Photophysical studies in solution of the tetranuclear copper(I) clusters Cu4I4L4 (L = pyridine or substituted pyridine)

Photoluminescence of [Sn6O4(OCH3)4]

“…The Stokes shift of A8= 13074 cm-' occurs in an energy range which has been also observed for Sn*+ in some oxidic matrices [ Finally, a certain analogy between s* and d'O clusters should be pointed out. In both cases a filled s2 or dr" subshell prevents strong metal-metal bonding in the ground state but favors it in the excited state, The emission spectra of d'O clusters of transition metals such as Cu (I) [20,21], Ag(I) [22] and Au [23,24] can be explained by the same type of excited state distortion which we considered here for s* clusters.…”

Luminescent Complexes Containing Halogeno-bridged Dicopper(I) Unit {Cu2(µ-X)2} (X = Cl, Br, and I)

“…10 Because the lack of ³* orbital on Et 4 en precludes CT transition to L, the emission is assigned to the transition from HOMO to the unoccupied bonding combination of Cu 4s and 4p orbitals which is stabilized by overlap of the orbitals due to the short Cu I £Cu I separation. 3,10 As another aliphatic amine complexes, complexes with piperazine derivatives have been reported to show emission around 450 nm, which is also ascribed to the same transition in the {Cu 2 X 2 } unit. 24 As complexes with P donor atoms, complexes with diphosphine ligand, dppbz (bisdiphenylphosphinobenzene) [Cu 2 X 2 (dppbz) 2 ] (X = Cl, Br, and I) have been reported as strongly emissive material.…”

“…1 Following the development of these studies, research on luminescent d 10 metal complexes, such as gold(I) and copper(I) as well as silver(I) complexes, has been rapidly expanding from the 1990s, because of their strong luminescence at ambient temperatures, characteristic metal metal interactions, and the low cost especially for copper complexes. 2 Another feature of luminescent d 10 metal complexes is the wide variety of structures and available ligands, which will be useful for material design and synthesis.…”

“…While the luminescent d 6 and d 8 metal complexes prefer specific types of ligands, such as polypyridines and their derivatives and octahedral or square-planar geometry, the d 10 metal complexes of gold(I) and copper(I) are known to be emissive with various ligands such as phosphine derivatives, pyridine derivatives, acetylides, and chalcogenides as well as halides and to assume structures with various nuclearities and linkage modes due to the flexible coordination geometry of d 10 metal ions. 24 In accordance with the diverse coordination circumstances, the emissive excited states of d 10 metal complexes include the ds transition on the metal center(s), the charge transfer (CT) between metal center and ligands, and inter-and intraligand transfer depending on the metal and ligand combinations. 2 The relation between ligand sets and their emissive properties, therefore, should be clarified to design and utilize the d 10 emissive materials.…”

“…24 In accordance with the diverse coordination circumstances, the emissive excited states of d 10 metal complexes include the ds transition on the metal center(s), the charge transfer (CT) between metal center and ligands, and inter-and intraligand transfer depending on the metal and ligand combinations. 2 The relation between ligand sets and their emissive properties, therefore, should be clarified to design and utilize the d 10 emissive materials. In this review, recent progress in luminescent halogeno copper(I) complexes containing {Cu I 2 (¯-X) 2 } (X = Cl, Br, and I) unit will be focused on from the view point of the effect of coligands over the luminescent properties.…”