Solvothermal Syntheses, Crystal Structures and Catalytic Properties of Four Chiral Compounds Built from (R)-4-(4-(1-Carboxyethoxy)penoxy) Benzoic Acids

摘要

A series of chiral metal-organic compounds [Ag(cpfa)(phen)] (1), [Ag(cpna)(phen)] (2), [Cu(cpna)(phen)]*2H2O (3), [Cd2(cpna)2 (phen)2]n (4) (H2cpfa=(R)-4-(4-(1-carboxyethoxyphenoxy) phenoxy-3-fluorobenzoic acid; H2cpna=(R)-4-(4-(1-carboxyethoxy) phenoxy)-3-nitrobenzoic acid; phen=1,10-phenanthroline) has been successfully obtained via solvothermal reactions and characterized by IR spectra, elemental analyses, thermo gravimetric analyzer (TGA), solid-state circular dichroism (CD) and powder X-ray diffraction (PXRD). Compounds 1–4 all crystallize in chiral space groups and their CD spectra exhibit obvious positive or negative Cotton effects, indicating their homochirality. Rich hydrogen bonds based on carboxylic groups and π-π interactions between adjacent phen molecules are present in the four compounds. It is also found that the pH value and reactant ratio have an impact on the growth of the compounds. In addition, their asymmetric catalytic activities for Henry reaction have also been investigated.