Abstract
Reaction of [PPN]2[Mn(S,S-C6H4)2]2 (2) and NO(g) afforded a discrete mononitrosyl-manganese [PPN][(NO)Mn(S,S-C6H4)2] (3) assigned as a {MnII(NO+)}5 electronic structure based on IR spectroscopy and X-ray crystallography diffraction analysis. Compound 2 was reduced by [Me4N][BH4] to yield [PPN]2[Mn(S,S-C6H4)2] (4) which was then nitrosylated to produce [PPN]2[(NO)Mn(S,S-C6H4)2] (5). A single-crystal X-ray structure determination of 5 reveals distorted square pyramidal with linearly coordinated nitrosyl ( ∠Mn-N-O is 177.1(6) ) having Mn-N bond length of 1.607(6) Å . Spectroscopic characterization of complex 5 reveals NO stretching frequency at 1651 cm-1. Comparing with other Mn-nitrosyl complexes, compound 5 was best described as a {MnIII (NO—)}6 core. Among small molecules, NO, CO and O2, only NO can be trapped by compounds 1 and 4 to convert to compounds 3 and 5, respectively. Based on these results, compounds 1 and 4 can be utilized to discriminate the small molecules NO, CO and O2. Upon contact with dry O2, [PPN]2[(NO)Mn(S,S-C6H4)2] (5) was transformed into [PPN]2[Mn(S,S-C6H4)3] (6) which was identified by X-ray crystallography diffraction analysis.