Inorganic Chemistry, Vol.42, No.22, 7266-7272, 2003
Reactivity of dioxoosmium(VI) porphyrins toward arylhydrazine. Isolation of hydrazidoosmium and amidoosmium porphyrins
Reactions of dioxoosmium(VI) porphyrins [Os-VI(Por)O-2] with excess 1,1-diphenylhydrazine in tetrahydrofuran at ca. 55degreesC for 15 min afforded bis(hydrazido(1-))osmium(IV) porphyrins [Os-IV(Por)(NHNPh2)(2)] (1a, Por = TPP (mesotetraphenylporphyrinato dianion); 1b, Por = TTP (meso-tetrakis(p-tolyl)porphyrinato dianion)), hydroxo(amido)osmium(IV) porphyrins [Os-IV(Por)(NPh2)(OH)] (2a, Por = TPP; 2b, Por = TTP), and bis(hydrazido(2-))osmium(VI) porphyrin [Os-VI(Por)(NNPh2)(2)] (3c, Por = TMP (meso-tetramesitylporphyrinato dianion)). The same reaction under harsher conditions (in refluxing tetrahydrofuran for ca. 1 h) gave a nitridoosmium(VI) porphyrin, [Os-VI(Por)(N)(OH)] (4b, Por = TTP). Oxidation of 1a,b with bromine in dichloromethane afforded bis(hydrazido(2-)) complexes [Os-VI(TPP)(NNPh2)(2)] (3a) and [Os-VI(TTP)(NNPh2)(2)] (3b), respectively. All the new osmium porphyrins were identified by H-1 NMR, IR, and UV-vis spectroscopy and mass spectrometry; the structure of 2b was determined by X-ray crystallography (Os-NPh2 = 1.944(6) Angstrom, Os-OH = 1.952(5) Angstrom).