Synthesis, Structure, and Properties of a New Calcium(II) Complex of 1,10‐Phenanthroline, 1,2,4,5‐Benzenetetracarboxylic Acid, and a New Precursor to Produce Pure Phase Micro‐crystalline Calcite Particles

The self‐assembly of 1, 0‐phenanthroline (phen) and 1,2,4,5‐benzenetetracarboxylic acid(H 4 btc) with Ca(NO 3 ) 2 gives rise to a two‐dimensional network structure coordination polymer, [Ca(phen)(btc) 0.5 (H 2 O)] ( 1 ), which was characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. This compound is monoclinic, space group C 2/ c , with Z = 8 in a unit cell with dimensions a = 21.744(3) Å, b = 10.0151(12) Å, c = 14.7122(17) Å, β = 110.2850(10)°. The structure contains one crystallographic unique Ca II atom, one phen coordinated molecule and a half of btc 4– anion. The phen molecule acts as a didentate ligand chelating with a Ca II atom, whereas the btc 4– anion acts as a μ 6 ‐bridge linking six different Ca II atoms to form a two‐dimensional network with (4, 4) topological structure. The three dimensional stacking structures are formed by C–H ··· O hydrogen bonding and π–π interaction. The thermal stability and fluorescent properties of 1 were investigated. Calcite particles are produced by calcination of compound 1 at 580 °C. The obtained calcite was characterized by XRD and SEM analyses.