Mass connectivity index, a new molecular parameter for the estimation of ionic liquid properties

A new concept named mass connectivity index (MCI) to encode bond contributions and to allow quantifying the extent of branching in a molecule, especially of ionic liquids, is proposed. The concept is based on the molecular connectivity concept first introduced by Randic in 1975 and modified in different forms by several authors. The proposed concept is much easier to calculate than any of the connectivity indexes available in the literature. Thus the only data required for determining the MCI are the groups forming the molecule and the mass of the groups. The groups forming the molecule are defined as commonly done in group contribution methods. The index is used as a variable in generalized correlations to accurately estimate the density and the heat capacity of ionic liquids.

[1]  João A. P. Coutinho,et al.  Group Contribution Methods for the Prediction of Thermophysical and Transport Properties of Ionic Liquids , 2009 .

[2]  D. V. Velzen,et al.  Liquid Viscosity and Chemical Constitution of Organic Compounds: A New Correlation and a Compilation of Literature Data. EUR 4735. , 1972 .

[3]  E. Maginn,et al.  Molecular simulation study of some thermophysical and transport properties of triazolium-based ionic liquids. , 2006, The journal of physical chemistry. B.

[4]  G. J. Kabo,et al.  Low-temperature heat capacity of hydrophilic ionic liquids [BMIM][CF3COO] and [BMIM][CH3COO] and a correlation scheme for estimation of heat capacity of ionic liquids , 2008 .

[5]  L B Kier,et al.  Issues in representation of molecular structure the development of molecular connectivity. , 2001, Journal of molecular graphics & modelling.

[6]  C. Ye,et al.  Rapid and accurate estimation of densities of room-temperature ionic liquids and salts. , 2007, The journal of physical chemistry. A.

[7]  A. Pádua,et al.  Prediction of ionic liquid properties. I. Volumetric properties as a function of temperature at 0.1 MPa , 2008 .

[8]  José O. Valderrama,et al.  The state of the cubic equations of state , 2003 .

[9]  J. Torrecilla,et al.  Density and Molar Volume Predictions Using COSMO-RS for Ionic Liquids. An Approach to Solvent Design , 2007 .

[10]  João A. P. Coutinho,et al.  A Group Contribution Method for Heat Capacity Estimation of Ionic Liquids , 2008 .

[11]  A. Lewandowski,et al.  Heat capacities of ionic liquids and their heats of solution in molecular liquids , 2005 .

[12]  J. Coutinho,et al.  Extension of the Ye and Shreeve group contribution method for density estimation of ionic liquids in a wide range of temperatures and pressures , 2008 .

[13]  Stanley M. Walas,et al.  Phase equilibria in chemical engineering , 1985 .

[14]  Seda Keskin,et al.  A review of ionic liquids towards supercritical fluid applications , 2007 .

[15]  J. Valderrama,et al.  Critical Properties, Normal Boiling Temperatures, and Acentric Factors of Fifty Ionic Liquids , 2007 .

[16]  W. Arlt,et al.  Tailor-made ionic liquids , 2005 .

[17]  João Aires-de-Sousa,et al.  Estimation of melting points of pyridinium bromide ionic liquids with decision trees and neural networks , 2005 .

[18]  George Wypych,et al.  Handbook of Solvents , 2000 .

[19]  E. I. Lozinskaya,et al.  Thermochemical properties of 1-butyl-3-methylimidazolium nitrate , 2008 .

[20]  L. Hall,et al.  Molecular connectivity in chemistry and drug research , 1976 .

[21]  Alessio Micheli,et al.  Ionic liquids: prediction of their melting points by a recursive neural network model , 2008 .

[22]  S. Unger.  Molecular Connectivity in Structure–activity Analysis , 1987 .

[23]  J. Valderrama,et al.  Critical Properties of Ionic Liquids. Revisited , 2009 .

[24]  José O. Valderrama,et al.  A simple and generalized model for predicting the density of ionic liquids , 2009 .

[25]  R. Reid,et al.  The Properties of Gases and Liquids , 1977 .

[26]  K. Marsh,et al.  Room temperature ionic liquids and their mixtures—a review , 2004 .

[27]  J. Valderrama,et al.  Density of Ionic Liquids Using Group Contribution and Artificial Neural Networks , 2009 .

[28]  Juan A. Lazzús,et al.  Critical Properties, Normal Boiling Temperature, and Acentric Factor of Another 200 Ionic Liquids , 2008 .

[29]  David Rooney,et al.  Heat capacities of ionic liquids as a function of temperature at 0.1 MPa. measurement and prediction , 2008 .

[30]  M. Randic.  Characterization of molecular branching , 1975 .

[31]  Shu-fen Li,et al.  Molecular connectivity indices method for correlating and estimating solubility of fatty acids, alcohols, esters and triglycerides in supercritical carbon dioxide , 2008 .