1 research outputs found
Copper(I) Nitrosyls from Reaction of Copper(II) Thiolates with <i>S</i>âNitrosothiols: Mechanism of NO Release from RSNOs at Cu
<i>S</i>-nitrosothiols (RSNOs) serve as ready sources
of biological nitric oxide activity, especially in conjunction with
copper centers. We report a novel pathway for the generation of NO
within the coordination sphere of copper model complexes from reaction
of copperÂ(II) thiolates with <i>S</i>-nitrosothiols. Reaction
of trisÂ(pyrazolyl)Âborate copperÂ(II) thiolates <sup>iPr2</sup>TpCuâSR
(R = C<sub>6</sub>F<sub>5</sub> or CPh<sub>3</sub>) with <sup>t</sup>BuSNO leads to formation of <sup>iPr2</sup>TpCuÂ(NO) and the unsymmetrical
disulfide RSâS<sup>t</sup>Bu. Quantum mechanical investigations
with B3LYP-D3/6-311GÂ(d) suggest formation of a Îş<sup>1</sup>-NâRSNO adduct <sup>iPr2</sup>TpCuÂ(SR)Â(Râ˛SNO) that
precedes release of RSSRⲠto deliver <sup>iPr2</sup>TpCuÂ(NO).
This process is reversible; reaction of <sup>iPr2</sup>TpCuÂ(NO) (but
not <sup>iPr2</sup>TpCuÂ(NCMe)) with C<sub>6</sub>F<sub>5</sub>SâSC<sub>6</sub>F<sub>5</sub> forms <sup>iPr2</sup>TpCuâSC<sub>6</sub>F<sub>5</sub>. Coupled with the facile, reversible reaction between <sup>iPr2</sup>TpCuÂ(NO) and C<sub>6</sub>F<sub>5</sub>SNO to give <sup>iPr2</sup>TpCuâSC<sub>6</sub>F<sub>5</sub> and 2 equiv NO,
we outline a new, detailed catalytic cycle for NO generation from
RSNOs at Cu