r******0
发帖数: 2753 | 1 原来学过的，可惜过了这么多年没碰，都还给老师了。因为高分子的relaxation time的缘故，T１是该增加还是减小来着？我记得是增加，隐隐约约记得我用过10s。可有人跟我说是减小，我就糊涂了。哪位给我个正确答案。
另外，除了改T１外，做高分子的NMR相对于小分子的NMR还要改点什么设置，改sequence之类的高难度的就不用讲了，俺只要点basic的东西。谢谢。
BTW, it is for solution NMR not solid. |
t***u
发帖数: 20182 | |
r******0
发帖数: 2753 | 3 The problem is we don't have NMR here. The manufacturing lab did that and
the repeatability was poor. I doubt if that is the problem but not sure. 10
years is long enough for an old man like me to forget a lot of things. :-(
【在 t***u 的大作中提到】
: just try it. wont hurt
|
t******t
发帖数: 3045 | 4 very short
that's why you get broad signals for those molecules |
t***l
发帖数: 222 | 5 T1=10s, lots of scans (>100), that's what i usually do. hope it helps. |
r******0
发帖数: 2753 | 6 Thanks. It helps. I barely remember that I used 10s too. Guess I am still
not too old. :-)
【在 t***l 的大作中提到】
: T1=10s, lots of scans (>100), that's what i usually do. hope it helps.
|
g*****n
发帖数: 36 | 7 You can use the normal t1, but increase the number of scan.
get more information here.
http://www.chinanmr.cn/forum.php |
f*******y
发帖数: 50 | 8 for polymer, the T1 will be much shorter, you can try T1 test and I guess
it may be less than 3s. The solvent peak normally is the longest t1 peak.
And if you need quantitative, you need five times t1 and for carbon
experiments, you need to supress NOE and just use nny for decoupling proton. |
r**k
发帖数: 3 | 9 T1 reaches the minimum at MW of around 500 Da, while T2 decreases with MW. |
