Synthesis of the donor–acceptor ligand 2-(4-dimethylaminobenzylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (dbpcd) and X-ray diffraction structure of the platinum(II) compound PtCl2(dbpcd)·1.5CH2Cl2
作者:Silvia Atim、Xiaoping Wang、Michael G. Richmond
DOI:10.1016/j.ica.2009.11.011
日期:2010.1
Knoevenagel condensation of 4-(dimethylamino)benzaldehyde with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) gives the donor-acceptor ligand 2-(4-dimethylaminobenzylidene)-4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (dbpcd). The reaction of dbpcd with PtCl2(cod) affords the platinum(II) complex PtCl2(dbpcd) in high yield. The free dbpcd ligand and PtCl2(dbpcd) have been isolated and fully characterized in solution by IR and NMR spectroscopies, and the solid-state structure of PtCl2(dbpcd) determined by X-ray diffraction analysis. PtCl2(dbpcd), as the 1.5CH(2)Cl(2) solvate, crystallizes in the triclinic space group P (1) over bar, a = 11.7412(7) angstrom, b = 12.0486(7) angstrom, c = 14.4781(9) angstrom, alpha = 82.866(1), beta = 75.049(1), gamma = 83.905(1), V = 1957.6(2) angstrom(3), Z = 2, and D-calc = 1.678 mg/m(3), R = 0.0291 and wR(2) = 0.0723 for 8315 reflections with I > 2 sigma(I). The molecular structure of PtCl2(dbpcd)center dot 1.5CH(2)Cl(2) consists of a square-planar platinum architecture containing two chlorines and the ancillary dbpcd diphosphine ligand. The redox properties of the dbpcd ligand and PtCl2(dbpcd) have been explored by cyclic voltammetry, and these data are discussed with respect to extended Huckel MO calculations. (C) 2009 Elsevier B. V. All rights reserved.