Aryl and NHC compounds of technetium and rhenium

Air- and water-stable phenyl complexes with nitridotechnetium(V) cores can be prepared by straightforward procedures. [TcNPh(2)(PPh(3))(2)] is formed by the reaction of [TcNCl(2)(PPh(3))(2)] with PhLi. The analogous N-heterocyclic carbene (NHC) compound [TcNPh(2)(HL(Ph))(2)], where HL(Ph) is 1,3,4-triphenyl-1,2,4-triazol-5-ylidene, is available from (NBu(4))[TcNCl(4)] and HL(Ph) or its methoxo-protected form. The latter compound allows the comparison of different Tc-C bonds within one compound. Surprisingly, the Tc chemistry with such NHCs does not resemble that of corresponding Re complexes, where CH activation and orthometalation dominate.