SYNTHESIS, CHARACTERIZATION AND REACTIVITY OF COORDINATION-COMPOUNDS OF GROUP-12 METALS CONTAINING THE N-2-DONOR LIGAND BIS(3,4,5-TRIMETHYLPYRAZOL-1-YL)METHANE

The interaction between bis(3,4,5-trimethylpyrazol-1 -yl)methane, LT, and several MX(2) salts, gives 1:1 [L(T)]MX(2) (M = Zn, Cd or Hg; X = Cl, Br or I; M = Zn, X = trifluoroacetate, M = Hg, X = CN, SCN or sacc harinate) and 2: 1 [LT],MX, adducts (M = Zn, X = NO3, ClO4, BF4, B(C6H 5)(4) or CF3SO3; M = Cd, X = NO3, ClO4 or BF4; M = Hg, X = ClO4) which are air- and thermally stable, while the reaction of L(T) With Hg(Cf3 COO)(2) gives the basic salt [L(T)]Hg(CF3COO)(2) . 5/4HgO. The adduct [L(T)]ZnCl2 readily reacted with 1-phenyl-3-methyl-4-benzoyl-pyrazol-5 -one (Q'H), in the presence of a base, to yield the mixed-ligand compl ex [LT(Q')(2)Zn], whereas (Q')(2)Cd .[H2O] and (Q')(2)Hg .[Et(2)O] wer e obtained when a similar reaction was carried out with [L(T)]CdI2 and [L(T)]HgCl2, respectively, as starting materials. The compound [L(T)] ZnC1(2) reacted with the anionic pyrazolato ligand (pz(-)) and with th e neutral 1-methylimidazole (ImH') yielding the complexes (pz)(2)Zn an d (ImH')(2)ZnCl2, respectively. Displacement of the ligand L(T) was ob served also from the reaction of [L(T)]CdBr2 with 4-phenylimidazole (I mH) and from the reaction of [L(T)]ZnCl2 and [L(T)]ZnBr2 with 2,2'-bi pyridyl (Bipy), while no interaction was observed with pyridine (py), pyrazole (pzH), 4-bromopyrazole (4-BrpzH) or 3,5-dimethylpyrazole (3,5 -Me(2)pzH). All the compounds obtained were characterized from analyti cal and spectral data (IR, far-IR, H-1 and C-13).