A series of reactions have been performed by mixing 2-diphenylphosphino-6-methyl-pyridine (dpPyMe) and [Cu(CH3CN)4]BF4 in different molar ratios. Starting from equimolar quantities of dpPyMe and Cu+, a dinuclear Cu(I) complex with two P,N binucleating bridging ligands has been obtained. This compound is stable in the solid state, however ligand exchange reactions leading to a mixture of species have been evidenced in solution. By increasing the amount of dpPyMe, the reaction of dpPyMe and [Cu(CH3CN)4]BF4 afforded the dinuclear Cu(I) complex [Cu2(μ-dpPyMe)3(CH3CN)](BF4)2 in which the three bridging dpPyMe ligands are in a head-to-head arrangement. This compound is remarkably stable in solution. It has been also shown that the axial CH3CN ligand of [Cu2(μ-dpPyMe)3(CH3CN)](BF4)2 can be suitably exchanged with other nitrile ligands [benzonitrile, 4-(dimethylamino)-benzonitrile, 4-nitrobenzonitrile and bromoacetonitrile] but also with triphenylphosphine oxide. The electrochemical and photophysical properties of the resulting complexes have been systematically investigated. The [Cu2(μ-dpPyMe)3(L)](BF4)2 derivatives are weak emitters in solution but remarkable emission quantum yields (6 to 46%) have been found in rigid matrices at room temperature. One complex was utilized as active material for preliminary tests in LEC devices.
|Number of pages||15|
|State||Published - 4 Nov 2014|
Bibliographical noteFunding Information:
This research was supported by CNRS , University of Strasbourg , MIUR (PRIN 2010 INFOCHEM, contract no. CX2TLM; FIRB Futuro in Ricerca SUPRACARBON, contract no. RBFR10DAK6), CNR (MACOL PM. P04. 010; Progetto Bandiera N-CHEM), EC (contract PITN-GA-2008-215399 - FINELUMEN), ESF-EUROCORES (10-EuroSolarFuels-FP-006, SOLARFUELTANDEM) and Consorzio MIST E-R (project FESR-Tecnopolo AMBIMAT). We further thank O. Moudam and A. Kaeser for the initial preparation of compound 1 , M. Schmitt for high field NMR measurements, A. Saquet for electrochemical measurements and D. Tordera (University of Valencia, Spain) for helpful discussions on LEC devices.
© 2014 Elsevier Ltd. All rights reserved.
- Cu(I) complexes
- LEC devices
- Solar energy