Sanka Atapattu - Title: Determination of descriptors for semivolatile organosilicon compounds by gas chromatography and non-aqueous liquid-liquid partition Author(s):

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      Title: Determination of descriptors for semivolatile   organosilicon compounds by gas chromatography and non-aqueous   liquid-liquid partition Author(s): Atapattu, SN; Poole, CF   Source: JOURNAL OF CHROMATOGRAPHY A  Volume: 1216    Issue: 45  Pages: 7882-7888  Published: 2009

      Abstract:

      The measurement of retention factors by gas chromatography on up   to 15 stationary phases at several temperatures in the range   60-240°C for each stationary phase and liquid-liquid partition   coefficients in three biphasic organic solvent systems   (n-hexane-acetonitrile,   n-heptane-N,N-dimethylformamide, and   n-heptane-2,2,2-trifluoroethanol)   were used to calculate solute descriptors for 28 semivolatile   linear and cyclic organosilicon compounds for use in the   solvation parameter model. Regression analysis for oligomeric   compounds allowed the descriptor values for the dimethylsiloxane,   diethylsiloxane, methylvinylsiloxane, and methylhydrosiloxane   monomer groups to be estimated. These monomer groups contribute   significantly to the hydrogen-bond basicity (B descriptor) and   cavity formation and dispersion interactions (L and V   descriptors) of oligomeric organosilicon compounds, are   non-hydrogen-bond acidic (A descriptor = 0), are slightly less   dipolar/polarizable than an n-alkane (S descriptors are negative   and close to zero), and bind electron lone pairs more tightly   than an n-alkane (E descriptor is small and negative). The   semivolatile organosilicon compounds with polar functional groups   in their side chain demonstrate a much wider range of selective   intermolecular interactions than alkylsiloxanes and have   solvation properties closer to those of polar organic compounds.

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