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(CH₂ ^tBu)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, 3 h, 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.