Phosphine/thiolate-containing dinitrosyl cobalt complexes (DNCCs): synthesis, characterization, interconversion, X-ray diffraction identification and NO release

Cobalt carbonyl/nitrosyl complexes, (PPh 3 )(CO) 2 Co(NO) ( 1 ) and (PPh 3 ) 2 (CO)Co(NO) ( 2 ), were obtained by reacting (CO) 3 Co(NO) with one equiv. and two equiv. of PPh 3 , respectively. The process of isoelectronic replacement of CO with NO + resulted in the formation of a cationic complex {Co(NO) 2 } 10 [(PPh 3 ) 2 Co(NO) 2 ][BF 4 ] ( 3 ). Complex (PPh 3 )(SPh)Co(NO) 2 ( 4 ), which contains a thiophenolate ligand, was synthesized by ligand exchange of complex 3 with [PPh 4 ][SPh] in a 1 : 1 molar ratio in THF solution. The addition of one equiv. of [PPh 4 ][SPh] to complex 4 led to the formation of complex [PPh 4 ][(SPh) 2 Co(NO) 2 ] ( 5 ). The interconversions among complexes 1-5 were substantiated with the application of IR spectroscopy and X-ray single-crystal diffraction techniques. Notably, complex 4 exhibited commendable NOs (nitric oxide species: NO + /&z.rad;NO/NO − ) transfer capabilities in the presence of [Fe(TPP)Cl] (5,10,15,20-tetraphenyl-21 H ,23 H -porphine iron( iii ) chloride). DiNitrosyl Cobalt Complexes : This article describes the synthesis and characterization of cationic, neutral, and anionic DNCCs, demonstrating the interconversions and NO releasing ability akin to what is observed in DNICs.