STRUCTURE OF TRANS-AQUANITRIDO(1,4,8,11-TETRAAZACYCLOTETRADECAN-5-ONATO-N,N',N'',N''')TECHNETIUM(V) CHLORIDE DIHYDRATE

[TcN(C10H21N4O)(H2O)]+.Cl-.2H2O, M(r) = 415.81, monoclinic, P2(1)/c, a = 7.609 (1), b = 16.405 (3), c = 13.642 (3) angstrom, beta = 99.57 (1)-degrees, V = 1679.2 (5) angstrom 3, Z = 4, D(x) = 1.64 Mg m-3, lambda(Mo K-alpha) = 0.71069 angstrom, mu = 1.018 mm-1, F(000) = 856, T = 298 K, R = 0.021 for 3262 observed reflections. The complex cation displays a distorted octahedral structure, with a water molecule in the trans position with respect to the Tc = N group and the four N atoms of the ligand in the equatorial position. The degree of pyramidalization of the coordination polyhedron is important [average N = Tc-N angle of 101 (3)-degrees] and the Tc-OH2 bond distance is abnormally long (2.560 angstrom), as a consequence of the strong trans influence exerted by the nitrido group. These facts are consistent with an incipient transition from a square pyramidal to octahedral geometry of the coordination polyhedron caused by the incoming water molecule.