Coordination Chemistry of Rh(III) Porphyrins:  Complexes with Hydrazine, Disulfide, and Diselenide Bridging Ligands

Rh(III) porphyrin complexes with bridging hydrazine and substituted hydrazine ligands were characterized in solution by ¹H NMR spectroscopy and in the solid state by X-ray diffraction. Addition of further ligand to these species afforded 1:1 complexes in which methylhydrazine and N,N-dimethylhydrazine preferentially bound to the Rh center through the substituted nitrogen atom, as evidenced by ¹H NMR chemical shifts. An alkylated Rh(III) porphyrin was isolated as a decomposition product of the reaction of N,N-dimethylhydrazine with Rh(III) porphyrin in the presence of light and oxygen. Me₂Se₂ and Me₂S₂ formed bridging and nonbridging complexes with Rh(III) porphyrin, analogous to that observed with N,N‘-dimethylhydrazine.