Synthesis, structure and photoluminescence of Cu(I) complexes containing new functionalized 1,2,3-triazole ligands

The reaction of a triazole ligand, 2-(1H-1,2,3-triazol-4-yl)pyridine (L1), with 2-bromopyridine afforded three new ligands, 2,2'-(1H-1,2,3-triazole-1,4-diyl)dipyridine (L2), 2,2'-(2H-1,2,3-triazole-2,4-diyl)dipyridine (L3) and 2,2'-(1H-1,2,3-triazole-1,5-diyl)dipyridine (L4). A series of luminescent mononuclear copper(I) complexes of these ligands [Cu(Ln)(P^P)](ClO4) [n = 1, P^P = (PPh3)2 (1); n = 1, P^P = POP (2); n = 2, P^P = (PPh3)2 (3); n = 2, P^P = POP (4); n = 3, P^P = (PPh3)2 (5); n = 3, P^P = POP (6); n = 4, P^P = (PPh3)2 (9); n = 4, P^P = POP (10)] have been obtained from the reaction of Ln with [Cu(MeCN)4]ClO4 in the presence of PPh3 and POP. L3 was also found to form dinuclear compounds [Cu2(L3)(PPh3)4](ClO4)2 (7) and [Cu2(L3)(POP)2](ClO4)2 (8). All of the Cu(I) compounds have been characterized by IR, UV/vis, CV, 1H NMR, and 31P{1H} NMR. The molecular structures of 1-3, 5, and 7 have been further determined by X-ray crystallography. In CH2Cl2 solutions, these Cu(I) complexes exhibit tunable green to orange emissions (563-621 nm) upon excitation at λex = 380 nm. In the solid state, these complexes show intense emissions and it is interesting to note that 1 and 3 are blue-light emitters. Density functional theory (DFT) calculations revealed that the lowest energy electronic transition associated with these complexes predominantly originates from metal-to-ligand charge transfer transitions (MLCT).

Crystal-engineering and luminescence studies of 1,3,5-tris(3-pyridylethynyl)benzene or 1,3,5-tris(4-pyridylethynyl)benzene with copper(i) iodides

The interlocking of 1-D frameworks into the 28-membered rings of the adjacent chains generates a novel 1-D (1-D → 1-D) polyrotaxane framework of 3.

A new 3-D coordination polymer as a precursor for CuI-based thermoelectric composites

Two complexes, [Cu6I6(L1)3]n (I) and [Cu4I4(L2)2]n (II) (L1 = 1,4-bis(phenylthio)but-2-yne; L2 = 1,4-bis(phenylthio)butane), as precursors for thermoelectric composites were prepared using a literature procedure. During the preparation of I, an unexpected 3-D polymorph [Cu4I4(L1)2]n (1) with a triclinic space group and an infinite [CuI]n staircase structure was obtained. This new polymorph (1) exhibited the same structure at both room temperature and 173 K. Complexes 1 and II were therefore pyrolysed to composites 2 and 3, respectively, at 400 °C under a nitrogen gas flow. Composite 3 was pale in color with a low carbon content (0.05 wt%) and easily disassembled during handling. By comparison, the high carbon containing (10.2 wt%) composite 2 can be compressed into a robust, light pellet (density 3.58 g cm-3), which showed a moderate to high Seebeck coefficient (543-1308 μV K-1) over the temperature range 70-240 °C.

A One-Dimensional Coordination Polymer Containing Cyclic [Ag4] Clusters Supported by a Hybrid Pyridine and Thioether Functionalized 1,2,3-Triazole

A pyridine and thioether co-supported triazole ligand L (L = 2-((4-(3-(cyclopentylthio)propyl)-1H-1,2,3-triazol-1-yl)methyl)pyridine) has been synthesized using the CuAAC click reaction. This ligand supports the formation of a thermally stable, one-dimensional coordination polymer [L2Ag4]n·4n(BF4) (1) possessing a cationic polymeric structure with [Ag4] metallomacrocycles, in which the ligand L displays chelate/bridging coordination modes using all four potential donors of nitrogen (N) and thioether (S). The dominant direction of the prism crystals of 1 aligns with the propagation of the chain in the lattice.

Functional metallosupramolecular architectures using 1,2,3-triazole ligands: it's as easy as 1,2,3 “click”

Self-assembled metallosupramolecular architectures generated using “click” ligands have become an increasingly popular area of inorganic chemistry.

cis-1,2-Bis(diphenylphosphino)ethylene copper(i) catalyzed C–H activation and carboxylation of terminal alkynes

Reaction of CuX (X = CN, SCN) and cis-1,2-bis(diphenylphosphino)ethylene (dppet) in 1 : 1 molar ratio in DCM–MeOH (50 : 50 V/V) afforded copper(i) complexes. These complexes were shown to be efficient catalysts in comparison to CuCN/CuSCN for the conversion of terminal alkynes into propiolic acids with CO₂ at room temperature.

