C−H···O Hydrogen Bond betweenN-Methyl Maleimide and Dimethyl Sulfoxide:  A Combined NMR and Ab Initio Study

2003 ◽  
Vol 107 (23) ◽  
pp. 4683-4687 ◽  
Author(s):  
Bing Wang ◽  
James F. Hinton ◽  
Peter Pulay
2015 ◽  
Vol 93 (6) ◽  
pp. 626-631
Author(s):  
Zahra Fallah Ebrahimi ◽  
Mehdi D. Esrafili ◽  
Esmail Vessally

A comparative ab initio study is performed to investigate the cooperativity between the N···H hydrogen bond and the N···Y interactions in XCN···HCN···YCN complexes, where X = H, F, and Y = H, Li, F, Cl, and Br. To understand the properties of the systems better, the corresponding dimers are also studied. It is found that the lithium bond has a larger influence on the hydrogen bond than vice versa. The shortening of the N···H distances in the trimers is dependent on the strength of the H···Y interactions and they become larger in the order lithium bond > hydrogen bond > halogen bond. The estimated values of cooperative energy Ecoop are all negative with much larger Ecoop in absolute value for the systems including lithium.


1999 ◽  
Vol 103 (23) ◽  
pp. 4572-4579 ◽  
Author(s):  
Brooke L. Bedell ◽  
Leah Goldfarb ◽  
Erin R. Mysak ◽  
Cindy Samet ◽  
Andy Maynard

1972 ◽  
Vol 94 (24) ◽  
pp. 8301-8308 ◽  
Author(s):  
Peter Merlet ◽  
Sigrid D. Peyerimhoff ◽  
Robert J. Buenker

1993 ◽  
Vol 71 (3) ◽  
pp. 303-306 ◽  
Author(s):  
Miguel A. Ríos ◽  
Jesús Rodríguez

The hydrogen maleate ion was studied by ab initio methods with complete optimization at the 3-21G, 6-31G, 6-31G**, and 6-31+G(2d,1p) levels. To study the influence of electron correlation, MP2 calculations have been done for the 6-31G** geometry. All calculations at the HF level predicted an asymmetric hydrogen bond with a double minimum potential governing transfer between the two equivalent structures. Moreover, both asymmetry and proton transfer barrier increase systematically with the power of the basis set used, with calculated barrier heights of 0.12 (3-21G), 1.59 (6-31G), 1.64 (6-31G**), and 2.00 kcal/mol (6-31+G). Only the introduction of the electron correlation at the MP2 level seems to predict a single minimum potential.


2000 ◽  
Vol 56 (6) ◽  
pp. 1018-1028 ◽  
Author(s):  
Concepción Foces-Foces ◽  
Ibon Alkorta ◽  
José Elguero

The secondary structure of 1H-unsubstituted pyrazole derivatives bearing only one hydrogen donor group and one or more acceptor groups has been analyzed in terms of some descriptors representing the substituents at C3 and C5. The substituent at C4 appears to affect mainly the tertiary or quaternary structure of these compounds. The proposed semi-quantitative model, which explains most hydrogen-bonded motifs as a combination of the effects of substituents at C3 and C5, has also been examined as a function of the steric and polarizability effects of these substituents represented by molar refractivity. The model also applies to other five-membered rings (1,2,4-triazoles, 1,2,4-diazaphospholes and 1,2,4-diazaarsoles). Furthermore, ab initio calculations at RHF/6-31G* have been performed to discover the relative stability of three of the four hydrogen-bond patterns displayed by several symmetrical pyrazoles (dimers, trimers, tetramers). The fourth motif, catemers, has only been discussed geometrically.


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