| Abstract: | In a complex with [ Z -5-(2-chlorobenzylidene)-4-oxoimidazolin-2-yl]-3-amino-propanoate acid (APAC), potassium ion adopts distorted square-bipyramidal (4 + 2) coordination. All donor atoms are oxygens; four of them originate from carboxylate groups of APAC, while the remaining ones are water oxygens. The equatorial plane of coordination polyhedron is composed of two carboxylate oxygens (with K-O distances of 2.769 and 2.806 Å) and two water oxygens (with K-O distances of 2.722 and 2.749 Å). Two axial K-O bonds (2.663 and 2.664 Å), involving the remaining carboxylate O atoms, complete the sixfold coordination of the K atom. Coordination polyhedra are condensed in two ways. The distance between two potassium pairs are significantly different, 4.224 and 3.801 Å. APAC molecules are held together by a network of hydrogen bonds and create a gap along the [ab] plane with molecular ribbons of potassium ions and water molecules inside. Due to the potassium alignment of aliphatic chains in two neighbouring, crystalgraphically independent APAC molecules, small cavities are created, which form small channels along the b axis with the remaining water molecule. |
