AN ANALYSIS OF THE METAL-METAL BONDING IN ORGANODIRHENIUM COMPLEXES CONTAINING RE-RE DOUBLE-BONDS

Fenske-Hall molecular orbital calculations are used to describe the Re -Re bonding in the low-valent d6-d6 dimer [CpRe(CO)2]2 (1) and the hig h-valent d2-d2 dimer [HCRe(OH)2]2 (2), which are models for recently s ynthesized compounds. Both 1 and 2 contain Re-Re double bonds, corresp onding to diamagnetic sigma2pi4delta2delta2pi*2 and sigma2pi2 metal-m etal bonding configurations, respectively. The bonding in the hypothet ical low-valent/high-valent complex [CpRe(CO)2][Re(CH)(OH)2] is also d iscussed.