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Group 11 complexes with the bidentate di(1H-indazol-1-yl)methane and di(2H-indazol-2-yl)methane) ligands

Twenty-four new copper, silver and gold complexes based on a bis(pyrazolyl)methane ligand L (in detail L = L1, di(1H-indazol-1-yl)methane; L = L2, di(2H-indazol-2-yl)methane) are prepared. The [Cu(L)(PR3)2]X species have been obtained from the reaction of [CuX(PR3)2] with L upon the displacement of X from the copper coordination sphere. 1 : 1 [CuX2(L)] complexes were obtained when L1 reacts with CuX2 whereas under the same conditions, L2 gave the ionic species [CuX(L)2]X. When L1 reacts with CuCl2, however, the dinuclear [CuCl2(L1)]2 complex is formed which, upon treatment with dimethylformamide (DMF), gave the mononuclear derivative [CuCl2(L1)(DMF)]. L1 and L2 often show a different reactivity toward silver salts. For example, in the reaction with AgNO3, the ionic compound [Ag(L1)2]NO3 is obtained when L1 is used as a starting reagent and the neutral 1 : 2 adduct [AgONO2(κ-L2)(κ2-L2)] containing a mono and a bidentate ligand is formed when L2 is employed as a ligand. L1 gave 2 : 1 adducts with AgCX3SO3 (X = H or F) and AgClO4, whereas 1 : 1 adducts are formed under the same conditions with L2. L1 and L2 give analogous dinuclear ([Ag(O2CCF3)(L)]2) and mononuclear ionic species ([Ag(L)2]BF4) when they react with Ag(O2CCF3) and AgBF4 species. Two analogous gold(III) complexes [AuCl2(L)][AuCl4] have also been obtained in the reaction of L with AuCl3 when the reaction was carried out in an excess of the ligands. All the air- and thermally stable complexes have been characterized by analytical and spectral (IR, conductivity, ESI-MS, 1H and 13C NMR solution data) methods.