Addition of organic halides to bis{(2-vinylphenyl) diphenylphosphine} palladium(0). X-Ray structure of the chelate σ-alikylpalladium(II) complex PdI{o-CH(CH3)C6H4PPh2} - {(E)-o-Ph2PC6H4CHCHC6H6}

Abstract

Iodobenzene adds to the palladium(0) complex Pd(VP)2 (2) (VP = (2-vinylphenyl)diphenylphosphine, o-CH2CHC6H4PPh2) to give the planar palladium(II) complex PdI{o-CH(CH3)C6H4PPh2}{(E)-o-Ph2PC6H4CHCHC6H5} (5), which has been characterized by NMR (1H, 31P) spectroscopy and by single crystal X-ray analysis. Crystals of 5 are triclinic, space group P1, a 13.404(5); b 13.850(6), c 14.158(7) Å, α 118.39(3), β 92.28(4), γ 95.58(3)°, Z 2; 2139 data with I > 2σ(I) were refined to R 0.087, Rw 0.049. The complex contains a five-membered chelate σ-alkyl group (PdP(1) 2.279(6), PdC(1) 2.05(3) Å) and monodentate P-bonded E-(2-styrylphenyl)diphenylphosphine (PdP(2), 2.346(7) Å). 5 is believed to be formed by a sequence of oxidative addition, phenyl migration from palladium to one of the vinyl groups, and β-hydride transfer from one P-donor ligand to the other. Bromobenzene reacts with 2 to give the bromo analogue of 5 together with an unidentified minor isomer. Allyl bromide gives PdBr(η3-C3H5)(VP) containing monodentate P-bonded VP, but the products of reaction of 2 with methyl iodide and benzyl bromide have not been fully characterized. Show more