Solid phase synthesis and structural characterization of an oxo-molybdenum(V) porphyrin: triplet state ESR spectrum of μ-oxo bridged molybdenum(V) dimer

Abstract

The solid state synthesis of molybdenum porphyrin using [ Mo ( NO )2( py )2( Cl )2] as the metal source and H 2 TPP (5,10,15,20-meso-tetraphenylporphyrin) in 3,5-dinitrobenzoic acid melt is described. Complex [ Mo V O ( TPP )(3,5- DNB )] (1) (3,5-DNB = 3,5-dinitrobenzoate ion) is isolated in almost quantitative yield. 1 is characterized by single-crystal X-ray structure analysis, electron paramagnetic resonance, electronic, FT-IR spectroscopy, and by magnetic moment measurements. 1 in basic alumina column on elution with DCM/Ethyl acetate as solvent hydrolyzed to μ-oxo bridged dimeric molybdenum(V) complex [{ Mo V ( O )( TPP )}2 O ] (2). 2 shows a interesting triplet state ESR spectrum in the solid state with half field signal suggesting two independent Mo ( V ) centers in the complex.