Synthesis and Structures of 1,3-Dicarbonyl Compounds Based on 9,10-Phenanthrenequinone. Crystal and Molecular Structure of the Lantern-Type Binuclear Copper(II) Complex Cu2[μ2-OOCCH2(C14H8)(CO)2OC2H5]4(NCCH3)2

Abstract

1,3-Dicarbonyl compounds were synthesized by the reaction of 9,10-phenanthrenequinone with acetylacetone and acetoacetic ester followed by the reduction and were characterized by spectroscopic and quantum-chemical methods. In the crystalline state and in solution, these compounds were found to exist in the keto form. The molecular and crystal structure of the binuclear lantern-type copper(II) carboxylate complex Cu2[μ2-OOCCH2(C14H8)(CO)2OC2H5]4(NCCH3)2, which was formed through the oxidation of the starting 1,3-dicarbonyl compound upon the complexation, was determined by X-ray diffraction. The coordination polyhedron of each copper atom can be described as a (4 + 1) square pyramid with four O atoms of four carboxyl groups at the base and the acetonitrile N atom in the apical position. The formation of the lantern-type dimer is attributed to the μ2-O,O' bidentate-bridging coordination mode of carboxyl groups.