Zinc(II), cadmium(II) and mercury(II) derivatives of bis(4-halopyrazol-l-yl)alkanes: synthesis, spectroscopic characterization and behaviour in solution

The interaction between various bis(4-halopyrazol-1-yl)alkanes L (L* = bis(3,5-dimethyl-4-chloropyrazol-1-yl)methane, L# = bis(4-bromopyrazol-1-yl)methane, L° = bis(4-chloropyrazol-1-yl)methane) and zinc(II), cadmium(II) and mercury(II) acceptors gave 1 : 1 [LMX2] (L = L*, M = Zn, X = Cl, Br, I, NO3 or CF3CO2; L = L*, M = Cd, X = Cl or Br; L = L*, M = Hg, X = Cl, Br or I; L = L#, M = Zn, X = Cl, Br, I or NO3; L = L#, M = Cd, X = Cl, Br, I or NO3; L = L#, M = Hg, X = Cl or Br; L = L°, M = Zn, X = Cl, M = Cd, X = I, M = Hg, X = Br), 3 : 2 [(L*)3{Zn(CF3SO3)2} 2]·3H2O and [(L*)3{Cd(NO3)2} 2]·2H2O, 2 : 1 [L2M]X2 (L = L*, M = Zn or Cd, X = ClO4 or BF4; L = L*, M = Hg, X = ClO4; L = L#, M = Zn, X = ClO4 or CF3SO3, M = Cd, X = ClO4 or BF4; L = L , M = Cd, X = BF4) and finally 3 : 1 [(L#)3Zn](BF4)2 adducts; these derivatives have been characterized through elemental analyses, spectral data (IR, 1H and 13C NMR in the case of the sufficiently soluble derivatives), conductivities and molecular weight measurements. Comparison is made with the results obtained with other bis(pyrazol-1-yl)alkanes.