Synthesis, Crystal Structures and DFT Molecular Orbital Surface Calculations of Two New Salts of a Piperazine Derivative

Abstract

Two new salts of a piperazine derivative, namely 4(C17H20ClN2)+·2(C4H5O4)−·(C4H4O4)2−·H2O (I) and 2(C17H20ClN2)+·C6Cl2O4 −·3(H2O) (II) have been synthesized and characterized by means of NMR, single-crystal X-ray diffraction and DFT molecular orbital calculations. Complex (I) crystallizes in the triclinic space group P-1, with Z = 2 in cells with a = 9.6834(6) A, b = 16.9920(8) A, c = 24.9813(13) A, α = 98.265(4)°, β = 90.327(4)°, γ = 105.929(5)°, V = 3907.1(4) A3 and displays R 4 4 [12] ring motifs formed by hydrogen bonds and weak π-ring intermolecular interactions which contribute to the crystal packing forming a 2D network along (0 0 1). Complex (II) crystallizes in the monoclinic space group C2/c, with Z = 8 in cells with a = 28.9941(7) A, b = 17.7719(9) A, c = 15.9647(10) A, β = 98.948(6)°, V = 8126.2(8) A3 and displays bifurcated three center hydrogen bonds involving two of the three water molecules in the asymmetric unit and weak π–π and π-ring intermolecular interactions which pack the molecules into a 2D network along (1 0 0). Additionally, the frontier molecular orbitals of each independent cation of each salt are displayed and correlation between the calculated molecular orbital energies (eV) for the surfaces of the frontier molecular orbitals to the electronic excitation transitions from the absorption spectra of the independent cation in each salt has been proposed. Synthesis, crystal structures, density functional theory (DFT) molecular orbital surface calculations of two new salts of piperazine derivatives: tetrakis-[1-((4-chlorophenyl)(phenyl)methyl)piperazinium] bis-(monohydrogensuccinate)succinate monohydrate (I) and bis[1-((4 chlorophenyl)(phenyl)methyl) piperazinium] chloranilate trihydrate (II).