THE RELATION OF N-15 NMR, H-1 NMR CHEMICAL SHIFTS WITH THE ATOMIC NET   CHARGE AND MOLECULAR STRUCTURES

doi:10.3866/PKU.WHXB19870614

CORC > 北京大学 > 化学与分子工程学院

	THE RELATION OF N-15 NMR, H-1 NMR CHEMICAL SHIFTS WITH THE ATOMIC NET CHARGE AND MOLECULAR STRUCTURES
	Chen Yuehua ; Guo Guolin ; Shen Qifeng ; Zhao Yufen ; Xi Shekang ; Ji Gaijiao ; Song Aiteng
刊名	物理化学学报
	1987
DOI	10.3866/PKU.WHXB19870614
英文摘要	The acetyl, sulfonyl and phosphoryl are three amino protecting groups. The natural abundance N-15-NMR of their derivatives of the phenylethylglycine and beta-phenylethylamine has been studied. We found that there are great difference in the chemical shifts of the three protected compounds, delta N-15 is shifted to upfield in turn. Among these three amino protecting groups, the diisopropoxyphosphinyl one produces the least deshielding effect, while the acetyl group gives the strongest deshielding effect, and the tosyl group is in the middle. The trend of deshieding effect of the three protecting groups occured also in the H-1 NMR (Table 1). Furthermore, we have studied the relation of chemical shifts to the atomic charge and molecular structures by means of semiempirical molecular orbital CNDO/2 and X-ray diffraction of single crystal structure analysis. Model moleculae has been calculated by semiempirical molecular orbital CNDO/2 method. The results were shown in Table 2. The trend of the nitrogen net charges of these moleculae is the same as the N-15 NMR chemical shifts. These data show that the phosphoryl group is the most effective nitrogen lone pair electron localizing group among the three kinds of protecting groups. And the acetyl one is the least one. By using the data of the single crystal structure of N-diisopropoxyphosphinyl-N-2-(3,4-methylenedioxy) phenyl) ethylglycine. The bonding types of the P-N, S-N and C-N of the related compounds were analyzed. The localizing effect of the phosphoryl group on the lone pair electron of nitrogen has been discussed. The one bond coupling constants of the N-phosphoryl system (Table 1) showed that the nitrogen through sp(2) hybrides formed bonds with one phosphorus atom and two carbon atoms. Thus, the nitrogen is in a planar conformation. It is consistent with the results of X-ray diffraction.; Chemistry, Physical; SCI(E); 0; ARTICLE; 6; 632-637; 3
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/312907]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Chen Yuehua,Guo Guolin,Shen Qifeng,et al. THE RELATION OF N-15 NMR, H-1 NMR CHEMICAL SHIFTS WITH THE ATOMIC NET CHARGE AND MOLECULAR STRUCTURES[J]. 物理化学学报,1987.
APA	Chen Yuehua.,Guo Guolin.,Shen Qifeng.,Zhao Yufen.,Xi Shekang.,...&Song Aiteng.(1987).THE RELATION OF N-15 NMR, H-1 NMR CHEMICAL SHIFTS WITH THE ATOMIC NET CHARGE AND MOLECULAR STRUCTURES.物理化学学报.
MLA	Chen Yuehua,et al."THE RELATION OF N-15 NMR, H-1 NMR CHEMICAL SHIFTS WITH THE ATOMIC NET CHARGE AND MOLECULAR STRUCTURES".物理化学学报 (1987).