Efeito das interações hiperconjugativas na constante de acoplamento ¹J CH da hexametilenotetramina e do adamantano: estudo teórico e experimental


Autoria(s): Santos,Francisco P. dos; Ducati,Lucas C.; Tormena,Cláudio F.; Rittner,Roberto
Data(s)

01/01/2007

Resumo

The objective of this work was to determine the influence of hyperconjugative interactions on the ¹J CH coupling constant for hexamethylenetetramine (1) and adamantane (2). For this end, theoretical and experimental ¹J CH were obtained and hyperconjugative interactions were investigated using NBO. It was observed, theoretically and experimentally, that ¹J CH in 1 is 20 Hz larger than in 2, mainly due to the nN<FONT FACE=Symbol>®s</FONT>*C-H hyperconjugative interaction. This interaction occurs only in 1, with an energy of 9.30 kcal mol-1. It increases the s-character of the carbon atom in the C-H bond and the occupancy of the sigma*C-H orbital in (1).

Formato

text/html

Identificador

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422007000700035

Idioma(s)

pt

Publicador

Sociedade Brasileira de Química

Fonte

Química Nova v.30 n.7 2007

Palavras-Chave #nmr #coupling constants #hyperconjugative interactions
Tipo

journal article