Palladium(II) complexes of N-(2-thienylmethylidene)aniline derivatives

Coordination reactions of N-(2-thienylmethylidene)aniline derivatives, L, w ith PdCl2 or [PdCl4](2-) in ethanol yield stable complexes of the type tran s-(L)(2)PdCl2 with the azomethine nitrogen atoms as sigma donors. These are not readily convertible to othor-palladated complexes. An X-ray crystallog raphic study of the complex (L-2)(2)PdCl2 reveals a centrosymmetric geometr y. The structure is in the triclinic space group P (1) over bar with a = 8. 633(2) Angstrom, b = 12.759(3) Angstrom, c = 8.398(2) Angstrom, alpha = 96. 65(5)degrees, beta = 111.47(5)degrees, gamma = 101.28(6)degrees, and Z = 1. The final R factor is 0.043 (Rw = 0.044) for 2396 observed reflections. Th ere is no real bonding between a thiophene sulfur atom and a central pallad ium ion. However, a long distance interaction between S and Pd does exist.