• K C Rajanna

      Articles written in Journal of Chemical Sciences

    • A newB-Z osiillatory reaction with mixed organic substrates

      M K Ram Reddy K C Rajanna P K Saiprakash

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      Reaction systems, viz., (i) KBrO3/Mn(II)/organic substrate/H2SO4 and (ii) KBrO3/ferroin/organic substrate/H2SO4 (where organic substrate=glycollic or mucic acid) could not exhibit chemical oscillations. However,B-Z chemical waves have been recorded under, novel conditions by taking mixtures of centimolar glycollic acid and millimolar mucic acid as organic substrate in the presence of mixtures of Mn(II) and ferroin as catalyst. The use of teflon beakers as reaction vessels for the reproductibility of chemical waves is a new feature of this study.

    • Synthesis and characterisation of 1-methacroyl 3-salicyloyl 2-hydroxy propane and its derivatives—A structure-reactivity kinetic study

      N Vijaya Babu K C Rajanna C Janaki Ram Rao

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      1-Methacroyl-3-salicyloyl-2-hydroxy propane (MSHP) and its derivatives (methyl, methoxy, acetyl, thio, amino, chloro and bromo) have been prepared and characterised on the basis of elemental anaylsis, mass, IR, PMR and 13C-NMR spectroscopic results. Formation of MSHP obeyed second order kinetics with a first order dependence on each of the [reactant]viz., [salicylic acid] and [glycidyl methacrylate]. A structural change (substituent change) in the salicylic acid brought about a change in its reactivity during the formation of MSHP. Second order rate constants are in the order: 5-bromo<5-chloro< acetyl<H<thio<4-amino<4-methyl<4-methoxy<4-chloro. Hammett’s plot indicated a rho (p) value of 0·43. Deviation in the case ofp-chloro substituent has been explained in terms of resonance interaction energy (ΔΔG) parameters. Effective sigma (δ) value ofp-chloro has been found to be 0·86 with ΔΔGp being 1–274 cal/mol. Isokinetic temperature (β) is far be low the experimental temperature range (325–355 K) indicating the importance of entropy factors in controlling the reaction.

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