Hybrid 1,2,3-Triazole Supported CuII Complexes: Tuning Assembly and Weak Interaction-Driven Crystal Growth

Two new dinuclear CuII complexes [Cu2Cl4(L1)2] (1) and [Cu2Cl4(L2)2] (2) (L1 = 2-((4-(2-(cyclopentylthio)ethyl)-1H-1,2,3-triazol-1-yl)methyl)pyridine; L2 = 2-((4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)methyl)benzonitrile) were synthesised and characterised by single-crystal X-ray diffraction (XRD), powder XRD, thermogravimetric analysis, elemental analysis and IR measurements. The picolyl-triazole ligand L1 coordinates in a chelate-bridging mode forming a dinuclear structure 1. The more rigid pyridyl-triazole ligand L2 chelates only, generating a chloride-bridged dinuclear complex 2. Both crystals of complexes 1 and 2 show dominant plate shapes that correlate with weak 2D H-bonding interactions in the lattice. A mononuclear structure (3, [CuCl2(L3)2]⋅6H2O, L3 = 3-((4-(pyridin-2-yl)-1H-1,2,3-triazol-1-yl)methyl)benzonitrile) yields block shape crystals that correlate with 3D H-bonding interactions. This study demonstrates tunable assembly at the molecular level and the relationship of crystal shape with weak lattice interactions.

Luminescent [Cu4I4] aggregates and [Cu3I3]-cyclic coordination polymers supported by quinolyl-triazoles

A series of quinolyl-1,2,3-triazole supported luminescent [Cu₄I₄] aggregates and six-membered [Cu₃I₃]-cyclic coordination polymers.

Assembly of photoluminescent [CunIn] (n = 4, 6 and 8) clusters by clickable hybrid [N,S] ligands

The controlled growth of luminescent copper(i)-iodide clusters has been achieved by tuning the structure of hybrid NS ligands using click chemistry.

1,1′-Bis(di-tert-butylphosphino)ferrocene copper(i) complex catalyzed C–H activation and carboxylation of terminal alkynes

Reaction of CuX (X = Br, I) and 1,1′-bis(di-tert-butylphosphino) ferrocene (dtbpf) in 1 : 1, 2 : 1 and 6 : 1 molar ratio in DCM–MeOH (50 : 50 V/V) afforded copper(i) complexes. These complexes were shown to be efficient catalysts in comparison with CuI for the conversion of terminal alkynes into propiolic acids with CO₂ at room temperature.

Five Cu(i) and Zn(ii) clusters and coordination polymers of 2-pyridyl-1,2,3-triazoles: synthesis, structures and luminescence properties

2-Pyridyl-1,2,3-triazoles with flexible substituents demonstrate rare coordination modes and support new luminescent clusters and coordination polymers.

Syntheses, characterization, and structural studies of copper(i) complexes containing 1,1′-bis(di-tert-butylphosphino)ferrocene (dtbpf) and their application in palladium-catalyzed Sonogashira coupling of aryl halides

The syntheses and characterization of halo- and cyano-bridged copper(i) complexes are reported.

A white phosphorescent coordination polymer with Cu2I2 alternating units linked by benzo-18-crown-6

A 1D polymer of {[K(benzo-18-crown-6)]₂(Cu₂I₄)}_n with a Cu₂I₂ rhombus alternately connected by sandwich-like [K(benzo-18-crown-6)]₂ displays direct white light in the solid state.

Polymorph and isomer conversion of complexes based on CuI and PPh3 easily observed via luminescence

Reactions between copper(I) iodide and triphenylphosphine have been explored in solution and in the solid state and six luminescent coordination complexes have been obtained and characterized by X-ray diffraction and UV-vis spectroscopy and photophysics. Solid-state reactions of CuI with PPh(3) in different conditions (kneading, vapour digestion) and stoichiometries resulted in the formation of high ratio ligand:metal compounds while tetrameric structures could be obtained only by solution reactions. Crystal structures were determined by single crystal X-ray diffraction while purity of the bulk product was checked by powder diffraction (XRPD). Three different tetrameric structures with 1:1 stoichiometry have been synthesized: two closed cubane-type polymorphs [CuI(PPh(3))](4) (form 1a) and [CuI(PPh(3))](4) (form 1b) and an open step-like isomer [CuI(PPh(3))](4) (form 2). The conversions between the polymorphs and isomers have been studied and characterized by XRPD. The most stable form [CuI(PPh(3))](4) (form 1b) can convert into the open step-like isomer [CuI(PPh(3))](4) (form 2) in a slurry experiment with EtOH or CH(2)Cl(2) or AcCN and converts back into [CuI(PPh(3))](4)1b when exposed to vapors of toluene. At room temperature all the tetrameric compounds exhibit luminescence in the solid state and, notably, the two polymorphs show a dissimilar dual emission at low temperature. The luminescence features in the solid state seem to be peculiarly related to the presence of the aromatic phosphine ligand and depend on the Cu-Cu distance in the cluster.