MONONUCLEAR PALLADIUM(II) COMPLEXES WITH THE PHENYLSELENOLATO LIGAND - THE CRYSTAL AND MOLECULAR-STRUCTURE OF TRANS-[PD(SEPH)(2)(P(N-BU)(3))(2)]

Mononuclear palladium(II) complexes of the type [Pd(SePh)(2)L-2] [wher e L = pMe(3), PEt3, p(n-Ba)(3), PMePh2 or TPA (1,3,5-triaza-7-phosphaa damantane)] have been prepared and characterized by elemental analysis , H-1, C-13{H-1} and P-31{H-1} NMR data and in the case of [Pd(SePh)(2 )(P(n-Bu)(3))(2)] by single-crystal X-ray diffraction methods. Crystal s of [Pd(SePh)(2)(P(n-Bu)(3))(2)] are triclinic, space group P (1) ove r bar, a=8.4798(7), b = 10.3002(15), c = 12.254(2)Angstrom, alpha = 77 .957(15), beta = 85.806(11), gamma= 83.550(9)degrees, Z=1. The structu re was refined by full-matrix least-squares calculations on F-2 to fin al R values R-obs = 0.0267 (for 3187 reflections with I greater than o r equal to 2 sigma(I)) and wR(F-2)= 0.0657 (for all 4549 measured refl ections). The structure determination shows that the Pd atom lies on a n inversion centre so that the coordination geometry is necessarily tr ans:and planar. Main bond lengths are Pd-P 2.3334(7) and Pd-Se 2.4609( 4)Angstrom. (C) 1998 Elsevier Science Ltd. All rights reserved.