DFT calculations on the hydrogen bonding interactions between adrenaline and trimethoxysilylpropylamine

Abstract

The hydrogen bonding interactions between adrenaline (Drug) and 3-(trimethoxysilyl)-1-propanamine (TMSA) have been calculated using Gaussian 98 software. Ten possible forms (1-10) for the hydrogen bonding interactions were computed at HF and B3LYP levels of theory with 6-31 G(d) and 6-31 + G(d,p) standard basis sets. The binding energies, ΔE(binding), were obtained from the equation ΔE(binding) = E(complex)- [E(Drug) + E(TMSA)] + BSSE. The most stable forms (complexes 4 and 5) interact through O-H ... N hydrogen bond, with calculated binding energies at B3LYP/6-31G* level equal to-10.93 and-12.84 kcal mol-1, respectively. Other compounds containing N-H ... N (1), N-H ... O (2, 3, 6, 9) and O-H ... O (7, 8 and 10) hydrogen bonds show lower ΔE(binding) values. The nuclear quadrupole coupling constants (NQCCs or χs) were calculated for 17O, 14N and 2H nuclei about 10.0, 4.0-5.0 MHz and 180.0-360.0 kHz, respectively, that are in agreement with the experimental data.