Heteroleptic Binuclear Pivalate-, Pyrazolate-Bridged Copper(II) Complexes with 1,10-Phenanthroline

The reaction of the mononuclear complex [PhenCu(OOCtBu)2(H2O)] (I) with [PhenCu(CH3CN)(Otf)2] (Phen = 1,10-phenanthroline, Otf = CF3S $${\text{O}}_{3}^{ - }$$ ) in dichloromethane at room temperature gave the binuclear complex [Phen2Cu2(µ-OOCtBu)2(Otf)2] (II). The reaction of II with pyrazole (PzH) involved the displacement of the triflate anions to the outer sphere and gave the ionic complex [Phen2Cu2(µ-OOCtBu)2(PzH)2](Otf)2 (III), while a similar reaction with 3,5-bis(trifluoromethyl)pyrazole ((CF3)2PzH) was accompanied by its deprotonation and gave the heteroleptic complex [Phen2Cu2(µ-OOCtBu)(µ-(CF3)2Pz)(µ-Otf)]Otf (IV). Compounds I–IV were characterized by X-ray diffraction (CCDC nos. 2332399 (I), 2332400 (II), 2332402 (III), and 2332401 (IV)), IR spectroscopy, and elemental analysis. According to X-ray diffraction data, the copper atoms in I–IV occur in a square pyramidal environment. The crystal packing of complexes I–III involves stacking interactions between phenanthroline molecules giving rise to supramolecular chains.