Can high-hydride content hypoelectronic rhenaborane clusters take up dihydrogen? A theoretical study

DFT calculations were performed to gain insight of possible dihydrogen uptake by the electron-deficient metallaborane (CpRe)2B6H6 (A). Results first revealed a possible H–H insertion in A, giving rise to the formation of (CpRe)2B6H8 isomers accompanied with an opening of B–B bonds in the B6H6 ring and Re–B bonds breaking. A two-step pathway was calculated to be the lowest-energy route with the highest activation barrier at ca. 25 kcal/mol at the B3LYP/6-311G++(d,p) level of theory. Addition of a second dihydrogen molecule to A is also found possible leading to the hydrogen-saturated species (CpRe)2B6H10.

Graphical abstractInsertion of one H2 molecule in the electron-deficient metallaborane (CpRe)2B6H6 is theoretically possible via a low energy barrier.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► DFT calculations were performed on the electron-deficient metallaborane (CpRe)2B6H6. ► H2 insertions are theoretically possible via a low energy barrier. ► Similar reactions should occur with any electron-deficient metallaborane clusters.