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The reaction of ((eta)-Arene)Cr(CO)(,2)(CX) (X = S, Se) complexes with excess (RO)(,3)P (R = Me, Et, n-Bu, Ph) yields Cr(CO)(,2)(CX) (RO)(,3)P (,3), predominantly as the mer I isomer, in which a phosphite ligand is trans to CX. Arene displacement from ((eta)-C(,6)H(,6))Cr(CO)(,2)(CX) by tridentate phosphine ligands L-L-L L-L-L = (Me)C(CH(,2)P(Ph)(,2))(,3), (Ph(,2)PCH(,2)CH(,2))(,2)PhP gives fac-(L-L-L)Cr(CO)(,2)(CX) products. The molecular structures of Cr(CO)(,2)(CX) (MeO)(,3)P (,3) have been determined by single crystal X-ray diffraction. Intramolecular isomerization of these complexes as well as their tricarbonyl analogue has been demonstrated and activation parameters have been calculated for the rearrangement processes. Two-dimensional ('31)P NMR spectroscopy has provided evidence that isomerization occurs via trigonal prismatic intermediates. Kinetic investigations of the reaction of ((eta)-C(,6)H(,6))Cr(CO)(,2)(CX) with (MeO)(,3)P have established a first-order rate dependence on both the complex and the entering ligand. The faster reaction rate of the selenocarbonyl derivative relative to its thiocarbonyl analogue originates in a lower entropy of activation in the former case. The effect on the reaction rate of variation in the nature of the arene and of the entering ligand has been investigated. / An approach to hormonal receptor assay involving the detection by FT-IR spectroscopy of Cr(CO)(,3)-labelled modified estradiol bound to estrogen receptors in target tissue is reported. / The FT-IR spectra of FeTPP(CX) FeTPP = (5,10,15,20-tetraphenyl-porphinato)Fe(II); X = S, Se and FeTPP(CX)L (X = S, Se; L = pyridine, ethanol) have been obtained. Some changes in the porphyrin spectrum were observed with variation or removal of L, but not with variation of X.

Phenylgermane, benzylgermane and p-tolylgermane were obtained by reduction of the corresponding organotrichlorgermanes prepared by organomercuration reactions of germanium tetrachloride. Phenylgermane was also prepared by the reaction of germyl bromide with phenyllithium, and p-digermylbenzene, with p-bromogermylbenzene, by reaction of germyl bromide with the exchange products from the reaction of n-butyllithium and p-dibromobenzene. The effectiveness of the reagent sodium germyl (and potassium germyl) was investigated in reactions with methylene chloride and bromide for the preparation of digermylmethane, which was also made by reduction of bis(trichlorogermyl)methane prepared from cesium trichlorogermanate(II). The usefulness of the halogenation of germane by carbon tetrachloride and tetrabromide, and methyl and hydrogen bromide, for the preparation of germyl chloride and bromide was investigated. Vibrational assignments were made to characteristic bands in the infrared spectra of the new aromatic germanium hydrides and some chloro derivatives. Ion fragmentation patterns were examined. The proton nuclear magnetic resonance spectra of the organogermanium hydrides and chloro derivatives were interpreted on the basis of the existence of germanium-aromatic ring (p → d) π bonding, but this effect was not very important for the interpretation of the ultraviolet spectra. Calculation of the energy levels of toluene, phenylsilane and phenylgermane by the Extended Hückel method and comparison with ultraviolet spectral data indicated that (p → d) π bonding was important only in phenylsilane. / French abstract, if available fr

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The complexes L(,2)Pt(SR)(,2), where L = PPh(,3), PMePh(,2), PMe(,2)Ph, were prepared in high purity and yield by treating the dichlorides with thiols and triethylamine under nitrogen atmosphere. Their geometry is cis for R = ('n)Pr, ('i)Pr, CH(,2)Ph and trans for R = 4-C(,6)H(,4)Me. Reactions of cis-L(,2)PtCl(,2) and H(,2)S/K(,2)CO(,3) or NaSH in the presence of dichloromethane afforded the complexes L(,2)Pt(S(,2)CH(,2)), containing the novel bidentate methanedithiolato ligand. The thiolato-bridged dimers {LPt(SR')(,2)}(,2), where R' = CH(,2)Ph, 4-C(,6)H(,4)Me, were isolated by fusion of the appropriate monomers in vacuo. The compound {(PMePh(,2))Pt(SCH(,2)Ph)((mu)-SCH(,2)Ph)}(,2) has the cis-symmetrical structure. Treatment of the complexes cis-L(,2)Pt(SCH(,2)Ph)(,2) with phtNSSNpht, where H-Npht = phthalimide, led to stepwise displacement of the phenylmethanethiolato ligands by phthalimido groups. / The first platinadisulfanes, complexes of the type cis-(PPh(,3))(,2)Pt(Npht)(SSR''), where R'' = ('n)Pr, ('i)Pr, CH(,2)Ph, 4-C(,6)H(,4)Me and Npht, were synthesized in good yield by the oxidative addition of R''SSNpht to (PPh(,3))(,2)Pt(C(,2)H(,4)). Similarly, addition of R''SNpht gave cis-(PPh(,3))(,2)Pt(Npht)(SR'').