Structure of a neutral N-alkylated diaminedithiol (dadt) 99TcV complex: syn[99TcO(NEt-tmdadt)]

syn-(4-Ethyl-2,9-dimethyl-4,7-diaza-2,9-decanedithiolato)oxo (99Tc) technetium(V), syn-[99TcO(NEt-tmdadt)], [Tc(O)(C12H25N2S2)], Mr = 375, monoclinic, P2(1)/n, a = 9.638(2), b = 14.371(5), c = 11.893(3) A, beta = 100.79(2) degrees, V = 1618.15(75) A3, Z = 4, Dx = 1.54 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 11.0 cm-1, F(000) = 776, T = 293 K, R = 0.028, wR = 0.042 for 2788 unique observed reflections with I greater than sigma(I). This study is the first which conclusively establishes the structure of the major complex derived from the reaction of an N-substituted diaminedithiol ligand with reduced pertechnetate. An intramolecular repulsion exists between the ethyl substituent and the oxo-metal core, resulting in a larger-than-expected angle for N(2)-Tc-O, 104.7(1) degrees.