Aggregation behavior of dihexadecylviologen bistriflimide ionic liquid crystal in different solvents: influence of polarity and concentration

doi:10.1039/c8cp03055c

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	Aggregation behavior of dihexadecylviologen bistriflimide ionic liquid crystal in different solvents: influence of polarity and concentration
	Li, S 4; Saielli, G 1,3; Wang, YT
刊名	PHYSICAL CHEMISTRY CHEMICAL PHYSICS
	2018
卷号	20 期号:35 页码:22730-22738
关键词	ELECTROCHROMIC DEVICES DIELECTRIC-CONSTANT MOLECULAR-SOLVENTS ORGANIC-MOLECULES AQUEOUS-SOLUTIONS DFT CALCULATIONS FORCE-FIELD VIOLOGEN NMR SIMULATIONS
ISSN号	1463-9076
DOI	10.1039/c8cp03055c
英文摘要	Solutions of 1,1-dihexadecyl-4,4-bipyridinium di[bis(trifluoromethanesulfonyl)imide] salt, also known as dihexadecylviologen bistriflimide, in deuterated acetonitrile (ACN), dichloromethane (DCM) and chloroform (CDCl3), respectively, were investigated by the combination of H-1 and DOSY NMR spectroscopy, DFT calculations and MD simulation to understand the influence of solvent polarity and solute concentration (10(-5)-10(-1) M) on its aggregation behavior. We found that the polar solvent acetonitrile (ACN) does not favor ion aggregation and cluster formation. In the whole range of concentrations investigated, the system appears to be dominated by neutral ion pairs composed of one cation and two anions, possibly in fast equilibrium (on the NMR time scale) with small or slightly larger aggregates. The diffusion coefficient of the cationic species is only weakly affected by concentration. In contrast, the low-polar solvents of chloroform (CDCl3) and dichloromethane (DCM) strongly favor cluster formation above a certain concentration and the viologen diffusion coefficient in CDCl3 is much smaller and more strongly dependent on concentration than that in ACN. The information obtained from the MD simulations suggests that the aggregates have a structure similar to the isotropic liquid phase of the viologen-based ionic liquids and ionic liquid crystals. The lifetimes of such large clusters appear to be relatively long, beyond the time scale of tens of nanoseconds. Moreover, the results from the aromatic proton NMR resonances provide some insights on the dielectric constants inside the viologen aggregates.
学科主题	Chemistry ; Physics
语种	英语
内容类型	期刊论文
源URL	[http://ir.itp.ac.cn/handle/311006/22810]
专题	理论物理研究所_理论物理所1978-2010年知识产出
作者单位	1.Univ Chinese Acad Sci, Sch Phys Sci, 19A Yuquan Rd, Beijing 100049, Peoples R China 2.Univ Padua, Dept Chem Sci, Via Marzolo 1, I-35131 Padua, Italy 3.Univ Padua, CNR, Ist Tecnol Membrane, Sez Padova, Via Marzolo 1, I-35131 Padua, Italy 4.Chinese Acad Sci, Inst Theoret Phys, CAS Key Lab Theoret Phys, 55 East Zhongguancun Rd,POB 2735, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Li, S,Saielli, G,Wang, YT. Aggregation behavior of dihexadecylviologen bistriflimide ionic liquid crystal in different solvents: influence of polarity and concentration[J]. PHYSICAL CHEMISTRY CHEMICAL PHYSICS,2018,20(35):22730-22738.
APA	Li, S,Saielli, G,&Wang, YT.(2018).Aggregation behavior of dihexadecylviologen bistriflimide ionic liquid crystal in different solvents: influence of polarity and concentration.PHYSICAL CHEMISTRY CHEMICAL PHYSICS,20(35),22730-22738.
MLA	Li, S,et al."Aggregation behavior of dihexadecylviologen bistriflimide ionic liquid crystal in different solvents: influence of polarity and concentration".PHYSICAL CHEMISTRY CHEMICAL PHYSICS 20.35(2018):22730-22738.