Pyranopterin Related Dithiolene Molybdenum Complexes as Homogeneous Catalysts for CO₂ Photoreduction

Abstract

Twooriginal dithiolenes,with ap yrazine ring fused with ap yran ring carrying the dithiolene chelate,m imicking molybdopterin (MPT) present in the active site of formate dehydrogenases (FDHs), have been synthesized. The first one mimicks MPT in the dihydropyrazine form while the second mimicks MPT in the more biologically relevant tetrahydropyrazine form. Both have been structurally characterized as al igand within ac obalt(cyclopentadienyl)(dithiolene) complex. The corresponding MoO(dithiolene) 2 complexes have been also prepared and are reported as the first functional and stable catalysts inspired by the Mo center of FDHs so far:they indeed catalyze the photoreduction of CO 2 into formic acid, as the major product, and carbon monoxide,achieving more than 100 turnover numbers in about 8h.Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

Second Coordination Sphere Effects in an Earth-Abundant Monometallic Complex as Catalyst Dictate Highly Selective Photochemical Conversion of CO2 to HCOOH

“…Few molecular transition metal based catalysts have been reported for photochemically driven HCOOH production from CO2 till date, albeit mostly with noble metals. [4][5][6][7][8][9][10][11][12][13] Earth abundant transition metal containing catalysts for the photoreduction of CO2 to HCOOH in high yields are scarce. 10,12,14,15 A recent report by Guao et al showcased a di-cobalt polypyridyl photocatalyst to reduce CO2 to HCOOH with high selectivity and turnover number (TON).…”