TY - JOUR
T1 - Competing Intramolecular Hydrogen Bond Strengths and Intermolecular Interactions in the 4-Aminobutanol-Water Complex
AU - Hohl, Jenna A.
AU - Harris, Michael W.
AU - Strasser, Nina
AU - Kelterer, Anne Marie
AU - Lavrich, Richard J.
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018
Y1 - 2018
N2 - We seek to determine the effect of competing intermolecular hydrogen bonds from water on the preferred conformation of 4-aminobutanol (4AB) monomers stabilized by intramolecular hydrogen bonds. Toward this end, the rotational spectrum of the 4-aminobutanol-H2O complex was recorded using Fourier transform microwave spectroscopy and fit to the rotational, quadrupole coupling, and centrifugal distortion constants of the Watson S-reduction Hamiltonian. The experimental results are consistent with a 4AB-water complex that preserves the intramolecular hydrogen bond within the 4AB monomer and forms a single intermolecular bond with water acting as a donor. The experimental monomer structure agrees well with the lowest energy conformation calculated at the MP2/6-311++G(d,p) level of theory. Upon complex formation and the introduction of competing intermolecular bonds from water, only small changes in the OH···N intramolecular hydrogen bond and backbone torsional angles of the 4-aminobutanol monomer are observed. Similar small changes were observed for the shorter chain 3-aminopropanol amino alcohol monomer when complexed with water, in contrast to the 2-aminoethanol-H2O complex. In the latter, a large change in the backbone torsional angle and a breaking of the intramolecular hydrogen bond were observed. Thus, extending the methylene chain results in an increase in the strength of the intramolecular hydrogen bond in unbranched amino alcohols.
AB - We seek to determine the effect of competing intermolecular hydrogen bonds from water on the preferred conformation of 4-aminobutanol (4AB) monomers stabilized by intramolecular hydrogen bonds. Toward this end, the rotational spectrum of the 4-aminobutanol-H2O complex was recorded using Fourier transform microwave spectroscopy and fit to the rotational, quadrupole coupling, and centrifugal distortion constants of the Watson S-reduction Hamiltonian. The experimental results are consistent with a 4AB-water complex that preserves the intramolecular hydrogen bond within the 4AB monomer and forms a single intermolecular bond with water acting as a donor. The experimental monomer structure agrees well with the lowest energy conformation calculated at the MP2/6-311++G(d,p) level of theory. Upon complex formation and the introduction of competing intermolecular bonds from water, only small changes in the OH···N intramolecular hydrogen bond and backbone torsional angles of the 4-aminobutanol monomer are observed. Similar small changes were observed for the shorter chain 3-aminopropanol amino alcohol monomer when complexed with water, in contrast to the 2-aminoethanol-H2O complex. In the latter, a large change in the backbone torsional angle and a breaking of the intramolecular hydrogen bond were observed. Thus, extending the methylene chain results in an increase in the strength of the intramolecular hydrogen bond in unbranched amino alcohols.
UR - http://www.scopus.com/inward/record.url?scp=85055856068&partnerID=8YFLogxK
U2 - 10.1021/acs.jpca.8b05888
DO - 10.1021/acs.jpca.8b05888
M3 - Article
C2 - 30299959
AN - SCOPUS:85055856068
SN - 1089-5639
VL - 122
SP - 8505
EP - 8510
JO - The Journal of Physical Chemistry A
JF - The Journal of Physical Chemistry A
IS - 43
ER -