| ²é¿´: 2547 | »Ø¸´: 24 | ||
| ¡¾½±Àø¡¿ ±¾Ìû±»ÆÀ¼Û16´Î£¬×÷Õßbobo0621Ôö¼Ó½ð±Ò 14 ¸ö | ||
| µ±Ç°Ö÷ÌâÒѾ´æµµ¡£ | ||
bobo0621ľ³æ (ÖøÃûдÊÖ)
|
[×ÊÔ´]
ÎÄÏ×NMR-double_water_peaks£¨Á½Ë®·åºÍË®·åÁÑ·ÖµÄÔÒò£©
|
|
|
·ÖÏíÎÄÏ×һƪ NMR Solvents The Observation of ¡°Double Water Peaks¡± in Deuterated NMR Solvents ÄÚÈݽéÉÜ£º Generally speaking, water takes three forms in a deuterated solvent environment: HOH, HOD, and DOD. In the proton NMR spectrum of a pure NMR solvent, both the HOH and HOD peaks are observed, but not the DOD. In a proton NMR Spectrum, HOH appears as a singlet. However, due to coupling from the D nucleus which has a nuclear spin quantum number I = 1, HOD appears as a triplet. The observed splitting 2JHD of the HOD peak is about 1-2 Hz. The chemical environments of the protons in HOH and HOD are similar, but not identical. Therefore, the HOH and HOD peaks appear to be close in chemical shift, but not overlapped. They are typically 0.03 ppm apart. HOD Peaks - NMR spectra of ¡°neat¡± deuterated solvent always exhibit a peak due to H20 in addition to the residual solvent peak. When the exchange rate between H20 and HDO is slow on the NMR timescale the water peak appears as two peaks, a singlet corresponding to H20 and a 1:1:1 triplet corresponding to HDO. ×ÔÎÒÆÀ¼Û£º ±¾ÌûÖ÷Òª½²Ë®·åÁÑ·ÖµÄÔÒò¡£ºÍÁ½¸öË®·åµÄÔÒò¡£ ¾ßÌåÄÚÈݼû¸½¼þ¡£»òÕßµã»÷ÒÔÏÂÍøÖ·ÏÂÔØhttp://www.sigmaaldrich.com/etc/ ... ble_water_peaks.pdf ÓÐÓõϰÇë´ó¼Ò¸úÌûÖ§³Ö£¬Ð»Ð» [ Last edited by bobo0621 on 2009-1-8 at 22:40 ] |
» ²ÂÄãϲ»¶
0817 »¯Ñ§¹¤³Ì 299·ÖÇóµ÷¼Á ÓпÆÑоÀú ÓжþÇøÎÄÕÂ
ÒѾÓÐ17È˻ظ´
Ò»Ö¾Ô¸Î人Àí¹¤²ÄÁϹ¤³Ìר˶µ÷¼Á
ÒѾÓÐ5È˻ظ´
0856µ÷¼Á£¬ÊÇѧУ¾ÍÈ¥
ÒѾÓÐ7È˻ظ´
É격26Äê
ÒѾÓÐ3È˻ظ´
Ò»Ö¾Ô¸¼ªÁÖ´óѧ²ÄÁÏѧ˶321Çóµ÷¼Á
ÒѾÓÐ10È˻ظ´
0703»¯Ñ§µ÷¼Á £¬Áù¼¶Òѹý£¬ÓпÆÑоÀú
ÒѾÓÐ12È˻ظ´
294Çóµ÷¼Á²ÄÁÏÓ뻯¹¤×¨Ë¶
ÒѾÓÐ13È˻ظ´
288Çóµ÷¼Á
ÒѾÓÐ14È˻ظ´
307Çóµ÷¼Á
ÒѾÓÐ8È˻ظ´
Ò»Ö¾Ô¸ÄϾ©Àí¹¤´óѧ085701×ÊÔ´Óë»·¾³302·ÖÇóµ÷¼Á
ÒѾÓÐ5È˻ظ´
bobo0621
ľ³æ (ÖøÃûдÊÖ)
- Ó¦Öú: 0 (Ó×¶ùÔ°)
- ¹ó±ö: 0.01
- ½ð±Ò: 3608.9
- Ìû×Ó: 1051
- ÔÚÏß: 27.4Сʱ
- ³æºÅ: 676514
2Â¥2008-12-22 22:23:43
bobo0621
ľ³æ (ÖøÃûдÊÖ)
- Ó¦Öú: 0 (Ó×¶ùÔ°)
- ¹ó±ö: 0.01
- ½ð±Ò: 3608.9
- Ìû×Ó: 1051
- ÔÚÏß: 27.4Сʱ
- ³æºÅ: 676514
ÄÚÈݽéÉÜ£º
|
