Reduction of CO2 and Related Compounds with a Low‐Valent CaI Synthon

The reduction of CO2 with low‐valent s‐block metal complexes is limited to MgI reducing agents. Herein, the reduction of a series of CX2 reagents (X = O, S, NiPr) with the CaI synthon [(BDI)Ca(THP)]2(N2) (VI) is described, which is a CaII complex that reacts like the hypothetical CaI complex (BDI)Ca...

Full description

Saved in:
Bibliographic Details
Main Authors: Stefan Thum, Jonathan Mai, Neha Patel, Jens Langer, Sjoerd Harder
Format: Article
Language:English
Published: Wiley-VCH 2025-07-01
Series:ChemistryEurope
Subjects:
Online Access:https://doi.org/10.1002/ceur.202500080
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The reduction of CO2 with low‐valent s‐block metal complexes is limited to MgI reducing agents. Herein, the reduction of a series of CX2 reagents (X = O, S, NiPr) with the CaI synthon [(BDI)Ca(THP)]2(N2) (VI) is described, which is a CaII complex that reacts like the hypothetical CaI complex (BDI)CaCa(BDI); BDI = HC[(Me)‐N(DIPeP)]2, DIPeP = 2,6‐Et2CH‐phenyl, THP = tetrahydropyran. Reaction of VI with excess CO2 led to crystallization of a carbonate complex with a Ca4(CO3)24+ core. The stabilizing BDI ligands also react by nucleophilic addition of CO2 at the backbone γ‐C atom. Reaction with only two equivalents of CO2 gave the presumed carbonite (CO22−) intermediate, but this could not be confirmed by X‐ray diffraction. Reaction with CS2 gave the first unique s‐block metal complex with a CS22− anion. This anion bridges between two (BDI)Ca+ cations by CaC and CaS bonding. The reduction of iPrN=C=NiPr with VI gave C–C coupling to a [(iPrN)2C–C(NiPr)2]2− dianion. An intermediate with a C(NiPr)22− dianion could not be isolated.
ISSN:2751-4765