Facile synthesis of Copper(I) formamidinates and their photoluminescence properties

As a part of investigating the reaction of group 11 metal oxides with proligands, a series of luminescent dinuclear Cu(I) formamidinates, [Cu₂(DippForm)₂] (1) (DippForm = N, N’-bis(2,6-diisopropylphenyl)formamidinate), [Cu₂(EtForm)₂py] (2) (EtForm = N, N’-bis(2,6-diethylphenyl)formamidinate, py = pyridine), {[Cu₂(XylForm)₂py]⋅py} (3) (XylForm = N, N’-bis(2,6-dimethylphenyl)formamidinate), [Cu₂(MesForm)₂py] (4) (MesForm = N, N’-bis(2,4,6-trimethylphenyl)formamidinate), [Cu₂(o-TolForm)₂py] (5) (o-TolForm = N, N’-bis (2-methylphenyl)formamidinate), [Cu₂(CF₃Form)₂] (6) (CF₃Form = N, N’-bis(2-trifluoromethylphenyl)for-mamidinate), and [Cu₂(DFForm)₂(py)₂] (7) (DFForm = N, N’-bis(2,6-difluorophenyl)formamidinate), were
synthesized by the direct reaction of cuprous oxide with the corresponding formamidine in pyridine. One of the metal centres was coordinated by pyridine in complexes 2–5 and each metal centre was coordinated by solvent molecules in complex 7. The luminescent bimetallic complexes were investigated for their photophysical properties in their solid state. Solid state measurements of the complexes at ambient temperature and at low temperature show phosphorescence emission.