ÄÚÈݽéÉÜ£º Generally speaking, water takes three forms in a deuterated solvent environment: HOH, HOD, and DOD. In the proton NMR spectrum of a pure NMR solvent, both the HOH and HOD peaks are observed, but not the DOD. In a proton NMR Spectrum, HOH appears as a singlet. However, due to coupling from the D nucleus which has a nuclear spin quantum number I = 1, HOD appears as a triplet. The observed splitting 2JHD of the HOD peak is about 1-2 Hz. The chemical environments of the protons in HOH and HOD are similar, but not identical. Therefore, the HOH and HOD peaks appear to be close in chemical shift, but not overlapped. They are typically 0.03 ppm apart. HOD Peaks - NMR spectra of ¡°neat¡± deuterated solvent always exhibit a peak due to H20 in addition to the residual solvent peak. When the exchange rate between H20 and HDO is slow on the NMR timescale the water peak appears as two peaks, a singlet corresponding to H20 and a 1:1:1 triplet corresponding to HDO. ×ÔÎÒÆÀ¼Û£º ±¾ÌûÖ÷Òª½²Ë®·åÁÑ·ÖµÄÔÒò¡£»òÁ½¸öË®·åµÄÔÒò¡£ [ Last edited by bobo0621 on 2008-12-23 at 13:45 ] |
3Â¥2008-12-23 10:15:08
zhaoyt19798595
Ìú¸Ëľ³æ (ÕýʽдÊÖ)
- Ó¦Öú: 2 (Ó×¶ùÔ°)
- ½ð±Ò: 7524.9
- Ìû×Ó: 615
- ÔÚÏß: 224.4Сʱ
- ³æºÅ: 569262
4Â¥2008-12-23 10:51:02
5Â¥2008-12-23 11:33:07
bobo0621
ľ³æ (ÖøÃûдÊÖ)
- Ó¦Öú: 0 (Ó×¶ùÔ°)
- ¹ó±ö: 0.01
- ½ð±Ò: 3608.9
- Ìû×Ó: 1051
- ÔÚÏß: 27.4Сʱ
- ³æºÅ: 676514
ÐÂÁ´½Ó£¬¿Éµ¥»÷ÏÂÔØ
|
ÒòΪ¿¼Âǵ½´ó¼ÒÏÂÔØÐèÒª½ð±Ò£¬¹ÊÎÒÓÖÕÒÁËÒ»¸öÁ´½Ó£¬´ó¼Ò¿ÉÒÔµ¥»÷ÏÂÔØ http://www.sigmaaldrich.com/etc/ ... ble_water_peaks.pdf Èç¹ûºÃµÄ»°£¬Çë¶à¶àÖ§³Ö£¬Ð»Ð» |
6Â¥2008-12-23 14:17:15
7Â¥2008-12-25 17:39:32
bobo0621
ľ³æ (ÖøÃûдÊÖ)
- Ó¦Öú: 0 (Ó×¶ùÔ°)
- ¹ó±ö: 0.01
- ½ð±Ò: 3608.9
- Ìû×Ó: 1051
- ÔÚÏß: 27.4Сʱ
- ³æºÅ: 676514
8Â¥2008-12-25 20:20:36
gleam0316
Ìú¸Ëľ³æ (ÖøÃûдÊÖ)
- Ó¦Öú: 0 (Ó×¶ùÔ°)
- ¹ó±ö: 0.756
- ½ð±Ò: 8721.6
- Ìû×Ó: 1592
- ÔÚÏß: 108.5Сʱ
- ³æºÅ: 611337
9Â¥2008-12-26 13:14:09
10Â¥2008-12-28 14:10:48
12Â¥2008-12-30 10:24:30
15Â¥2008-12-30 15:36:27
16Â¥2009-01-01 17:11:44
18Â¥2009-01-06 07:42:34
chinajinlei
ÖÁ×ðľ³æ (ÖøÃûдÊÖ)
- Ó¦Öú: 4 (Ó×¶ùÔ°)
- ½ð±Ò: 11204.4
- Ìû×Ó: 2726
- ÔÚÏß: 1113.6Сʱ
- ³æºÅ: 284497
19Â¥2009-01-06 19:26:47
bobo0621
ľ³æ (ÖøÃûдÊÖ)
- Ó¦Öú: 0 (Ó×¶ùÔ°)
- ¹ó±ö: 0.01
- ½ð±Ò: 3608.9
- Ìû×Ó: 1051
- ÔÚÏß: 27.4Сʱ
- ³æºÅ: 676514
20Â¥2009-01-09 22:12:47
21Â¥2009-01-12 20:49:38
23Â¥2009-03-05 04:32:47
24Â¥2009-03-09 22:47:22
¼òµ¥»Ø¸´
Æó¶ì721111Â¥
2008-12-28 21:32
»Ø¸´
¶¥£¡£¡£¡£¡
zhwj13Â¥
2008-12-30 11:55
»Ø¸´
seusioc14Â¥
2008-12-30 12:42
»Ø¸´
лл·ÖÏí!
Ã÷Ô·ɹâ17Â¥
2009-01-06 00:24
»Ø¸´

chxidongn22Â¥
2009-01-13 07:34
»Ø¸´


success85925Â¥
2009-03-29 18:57
»Ø¸´














»Ø¸´´ËÂ¥
50