Air-Stable Copper(I) Borohydride for Carbon Disulfide Mitigation through Sustainable Hydride Transfer

We
report the synthesis and characterization of an air-stable copper(I)
borohydride, [Cu(PNN)(μ-BH4)], stabilized by a koneramine-derived
PNN ligand featuring mixed phosphorus and nitrogen donors. The ligand
framework imparts high oxidation resistance, enabling the isolation
of a mononuclear Cu(I)–borohydride. The complex displays efficient
hydride transfer reactivity with environmentally harmful small molecules,
including CS2, CH3I, and SO2, cleanly
affording copper(I) xanthate, halide, and bisulfate derivatives under
mild conditions. Complementary density functional theory (DFT) analysis
provides mechanistic insights into the hydride transfer process and
pollutant activation. Overall, this work establishes [Cu(PNN)(μ-BH4)] as a well-defined, air-stable Cu(I)–borohydride
that enables sustainable pollutant remediation and selective C–S/C–X
bond formation. By combining structural robustness, selective reactivity,
and the use of an earth-abundant metal, this study highlights a sustainable
organometallic strategy for pollutant remediation without reliance
on precious metals.