Photophysical andab InitioStudies of Mononuclear Copper(I) Complexes

Abstract

Described are the photophysical properties of the mononuclear copper(I) complexes CuL(4)(+) (L = pyridine (py), 4-methylpyridine, 4-phenylpyridine, or acetonitrile), Cu(lut)(3)(+) (lut = 2,6-lutidine), and Cu(lut)(2)(+). Each of these compounds as their solid PF(6)(-) salts display a relatively long-lived (>1 &mgr;s), visible range emission at both ambient temperature and at 77 K but not in fluid solutions. Also reported are the results for ab initio calculations at the restricted Hartree-Fock self-consistent field level to probe the natures of lower energy excited states of the hypothetical species CuL(n)()(+) (L = NH(3), CH(3)CN, or py; n = 1-4). These results point to an assignment of the lowest energy, luminactive excited states as being largely metal centered, d --> s in character for each of the above complexes with the possible exception of the CuL(4)(+) species where L is py or a substituted analogue. In the case of Cu(py)(4)(+) the ab initiocalculations indicate a metal-to-ligand charge transfer to be the lowest energy Franck-Condon state, although the similarities of emission band shapes, energies, and lifetimes among the various complexes suggest a common d --> s assignment.

Solvent Induced Luminescence in Supramolecular Heterobimetallic Gold(I)-Copper(I) Complexes with a Bidentate Nitrile Ligand

“…Thus, in complex 2 with a polymeric structure built with copper atoms and nitrile ligands and without metal-metal interactions, only the high energy emission was detected, which appeared at similar wavelength than in the free ligand. This fact precludes a transition located in the pentaflourophenyl rings, a metal to ligand charge transfer or a copper centered emission, which should appear at higher wavelengths [9][10][11][12]. The similar behaviour of complex 1 is indicative of a similar structure and properties.…”

A Bifunctional Diketimine Ligand for Secondary Building Blocks: Formation of a 2D Copper–Zinc Coordination Polymer

“…The emission is short-lived and excited-state lifetimes are shorter than 30 ns (instrumental limit). Emission from 4 in the solid state occurs at significantly lower energy than that reported for [CuPy 4 ] + cations (525 nm) [22] or for other coordination polymers based on [CuPy R 4 ]-units (540 nm). [23] The zinc complex 2, on the other hand, shows a weak absorption band (λ max = 510 nm) in toluene solution, the excitation of which leads to a weak emission band at 550 nm.…”

μ-4,4′-Bipyridine-κ2N:N′-bis[(2,2′-bipyridine-κ2N,N′)(triphenylphosphine-κP)copper(I)] bis(tetrafluoroborate)

“…Copper(I) complexes with various N, S, P and halide donor ligands are of growing interest owing to their wide variation in structural format and rich photophysical and photochemical properties. Many of these complexes have been reported to be luminescent with emission behavior that varies with structure, the identity of halides, and steric and electronic effects of the ligands (Yam et al, 1996;Yam & Lo, 1999;Simon et al, 1996;Su et al, 1997;Li et al, 2005;Wu et al, 2005).…”