Metallocyclic carbene complexes of chromium(0). The crystal and molecular structure of a chronium(0) complex with an aminoarylcarbene chelating ligand

Summary o-Lithiated reagents,o-LiC₆H₄XMe (X=O, S, or NMe), react with Cr(CO)₆] to yield, after alkylation with Et₃O]BF₄], the pentacarbonyl carbene complexes Cr{C(OEt)C₆H₄XR}(CO)₅] and tetracarbonyl metallocyclic carbene complexes. An analogous five-membered chelate is obtainable from the lithiated vinylsulphide PhSCHCH₂. The x-ray structure of was determined by single crystal x-ray diffraction. It crystallizes in the monoclinic space groupP2₁/n witha=7.054(3),b=11.746(1),c=19.443(3) Å, = 95.35(2)^c and Z = 4. The final R-factors were R = 0.099 and R_w=0.044. Bond distances of 1.990(7) Å for Cr–C(carbene) and 2.240(6) Å for Cr–N were found.