Copper(II) complexes with box or flower type morphology: Sustainability versus perishability upon catalytic recycling

•Monomeric copper(II) complexes of a benzimidazolyl schiff base ligand.•Oxidation of p-chlorobenzyl alcohol to p-chlorobenzaldehyde, heterogeneously.•Rectangular box type morphology found for [Cu(L)Cl] while flower type with micro petals for [Cu(L)SCN].•Loss of PXRD peaks associated with certain planes with reuse of catalyst.•Box type morphology sustains catalysis upon recycling compared to the flower type.

Copper(II) complexes derived from a benzimidazolyl schiff base ligand are used heterogeneously for the selective oxidation of p-chlorobenzyl alcohol to p-chlorobenzaldehyde. Complex (1) shows rectangular box type morphology while complex (2) shows a flower like morphology with micropetals. Powder X-ray diffraction pattern upon reuse of catalyst (1) shows loss of peaks associated with planes 0 0 1 and 1 0 0 suggesting preferential exposure of these planes during the catalytic cycle, while the catalyst (2) shows loss in activity with planes associated with 0 1 1 and 0 2 1 (axis b & c) implying a non-preferential activity. It is interesting to note that the box type morphology (1) sustains catalysis upon recycling to a greater extent in comparison to the flower type (2).

Graphical abstractSelective oxidation of p-chlorobenzyl alcohol to p-chlorobenzaldehyde is carried out by new copper(II) complexes of a benzimidazolyl schiff base ligand. Efficiency of oxidation depends on the morphology of the complexes; box type morphology sustains catalysis upon recycling to a greater extent in comparison to the flower type.Figure optionsDownload full-size imageDownload as PowerPoint slide