Synthesis of a novel class of trigonal bipyramidal nitrido Tc(V) complexeswith phosphino-thiol ligands. Crystal structure of [Tc-99g(N)(L-1)(2)] [L-1=2-(diphenylphosphino)ethanethiolato] and [Tc-99g(N)(L-5)(2)] [L5=2-(ditolylphosphino)propanethiolato]

Reactions of the precursor complexes [Tc-99g(N)Cl-2(PPh3)(2)] and [Tc-99g(N )CL4](-) with phosphine-thiol ligands (HLn) of the type R2PCH2CH2SH (R " = phenyl, methoxypropyl), R-2'PCH2CH2CH2SH (R' phenyl. tolyl), and R-2 " Po-C 6H4SH (R" = phenyl) afforded the five-coordinated, disubsituted nitrido tec hnetium(V) complexes [Tc-99g (N)(L-n)(2)]. The complexes were characterized by elemental analysis, H-1 and P-31 NMR spectroscopy, FT IR, and positive FAB MS spectra. Structural characterization of [Tc-99g(N)(L-1)(2)] (1) [HL1 = (C6H5)(2)PCH2CH2SH] and [(TC)-T-99g(N)(L-5)(2)] (5) [HL5 = (o-CH3C6H4)(2 )PCH2CH2CH2SH] showed that the bidentate phosphino-thiol ligands are coordi nated to the technetium center through the neutral phosphorus atom and the deprotonated thiol sulfur atom. These complexes possess an uncommon trigona l bipyramidal geometry with the two phosphorus atoms occupying the two tran saxial positions and the two sulfur atoms on the equatorial plane along wit h the nitrido nitrogen atom. Compound 1 crystallizes in the monoclinic spac e group C2/c, a = 24.84(2) Angstrom, b = 7.327(6) Angstrom, c = 31.52(2) An gstrom, beta = 111.06(10)degrees, and Z = 8, Compound 5 crystallizes in the monoclinic space group P2(1)/n, a = 11.090(1) Angstrom, b = 14.387(2) Angs trom, c = 11.087(1) Angstrom, beta = 113.62(1)degrees and Z = 2.