Ab initio calculations on the hydrogen bonding interactions among pseudoephedrinium cation isomers and methacrylic acid

作者：Shariatinia Zahra^*; Arabzadeh Naghmeh; Abdous Majid

来源：Main Group Chemistry, 2011, 10(1): 1-16.

DOI：10.3233/MGC-2010-0019

• Ab initio computations
• pseudoephedrinium cation
• hydrogen bonding interactions
• NQR

The hydrogen bonding interactions between both 1R-2R and 1S-2S isomers of pseudoephedrinium cation (Drug) and methacrylicacid (MAA) were calculated using Gaussian 98 software. Eight possible forms for the H-bond interactions were computed at HF and B3LYP levels of theory with 6-31G(d) and 6-31+G(d,p) basis sets and for all of the molecules the B3LYP/6-3IG* provides the highest stabilization energies. The hydrogen bonding energies, E((H-bond)), were obtained from the equation E((H-bond)) = E((complex)) - [E((Drug)) + E((MAA))] and among four computational methods, B3LYP/6-31G(d) provides the highest hydrogen bonding energy for all of the complexes. The nuclear quadrupole coupling constants (chi) for (17)O, tetrahedral (14)N nuclei were calculated about 10.0, 0.5-1.0 MHz and for (2)H atoms varied from nearly 150.0 kHz to almost 350.0 kHz.

• 出版日期2011