Tetranuclear Copper(I) Iodide Complexes of Chelating Bis(1-benzyl-1H-1,2,3-triazole) Ligands: Structural Characterization and Solid State Photoluminescence

Abstract

A series of tetranuclear Cu(4)I(4)(L(n))(2) clusters (1-3) supported by the chelating 4,4'-(4,5-diX-1,2-phenylene)bis(1-benzyl-1H-1,2,3-triazole) ligands (L1, X = H; L2, X = CH(3); L3, X = F) have been prepared. Crystal structure determinations have shown that the clusters adopt a distorted "step-type" geometry in which the triazole ligands exhibit both chelating and bridging coordination modes to Cu(I) ions. When L3 was employed in a 3:2 CuI/L3 ratio, a crystalline product, 4, was obtained. Product 4 is actually a 1:1 cocrystallization of the tetranuclear cluster 3 (denoted 4a) and the dinuclear Cu(2)I(2)(L3)(2) complex (4b). X-ray structures of 1, 2, and 4 show the presence of close Cu...Cu contacts in the tetranuclear and dinuclear forms. (1)H NMR experiments indicate that rapid exchange occurs in these systems. All clusters are brightly luminescent in the solid state at 77 K and at room temperature with lambda(max) = 495-524 nm. Emission intensity decays fit a single exponential with lifetimes on the order of 10 to 35 microseconds at room temperature and 90 to 140 microseconds at 77 K. The origin of emission is tentatively assigned as a metal-to-ligand phenylene pi* charge transfer.

Jack of all trades: anion and transition metal binding by bis-triazole receptors

“…7. This arrangement where one triazole group in a bis-triazole ligand bridges two copper ions has previously been observed by Eisenberg et al who prepared complexes of the form [Cu 4 L 2 I 4 ], where L is a ligand derived from the CuAAC reaction of substituted 1,2-diethylnyl benzenes and benzyl azide (22). The gross structure of the complex is surprisingly similar to that obtained by Crowley et al for a silver complex of the pyridyl-triazole ligand, 2-[(4-phenyl-1,2,3-triazol-1-yl)methyl]pyridine.…”

Multistimuli Response Micro‐ and Nanolayers of a Coordination Polymer Based on Cu2I2 Chains Linked by 2‐Aminopyrazine

“…Additionally, in order to evaluate the possible presence of emission arising from a ligand-centered (LC) transition, the free ligand 2-aminopyrazine was also investigated at 300 K.[12, 21] The results show two very weak emission bands at 475 and 499 nm for 1m and 1n , respectively, corresponding to ligand-centered π→π* transitions (section S3, Figure S14). Moreover the influence of pyrazine substituent in the optical properties of the layers has also been evaluated by a comparative study.…”

A Codeposition Route to CuI−Pyridine Coordination Complexes for Organic Light-Emitting Diodes

“…1–4 Unfortunately, iridium is low in natural abundance, so there has been an increasing interest in luminescent copper(I) complexes 5–8 for use in high efficiency OLEDs. However, since most copper(I) complexes are unstable to sublimation, 9 and hence not amenable to the vacuum deposition methods typically used to fabricate OLEDs, few devices containing such emitters have been reported. 10–15 …”