A novel non-facial mode of azulene cluster co-ordination. Crystal and molecular structure of the dicarbenoid Os3(μ-H)2(CO)9(μ3-η1∶η1∶η1-C10H6)

Abstract

Azulene oxidatively added to Os₃(CO)₁₁(NCCH₃) to afford the triosmium cluster Os₃(μ-H)₂(CO)₉(μ₃-η¹∶η¹∶η¹-C₁₀H₆) 1 in high yield. The organic moiety is bound perpendicularly to the trimetallic plane and acts as a 4e⁻ donor forming one terminal and one bridging carbene–metal bond. An X-ray diffraction study of 1 was made and full spectroscopic assignment has been made using 1- and 2-D homo- and hetero-nuclear NMR; 2-D ¹³C EXSY experiments have also allowed the elucidation of the CO exchange process.