COSMO-RS method

In this book I will try to explain the different steps of the entire COSMO-RS method in detail, and give various examples of applications. For this purpose, we will start with the COSMO method in the next chapter. 

The COSMO method is also interesting as the basis of a very successful COSMO-RS method, which extends the treatment to solvents other than water [27,28]. The COSMO method is very popular in quantum chemical computations of solvation effects. For example, 29 papers using COSMO calculations were published in 2001. However, we are not aware of its use together with MM force fields. Compared with the BE method, COSMO introduces one more simplification, that of Eq. (22). On the other hand, the matrix A in Eq. (21) is positively defined [25], which makes solution of the system of linear equations simpler and faster. Also, because both A and B matrices contain only electrostatic potential terms, their computation in quantum chemistry is easier than calculation of the electric field terms in Eq. (12). Another potential benefit is that the long-range electrostatic potential contribution is easier to expand into multipoles than the electric field needed in BE methods, which may benefit linear-scaling approaches. 

Detailed kinetic investigations of the reaction of cumene with propene in [C2mim]Cl—AICI3 (X(AlCl3) = 0.67) were conducted by Joni et al. in a liquid-liquid biphasic reaction mode [24]. Various products (di-, tri- and tetraisopropylbenzene) result from a series of consecutive alkylation reactions. It is necessary to take the solubility of these products into account to fit kinetic models to the data. A conductor-like screening model for real solvent (COSMO-RS) method was used to predict the relative solubilities of the products. Higher alkylated products are less soluble in the reactive ionic liquid phase, leading to an irtproved selectivity for the monoalkylated product. 

C4mpyr]PF6) based on the combination of various scalar parameters. This trend was in accordance with that of infinite dilution activity coefficients of pyridine plus thiophene in ILs p redicted by quantum chemical based conductor like screening model-real solvents (COSMO-RS) method. The CH-x interaction between the CH group in the imidazolium cation and the aromatic ring in the sulfur-compound was considered as the main interaction between imidazolium ILs and sulfur-compounds (Ananthar Banerjee, 2011). 

On the other hand, Panayiotou has proposed a novel and potential groundbreaking method for estimating the surface tension components. This is a method based on a quantum mechanical approach and, in particular, the COSMO-RS method pioneered by Klamt and co-workers (see Klamt (2005) for a detailed review of the method). 

The enthalpies of vaporization Ay// of aprotic RTlLs were estimated by Schroder and Coutinho [188] by means of the COSMO-RS method and compared with results from other methods. The uncertainty from using this method was estimated as 10 kJ mol. Values of the ced and of were then derived for 102 RTlLs with a variety of cations and anions. 

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