SYNTHESIS, EPR AND X-RAY STRUCTURE OF MER -TRICHLORO(2,2'-BIPYRIDINE)NITRIDOTECHNETIUM(VI) - A NEW TECHNETIUM(VI) NITRIDO COMPLEX

er-Trichloro(2,2'-bipyridine)nitridotechnetium(VI) has been prepared b y the reaction of (NBu4)[TcNCl4] with 2,2'-bipyridine in acetonitrile, whereas the same procedure gives in methanol the technetium(V) cation [TcNCl(bipy)2]+. The EPR spectrum of [TcNCl3(bipy)] suggests a meridi onal coordination of the three chloro ligands. [TcNCl3(bipy)] crystall izes monoclinic in the space group P2(1)/n; a = 8.572(1), b = 15.462(1 ), c = 10.110(1) angstrom, beta = 104.21(1)-degrees, Z = 4. The R valu e converged at 0.034 on the basis of 3040 reflections. The technetium atom is distorted octahedrally coordinated with the chloro ligands mer idionally cis with respect to the nitrido nitrogen. The Tc-N(1) bond l ength is 1.669(4) angstrom, and the Tc-N(3) bond (2.371(4) angstrom) i s significantly lengthened due to the structural trans labilizing infl uence of the ''N3-''ligand.