Evidence of C-F-P and aromatic π-F-P weak interactions in imidazolium ionic liquids and its consequences

被引：11

作者：

Panja, Sumit Kumar ^{[1
,4
]}

Srivastava, Nitin ^{[1
]}

Srivastava, Jyoti ^{[2
]}

Prasad, Namburi Eswara ^{[2
]}

Noothalapati, Hemanth ^{[3
,5
]}

Shigeto, Shinsuke ^{[3
,6
]}

Saha, Satyen ^{[1
]}

机构：

[1] Banaras Hindu Univ, Inst Sci, Ctr Adv Studies, Dept Chem, Varanasi 221005, Uttar Pradesh, India

[2] Def Mat & Stores Res & Dev Estab, Kanpur, Uttar Pradesh, India

[3] Natl Chiao Tung Univ, Dept Appl Chem, Hsinchu 30010, Taiwan

[4] Indian Inst Sci, Dept Inorgan & Phys Chem, Bangalore 560012, Karnataka, India

[5] Shimane Univ, Raman Ctr Med & Biol Applicat, Matsue, Shimane 6908504, Japan

[6] Kwansei Gakuin Univ, Sch Sci & Technol, Dept Chem, Sanda 6691337, Japan

来源：

SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY | 2018年 / 194卷

关键词：

Ionic liquids (ILs); Aromatic and aliphatic H-bonding interaction; Weak interactions; C-F-P interaction; DENSITY-FUNCTIONAL THEORY; HYDROGEN-BONDS; CONFORMATIONAL EQUILIBRIUM; INITIO CALCULATIONS; DISPERSION FORCES; ELECTRON-DENSITY; INFRARED-SPECTRA; DIFFERENT ANIONS; RATIONAL DESIGN; AB-INITIO;

D O I：

10.1016/j.saa.2017.12.048

中图分类号：

O433 [光谱学];

学科分类号：

0703 ; 070302 ;

摘要：

A simple change from alkyl group to alkene in side chain of imidazolium cation with same anion resulted in a drastic impact on physical properties (e.g., melting point) from bmimPF(6) IL to cmimPF(6) IL The underlying reasons have been elucidated by structural and interaction studies with the help of DSC, SCXRD, vibrational and multi-nuclear NMR spectroscopic techniques. Experiments reveal existence of new weak interactions involving the carbon and pi cloud of the imidazolium aromatic ring with fluoride of PF6 anion (i.e., C-2-F-P and pi-F-P) in cmimPF(6) but are absent in structurally similar prototype IL bmimPF(6). Though weak, these interactions helped to form ladder type supramolecular arrangement, resulting in quite high melting point for cmimPF(6) IL compared to bmimPF(6) IL These findings emphasize that an IL system can behave uniquely because of the existence of uncommon weak interactions. (C) 2017 Elsevier B.V. All rights reserved.

引用

页码：117 / 125

页数：9

共 93 条

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