Highly Selective and Efficient Perdeuteration of n‐Pentane via H/D Exchange Catalyzed by a Silica‐Supported Hafnium‐Iridium Bimetallic Complex

Abstract

A Surface OrganoMetallic Chemistry (SOMC) approach is used to prepare a novel hafnium‐iridium catalyst immobilized on silica, HfIr/SiO2, featuring well‐defined [≡SiOHf(CH2tBu)2(μ‐H)3IrCp*] surface sites. Unlike the monometallic analogous materials Hf/SiO2 and Ir/SiO2, which promote n‐pentane deuterogenolysis through C‐C bond scission, we demonstrate that under the same experimental conditions (1 bar D2, 250°C, 3h, 0.5 mol%), the heterobimetallic catalyst HfIr/SiO2 is highly efficient and selective for the perdeuteration of alkanes with D2, exemplified on n‐pentane, without substantial deuterogenolysis (<2% at 95% conversion). Furthermore this HfIr/SiO2 catalyst is robust and can be re‐used several times without evidence of decomposition. This represents substantial advance in catalytic H/D isotope exchange (HIE) reactions of C(sp3)‐H bonds.