Polynuclear Cu(i) and Ag(i) phosphine complexes containing multi-dentate polytopic ligands: syntheses, crystal structures and photoluminescence properties

Abstract

A series of polynuclear Cu(i)/Ag(i) complexes have been obtained on the basis of three polytopic ligands. Their structures and photophysical properties have been investigated in detail.

Synthesis and Photophysical Properties of Emissive Silver(I) Halogenido Coordination Polymers Composed of {Ag2X2} Units Bridged by Pyrazine, Methylpyrazine, and Aminopyrazine

“…Compared to that of copper­(I) and gold­(I) complexes, the development of luminescent silver­(I) complexes has started only recently; however, several silver complexes exhibiting strong luminescence at room temperature, − thermally activated delayed fluorescence, − thermochromic luminescence, − and stimuli-responsive luminescence , have already been reported. Because the coordination properties and electronic structures of silver­(I) complexes are similar to those of copper­(I) complexes, the ligands affording luminescent copper­(I) complexes have also been exploited to synthesize luminescent silver­(I) complexes. ,− The obtained complexes typically display emission in the near-ultraviolet (UV) or blue region even though the corresponding copper­(I) complexes show colorful emission in the visible region. ,− Because the stability of the 4d orbitals of the silver­(I) center is higher than that of the 3d orbitals of the copper­(I) center, ,− the metal-to-ligand CT ES increases in energy, approaching those of the other ESs, which causes a mixing of the ESs and complicates their emissive ESs, hampering the rational design of a ligand set for luminescent silver­(I) complexes.…”

Photophysical properties of homobimetallic Cu(i)–Cu(i) and heterobimetallic Cu(i)–Ag(i) complexes of 2-(6-bromo-2-pyridyl)-1H-imidazo[4,5-f][1,10]phenanthroline

“…All the bond lengths are comparable to those of similar complexes previously reported. 19,29,30,[38][39][40][41][42][43][44]46,56,61,63,[67][68][69][70] As expected, in heterobinuclear Cu(I)-Ag(I) complexes, deprotonated imidazole rings tend to act as softer donors and bind with the softer Lewis acid, Ag(I) ions. It is obvious that the distances of Ag-N and Ag-P are longer than those of the corresponding Cu-N and Cu-P because of the larger radii of Ag(I) ions.…”

“…However, the reported α-diimine-Cu( i )–diphosphine complexes so far mainly focused on homonuclear systems, and the heteronuclear analogues were rarely exploited. On the other hand, the electronic configurations and coordination modes of the Ag( i ) ions are similar to those of Cu( i ) ions, and the latter was confirmed by some pairs of isostructural and isomorphous Cu( i ) and Ag( i ) complexes such as [Cu 2 ( μ -bbim)(PPh 3 ) 4 ] 52 and [Ag 2 ( μ -bbim)(PPh 3 ) 4 ] (bbimH 2 = 2,2′-bi-(1 H )-benzimidazole), 53 [Cu 2 I 2 (PPh 3 ) 2 (4,4′-bpy)] 54 (4,4′-bpy = 4,4′-bipyridine) and [Ag 2 I 2 (PPh 3 ) 2 (4,4′-bpy)], 55 [Cu 2 (L)(PPh 3 ) 4 ] 2+ and [Ag 2 (L)(PPh 3 ) 4 ] 2+ cations (L = 2,3-bis(2-pyridyl)pyrazine), 56 as well as by the successfully synthesized mixed-metal complexes [(Cu x Ag 1− x ) 2 I 2 (PPh 3 ) 2 (bpy)] ∞ ( x < 0.01 or x = 0.15, 0.5) 57 and [Ag 0.55 Cu 1.45 ( μ -bbim)(PPh 3 ) 4 ]. 58 The complexes [(Cu x Ag 1− x ) 2 I 2 (PPh 3 ) 2 (bpy)] ∞ ( x < 0.01 or x = 0.15, 0.5) showed better luminescence behaviors than their parent complexes [Cu 2 I 2 (PPh 3 ) 2 (4,4′-bpy)] and [Ag 2 I 2 (PPh 3 ) 2 (4,4′-bpy)] due to the efficient energy transfer from Ag( i ) to Cu( i ) centers.…”

Syntheses and Characterization of Tetrazolate-Based Lanthanide Compounds and Selective Crystallization Separation of Neodymium and Dysprosium

“…Also, H 2 dtp and H 3 ibt each have 10 potential coordination modes via N atoms in one molecule (Scheme S1). The combination of multiple binding sites and charge flexibility is beneficial for generating structures with different complexities and dimensionalities. − Structurally characterized H 2 dtp- and H 3 ibt-derived compounds to date have been limited to cations Ag­(I), Cu­(I)/Cu­(II), and Zn­(II) for H 2 dtp and to Ag­(I), Co­(II)/Co­(III), , Cu­(I)/Cu­(II), Mn­(II), and Zn­(II) − for H 3 ibt. These two ligands show monodentate/chelating/bridging coordination modes and can coordinate to one metal ion or connect two metal ions forming coordination polymers.…”