Mesogenic Dinuclear Cyclopalladated Derivatives with Mixed Bridges - Crystal Structure of cis-[Bis({4, 4'-di-n-butoxy}benzylideneaniline-C~2, N)-(μ-n-butylthiolato)(μ-chloro)dipalladium(II)]

摘要

The dinuclear cyclopalladated compounds [Pd(μ-Cl)Ln]_2 (2) [HLn = p-C_nH_(2n + 1)OC_6H_4CH=NC_6H_4OC_nH_(2n + 1)-p (n = 6, 8, and 10)] react with silver thiolates AgSRm (Rm = C_mH_(2m + 1), m = 6, 8, 10, and 18) to give dinuclear derivatives with mixed bridges [Pd_2(μ-Cl)(μ-SRm)Ln_2] (3). Treatment of derivatives 2 with silver acetate (Pd/AgOAc = 2:1) or treatment of [Pd(μ-OAc)Ln]_2 (1) with thiols HSRm (Pd/thiol = 2:1) affords acetato-thiolato bridged complexes [Pd_2(μ-OAc)(μ-SRm)Ln_2] (4). In addition to their mesogenic behavior, the most interesting feature of these complexes is the cis disposition of the palladium-imine moieties, that can be inferred from their ~1H-NMR spectra. The cis structure as well as the disposition of the bridges was confirmed by the X-ray diffraction study of 3 (n = m = 4).