233665-17-3Relevant academic research and scientific papers
Metal π complexes of benzene derivatives. 53 [1] tin in the periphery of bis(arene)metal complexes of vanadium and chromium
Elschenbroich, Christoph,Schmidt, Eckhardt,Metz, Bernhard,Massa, Werner,Wocadlo, Sigrid,Burghaus, Olaf
, p. 875 - 886 (2008/10/08)
By means of metal-atom ligand-vapor cocondensation as well as via wet chemical methods (lithiation and follow-up reaction) the first organostannyl substituted bis(arene)metal complexes (R3Sn-η6-C6H5)2M have been prepared: 15 (R = Me, M = V), 16 (R = Ph, M = V), 13 (R = Me, M = V), 17 (R = Ph, M = Cr). Despite the bulkiness of the Ph3Sn groups the geometry of the central sandwich unit in 17 deviates only marginally from that of the parent complex (C6H6)2Cr (2). The triclinic unit cell of 17 (space group: P1; a = 9.414(4), b = 9.877(5), c = 11.012(13) A; α = 83.51(7), β = 87.95(7), γ = 72.67(4)°) contains one independent molecule. Perturbation of the electronic structure of the bis(arene)metal unit by organostannyl groups appears to be minute because EPR spectra of the M(d5) species fail to reveal deviations from axial symmetry. The potentials for reversible oxidation of the Me3Sn-substituted complexes 13 and 15 differ insignificantly (anodic shifts ≤ 20 mV) from those of the parent species 1 and 2; reductions are irreversible in both cases. More sizeable anodic shifts are observed for the Ph3Sn-derivatives 16 and 17; here as well, only the redox pairs 0/+ are reversible. The resistance of the neutral complexes to protic media contrasts to ready hydrodestannylation of the complex cations. By way of metal exchange, employing n-butyl lithium, 13 affords (Li-η6-C6H5)2Cr strictly 1,1′-disubstituted and devoid of auxiliary base.
