Longitudinal nuclear relaxation in an A2 spin system initially polarized through para-hydrogen

被引：49

作者：

Aime, S

Gobetto, R

Canet, D

机构：

[1] Univ Turin, Dipartimento Chim Inorgan Chim Fis & Chim Mat, Lab Spettroscopia NMR, I-10125 Turin, Italy

[2] Univ Nancy 1, Lab Methodol RMN, INCM, CNRS,UPRESA 7042,FR 1742, F-54506 Vandoeuvre Nancy, France

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 1998年 / 120卷 / 27期

关键词：

D O I：

10.1021/ja973240w

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Os-3(CO)(10)(NCCH3)(2) has been hydrogenated with para-hydrogen to yield H2Os3(CO)(10) where the two hydrogen nuclei remain magnetically equivalent and therefore in a singlet state. Despite this equivalence, an enhanced longitudinal magnetization is observed to decrease toward thermal equilibrium. It is postulated that this enhanced magnetization is created through a nuclear relaxation interference mechanism (cross-correlation between dipolar interaction and chemical shift anisotropy); decay curves are then successfully analyzed by means of a spin relaxation theory adapted to this situation.

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页码：6770 / 6773

页数：4

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