- Synthesis and structures of cyclic gold complexes containing diphosphine ligands and luminescent properties of the high nuclearity species
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A mixture of cyclic gold(i) complexes [Au2(μ-cis-dppen) 2]X2 (X = OTf 1, PF63) and [Au(cis-dppen) 2]X (X = OTf 2, PF64) is obtained from the reaction of [Au(tht)2]X (tht = tetrahydrothiophene) with one equivalent of cis-dppen [dppen = 1,2-bis(diphenylphosphino)ethylene]. The analogous reaction with trans-dppen or dppa [dppa = bis(diphenylphosphino)acetylene] affords the cyclic trinuclear [Au3(μ-trans-dppen)3]X3 (X = OTf 11, PF612) and tetranuclear [Au4(μ-dppa) 4]X4 (X = OTf 13, PF614, ClO415) gold complexes, respectively. Recrystallization of 15 from CH2Cl 2/MeOH yielded a crystal of the octanuclear gold cluster [Au 8Cl2(μ-dppa)4](ClO4) 216. Attempts to prepare dicationic binuclear gold(ii) species from the reaction of a mixture of 3 and 4 with halogens gave a mixture of products, the components of which confirmed to be acyclic binuclear gold(i) [Au 2X2(cis-dppen)] (X = I 5, Br 7) and cyclic mononuclear gold(iii) [AuX2(cis-dppen)]PF6 (X = I 6, Br 8) complexes. Complexes 11-14 reveal weak emission in butyronitrile glass at 77 K, but they are non-emissive at room temperature. Ab initio modelling was performed to determine the charge state of the gold atoms involved. Extensive structural comparisons were made to experimental data to benchmark these calculations and rationalize the conformations. The Royal Society of Chemistry 2012.
- Bhargava, Suresh,Kitadai, Kunihiko,Masashi, Takahashi,Drumm, Daniel W.,Russo, Salvy P.,Yam, Vivian Wing-Wah,Lee, Terence Kwok-Ming,Wagler, Joerg,Mirzadeh, Nedaossadat
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p. 4789 - 4798
(2012/06/04)
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- Synthesis, structures and anti-malaria activity of some gold(i) phosphine complexes containing seleno- and thiosemicarbazonato ligands
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A series of both mono- and dinuclear gold(i) phosphine complexes containing monoanionic seleno- and thiosemicarbazones as ligands were prepared and fully characterized by spectroscopic methods and, in some cases, by single crystal X-ray diffraction. The in vitro anti-malaria activity of some of these compounds was investigated in chloroquine sensitive strains of Plasmodium falciparum. The IC50 results show that the sulfur containing compounds exhibit activity similar to that of chloroquine, whilst the selenium derivatives display only moderate anti-malaria activity.
- Molter, Anja,Rust, Joerg,Lehmann, Christian W.,Deepa, Ganesh,Chiba, Peter,Mohr, Fabian
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p. 9810 - 9820
(2011/12/03)
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- Chemistry of Polynuclear Metal Complexes with Bridging Carbene or Carbyne Ligands. Part 114. Ditungsten-Digold Compounds having two W(CC6H4Me-4)(CO)2(η5-C2B9H9Me2) Fragments linked by AuP(Ph)2(CH2)n(Ph)2PAu (n = 2-6) Groups
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Treatment of 1 equivalent of the reagent CR)(CO)2(η5-C2B9H9Me2)> (R = C6H4Me-4), in the presence of TlBF4, with 0.5 equivalent of the compounds > (n = 2-6) in CH2Cl2 affords the complexes (CO)4(η5C2B9H9Me2)2>.The crystal structure of the species with n = 4 has been determined by X-ray crystallography, confirming that the molecule has two RCW(CO)2(η5-C2B9H9Me2) fragments bridged by an AuP(Ph)2CH2CH2CH2CH2(Ph)2PAu unit, with a centre of inversion at the midpoint of the chain of methylene groups.The W-Au bonds are asymmetrically bridged by the p-tolylmethylidyne ligands .In a similar manner, the compounds 5-C2B9H9Me2)2> have been prepared from reactions between the gold compounds and the salt CR)(CO)2(η5-C2B9H9Me2)>.Addition of (cod = cycloocta-1,5-diene) to the complexes (CO)4(η5C2B9H9Me2)2> affords the chain cluster compounds 3-CR)2(μ-Ph2P(CH2)nPPh2>(CO)4(cod)2(η5-C2B9H9Me2)2>.The NMR data (1H, 13C-, 31P- and 11B- for the new complexes are reported and discussed.
- Goldberg, Justin E.,Mullica, Donald F.,Sappenfield, Eric L.,Stone, F. Gordon A.
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p. 2495 - 2502
(2007/10/02)
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- Gold(I) complexes with bidentate tertiary phosphine ligands: Formation of annular vs. tetrahedral chelated complexes
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Titrations of gold(I) complexes [(AuCl)2(P-P)] with ligand (P-P) were studied by 31P NMR for the bidentate tertiary phosphine ligands Ph2P(CH2)nPPh2, where n = 1 (dppm), 2 (dppe), 3 (dppp), and 4 (dppb), cis-Ph2PCH=CHPPh2 (dppey), Ph2P(CH2)2PEt2 (eppe), and Et2P(CH2)2PEt2 (depe). Bis-chelated four-coordinate gold(I) phosphine complexes [Au(P-P)2]+ containing either five- or six-membered chelate rings (n = 2 or 3) all exhibited exceptionally high thermodynamic and kinetic stabilities in solution. The species containing phenyl-substituted phosphines existed in CDCl3 solutions at Au:P-P ratios of less than 1:1. They were isolated and characterized with Cl- as the counteranion. [Au(depe)2]+ existed in solution at Au:depe ratios >1:1 and was isolable as a PF6- or SbF6- salt. Four-coordinate complexes containing either four- (n = 1) or seven-membered (n = 4) chelate rings were not observed as stable species in CDCl3 solutions. The solution behavior of species with a 1:1 Au:P-P ratio was also investigated by 31P NMR. In D2O the 31P NMR spectrum of the 1:1 Au:eppe species consisted of two overlapping AA′BB′ multiplets corresponding to the two isomers of the annular complex [Au2(eppe)2]2+. The isomer containing two Et2P-Au-PPh2 linkages (X) predominated by 2:1 over the other isomer (Y). For the ligands dppe and eppe, the 1:1 Au:P-P complexes were stable in aqueous solution but were involved in dissociative equilibria in CDCl3 with ring-closed species. The analogous complexes of depe, dppm, and dppb appeared to be stable in chloroform. These observations are discussed in terms of a destabilization of the annular [Au2(P-P)2]2+ complexes by steric effects.
- Berners-Price, Susan J.,Sadler, Peter J.
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p. 3822 - 3827
(2008/10/08)
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