Light‐induced NO release from iron‐nitrosyl‐thiolato complex: The role of noncovalent thiol/thioether

This is the authors' abstract. We don't add key points for this paper.

Four low‐spin {FeNO} 6 complexes, [Fe(NO)(PS2)(PS2H)] ( 1 , PS2H 2 = bis(2‐dimercaptophenyl)phenylphosphine) with a pendant thiol, [Fe(NO)(PS2)(PS2CH 3 )] ( 2 ) bearing a pendant thioether, and [Fe(NO)(PS2)( R PS)] (RH, 4a ; RTMS, 4b ) without the noncovalent thiol/thioether group are spectroscopically and structurally characterized. In comparisons of the ν NO , absorption energy in UV/vis spectra and structural parameters from single X‐ray diffraction studies, the four iron‐nitrosyl‐thiolato compounds share similarity in electronic structure. Complex 1 with a pendant thiol leads to NO and HNO production upon exposure to the light. Photolysis of 2 bearing a pendant thioether only affords NO. Effective detection of HNO or NO from 1 or 2 is achieved by the employment of [Mn III ( TMS PS3)(DABCO)]. In contrast, 4a and 4b show inertness toward visible‐light stimulus. Photolysis and having pendant thiol/thioether group play key roles in NO production from these iron‐nitrosyl‐thiolato complexes, that is, the Fe‐NO bond is weakened by exposure to light and the noncovalent SH of 1 or SCH 3 of 2 can serve as an incoming ligand to interact with Fe atom, resulting in a transient with intramolecular [RS⋅⋅⋅Fe⋅⋅⋅NO] interaction (RH and CH 3 ) which could facilitate NO dissociation.