Relações lineares múltiplas entre deslocamentos químicos em RMN 13C de haletos alifáticos
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Data
1999-01-01
Autores
DOYAMA, Julio Toshimi [UNESP]
TORNERO, Maria Teresinha Trovarelli [UNESP]
YOSHIDA, Massayoshi [UNESP]
Título da Revista
ISSN da Revista
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Editor
Editora Unesp
Resumo
Os deslocamentos químicos de RMN 13C de carbonos a , b , g e d de 17 conjuntos de haletos (F, Cl Br e I) alifáticos, inclusive compostos mono, bi e tricíclicos, podem ser reproduzidos por uma equação linear de duas constantes e duas variáveis do tipo : d R-X = A*d R-X1 + B*d R-X2 onde A e B são constantes obtidas por regressão multilinear a partir de deslocamentos químicos de 13C; d R-X, o deslocamento químico de 13C do composto com halogênio (R-X); d R-X1 e d R-X2 deslocamentos químicos de outros haletos. Para brometos (R-X) alifáticos a melhor correlação foi obtida com os dados de fluoretos (R-X1) e iodetos (R-X2) com R2 de 0,9989 e desvio médio absoluto (DM) de 0,39ppm. Para cloretos (R-X) a melhor correlação foi com dados de brometos (R-X1) e iodetos (R-X2) com R2 de 0,9960 e DM de 0,76ppm. Para fluoretos (R-X) a melhor correlação foi com brometos (R-X1) e iodetos (R-X2) com R2 de 0,9977 e DM de 1,10ppm e para iodetos (R-X) foi com fluoretos (R-X1) e brometos (R-X2) com R2 de 0,9972 e desvio médio absoluto de 0,60 ppm.
The 13C NMR chemical shifts of the a , b , g and d carbons of 17 sets of aliphatic halides (F, Cl, Br and I ), including mono, bi and tricyclic componds, can be reproduced by a linear equation composed with two constants and two variables: d R-X = A * d R-X1 + B* d R-X2, where A and B are constants derived from multilinear regression of 13C chemical shifts observed; d R-X, the chemical shifts of aliphatic halide (R-X) and d R-X1, d R-X2 the chemical shifts of other halides. Were observed better correlation for aliphatic bromides (R-X) by using data of aliphatic fluorides (R-X1) and aliphatic iodides (R-X2), resulting R2 of 0.9989 and average absolute deviation (AVG) of 0.39 ppm. For the clorides (R-X), the better correlation were observed by using data of bromides (R-X1) and iodides (R-X2), R2 of 0.9960 and AVG of 0.76ppm. For the fluorides (R-X) were observed better correlation with data of bromides (R-X1) and iodides (R-X2), R2 of 0.9977 and AVG of 1.10 ppm. For the iodides (R-X) were observed better correlation with data of fluorides (R-X1) and bromides (R-X2), R2 of 0.9972 and AVG of 0.60.
The 13C NMR chemical shifts of the a , b , g and d carbons of 17 sets of aliphatic halides (F, Cl, Br and I ), including mono, bi and tricyclic componds, can be reproduced by a linear equation composed with two constants and two variables: d R-X = A * d R-X1 + B* d R-X2, where A and B are constants derived from multilinear regression of 13C chemical shifts observed; d R-X, the chemical shifts of aliphatic halide (R-X) and d R-X1, d R-X2 the chemical shifts of other halides. Were observed better correlation for aliphatic bromides (R-X) by using data of aliphatic fluorides (R-X1) and aliphatic iodides (R-X2), resulting R2 of 0.9989 and average absolute deviation (AVG) of 0.39 ppm. For the clorides (R-X), the better correlation were observed by using data of bromides (R-X1) and iodides (R-X2), R2 of 0.9960 and AVG of 0.76ppm. For the fluorides (R-X) were observed better correlation with data of bromides (R-X1) and iodides (R-X2), R2 of 0.9977 and AVG of 1.10 ppm. For the iodides (R-X) were observed better correlation with data of fluorides (R-X1) and bromides (R-X2), R2 of 0.9972 and AVG of 0.60.
Descrição
Palavras-chave
Equação empírica, deslocamento químco, RMN13C, haletos alifáticos, Empiric equation, aliphatic halide, 13C NMR, chemical shifts
Como citar
Eclética Química. Fundação Editora da Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP, v. 24, p. 61-68, 1999.