Molecular, supramolecular structure and catalytic activity of transition metal complexes of phenoxy acetic acid derivatives

Six mononuclear complexes [M(L1)2(H2O)4] (M = Co(II), 1a and M = Mn(II), 1b), [Cu(L1)2(H2O)2] (1c), [Cu(L1)2(H2O)(Py)2] (1d), [Cu(L3)(H2O)Cl] · H2O (3a) and [Co(Sal)(H2O)(Py)3] · 2ClO4 · H2O (3b) of phenoxyacetic acid derivatives and Schiff base were determined by single crystal X-ray diffraction. The Co(II) (1a) and Mn(II) (1b) complexes are isomorphous. X-ray crystal structural analyses reveal that these coordination complexes form polymeric structure via formation of different types of hydrogen bonding and π-stacking interactions in solid. Thermal analysis along with the powder X-ray diffraction data of these complexes shows the importance of the coordinated and/or crystal water molecules in stabilizing the MOF structure. Complexes 1a, 1c, 3a show marginal catalytic activity in the oxidation of olefins to epoxides in the presence of i-butyraldehyde and molecular oxygen.

Graphical abstractSingle crystal X-ray diffraction studies revealed that control on the environment of first coordination sphere of six mononuclear complexes of phenoxyacetic acid derivatives has a significant effect on the ultimate MOF structure, thermal and catalytic behaviour.Figure optionsDownload full-size imageDownload as PowerPoint slide