Tailoring the dimensionality of metal complexes via ligand modifications.

A series of Cu II complexes obtained under the same reaction conditions has been analyzed to gain insight into the effect of the ligand composition on the final reaction product. Dipodal ligands containing N-donor imidazole rings and a benzene ring as a spacer with different numbers of methyl substituents on the aromatic rings were selected for the study such as 1,3-bis(imidazol-1-ylmethyl)benzene (L1), 1,3-bis(imidazol-1-ylmethyl)-5-methylbenzene (L2), 1,3-bis(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene (L3), 1,3-bis(2-methylimidazol-1-ylmethyl)-2,4,6-trimethylbenzene (L4). L4 has not been reported previously and was synthesized for this study. The formed metal complexes show the presence of polymeric (ligand with no or one methyl substituent; 1-4), or discrete motifs (3- or 5-methyl substituents; 5-7). The new metal complexes 3, 5 and 6 were analyzed using single-crystal X-ray diffraction and powder diffraction. In addition, the structural analyses were supported by computational methods.