Crystal and geometry-optimized structure, Hirshfeld surface analysis and spectroscopic studies of tetrachlorocuprate and nitrate salts of 1-(2-fluorophenyl)piperazine cations, (C10H15FN2)[CuCl4] (I) and (C10H14FN2)[NO3] (II)

Abstract

Two new organic-inorganic hybrid materials, 1-(2-fluorophenyl)piperazine-1,4-diium tetrachlorocuprate, (C10H15FN2)[CuCl4] (I) and 1-(2-fluorophenyl)piperazin-4-ium nitrate, (C10H14FN2)[NO3] (II), have been synthesized by an acid/base reaction at room temperature in the presence of 1-(2-fluorophenyl)piperazine as an organic-structure directing agent and their structures were determined by single crystal X-ray diffraction. Compound (I), (C10H15FN2)[CuCl4], crystallizes in the monoclinic system and P21/c space group with a=7.5253 (2), b=20.6070 (7), c=9.7281 (3) Å, β=103.6730 (17)°, V=1465.82 (8)Å3 with Z=4. Full-matrix least-squares refinement converged at R=0.037 and wR(F2)=0.088. Compound (II), (C10H14FN2)[NO3], belongs to the monoclinic system, space group P21/c with the following parameters: a=10.8034 (2), b=7.5775 (1), c=14.4670 (3) Å, β=111.761 (2)°, V=1099.91 (4) Å3 and Z=4. The structure was refined to R=0.044, wR(F2)=0.136.In the structures of (I) and (II), the anionic and cationic entities are interconnected by means of set of hydrogen bonding contacts forming three-dimensional networks. Intermolecular interactions were investigated by Hirshfeld surfaces and the contacts of the four different chloride atoms were notably compared. The results of the optimized molecular structure are presented and compared with the experimental one. The Molecular Electrostatic Potential (MEP) maps and the HOMO and LUMO energy gap of both compounds were computed. The vibrational absorption bands were identified by infrared spectroscopy. Theory (DFT) calculations of normal mode frequencies are compared with experimental ones.