Abstract
The geometries, energies, and IR characteristics of 1:1 noradrenaline–water (NA–H2O) complexes are studied at the ωB97XD/6-311++G(d,p) level. Various type of hydrogen bonds (H-bonds) are formed in these NA–H2O complexes, and the quantum theory of the atoms in molecules and natural bond orbital analyses are used to understand the nature of hydrogen bonding interactions. The intramolecular H-bond formed between the hydroxyl group and the amino N atom in free NA molecule is replaced by two intermolecular H-bonds and results in the formation of the most stable NA–H2O complex. In addition, the intramolecular H-bond keeps untouched in other NA–H2O complexes, moreover, it is strengthened by the intermolecular H-bonds in some NA–H2O complexes due to the cooperativity, whereas no such cooperativity is found in the other NA–H2O complexes in which the intermolecular H-bonds are away from the side chain of NA. Our researches show that the hydrogen bonding interaction is not the unique factor for the relative stabilities of NA–H2O complexes, and the structural deformation plays an important role as well.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call