Synthesis and spectral characterization of alkaline earth metal complexes: Crystal structure of a Ca(II) hippuric acid complex

Alkaline earth metal (Mg, Ca, Sr and Ba) complexes of hippuric acid (hipH) have been synthesized and characterized by elemental analyses and IR spectroscopy. One of the complexes, [Ca(hip)2(H2O)2]·H2O, was characterized by single crystal X-ray diffraction studies. The polymeric structure is based on a dimeric unit and each calcium is coordinated to four hippurate anions and two coordinated water molecules. The hippurate anion functions as a bidentate ligand through the oxygen atoms of the carboxylate groups, one of which is bridging, forming a two dimensional coordination polymer. The water coordination is further confirmed by thermal analysis. The non-linear optical activity of the complexes was also measured.

Graphical abstractAlkaline earth metal complexes of hippuric acid have been synthesized and characterized. One of the complexes, [Ca(hip)2(H2O)2]·H2O, was characterized by single crystal X-ray diffraction studies. The hippurate anion functions as a bidentate ligand and is linked to calcium through the oxygen atoms of the carboxylate groups, one of which is bridging, forming a two dimensional coordination polymer.Figure optionsDownload full-size imageDownload as PowerPoint slide