry - A European Journal 14, no 11 (7 avril 2008) : 3273–89. http://dx.doi.org/10.1002/chem.200701392.

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40

Štíbr, Bohumil. « Acyl chloride carbon insertion into dicarbaborane cages – new route to tricarbollide cages ». Pure and Applied Chemistry 87, no 2 (1 février 2015) : 135–42. http://dx.doi.org/10.1515/pac-2014-0937.

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AbstractReactions between the arachno-6,9-C2B8H14 dicarbaborane and acyl chlorides, RCOCl, in the presence of amine bases in CH2Cl2, followed by acidification with conc. H2SO4 at 0 °C, generate in high yields a series of neutral alkyl and aryl tricarbollides of structure 8-R-nido-7,8,9-C3B8H11 (where R=alkyls and aryls). These skeletal alkylcarbonation (SAC) reactions are consistent with an aldol-type condensation between the RCO group and open-face dicarbaborane hydrogen atoms, which is associated with the insertion of the acyl chloride RC unit into the structure under elimination of three extra hydrogen atoms as H2O and HCl. The reactions thus result in an effective cross-coupling between R and the tricarbollide cage. High-temperature reactions between 8-Ar-nido-7,8,9-C3B8H11 (where Ar=Ph, 1-C10H7, and 2-C10H7) compounds and [CpFe(CO)2]2 produced the first types of monoaryl substituted twelve-vertex ferratricarbollide complexes of general constitution [1-(CpFe)-closo-ArC3B8H10] with three different arrangements of cluster carbon vertexes. The Fe-complexation is accompanied by extensive rearrangement of the cluster carbon atoms over the twelve-vertex cage and the complexes isolated can be regarded as ferrocene analogues.
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41

Boucher, Sylvain, et Davit Zargarian. « 1-Bromoindene — A new synthon for the preparation of (indenyl)Ni(II)(PPh3)Br ». Canadian Journal of Chemistry 84, no 2 (1 février 2006) : 233–37. http://dx.doi.org/10.1139/v05-248.

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The oxidative addition of the carbon–bromine bond in 1-bromoindene to Ni(PPh3)4 gives the complex (indenyl)Ni(PPh3)Br (1) in 95% yield. In contrast, other nickel(0) species such as Ni(PMe3)4 and Ni(COD)2 promote the oxidative coupling of 1-bromoindene to 1,1′-biindene. Complex 1 has been characterized by NMR spectroscopy (1H, 13C, 31P) and single-crystal X-ray structural analysis.Key words: indenyl complexes, oxidative addition, oxidative coupling.
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42

Vichi, Eduardo J. S., Fred Y. Fujiwara et Edison Stein. « Structural and electronic effects in (benzylideneacetone)dicarbonyl(phosphine)iron(0) and (benzylideneacetone)dicarbonyl(phosphite)iron(0) complexes. A carbon-13 magnetic resonance study ». Inorganic Chemistry 24, no 3 (janvier 1985) : 286–90. http://dx.doi.org/10.1021/ic00197a009.

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43

Espinosa, Javier, Miguel Angel Castells, Karim Boumediene Laichoubi, Karl Forchhammer et Asunción Contreras. « Effects of spontaneous mutations in PipX functions and regulatory complexes on the cyanobacterium Synechococcus elongatus strain PCC 7942 ». Microbiology 156, no 5 (1 mai 2010) : 1517–26. http://dx.doi.org/10.1099/mic.0.037309-0.

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In Synechococcus elongatus sp. PCC 7942, PipX forms complexes with PII, a protein found in all three domains of life as an integrator of signals of the nitrogen and carbon balance, and with the cyanobacterial nitrogen regulator NtcA. We recently showed that previous inactivation of pipX facilitates subsequent inactivation of the glnB gene. Here, we show that the three spontaneous pipX point mutations pipX-92delT, pipX160C>T and pipX194T>A, initially found in different glnB strains, are indeed suppressor mutations. When these mutations were reconstructed in the wild-type background, the glnB gene could be efficiently inactivated. Furthermore, the point mutations have different effects on PipX levels, coactivation of NtcA-dependent genes and protein–protein interactions. Further support for an in vivo role of PipX–PII complexes is provided by interaction analysis with the in vivo-generated PII T-loop+7 protein, a PII derivative unable to interact with its regulatory target N-acetyl-l-glutamate kinase, but which retains the ability to bind to PipX. The implications of these results are discussed.
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44

Al-Marzouqi, Ali, Baboucarr Jobe, Giovanna Corti, Marzia Cirri et Paola Mura. « Physicochemical characterization of drug-cyclodextrin complexes prepared by supercritical carbon dioxide and by conventional techniques ». Journal of Inclusion Phenomena and Macrocyclic Chemistry 57, no 1-4 (18 janvier 2007) : 223–31. http://dx.doi.org/10.1007/s10847-006-9192-0.

