Ab initio studies on the interaction between copper(I) and 5-nitrotetrazolate anion

Ab initio molecular orbital calculations on the interaction between Copper(I) and 5-nitrotetrazolate anion were done using different basis sets, at the HF, B3LYP and MP2 levels of theory. Three minima were found to 1A, 1B and IC structures of Cu(I)-5-NTz complex. At the B3LYP/LanL2DZ level, the energy difference between 1A and 1B was computed to be 8.18 kcal/mol, while that between 1A and 1C is 22.76 kcal/mol. The presence of both Cu-N and Cu-O interactions is revealed in 1A structure using both natural bond orbital and atoms-in-molecules analyses, which makes more stable than those of 1B and 1C complexes. The binding energy corrected for both ZPE and BSSE for 1A is found to be -150.59 kcal/mol at the B3LYP/LanL2DZ level. The barrier for the 1B → 1A and 1C → 1B conversion is calculated to be 7.80 kcal/mol and 9.40 kcal/mol, respectively.