The Synthesis and Structure of Palladium 2,4-dimethyl-8-hydroselenoquinolinate

The internal complex palladium 2,4-dimethyl-8- hydroselenoquinolinate Pd[C9H4(CH3)2NSe]2 (I) has been synthesized in the course of study of the complexing activity of 8- hydroselenoquinoline and investigation of the nature of chemical bond metal-selenium in the five-membered metal-containing ring. X-ray diffraction data for I: Monoclinic, space group P21/n, a = 9.0092(4), b = 16.3290(7), c = 14.1073(6) A,  = 106.710(2)o, V = 1987.7(2) A3, Z = 4, R1=0.0477, wR2=0.1182 for 4499 reflections (diffractometer Bruker-Nonius KappaCCD, MoK). The crystal structure of the complex I is formed by neutral asymmetric molecules Pd[C9H4(CH3)2NSe]2 in which the central atom palladium is connected bidentically (Se,N) with two 2,4- dimethyl-8-hydroselenoquinoline ligands. The structure of palladium coordination polyhedron is cis-square (2Se+2N) somewhat tetrahedrally distorted. Dihedral angle between the SePdN / SePdN coordination planes is 20.15(1)o. The Pd–Se and Pd–N bonds are covalent. The transition of trans- (complex Pd(C9H6NSe)2 (II) to cis-coordination (complex I) causes the weakening of the Pd–N bonds (compare 2.162(5) and 2.159(5) A (I) , 2.065(3) A (II) ).