A B3LYP and MP2(full) theoretical investigation on the cooperativity effect between hydrogen-bonding and cation-molecule interactions and thermodynamic property in the 1: 2 (Naâº: N-(Hydroxymethyl)acetamide) ternary complex.
J Mol Model
; 20(3): 2154, 2014 Mar.
Article
en En
| MEDLINE
| ID: mdl-24562861
The cooperativity effects between the O/N-HâââO hydrogen-bonding and NaâºâââO cation-molecule interactions in the 1: 2 (Naâº: N-(Hydroxymethyl)acetamide) systems were investigated at the B3LYP/6-311++G**, MP2(full)/6-311++G** and MP2(full)/aug-cc-pvtz levels. The thermodynamic cooperativity calculations were also carried out for two pathways of the ternary-complex formation. The result shows that, in most ternary complexes, the O/N-HâââO and NaâºâââO interactions are weakened in comparison with those in binary systems, leading to the anti-cooperativity effects, in particular in the complexes in which only the NaâºâââO interactions exist. Shifts of electron density confirm the existence of anti-cooperativity. The increase of favorable enthalpic contribution leads to the positive cooperativity effect with negative ΔG(coop.) on forming the ternary complex by initial N-(Hydroxymethyl)acetamide dimer followed by addition of Naâº. In forming the ternary complex by NaâºâââN-(Hydroxymethyl)acetamide with the second N-(Hydroxymethyl)acetamide unit, the large unfavorable entropy change leads to the negative cooperativity effect with positive ΔG(coop.). The ternary complex is more easily formed by the pathway in which Na⺠binds to N-(Hydroxymethyl)acetamide dimer.
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1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Termodinámica
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Modelos Moleculares
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Cationes
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Acetamidas
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Modelos Químicos
Idioma:
En
Revista:
J Mol Model
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2014
Tipo del documento:
Article
País de afiliación:
China
Pais de publicación:
Alemania