Platinum, tris structure

Ellis, J.W., Harrison, K.N., Hoye, P.A.T., Orpen, A.G., Pringle, P.G., and Smith, M.B., Water-soluble tris(hydroxymethyl)phosphine complexes with nickel, palladium, and platinum. Crystal structure of Pd P(CH2OH)3 4].cntdot.CH3, Inorg. Chem., 31, 3026, 1992. 

The X-ray structural studies of Howard, Spencer and Stone have established the platinum tris (olefin) complexes, Pt(olefin)3 [31], do indeed have the anticipated planar arrangement. Furthermore, all the known PtLj (olefin) [32] and PtL2 (acetylene) complexes have the planar conformations shown in (10) and (11). 

Tin, nitratodiphenyltris(dimethy) sulfoxide)-structure, 1,77 Tin, nitratotris(triphenyltin)-structure, 1, 47 Tin,tetrakis(acetato)-stereochemistry, 1,94 Tin, tetrakis(diethyldithiocarbamato)-angular parameters, 1, 57 Tin, tetrakis(ethyldithiocarbamato)-angular parameters, 1, 57 Tin, tetranitrato-stereochemistry, 1, 94 Tin, tri-n-butylmethoxy-, 3, 208 Tin alkoxides physical properties, 2, 346 Tin bromide, 3, 194 Tin bromide hydrate, 3,195 Tin carboxylates, 3, 222 mixed valence, 3, 222 Tin chloride, 3, 194 hydroformylation platinum complexes, 6, 263 Tin chloride dihydrate, 3,195 Tin complexes, 3, 183-223 acetyl ace tone... 

Bulk electrochemical reduction of the platinum(IV) complex of the tridentate ligand l,l,l-tris(aminomethyl)ethane(tame), [Pt(tame)2]4+, leads to the quantitative formation of [Pt(tame)2]2+ (28), in which one of the amine donor groups in tame remains noncoordinated.141 The X-ray structure of the diprotonated complex [Pt(Htame)2]4+, as its tetrachlorozincate(II) salt, is also reported. 

Zinc dithiocarbamates have been used for many years as antioxidants/antiabrasives in motor oils and as vulcanization accelerators in rubber. The crystal structure of bis[A, A-di- -propyldithio-carbamato]zinc shows identical coordination of the two zinc atoms by five sulfur donors in a trigonal-bipyramidal environment with a zinc-zinc distance of 3.786 A.5 5 The electrochemistry of a range of dialkylthiocarbamate zinc complexes was studied at platinum and mercury electrodes. An exchange reaction was observed with mercury of the electrode.556 Different structural types have been identified by variation of the nitrogen donor in the pyridine and N,N,N, N -tetra-methylenediamine adducts of bis[7V,7V-di- .vo-propyldithiocarbamato]zinc. The pyridine shows a 1 1 complex and the TMEDA gives an unusual bridging coordination mode.557 The anionic complexes of zinc tris( V, V-dialkyldithiocarbamates) can be synthesized and have been spectroscopically characterized.558... 

In the absence of triphenylphosphine a tris-SPO platinum complex forms when SPO is reacted with Pt(cod)2, which is insoluble and for which the structure is not known it could be either a hydride (4) or an oligomeric or a dimeric S PO complex (5) lacking one molecule of hydrogen. The reaction with alkene, CO and H2 gives complex 6, which was identified as the acyl tris-SPO complex by NMR. It shows an... 

Since the late 1960s there has been some interest in the concept of a structure-sensitive reaction in heterogeneous catalysis (177, 178). In the case of supported metal catalysts, structure sensitivity is visualized as a dependence of metal particle size and catalytic behavior in a given reaction (activity and selectivity). Almost all of the possible kinds of relationships were reported in the past. Recently, Che and Bennett reviewed this problem (161). Our intention here is not to repeat most of their analysis, rather we shall try to present our view on the general characteristics of palladium versus other platinum metals. 

A low yield of the cycloheptatetraenone 370 has been prepared by dehy-drobomination of 4-bromotropone in the presence of tris(triphenylphos-phine)platinum(O) [Eq. (63)].154 The structure assignment is based on H NMR (including decoupling experiments), 3IP NMR, and high-resolution MS (FAB). The low yield precluded further study. 

The structure of platinum dioxide and its reactions with some di, tri, and tetravalent metal oxides have been investigated. Ternary platinum oxides were synthesized at high pressure (40 kUobars) and temperature (to 1600°C). Properties of the systems were studied by x-ray, thermal analysis, and infrared methods. Complete miscibility is observed in most PtO2-rutile-type oxide systems, but no miscibility or compound formation is found with fluorite dioxides. Lead dioxide reacts with Pt02 to form cubic Pb2Pt207. Several corundum-type sesquioxides exhibit measurable solubility in PtOz. Two series of compounds are formed with metal monoxides M2PtOh (where M is Mg, Zn, Cd) and MPt306 (where M is Mg, Co, Ni, Cu, Zn, Cd, and Hg). 

M. Green, J. A. K. Howard, J. L. Spencer, and F. G. A. Stone, Synthesis of Ethylene, Cyclo-octa- 1,5-diene, Bicyclo [2.2.1]heptene, and trans-Cyclo-octene Complexes of Palladium ) and Platinum(O) Crystal and Molecular Structure of Tris(bicyclo2.2.1]hepte-ne)platinum, J. Chem. Soc., Dalton Trans. 1977, 271-277. 

NMR data were used to prove the structure of peptide-coupling reagents -[(6-nitrobenzotriazol-lyl)oxy]tris(dimethylamino)-, -(pyrrolidino)phosphonium hexafluorophosphates [829-831], l-(2-nitrobenzenesulfonyloxy)-6-nitrobenzotri-azole [832], and l-(2-naphthylsulfonyloxy)-6-nitrobenzotriazole [833], complexes of 5-nitrobenzotriazole with palladium(II) and platinum(II) [834], some explosive substances such as 1-picrylbenzotriazole mono- and polynitro derivatives [835] as well as that of the Mesenheimer a-complexes and 4,6-dinitrobenzotriazole-l-oxide [836, 847],... 

Cositecan (Karenitecin , BNP 1350) 54 (BioNumerik and ASKA Pharmaceutical) is currently being evaluated in a Phase III trial for the treatment of patients with advanced ovarian cancer who have become resistant to platinum and taxane drugs.110 Cositecan 54,111 114 which is also being evaluated against solid tumours in a Phase I trial, is an orally bioavailable, lipophilic 7-[2-(tri-methylsilyl)ethyl] derivative of camptothecin 55 which is less sensitive to both common and camptothecin-specific resistance mechanisms. Camptothecin 55 was first isolated in 1958 from Camptotheca acuminata (Nyssaceae) and its structure was reported in 1966.115 117 Camptothecin 55 was later shown to be a topoisomerase I inhibitor two camptothecin derivatives, topotecan and iri-notecan, are approved for chemotherapy use. 

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