SYNTHESIS, STRUCTURAL AND SPECTROSCOPIC CHARACTERIZATIONS, HIRSHFELD SURFACE ANALYSIS OF TWO COORDINATION COMPOUNDS ASSEMBLED FROM COPPER AND CARBOXYLATES, 3,5-DIMETHYL-1H- PYRAZOLE

Two coordination compounds Cu(H2O)(DMPZ)(2)C2O4 (1) (DMPZ = 3,5-dimethyl-1H-pyrazole) and [Cu(H2O)(2)(CH3COO)Br](n) (2) have been synthesized by oxidative dissolution method. The crystal structures of both compounds have been determined by single-crystal X-ray diffraction analysis. Complex 1 crystallizes in the triclinic P (1) over bar space group, while complex 2 is orthorhombic crystals in the space group Pnma. In both compounds, the Cu(II) ion displays a slightly distorted square-pyramidal coordination environment. In complex 1, the coordination number of copper(II) ion is five, with the equatorial position formed by two nitrogen atoms belonging to the two monodentate coordinated 3,5-dimethyl-1H-pyrazole molecules, and two O atoms of the oxalate anion coordinated in a chelate mode. The axial position is occupied by the O atom of the water molecule. In complex 2, the copper equatorial surrounding consists of four oxygen atoms from two trans-disposed water molecules and two acetate groups that are bridged in syn-anti mode with neighboring copper atoms. The apical coordination site is occupied by the bromide ion. Elemental analysis and spectroscopy characterization of the complexes and 3,5-dimethyl-1H-pyrazole are also reported. The Hirshfeld surface analysis suggests that the main contribution to intermolecular interactions in both compounds comes from hydrogen bonds (H center dot center dot center dot O/O center dot center dot center dot H and H center dot center dot center dot Br/Br center dot center dot center dot H) and other close contacts involving hydrogen atoms.