Cis-Cisoid Helical Structures of Poly(3,5-disubstituted phenylacetylene)s Stabilized by Intramolecular n -> pi* Interactions
文献类型：期刊论文
| 作者 | Wang, Sheng; Shi, Ge; Guan, Xiaoyan; Zhang, Jie; Wan, Xinhua |
| 刊名 | MACROMOLECULES
 |
| 出版日期 | 2018-02-27 |
| 卷号 | 51期号:4页码:1251-1259 |
| ISSN号 | 0024-9297 |
| DOI | 10.1021/acs.macromol.8b00078 |
| 英文摘要 | A pair of enantiomeric cis-poly(phenylacetylene)s (PPAs) substituted at the meta-positions of pendant phenyl rings by an achiral methoxycarbonyl group and a chiral 1-methylpropyloxycarbonyl group (i.e., sP-Me-C4/rP-Me-C4) as well as two cis-PPAs bearing either just a methoxycarbonyl (i.e., m-aP-Me) or a 1-methylpropyloxycarbonyl (i.e., m-sP-C4) meta substituent were synthesized under the catalysis of [Rh(nbd)Cl](2) (nbd = norbornadiene). Various techniques including H-1 NMR, FTIR, Raman, UV-vis, CD, DSC, STM, DLS/SLS, and computer calculation were applied to characterize the helical structures of these polymers in both solution and solid states. sP-Me-C4/rP-Me-C4 adopted contracted cis-cisoid helical conformations in THF, toluene, CH2Cl2, and ClCH2CH2Cl but cis-transoid ones in CHCl3 and Cl2CHCHCl2. The cis-cisoid helices were considered to be stabilized by the existence of six n -> pi* interaction bands along the polyene backbones between vicinal carbonyl groups. Such interactions were insensitive to the dielectric constant and polarity of solvent but sensitive to the hydrogen bond donating ability of solvent and temperature. In hydrogen bond accepting solvent, the cis-cisoid helical structures were thermal stable, whereas the cis-cisoid to cis-transoid helix transition could be triggered by raising temperature in the hydrogen bond donating solvent. The stronger the hydrogen bondings between solvent molecules and carbonyl groups, the lower the temperature required to maintain cis-cisoid helix. Moreover, the cis-cisoid helices stabilized by intramolecular n -> pi* interactions had better tolerance to the polarity of solvent and faster recovery than those stabilized by intramolecular hydrogen bonds. No matter whether methoxycarbonyl or 1-methylpropyloxycarbonyl group was removed, only a cis-transoid helix was observed, implying the weak nature of n -> pi* interaction and the need for a delicate macromolecular design. This work provided an unusual strategy to build cis-cisoid PPAs. |
| 语种 | 英语 |
| WOS记录号 | WOS:000426618500002 |
| 出版者 | AMER CHEMICAL SOC |
| 源URL | [http://ir.iccas.ac.cn/handle/121111/45843]  |
| 专题 | 中国科学院化学研究所 |
| 通讯作者 | Wan, Xinhua |
| 作者单位 | Peking Univ, Beijing Natl Lab Mol Sci, Key Lab Polymer Chem & Phys, Minist Educ,Coll Chem & Mol Engn, Beijing 100871, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wang, Sheng,Shi, Ge,Guan, Xiaoyan,et al. Cis-Cisoid Helical Structures of Poly(3,5-disubstituted phenylacetylene)s Stabilized by Intramolecular n -> pi* Interactions[J]. MACROMOLECULES,2018,51(4):1251-1259. |
| APA | Wang, Sheng,Shi, Ge,Guan, Xiaoyan,Zhang, Jie,&Wan, Xinhua.(2018).Cis-Cisoid Helical Structures of Poly(3,5-disubstituted phenylacetylene)s Stabilized by Intramolecular n -> pi* Interactions.MACROMOLECULES,51(4),1251-1259. |
| MLA | Wang, Sheng,et al."Cis-Cisoid Helical Structures of Poly(3,5-disubstituted phenylacetylene)s Stabilized by Intramolecular n -> pi* Interactions".MACROMOLECULES 51.4(2018):1251-1259. |
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来源：化学研究所
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