Microsolvation of the formic acid dimer — (HCOOH)2(H2O)n clusters with n = 1, . . ., 5

2010 ◽  
Vol 88 (8) ◽  
pp. 736-743 ◽  
Author(s):  
Cara M. Nordstrom ◽  
Alaina J. McGrath ◽  
Ajit J. Thakkar
Keyword(s):  
Density Functional Theory ◽  
Perturbation Theory ◽  
Hydrogen Bonds ◽  
Formic Acid ◽  
Density Functional ◽  
Water Molecules ◽  
Spin Component ◽  
Functional Theory ◽  
Moller Plesset ◽  
Plesset Perturbation Theory

Density functional theory and spin-component-scaled Møller–Plesset perturbation theory calculations are used to examine the microsolvation of the formic acid dimer. The lowest energy structures with n water molecules consist of a n-water cluster, not necessarily of lowest energy, with two formic acid molecules attached to its surface by hydrogen bonds. The total number of hydrogen bonds does not correlate directly with relative stability.

scholarly journals Cis/Trans Energetics in Epoxide, Thiirane, Aziridine and Phosphirane Containing Cyclopentanols: Effects of Intramolecular OH⋯O, S, N and P Contacts

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2523 ◽  
Author(s):  
Ben E. Smith ◽  
Jeremy M. Carr ◽  
Gregory S. Tschumper
Keyword(s):  
Density Functional Theory ◽  
Perturbation Theory ◽  
Vibrational Frequency ◽  
Density Functional ◽  
Computational Analysis ◽  
Intramolecular Interactions ◽  
Coupled Cluster ◽  
Functional Theory ◽  
Moller Plesset ◽  
Plesset Perturbation Theory

A recent computational analysis of the stabilizing intramolecular OH⋯O contact in 1,2-dialkyl-2,3-epoxycyclopentanol diastereomers has been extended to thiiriane, aziridine and phosphirane analogues. Density functional theory (DFT), second-order Møller-Plesset perturbation theory (MP2) and CCSD(T) coupled-cluster computations with simple methyl and ethyl substituents indicate that electronic energies of the c i s isomers are lowered by roughly 3 to 4 kcal mol−1 when the OH group of these cyclopentanol systems forms an intramolecular contact with the O, S, N or P atom on the adjacent carbon. The results also suggest that S and P can participate in these stabilizing intramolecular interactions as effectively as O and N in constrained molecular environments. The stabilizing intramolecular OH⋯O, OH⋯S, OH⋯N and OH⋯P contacts also increase the covalent OH bond length and significantly decrease the OH stretching vibrational frequency in every system with shifts typically on the order of −41 cm−1.

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