大分子中磁偶极弛豫的分离

THE SEPARATION OF HETERONUCLEAR DIPOLAR RELAXATION IN MACROMOLECULE

提出采用仅与偶极弛豫有关的￣（１３）Ｃ核同￣１Ｈ核之间的核交叉弛豫速率来考察分子内部运动状况。给出了实际用于考察分子运动状况的关系式，从理论上阐明了本文方法比传统上直接采用常规测定的￣（１３）Ｃ核纵向弛豫时间Ｔ＿１、演向弛豫时间Ｔ＿２及ＮＯＥ增强因子η来研究分子运动状况的方法要合理。建立了既适用于小分子又适用于大分子自旋系统￣（１３）Ｃ核总自旋弛豫中偶极弛豫分离的公式．

It is proposed that only the heteronuclear cross relaxation rates between ^(13)C and^1H，which are only dependent on the diporlar relaxation，are used to investigate the mo-lecular internal motions，The new method is more reasonable than the conventional onein theory where the nuclear longitudinal relaxation time T_1 ，transvcrse relaxation T_2 andNOE factor n are used to study the molecular internal motions． The general formu-la separating the contribution of dipolar relaxation to the total ^(13)C spin relaxation isset up． It can bc applied not only to small moleculeS inside extreme narrowing condi-tion but also to macromolecules outside extreme narrowing.