active quinoxalines and dipyridophenazines were efficiently synthesized in excellent yield and less reaction time using inexpensive, easily recyclable sulfated titania (TiO2–SO42−). TiO2–SO42−, prepared by sol–gel method, was characterized by XRD, FT-IR and SEM techniques to confirm the sulfate loading. TiO2–SO42− has more acidic sites when compared to TiO2 (prepared )and TiO2–P25. Synthesis of quinoxalines
The coupling of carbon dioxide and epoxides by phenanthroline derivatives containing different Cu(II) complexes as catalyst
作者:Ahmet Kilic、Ahmet Arif Palali、Mustafa Durgun、Zeynep Tasci、Mahmut Ulusoy
DOI:10.1016/j.saa.2013.04.124
日期:2013.9
A series of the mononuclear Cu(II) metal complexes containing the ligand Bdppz [(9a,13a-dihydro-4,5,9,14-tetraaza-benzo[b]triphenylene-11-yl)-phenyl-methanone] (L-1) and Aqphen [(12,17-dihydronaphthol[2,3-h]dipyrido[3,2-a:2',3'-c]-phenazine-12,17-dione)] (L-2) were synthesized and used as catalyst for the coupling of carbon dioxide (CO2) and liquid epoxide which served as both reactant and solvent. Dimethylamino pyridine (DMAP) was used as co-catalyst. The yields of epoxides to corresponding cyclic carbonates were determined by comparing the ratio of product to substrate in the H-1 NMR spectrum of an aliquot of the reaction mixture. The mononuclear Cu(II) complexes of these ligands were synthesized by treating an ethanol solvent of the appropriate ligand with a different molar amount of CuCl2 center dot 2H(2)O. The Cu(II) complexes were characterized by FT-IR, UV-Vis, elemental analysis, melting point analysis, mass spectra, molar conductivity measurements and magnetic susceptibility techniques. The reaction of the Bdppz and Aqphen ligands in a 1:1, 1:2 or 1:3 mole ratio with CuCl2 center dot 2H(2)O afforded ionic Cu(II) complexes in the presence of Et3N. (C) 2013 Elsevier B.V. All rights reserved.