Polarisation combined mechanisms

Trichlorobenzene (TCB), a well known termite exterminator, is prepared selectively from 1,2-dichlorobenzene (DCB) using zeolite K-L as a catalyst and monochloroacetic acid as a promoter. An attempt has been made to apply the combination of molecular graphics, force field calculations and quantum chemical calculations to understand the mechanism of selective chlorination of 1,2-DCB to 1,2,4-TCB over K-L promoted by monochloroacetic acid. It was found that the zeolite lattice plays an important role in polarising the molecules. The peculiar "barrel shaped pore architecture allows zeolite L to act as a reactor vessel where monochloroacetic acid, chlorine and 1,2-DCB can be accommodated on a molecular level. 

The simple rigid dipole theory is not truly applicable to a molecule, because the polarisation is altered by the presence of the additional electron, i.e. we have a combination of the two mechanisms. Jordan and Luken [76] have set up a more elaborate ab initio model using a Hartree-Fock scheme, which accounts satisfactorily for molecular relaxation. 

Matthews, 2000). A phosphate salt solution and an aqueous suspension of HAp powder were used as an electrolyte for PEO and EPD, respectively. The corrosion resistance was assessed by potentiodynamic polarisation tests in a buffered physiological solution (see also Kwok et al., 2009). The results of this study indicated that a hybrid combination of PEO and EPD produces an osseoconductive phase-pure ITAp layer and an anticorrosive titania interlayer that promise to provide good mechanical and biochemical stability in the highly corrosive environment of the human body. Other studies involving titania bond coats include Albayrak and Altintas, 2010 Paluszkiewicz, Dlugon andKwiatek, 2012 Rath etal., 2012 and Jain etal. (2013). 

This is a theoretical study using ab initio quantum mechanics in combination with a polarisable continuum model (PCM) for the solvent. The theoretical approach is satisfactory both for the determination of stractures and energetic in the ground and transition states the latter refer to the transfer of a proton from water coordinated in the first, to water in the second coordination sphere. The reactions studied are ... 

The results of electrochemical decontamination of carbon steel proved that this type of decontamination can be effectively used to clean for free release chemically unsuccessfully decontaminated materials. Only small differences in time required for complete decontamination of material were observed by different polarisation of material. Efficiency of the process may be improved by short anodic polarization before the decontamination is completed. Combination of electrochemical decontamination and mechanical effect improves the efficiency of the process. 

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