The chemistry of technetium nitrido complexes

摘要: A characteristic feature of the chemistry technetium in +5–+7 oxidation states is formation a wide variety highly stable complexes containing terminal Tc≡N bond. The bond short (1.585–1.65 A) and formally triple with one σ component two π components formed by overlap px py orbitals on N Tc d xz , yz orbitals. Coordination numbers 5, 6 7 square pyramidal, trigonal bipyramidal, distorted octahedral pentagonal pyramidal bipyramidal geometries have been established X-ray crystallography. nitrido ligand exerts strong trans influence, either absent or only weakly bound. In complexes, NTc-Ltrans 0.1–0.3 longer than NTc-Lcis. IR spectrum v(TcN) observed as sharp band at 1100–1000 cm−1. [TcvN]2+ prepared diverse coordination spheres are monomeric except for example cyclic Tc4N4 core. Monomeric [TcVIN]3+ (d1) readily detected EPR spectroscopy this technique has extensively used to identify new species study exchange reactions. Substitution [TcVINX4]− (X=Cl, Br) thiols, phosphines, amines nitrogen heterocycles organic solvents generally yields reduced [TcVN]2+ complexes. aqueous solution dimerization occurs yield silent [NTcVI-O-TcVIN]4+ [NTcVI(μ-O)2TcVIN]2+ including structurally characterized (AsPh4)4[Tc4N4(O)2(ox)6] (AsPh4)2[(TcNX2)2(μ-O)2] (X-Cl, Br). Novel [TcVIIN]4+ Cs[TcN(O2)2Cl] (AsPh4)2[{TcN(O2)2}2(ox)]. 99mTcN investigated potential radiopharmaceuticals.