Hydrogen-bonding interactions in adrenaline-water complexes: DFT and QTAIM studies of structures, properties, and topologies.
ωB97XD/6-311++G(d,p) calculations were carried out to investigate the hydrogen-bonding interactions between adrenaline (Ad) and water. Six Ad-H(2)O complexes possessing various types of hydrogen bonds (H-bonds) were characterized in terms of their geometries, energies, vibrational frequencies, and electron-density topology. Natural bond orbital (NBO) and quantum theory of atoms in molecules (QTAIM) analyses were performed to elucidate the nature of the hydrogen-bonding interactions in these complexes. The intramolecular H-bond between the amino and carboxyl oxygen atom of Ad was retained in most of the complexes, and cooperativity between the intra- and intermolecular H-bonds was present in some of the complexes. H-bonds in which hydroxyls of Ad/water acted as proton donors were stronger than other H-bonds. Both hydrogen-bonding interactions and structural deformation play important roles in the relative stabilities of the complexes. The intramolecular H-bond was broken during the formation of the most stable complex, which indicates that Ad tends to break the intramolecular H-bond and form two new intermolecular H-bonds with the first water molecule.
Tianjin Key Laboratory of Structure and Performance for Functional Molecules, College of Chemistry, Tianjin Normal University, Tianjin 300387, People's Republic of China.
Hongke
H
Wang
Zhengguo
Z
Huang
Tingting
T
Shen
Lingfei
L
Guo
D004837:Epinephrine / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D011789:Quantum Theory; D014867:Water / Q000737:chemistry*
D014867:Water; D004837:Epinephrine