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Reactions of Fischer-type carbene complexes, M(CO)5(C(OMe)Ph) (M = Cr, W), with metal carbonyl anions (M‘^- = CpFe(CO)2^-, Re(CO)5^-, Mn(CO)4PPh3^-, Co(CO)3PPh3^-, Cp*Cr(CO)3^-, CpMo(CO)3^-) result in demethylation of the carbene complexes. The products are M(CO)5C(O)Ph^- and M‘−Me, characterized by infrared and NMR spectroscopy. A slower rate for reaction with W(CO)5(C(OEt)Ph) in comparison to the methyl analogue is consistent with nucleophilic attack of the metal carbonyl anion on the methyl of the methoxy group of the carbene. This is a new type of nucleophilic attack on a Fischer-type carbene.

Compounds of the type R2Ga(bdk) (R = Me, Et, Mes (mesityl); bdk = 2,4-pentanedionato (acac), 1,1,1-trifluoro-2,4-pentanedionato (tfac), 1,1,1,5,5,5-hexafluoro-2,4-penatedionato (hfac), 2,2,6,6-tetramethyl-3,5-heptanedionato (tmhd)) have been prepared by multiple routes, including hydrocarbon elimination, metathesis, and ligand redistribution reactions, and fully characterized by elemental analyses, cryoscopic molecular weight studies in benzene, and IR and multinuclear NMR spectroscopic studies. An X-ray structural study of Mes2Ga(hfac) demonstrated four-coordinate gallium with σ bonds to the two mesityl rings and to the two oxygen atoms of the β-diketonate ligand. The Lewis acidities of the diorganogallium β-diketonate derivatives toward NMe3 and/or pyridine were also investigated. Two adducts, Me2Ga(hfac)·NMe and Me2Ga(hfac)·py, were stable to dissociation at room temperature and thus were fully characterized by elemental analysis, cryoscopic molecular weight studies in benzene, vapor pressure−temperature studies, and IR and multinuclear NMR (including variable temperature) spectroscopic studies. The compound Me2Ga(hfac)·py was also characterized by an X-ray structural study. The structure involved five-coordinate gallium with one Ga−N, two (inequivalent) Ga−O, and two Ga−C bonds.

The compounds [Et2GaNEt2]2, [Et2GaN(H)(Me)]2, [Et2GaN(H)(t-Bu)]2, [Et2GaP(i-Pr)2]2, [Et2GaP(t-Bu)2]2, and [Et2GaS(SiPh3)]2 have been prepared in high yields at room temperature by the elimination of cyclopentadiene from Et2Ga(C5H5) and the corresponding amine, phosphine, or thiol. The three diethylgallium amides and [Et2GaP(i-Pr)2]2 are liquids, whereas the other phosphide and the thiolate are crystalline solids at room temperature. All compounds were fully characterized by elemental analyses, ¹H and ³¹P NMR spectroscopy, and cryoscopic molecular weight studies in benzene, as appropriate, and are dimeric in solution. The crystalline compounds [Et2GaP(t-Bu)2]2, and [Et2GaS(SiPh3)]2 were characterized by X-ray structural studies. Even though [Et2GaN(H)(t-Bu)]2 and [Et2GaS(SiPh3)]2 were prepared at room temperature and isolated in high yield, ¹H NMR studies revealed that neither compound was formed in high yield in solution. Removal of the cyclopentadiene by either dimerization or distillation and/or dimerization of the gallium product are necessary to prevent the back-reaction to re-form the reactants.