Hydrothermal synthesis, crystal structure, and properties of a novel tetranuclear calcium complex constructed with aromatic sulfonate-carboxylate ligand

abstract

A novel calcium complex, [Ca₄(SIP)₃(phen)₈(H₂O)₆]·(Hphen)·(phen)·27H₂O (1) (NaH₂SIP = 5-sulfoisophthalic monosodium salt, phen = 1,10-phenanthroline), has been synthesized by hydrothermal reaction at 160°C. It was characterized by X-ray single-crystal diffraction, infrared spectroscopy, and elemental and thermogravimetric analysis. Complex 1 features an approximate U-shaped structure, where the tetranuclear calcium ions are bridged by tridentate and tetradentate SIP³⁻ ligands, together with free 1H-protonated 1,10-phenanthroline balancing the charge. Each calcium ion is eight-coordinated showing distorted bicapped trigonal prism geometry. The luminescence spectrum indicates an emission maximum at 463 nm. Complex 1 shows a second harmonic generation response that is three times that of KH₂PO₄.

KEYWORDS:

• Crystal structure
• hydrothermal
• luminescence
• optical properties

Funding

The authors thank Liaoning Province Education Department (No. L2015299) for financial support.