title: Luminescent dinuclear Cu(I) complexes containing rigid tetraphosphine ligands.
abstract: The synthesis and the photophysics of three dinuclear copper(I) complexes containing bis(bidentate)phosphine ligands are described. The steric constraint imposed by tetrakis(di(2-methoxyphenyl)phosphanyl)cyclobutane) (o-MeO-dppcb) in combination with 2,9-dimethyl-1,10-phenanthroline in one of the complexes leads to interesting photophysical properties. The compound shows an intense emission at room temperature in deoxygenated acetonitrile solution (Φ = 49%) and a long excited-state lifetime (13.8 μs). Interestingly, at low temperature, 77 K, the emission maximum shifts to lower energy, and the excited-state lifetime increases. This observation leads to the conclusion that a mixing between the excited triplet and singlet states is possible and that the degree of mixing and population of state strongly depends on temperature, as the energy difference is quite small. The electroluminescent properties of this compound were therefore tested in light-emitting electrochemical cells (LEECs), proving that the bright emission can also be obtained by electrically driven population of the singlet state.
authors.affiliation: Physikalisches Institut and CeNTech, University of Münster , Heisenbergstrasse 11, D-48149, Münster, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Bizzarri
authors.forename: Christof
authors.initials: C
authors.lastname: Strabler
authors.forename: Johannes
authors.initials: J
authors.lastname: Prock
authors.forename: Barbara
authors.initials: B
authors.lastname: Trettenbrein
authors.forename: Martin
authors.initials: M
authors.lastname: Ruggenthaler
authors.forename: Cheng-Han
authors.initials: CH
authors.lastname: Yang
authors.forename: Federico
authors.initials: F
authors.lastname: Polo
authors.forename: Adriana
authors.initials: A
authors.lastname: Iordache
authors.forename: Peter
authors.initials: P
authors.lastname: Brüggeller
authors.forename: Luisa
authors.initials: L
authors.lastname: De Cola
mesh_terms: D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008024:Ligands; D049449:Luminescence; D049408:Luminescent Agents / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D008024:Ligands; D049408:Luminescent Agents; D009942:Organometallic Compounds; D010720:Phosphines; D003300:Copper