Synergistic Activation of Nitrite and Thiocarbonyl Compounds Affords NO and Sulfane Sulfur via (Per)thionitrite (SNO /SSNO ).

(Per)thionitrite (SNO /SSNO ) intermediates play vital roles in modulating nitric oxide (NO) and hydrogen sulfide (H S) dependent bio-signalling processes. Whilst the previous preparations of such intermediates involved reactive H S/HS or sulfane sulfur (S ) species, the present report reveals that relatively stable thiocarbonyl compounds (such as carbon disulfide (CS ), thiocarbamate, thioacetic acid, and thioacetate) react with nitrite anion to yield SNO /SSNO . For instance, the reaction of CS and nitrite anion (NO ) under ambient condition affords CO and SNO /SSNO .

Modeling Reactivity of Nitrite and Nitrous Acid at a Phenolate Bridged Dizinc(II) Site: Insights into NO Signaling at Zinc.

Although nitrite-to-NO transformation at various transition metals including Fe and Cu are relatively well explored, examples of such a reaction at the redox-inactive zinc(II) site are limited. The present report aims to gain insights into the reactivity of nitrite anions, nitrous acid (HONO), and organonitrite (RONO) at a dizinc(II) site. A phenolate-bridged dizinc(II)-aqua complex [L Zn (OH )] (ClO ) (1 -Aq, where L =tridentate N,N,O-donor monoanionic ligand) is illustrated to react with BuONO to provide a metastable arene-nitrosonium charge-transfer complex 2 .

HS Generation from CS Hydrolysis at a Dinuclear Zinc(II) Site.

The controlled generation of hydrogen sulfide (HS) under biologically relevant conditions is of paramount importance due to therapeutic interests. Via exploring the reactivity of a structurally characterized phenolate-bridged dinuclear zinc(II)-aqua complex {Zn(OH)}(ClO) () as a hydrolase model, we illustrate in this report that complex readily hydrolyses CS in the presence of EtN to afford HS. In contrast, penta-coordinated [Zn] sites in dinuclear {(Zn)(μ-X)}(ClO) complexes (, X = OAc; , X = dimethylpyrazolyl) do not mediate CS hydrolysis in the presence of externally added water and EtN presumably due to the unavailability of a coordination site for water at the [Zn] centers.