The chemical dynamics of base adducts with bis(N,N-dithiocarbamate)nickel(II)

Academic Article

Abstract

  • The chemical dynamics for the adduct reactions of the nitrogen bases pyridine, 2-picoline, 3-picoline, 4-picoline and 3,5-lutidine with bis(N,N-dialkyldithiocarbamate)nickel(II) were investigated. The thermodynamic parameters for adduct formation were determined by NMR techniques. The pyridine-Ni(diR,R′dtc)2 adducts have the stability order -CH2H5 < -n-C3H7 < -n-C4H9; the order is controlled by entropy rather than by enthalpy effects contrary to previously reported results from i.r. and vis spectral studies. At low temperatures the adduct stability order of Ni-(din-butyldtc)2 with pyridine type bases is 3,5-lutidine < 3-picoline < 4-picoline < pyridine. However, at 25°C the order changes to pyridine ∼3-picoline ∼3,5-lutidine < 4-picoline, the change in stability order with temperature being attributed to the T Δ S° term. The kinetic parameters ΔH≠, and ΔS≠ for 3-picoline and 4-picoline exchange with Ni(din-butyldtc)2 were determined by NMR line broadening techniques. The rate constants, κ≠, were found to be 12·5 × 104 sec-1 for 3-picoline and 6·2 × 104 sec-1 for 4-picoline. Temperature studies of contact shifts and INDO molecular orbital calculations are used to analyze the unpaired spin density transfer between the Ni(din-butyldtc)2 and the pyridine type bases. © 1975.
  • Digital Object Identifier (doi)

    Pubmed Id

  • 26212494
  • Author List

  • Vigee GS; Watkins CL
  • Start Page

  • 1739
  • End Page

  • 1746
  • Volume

  • 37
  • Issue

  • 7-8