TY - JOUR

T1 - Conformation and bonding of 2-methoxypyridine and its monohydrate from rotational spectra

AU - Cheng, Wanying

AU - Zheng, Yang

AU - Feng, Gang

AU - Grabow, Jens Uwe

AU - Gou, Qian

N1 - Funding Information: We are grateful for support from the National Natural Science Foundation of China (Grant Nos. 21703021 and U1931104), Natural Science Foundation of Chongqing, China (Grant Nos. cstc2017jcyjAX0068 and cstc2018jcyjAX0050), Venture and Innovation Support Program for Chongqing Overseas Returnees (Grant No. cx2018064), Foundation of 100 Young Chongqing University (Grant No. 0220001104428), the Land Niedersachsen, and the Deutsche Forschungsgemeinschaft (DFG).

PY - 2020/10/5

Y1 - 2020/10/5

N2 - Rotational spectra of 2-methoxypyridine and its monohydrate have been characterized by pulsed jet Fourier transform microwave spectroscopy and complementary ab initio calculations. Rotational spectra of the parent monomer and seven mono-substituted isotopologues (13C and 15N) were measured in natural abundance, which allow determining the accurate structure of the skeleton of 2-methyoxypyridine. The barrier to the methyl internal rotation was determined from the A/E torsional symmetry species of the rotational transitions. For the 2-methyoxypyridine⋯H2O complex, rotational spectra of the parent dimer and isotopologues formed with isotopically enriched water (H2 18O, HOD, DOH and D2O) indicate that the observed isomer is stabilized by a strong O[sbnd]H⋯N and a secondary bifurcated (C[sbnd]H)2⋯O weak hydrogen bonds. Bader's quantum theory of atoms in molecules and Johnson's non-covalent interaction analyses were applied and visualized to have a better understanding of the non-covalent interactions in 2-methyoxypyridine⋯H2O.

AB - Rotational spectra of 2-methoxypyridine and its monohydrate have been characterized by pulsed jet Fourier transform microwave spectroscopy and complementary ab initio calculations. Rotational spectra of the parent monomer and seven mono-substituted isotopologues (13C and 15N) were measured in natural abundance, which allow determining the accurate structure of the skeleton of 2-methyoxypyridine. The barrier to the methyl internal rotation was determined from the A/E torsional symmetry species of the rotational transitions. For the 2-methyoxypyridine⋯H2O complex, rotational spectra of the parent dimer and isotopologues formed with isotopically enriched water (H2 18O, HOD, DOH and D2O) indicate that the observed isomer is stabilized by a strong O[sbnd]H⋯N and a secondary bifurcated (C[sbnd]H)2⋯O weak hydrogen bonds. Bader's quantum theory of atoms in molecules and Johnson's non-covalent interaction analyses were applied and visualized to have a better understanding of the non-covalent interactions in 2-methyoxypyridine⋯H2O.

KW - 2-Methoxypyridine

KW - Hydrogen bond

KW - Rotational spectroscopy

KW - Water adducts

UR - http://www.scopus.com/inward/record.url?scp=85085131545&partnerID=8YFLogxK

U2 - 10.1016/j.saa.2020.118434

DO - 10.1016/j.saa.2020.118434

M3 - Article

C2 - 32438304

AN - SCOPUS:85085131545

VL - 239

JO - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy

JF - Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy

SN - 1386-1425

M1 - 118434

ER -