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45

Marr, J. CA, J. Lipton, D. Cacela, J. A. Hansen, J. S. Meyer et H. L. Bergman. « Bioavailability and acute toxicity of copper to rainbow trout (Oncorhynchus mykiss) in the presence of organic acids simulating natural dissolved organic carbon ». Canadian Journal of Fisheries and Aquatic Sciences 56, no 8 (1 août 1999) : 1471–83. http://dx.doi.org/10.1139/f99-089.

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Copper bioavailability and toxicity to early life stage rainbow trout (Oncorhynchus mykiss) were evaluated by laboratory toxicity testing performed using organic acid mixtures. Geochemical modeling was used to design exposure solutions that simulate dissolved organic carbon (DOC) of a natural aquatic system and to determine the fractions of total Cu present as inorganic species (e.g., Cu2+) and as individual Cu-organic complexes. Failure time modeling indicated that mortality was best predicted by a combination of total inorganic Cu and distinct Cu-organic complexes. The Cu-organic complexes that contributed to toxicity are characterized as low-affinity Cu-ligands, and our results support the hypothesis that Cu toxicity in nature is a function of the binding characteristics of individual ligands. Estimates of time-independent median lethal concentration thresholds determined at widely varying equivalent concentrations of DOC (0-16 mg/L) were constant (7.9-8.6 µg Cu/L) when modeled using the sum of inorganic Cu and Cu bound to the two low-affinity ligands as predictors of toxicity. Our results indicate that Cu bound to organic complexes may be available to fish and that acute toxicity of Cu is determined by the binding affinities of specific DOC components relative to Cu-binding affinity of fish gill.
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46

Shibli, Jamil Awad, Thayane Furtado Rocha, Fernanda Coelho, Ticiana Sidorenko de Oliveira Capote, Sybele Saska, Marcelo A. Melo, João Marcos Spessoto Pingueiro, Marcelo de Faveri et Bruno Bueno-Silva. « Metabolic activity of hydro-carbon-oxo-borate on a multispecies subgingival periodontal biofilm : a short communication ». Clinical Oral Investigations 25, no 10 (28 mars 2021) : 5945–53. http://dx.doi.org/10.1007/s00784-021-03900-0.

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Abstract Objective This study evaluated the metabolic activity of hydro-carbon-oxo-borate complex (HCOBc) on a multispecies subgingival biofilm as well as its effects on cytotoxicity. Materials and methods The subgingival biofilm with 32 species related to periodontitis was formed in the Calgary Biofilm Device (CBD) for 7 days. Two different therapeutic schemes were adopted: (1) treatment with HCOBc, 0.12% chlorhexidine (CHX), and negative control group (without treatment) from day 3 until day 6, two times a day for 1 min each time, totaling 8 treatments and (2) a 24-h treatment on a biofilm grown for 6 days. After 7 days of formation, biofilm metabolic activity was determined by colorimetry assay, and bacterial counts and proportions of complexes were determined by DNA-DNA hybridization. Both substances’ cytotoxicity was evaluated by cell viability (XTT assay) and clonogenic survival assay on ovary epithelial CHO-K1 cells and an osteoblast precursor from calvaria MC3T3-E1 cells. Results The first treatment scheme resulted in a significant reduction in biofilm’s metabolic activity by means of 77% by HCOBc and CHX treatments versus negative control. The total count of 11 and 25 species were decreased by treatment with hydro-carbon-oxo-borate complex and CHX, respectively, compared with the group without treatment (p < 0.05), highlighting a reduction in the levels of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Fusobacterium periodontium. CHX significantly reduced the count of 10 microorganisms compared to the group treated with HCOBc (p < 0.05). HCOBc and CHX significantly decreased the pathogenic red-complex proportion compared with control-treated biofilm, and HCOBc had even a more significant effect on the red complex than CHX had (p ≤ 0.05). For the second treatment scheme, HCOBc complex and CHX significantly decreased 61 and 72% of control biofilms’ metabolic activity and the counts of 27 and 26 species, respectively. HCOBc complex did not significantly affect the proportions of formed biofilms, while CHX significantly reduced red, orange, and yellow complexes. Both substances exhibited similar cytotoxicity results. Conclusions This short communication suggested that the HCOBc complex reduced a smaller number of bacterial species when compared to chlorhexidine during subgingival biofilm formation, but it was better than chlorhexidine in reducing red-complex bacterial proportions. Although HCOBc reduced the mature 6-day-old subgingival multispecies biofilms, it did not modify bacterial complexes’ ratios as chlorhexidine did on the biofilms mentioned above. Future in vivo studies are needed to validate these results. Clinical relevance HCOBc complex could be used to reduce red-complex periodontal bacterial proportions.
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47

