Oxygen-17 and Silicon-29

· NMR Basic Principles and Progress Livro 17 · Springer Science & Business Media
Livro eletrónico
238
Páginas
As classificações e as críticas não são validadas  Saiba mais

Acerca deste livro eletrónico

Although it was shown very early [1] that the isotope 29Si is very valuable for NMR research, severe technical difficulties had to be overcome before silicon spectra could be recorded. This was due to the low sensitivity of the isotope resulting from its low gyro magnetic ratio, its low abundance and the rather long relaxation times. The introduction of the Fourier-Transform-Technique (FT-NMR) helped to surmount most of these problems, with the result, that more and more papers concerning silicon NMR appear. Thus, it seems now that most of the salient features of 29Si-NMR are known today. Some resume of the state of the art of 29Si_NMR have been reported [1-4]. Although the theory of 29Si-NMR is not yet understood beyond the basic features, it promises to be of value mainly for two reasons: 1. Silicon is strategically located in the Periodic Table of the elements between the elements carbon, aluminum and phosphorus. For an unified theory of chemical shifts and coupling constants of the heavier elements silicon NMR values will be important. 2. The normal coordination number of silicon is four. If the current view of the chemical shifts of the heavier elements is correct, then the paramagnetic part is dominant for the measured shift data. Two of the parameters used for the calcu lation of the paramagnetic part are bond orders and angles. Bond angles are rare ly determined experimentally with high precision.

Classifique este livro eletrónico

Dê-nos a sua opinião.

Informações de leitura

Smartphones e tablets
Instale a app Google Play Livros para Android e iPad/iPhone. A aplicação é sincronizada automaticamente com a sua conta e permite-lhe ler online ou offline, onde quer que esteja.
Portáteis e computadores
Pode ouvir audiolivros comprados no Google Play através do navegador de Internet do seu computador.
eReaders e outros dispositivos
Para ler em dispositivos e-ink, como e-readers Kobo, tem de transferir um ficheiro e movê-lo para o seu dispositivo. Siga as instruções detalhadas do Centro de Ajuda para transferir os ficheiros para os e-readers suportados.