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 beensynthesized in the course of study of the complexing activity of 8-hydroselenoquinoline and investigation of the nature of chemicalbond 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) Å, beta = 106.710(2)o, V =1987.7(2) Å3, Z = 4, R1=0.0477, wR2=0.1182 for 4499 reflections(diffractometer Bruker-Nonius KappaCCD, [beta];MoK).The crystal structure of the complex I is formed by neutralasymmetric molecules Pd[C9H4(CH3)2NSe]2 in which the centralatom palladium is connected bidentically (Se,N) with two 2,4-dimethyl-8-hydroselenoquinoline ligands. The structure ofpalladium coordination polyhedron is cis-square (2Se+2N)somewhat tetrahedrally distorted. Dihedral angle between theSePdN / SePdN coordination planes is 20.15(1)o.The Pd-Se and Pd-N bonds are covalent. The transition oftrans- (complex Pd(C9H6NSe)2 (II) to cis-coordination (complex I)causes the weakening of the Pd-N bonds (compare 2.162(5) and2.159(5) Å (I) , 2.065(3) Å (II) ).