Structure of a metallacyclic metaloxycarbene vanadium complex prepared from CpV(CO)4

Abstract Treatment with (butadiene)hafnocene converted CpV(CO) 4 into the metaloxycarbene vanadium complex 12 , which was then trapped by coupling with cyclopentanone to give the nine-membered metallacyclic metaloxycarbene vanadium complex Cp 2 HfOC(C 4 H 8 )CH 2 CHCH=CH 2 C[=VCp(CO) 3 O ( 13 ), the crystal structure of which was determined. Complex 13 contains a trans -configurated C=C double bond inside the medium-size ring system and is chiral. The vanadium—C(carbene) bond length is 2.086(5) A and the short O(carbene)–C(carbene) distance of 1.282(6) A indicates considerable acylmetallate character for this metaloxycarbene vanadium complex.