US EPA

2255399 

Journal Article 

Tris-(1,3-diaryltriazenide) complexes of rhodium - Synthesis, structure and, spectral and electrochemical properties 

Guharoy, C; Drew, MGB; Bhattacharya, S 

2009 

1 

Proceedings of the Indian Academy of Sciences - Chemical sciences
ISSN: 0253-4134 

121 

3 

257-266 

WOS:000268244200002 

Reaction of 1,3-diaryltriazenes (abbreviated in general as HL-R, where R stands for the para-substituent in the aryl fragment and H stands for the dissociable hydrogen atom, R = OCH3, CH3, H, Cl, NO2) with [Rh(PPh3)(2)(CO)Cl] in ethanol in the presence of NEt3 produces a series of tris-diaryltriazenide complexes of rhodium of type [Rh(L-R)(3)], where the triazenes are coordinated to rhodium as monoanionic, bidentate N,N-donors. Structure of the [Rh(L-OCH3)(3)] complex has been determined by X-ray crystallography. The complexes are diamagnetic, and show characteristic H-1 NMR signals and intense MLCT transitions in the visible region. They also fluoresce in the visible region under ambient condition while excited at around 400 nm. Cyclic voltammetry on these complexes shows a Rh(III)-Rh(IV) oxidation (within 0.84-1.67 V vs SCE), followed by an oxidation of the coordinated tri- and azene ligand (except the R = NO2 complex). An irreversible reduction of the coordinated triazene is also observed for all the complexes below -1.03 V vs SCE. 

1,3-Diaryltriazenes; rhodium; tris complexes; N,N coordination; crystal structure; spectral and electrochemical properties