Hartnell, Regan D., Alison J. Edwards et Dennis P. Arnold. « Peripherally-metallated porphyrins : meso-η1-porphyrinyl-platinum(II) complexes of 5,15-diaryl- and 5,10,15-triarylporphyrins ». Journal of Porphyrins and Phthalocyanines 06, no 11 (novembre 2002) : 695–707. http://dx.doi.org/10.1142/s1088424602000828.

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Attempted metathesis reactions of peripherally-metallated meso-η1-porphyrinylplatinum(II) complexes such as trans-[ PtBr ( NiDPP )( PPh 3)2]( H 2 DPP = 5,15- diphenylporphyrin ) with organolithium reagents fail due to competitive addition at the porphyrin ring carbon opposite to the metal substituent. This reaction can be prevented by using 5,10,15-triarylporphyrins, e.g. 5,10,15-triphenylporphyrin ( H 2 TrPP ) and 5-phenyl-10,20-bis(3′,5′-di-t-butylphenyl)porphyrin ( H 2 DAPP ) as substrates. These triarylporphyrins are readily prepared using the method of Senge and co-workers by addition of phenyllithium to the appropriate 5,15-diarylporphyrins, followed by aqueous protolysis and oxidation. They are convenient, soluble building blocks for selective substitutions and subsequent transformations at the remaining free meso carbon. The sequence of bromination, optional central metallation and oxidative addition of Pt (0) tris(phosphine) complexes generates the organoplatinum porphyrins in high overall yields. The bromo ligand on the Pt (II) centre can be substituted by alkynyl nucleophiles, including 5-ethynyl NiDPP , to form the first examples of meso-η1-porphyrinylplatinum(II) complexes with a second Pt - C bond. The range of porphyrinylplatinum(II) bis(tertiary phosphine) complexes was extended to the triethylphosphine analogues, by oxidative addition of H 2 TrPPBr to Pt ( PEt 3)3, and the initially-formed cis adduct is only slowly thermally transformed to trans-[ PtBr ( H 2 TrPP )( PEt 3)2]16. The molecular structures of NiDAPP 9b, trans-[ Pt ( NiDPP )( C 2 NiDPP )( PPh 3)2]14 and 16 were determined by X-ray crystallography.
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Kusama, Hiroyuki, Fumiyasu Shiozawa, Masahide Shido et Nobuharu Iwasawa. « Tandem Cyclizations of Benzopyranylidenetungsten(0) Complexes with Electron-Rich Dienes for the Stereoselective Synthesis of Polycyclic Carbon Skeletons ». Chemistry Letters 31, no 2 (février 2002) : 124–25. http://dx.doi.org/10.1246/cl.2002.124.

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Baldoli, C., P. Del Buttero, E. Licandro, S. Maiorana, A. Papagni et A. Zanotti-Gerosa. « Pentacarbonyl(aminocarbene)chromium(0) Complexes : Reductive Cleavage of the Chromium-Carbon Double Bond to Secondary and Tertiary Amines ». Synlett 1994, no 08 (1994) : 677–78. http://dx.doi.org/10.1055/s-1994-22973.

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Cherkas, Andrew A., Susan M. Breckenridge et Arthur J. Carty. « Carbon-13 NMR shifts of bridging hydrocarbyls derived from the addition of nucleophiles to complexed organic ligands in DI- and polynuclear complexes ». Polyhedron 11, no 9 (janvier 1992) : 1075–84. http://dx.doi.org/10.1016/s0277-5387(00)84477-0.

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