Technetium complexes of capped tetradentate ligands Part II. The synthesis and electrochemistry of technetium(III) and (V) complexes of 2-diphenylphosphino-N,N-bis(2-diphenylphosphinoethyl)ethaneamine (NP3) and tris-2-diphenylphosphinoethylphosphine (PP3)

Abstract A series of cationic technetium complexes cis -[TcXY(L)] + has been prepared for XYCl; XN, YBr and XCl, YNNC 6 H 4 Cl, and LNP 3 and PP 3 and isolated as their tetraphenylborate or hexafluorophosphate salts. The cis -dichlorides show reversible one-electron reductions at −0.13 V versus SCE in dimethylformamide for both ligands whereas the other complexes are more difficult to reduce. Attempts to prepare cis -[TcO 2 (L)] + were not successful, but the novel complex [TcOCl 2 (L)][BPh 4 ] (LNP 3 ) was isolated and complexes formulated as [Tc(SO 4 ) 2 (L)][BPh 4 ] (LNP 3 and PP 3 ) were prepared using H 2 SO 4 as the acid.