91482-74-5Relevant articles and documents
Reactions of trans-Chloro(cyanomethyl)bis(triphenylphosphine)- and Chloro(cyanomethyl)palladium(II) Complexes with Various Thallium(I) β-Diketones
Ishio, Noriaki,Nakamura, Yukio,Okeya, Seichi
, p. 1012 - 1020 (2007/10/02)
Reactions of trans-chloro(cyanomethyl)bis(triphenylphosphine)palladium(II), trans (I), with an equimolecular amount of Tl(β-dik) (β-dik = etac, acac, tfac, bzac, and dbm) in dichloromethane afforded the O,O'-chelated β-dik complexes (3).Hydrogen peroxide oxidation and chloride abstraction by AgClO4 or AgBF4 of 1 gave the neutral n and the cationic mXm (X = ClO4 or BF4), respectively, from either of which complexes 3 were also obtained by the reactions with the β-dik anions.No pure product corresponding to 3 was isolated by a similar treatment of 1 with Tl(hfac).On the other hand, chloro(cyanomethyl)palladium(II), (2), reacted only with Tl(hfac) in refluxing acetone to give the cationic 2(hfac)2, which was also derived from 2 via Pd(CH2CN)(dppe)2X2 (X = ClO4 or BF4).
Light-induced Reactions of trans-Chloro(cyanomethyl)bis(triphenylphophine)palladium(II) and the Crystal and Molecular Structures of its Acetone, Acetonitrile, and Benzene Solvates
McCrindle, Robert,Ferguson, George,McAlees, Alan J.,Parvez, Masood,Roberts, Paul J.
, p. 1699 - 1708 (2007/10/02)
x-Ray structuredeterminations have been completed for the acetone, acetonitrile, and benzene solvates of (PdCl(CH2CN)(PPh3)) (2).Crystals of (2)*acetone and (2)*acetonitrile are isomorphous, monoclinic, space group P21/n with four formula units in the unit cell.The acetone solvate has cel data: a = 12.679(4), b = 14.553(1), c = 19.506(5) Angstroem, and β = 94.72(1) deg; for tha acetonitrile solvate a = 12.581(2), b = 14.323(2), c = 19.359(3) Angstroem, and β = 93.85(1).The (2)*benzene crystals are also monoclinic, space group P21/a, with four formula units ina unit cell of dimensions a = 22.140(3), b = 10.058(1), c = 18.699(6) Angstroem, and β = 114.78(2) deg.The stuctures were solved by the heavy-atom method and refined by full-matrix least squares calculations to R = 0.026, 0.028, and 0.050 for 4907, 2998, 3664 observed reflections for the acetone, acetonitrile, and benzene solvates, respectivly.In all three complexes molecule (2) has slightly distorted square planar co-ordination with Pd-P 2.319-2.342(1), Pd-Cl 2.369(2)-2.394(1), and Pd-C 2.063(2)-2.088(6) Angstroem.In (2)*acetone and (2)*acetonitrile the solvent molecules are trapped in polar pockets whereas in (2)*benzene the benzenes of solvation are in non-polar channels.The structures show little evidence of an interactionof the nitrile carbon atom with the metal atom nor any obvious structural features that might explain the photochromic behaviour of crystalline (2).Irradiation of (2) with u.v. or tungsten lamps, either in the solid state or in solution, leads to similar products.In the presence of oxygene, in benzene, the principal products are trans-(PdCl2(PPh3)2) (3), ((PdCl(CH2CN)(PPh3))n) (4), ((PdCl2(PPh3))2) (5), PPh3O (6), and acetonitrile.The accumulation of (4) and (5) results from a loss of PPh3 (from (2) and (3) respectivly), the oxidation of which is probably catalysed b ya reduced palladium species generated by photolysis of (2).In the absence of oxygene, in benzene, the only products identified were (3) and acetonitrile whilst in chloroform essentially quantitative conversion of (2) into (3), acetonitrile, and some succinonitrile is observed.Although an e.s.r. investigation showed that radicals are generated uppon irradiation of (2) the principal mode of formation of acetonitrile appears to involve proton abstraction from traces of water in the solvent.The red colour assumed by cristallone (2) upon irradiation is lilmited to the surface.Similar colours have been obtained by heating or irradiating (2) in solution and by treating ethanolic solution of (3) with base.It is suggested that reduced palladium species are responsible for these colours.
