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)2B 6H6 (A). Results first revealed a possible H-H insertion in A, giving rise to the formation of (CpRe)2B6H 8 isomers accompanied with an opening of B-B bonds in the B 6H6 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. © 2012 Elsevier Ltd. All rights reserved.