Structure and thermal properties of volatile copper(II) complexes with β-diimine derivatives of acetylacetone and the structure of 2-(methylamino)-4-(methylimino)-pentene-2 crystals

Copper(II) chelates with beta-diimine derivatives of acetylacetone that have a general formula of Cu((RC)-C-1(NR2)CHC(NR2)R-1)(2), where R-1, R-2 are alkyl substituents, are synthesized. The complexes were identified using elemental analysis, melting point measurements, and high-temperature mass spectrometry data. Knudsen technique is employed to determine the vapor pressure temperature dependence, and standard thermodynamic parameters of sublimation Delta H-T(0) and Delta S-T(0) are derived. A single crystal X-ray diffraction study is carried out for copper(II) complexes of Cu(CH3-C(NCH3)-CH-C(NCH3)-CH3)(2) (a = 10.363(1) angstrom, b = 11.978(1) angstrom, c = 12.653(1) angstrom, V = 1570.6(3) angstrom(3), space group Pnc2, Z = 4, d(calc) = 1.328 g/cm(3), R = 0.027), Cu(CH3-C(NC2H5)-CH-C(NC2H5)-CH3)(2) (a = 11.782(4) angstrom, b = 13.951(8) angstrom, c = 25.591(8) angstrom, V = 4206(3) angstrom(3), space group C222(1), Z = 8, d(calc) = 1.169 g/cm(3), R = 0.10), and also 2-(methylamino)-4-(methylimino)-pentene-2 CH3-(C=(NCH3))-CH=(C-(NHCH3))-CH3 (a = 12.129(2) angstrom, b = 12.034(2) angstrom, c = 5.692(1) angstrom, beta = 107.05(3)degrees, V = 794.3(3) angstrom(3), space group Cc, Z = 4, d(calc) = 1.055 g/cm(3), R = 0.06). Van der Waals lattice energy E-cryst is calculated for the cooper(II) complexes by the atom-atom potential technique. The calculated values are compared to experimental sublimation enthalpies Delta H (0)(T).