Conversion of rectangular tetrasulfide ligand in tetrarhodium complex, [{(RhCp*)2(μ-CH2)2} 2(μ4-S4)]2+ (Cp* = η5-C5Me5), into disulfide ligands in dirhodium complex, [(RhCp*)2(μ-CH2)2(μ-S2)] by chemical reduction
Reaction of [{(RhCp*)2(μ-CH2)2}2(μ4-S4)]2+ (Cp* = η5-C5Me5) (1) containing a rectangular S4 ligand with the reducing agent of NaBH4 affords [(RhCp*)2(μ-CH2)2(μ-S2)] (2) confirmed by FAB mass and 1H NMR spectra. This disulfide complex is so air-sensitive that the S2 ligand is easily oxygenated by oxygen to give an SSO ligand in [(RhCp*)2(μ-CH2)2(μ-SSO)] (3) whose structure is determined by X-ray analysis.