Structural tautomerism of 4-acylpyrazolone schiff bases and crystal structure of 5-methyl-2-phenyl-4-{1-[(pyridin-2-ylmethyl)-amino]-ethylidene}-2,4-dihydro-pyrazol-3-one

被引:15
作者
Amarasekara, A. S. [1 ]
Owereh, O. S. [1 ]
Lyssenko, K. A. [2 ]
Timofeeva, T. V. [3 ]
机构
[1] Prairie View A&M Univ, Dept Chem, Prairie View, TX 77446 USA
[2] Russian Acad Sci, Inst Organoelement Cpds, Moscow, Russia
[3] New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA
基金
美国国家科学基金会;
关键词
4-acylpyrazolone; Schiff-base; tautomerism; 4-ACYL PYRAZOLONE DERIVATIVES; LANTHANIDE COMPLEXES; METAL-COMPLEXES; PHOTOCHROMISM; THIOSEMICARBAZONE; FLUORESCENCE; CU(II);
D O I
10.1007/s10947-009-0170-4
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The Schiff base derivatives prepared from 4-acetyl-5-methyl-2-phenyl-2,4-dihydro-pyrazol-3-one and alkyl amines are shown to remain exclusively in the amine-one(I) tautomeric form in chloroform solutions at room temperature using a combination of (1)H, (13)C, APT, COSY, HMQC, and HMBC NMR spectroscopic methods. The crystal structure of 5-methyl-2-phenyl-4-{1-[(pyridin-2-ylmethyl)-amino]-ethylidene}-2,4-dihydro-pyrazol-3-one showed that this 4-acylpyrazolone Schiff base stays in the amine-one(I) form in the solid state as well, and the solid state structure supports the fact that strong hydrogen bonding between amine hydrogen and the pyrazolone C(3) carbonyl oxygen helps to stabilize the amine-one(I) tautomer.
引用
收藏
页码:1159 / 1165
页数:7
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