Dihydrogen complexes as prototypes for the coordination chemistry of saturated molecules

Gregory J. Kubas^†

Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545

Edited by Jay A. Labinger, California Institute of Technology, Pasadena, CA, and accepted by the Editorial Board February 26, 2007 (received for review November 14, 2006)

Abstract

The binding of a dihydrogen molecule (H₂) to a transition metal center in an organometallic complex was a major discovery because it changed the way chemists think about the reactivity of molecules with chemically “inert” strong bonds such as HH and CH. Before the seminal finding of side-on bonded H₂ in W(CO)₃(PR₃)₂(H₂), it was generally believed that H₂ could not bind to another atom in stable fashion and would split into two separate H atoms to form a metal dihydride before undergoing chemical reaction. Metal-bound saturated molecules such as H₂, silanes, and alkanes (σ-complexes) have a chemistry of their own, with surprisingly varied structures, bonding, and dynamics. H₂ complexes are of increased relevance for H₂ production and storage in the hydrogen economy of the future.

Footnotes

^†E-mail: kubas{at}lanl.gov
Author contributions: G.J.K. wrote the paper.
The author declares no conflict of interest.
This article is a PNAS Direct Submission. J.A.L. is a guest editor invited by the Editorial Board.
↵ ‡ In 1993 Zilm obtained solid-state ¹H NMR evidence for H₂ coordination (d _HH= 0.93 Å) on a sample we prepared.