Table 3: Selected optimized parameters (bond lengths in Å, bond angles in °) of [CuCl(pyz)4]+, [CuCl(pyz)4]+⋯ClO4−, and {CuCl(μ-pyz)4[ZnCl2(H2O)3]4}+
as obtained with M06-2X/6-31+G(d), 6-31G(d) in the gas phase (T = 298 K).
 System Cu-pyz-631+d1 Cu-ClO4-631+d2 Cu-pyz-631d3 Cu-Zn-631d4
Bond lengths
 Cu−N 2.100 2.136, 2.139, 2.0566 2.079 2.077, 2.080, 2.081
 Cu−Cl 2.363 2.388 2.349 2.340
 N−C 1.339, 1.3325 1.3497, 1.3295 1.339, 1.3315 1.338
 N⋯N 2.783 2.785 2.783 2.759 (avg)
 System Cu-pyz-631+d Cu-ClO4-631+d Cu-pyz-631d Cu-Zn-631d
Bond angles
 N−Cu−N 88.6 91.4, 86.86 88.2 87.7, 88.2
 N−Cu−Cl 98.8 95.46, 102.2, 104.4 100.0 100.3, 100.5, 100.8
 Cu−N−C 117.7, 124.4 117.266, 118.6 17.4, 124.9 117.3, 124.2 (avg)
 C−N−C 117.8, 116.85 124.96, 124.0, 122.8 117.7, 116.85 118.2, 188.87
1Cu-pyz-631+d = [CuCl(pyz)4]+/M06-2X/6-31+G(d); 2Cu-ClO4-631+d = [CuCl(pyz)4]+⋯ClO4−/M06-2X/6-31+G(d); 3Cu-pyz-631d = [CuCl(pyz)4]+/M06-2X/6-31G(d); 4Cu-Zn-631d = {CuCl(μ-pyz)4[ZnCl2(H2O)3]4}+/M06-2X/6-31G(d); 5Average value involving noncoordinated nitrogen atoms; 6Nitrogen in opposition to ClO4−; 7Nitrogen coordinated to Zn(II).