Effect of Added Dimethyl Sulphoxide on the Solvolysis of Cinnamoyl Chloride in Aqueous Acetone and Acetonitrile
Kinetic studies on solvolysis of cinnamoyl chloride in aqueous acetone and acetonitrile with lesser water content shows an order 2.6 with respect to water and it is comparable to that of benzoyl chloride. The relatively greater enthalpy and lesser negative entropy of activation compared to benzoyl chloride favours an S N 2 mechanism for cinnamoyl chloride rather than addition elimination mechanism. A sharp increase in rate observed in presence of small amounts of DMSO is due to its, strong basic and hydrogen bonding character leading to the liberation of strong nucleophile OH-, relatively greater stabilization of transition state than intial state which lowers the enthalpy and free energy of activation, distruction and interpenetration into the solvation shell of water and its direct interaction with the substrate.
Amino acids as catalysts for the enolisation study of m-Methylacetophenone
Abstract Amino acids have been used as catalysts for the study of kinetic of enolisation of m-Methylacetophenone, in which iodination has been the chosen method. Several parameters like effect of ketone concentration, effect of dielectric constant, effect of catalysts etc. have been investigated for their effect on enolisation kinetics. The study is focused on β-alanine, dl -alanine, l -alanine and Glycine for their effects on the rate. The order of the rate constants obtained has been found to be in the order of increasing dipole moments of the amino acids i.e. l -alanine  dl -alanine
Dating of Historical Manuscripts Using Spectrometric Methods: A Mini-Review
An overview is provided of spectrometric methods useful for age estimation of historical manuscripts (medieval ones in particular), in order to confirm their authenticity. Individual methods (infrared and Raman spectroscopy, mass spectrometry, atomic emission spectroscopy, X-ray spectroscopy, and electron scanning microscopy) are discussed and examples of their application described. The following general strategy can be recommended for dating and/or authenticating of historical manuscripts. First of all, the pigment analysis should be carried out using Raman spectroscopy (distinguishing the period and modern pigments), followed by PIXE ink analysis (solving the question of ink homogeneity). Finally, the radiocarbon dating of the writing support, potentially supplemented by the ink dating using scanning Auger microscopy should be performed.