Syntheses of new imidazole ligand series and evaluation of 1-, 2-and 4,5-imidazole substituent electronic and steric effects on N-donor strengths
文献类型：期刊论文
| 作者 | Eseola, Abiodun O.1; Sun, Wen-Hua4,5 ; Li, Wen3; Woods, Joseph A. O.2
|
| 刊名 | JOURNAL OF MOLECULAR STRUCTURE
 |
| 出版日期 | 2010-12-15 |
| 卷号 | 984期号:1-3页码:117-124 |
| 关键词 | Protonation-deprotonation Substituent Effects Spectroscopy Dft Calculations |
| ISSN号 | 0022-2860 |
| DOI | 10.1016/j.molstruc.2010.09.015 |
| 英文摘要 | A series of new imidazole based heterocycles (5-(4,5-diphenyl-1H-imidazol-2-yl)furan-2-yl)methyl acetate (Him-dp), (5-(1H-phenanthro(9,10-d]imidazol-2-yl)furan-2-yl)methyl acetate (HIm-pt), (5-(1H-imidazo(4,5-f][1,10]phenanthrolin-2-yl)furan-2-yl)methyl acetate (HIm-phen), 2-(2-nitrophenyl)-4,5-diphenyl-1H-imidazole (HIm-n), 1-methyl-2-(2-nitrophenyl)-4,5-diphenyl-1H-imidazole (MeIm-n), N-(2-(1-ethyl-4,5-diphenyl-1H-imidazol-2-yl)phenyl)benzamide (EtIm-ba) and 2,4-di-tertbutyl-6-(8-(1-ethyl-4,5-diphenyl-1H-imidazol-2-yl)-1,4-dihydroquinolin-2-yl)phenol (EtIm-q) were synthesized and studied for the dependence of their azole donor characteristics on substituent factors by means of experimentally determined ionization constant data (derived as pK(a)s), spectroscopic analyses and calculated properties of their OFT optimized molecular geometries performed at the B3LYP/6-311 + G* level. Results showed that the lowest donor strength recorded for HIm-pt (pK(a) = 2.67 +/- 0.07) could be traced to the extensive electronic conjugation of the azole pi-electrons with 4,5- and 2-substituents. On the other hand, the strongest imidazole donor strength in the series was obtained from EtIm-q (pK(a) = 4.61 +/- 0.04) for which the substituents possessed negligible pi-overlap with the azole ring. The experimental results and theoretical calculations lead to conclusions that effective conjugation between the imidazole ring and substituent aromatic groups is accountable for significant withdrawal of charge densities on the imidazole N-donor atom and vice versa. Furthermore, observed donor strengths in the series suggest that electronic inductive effects of the substituents provided lesser impact on donor strength modification of imidazole base and that alkylation of 1-imidazole position did not yield the anticipated push of electron density in favour of the N-donor atom. It is anticipated that the results should promote the understanding of azole-containing bio-macromolecular species and reactions as well as tuning and application of azole functions in molecular science. (C) 2010 Elsevier B.V. All rights reserved. |
| 语种 | 英语 |
| WOS记录号 | WOS:000285659400015 |
| 出版者 | ELSEVIER SCIENCE BV |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/70691]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Eseola, Abiodun O. |
| 作者单位 | 1.Redeemers Univ, Dept Chem Sci, Redemption City, Ogun State, Nigeria 2.Univ Ibadan, Dept Chem, Ibadan, Nigeria 3.Chinese Acad Sci, Tech Inst Phys & Chem, Key Lab Photochem Convers & Optoelect Mat, Beijing 100190, Peoples R China 4.Chinese Acad Sci, Inst Chem, Key Lab Engn Plast, Beijing 100190, Peoples R China 5.Chinese Acad Sci, Inst Chem, Beijing Natl Lab Mol Sci, Beijing 100190, Peoples R China |
| 推荐引用方式 GB/T 7714 | Eseola, Abiodun O.,Sun, Wen-Hua,Li, Wen,et al. Syntheses of new imidazole ligand series and evaluation of 1-, 2-and 4,5-imidazole substituent electronic and steric effects on N-donor strengths[J]. JOURNAL OF MOLECULAR STRUCTURE,2010,984(1-3):117-124. |
| APA | Eseola, Abiodun O.,Sun, Wen-Hua,Li, Wen,&Woods, Joseph A. O..(2010).Syntheses of new imidazole ligand series and evaluation of 1-, 2-and 4,5-imidazole substituent electronic and steric effects on N-donor strengths.JOURNAL OF MOLECULAR STRUCTURE,984(1-3),117-124. |
| MLA | Eseola, Abiodun O.,et al."Syntheses of new imidazole ligand series and evaluation of 1-, 2-and 4,5-imidazole substituent electronic and steric effects on N-donor strengths".JOURNAL OF MOLECULAR STRUCTURE 984.1-3(2010):117-124. |
入库方式： OAI收割
来源：化学研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。