GALLIUM AND INDIUM COMPOUNDS OF SULFUR DONOR LIGANDS - PYRIDINE-2-THIOLATES AND DIPHENYLTHIOPHOSPHINATES

The reaction of GaR(3) (R=(t)Bu, Me) with 1, 2, or 3 molar equivalents of 2-mercaptopyridine (HSpy) yielded Ga(R)(2)(Spy) [R=(t)Bu (1), Me(2 )], Ga(R)(Spy)(2) [R = (t)Bu (3), Me (4)], and Ga(Spy)(3) (5), respect ively. Reaction of GaCl3 and HSpy in the presence of NEt(3) does yield Ga(Spy)(3) if excess HSpy is employed, otherwise Ga(Cl)(Spy)(2) (NEt( 3)) (6) may be isolated. The indium compound, In(Spy)(3) (7), may be p repared both in an analogous manner to that for compound 5, but also f rom the reaction of HSpy with either InCl or InCl3 in the presence of NEt(3). In all the compounds, except compound 3, the 2-mercaptopyridin e acts exclusively as a chelating ligand. Reaction of Ga((t)Bu)(3) wit h Ph(2)P(S)(SH) yields [Ph(2)P(S)S](2) but only traces of the expected product [((t)Bu)(2)Ga(mu-S(2)PPh(2))](2) (8). In contrast, reaction o f Ga((t)Bu)(3) with HO(S)PPh(2) (E = S, O) yields the dimeric compound s [((t)Bu)(2)Ga(mu-O(E)PPh(2))](2), E = S (9), O (10). Compound 9 exis ts as a mixture of head-to-head (9a, syn) and head-to-tail (9b, anti) isomers due to the asymmetry of the bridging ligand. Reaction of GaCl3 with three molar equivalents of Na(S(2)PR(2)). 2(H2O), R = Me, Et, yi elds the tris-dithiophosphinate compounds, Ga(S(2)PR(2))(3), R = Me (1 1), Et (12). All new compounds have been characterized by NMR and IR s pectroscopy and mass spectrometry. In addition, the molecular structur es of compounds 4 and 10 have been determined by X-ray crystallography .