Atomically Defined Monocarborane Copper(I) Acetylides with Structural and Luminescence Properties Tuned by Ligand Sterics

Abstract

The weakly coordinatingc luster [CB 11 H 12 ] À is used as av ersatile building block for the preparation of luminescent copper(I) complexes. Treatment of [CB 11 H 11 -12-CCH] À with CuI and ammonia affords {(CB 11 H 11 -12-CC) 2 Cu 4 (NH 3 ) 3 } n (2). Addition of selected phosphine and pyridine ligands transforms 2 to ar ange of homometallic products 3-13.A ll compoundsh ave been characterizedb yX -ray crystallogra-phy,which reveals asurprising variety of structuralc omplexity featuring cores with two to ten Cu + centers. In the solid state, products 3-13 exhibit room-temperature phosphorescence across the visible spectrum in colors from blue to deep red. Lifetimes at room temperature are in the microsecond regime, and quantum yields of up to F = 0.99 are observed. Results and DiscussionAt the outset, we aimed at af acile and high-yielding synthesis of ac opper(I)/C complex that would serve as av ersatile starting materialt op repare polynuclear products with as eries of P and Nl igands. To that end, as olution of 1 in EtOH wasc om- [a]

Deep Blue Phosphorescence from Platinum Complexes Featuring Cyclometalated N-Pyridyl Carbazole Ligands with Monocarborane Clusters (CB11H12–)

“…78,79 In 2019, we utilized this weakly coordinating anion as a building block to synthesize copper clusters with complex structures. 80 This work demonstrated the important role of carborane acetylene anions in regulating the structure and optical properties of copper complexes. We remained interested in the use of CB 11 − as a sterically bulky substituent in phosphorescent metal complexes.…”

“…Despite the clear promise of these clusters, the analogous closo -monocarborane anion [ closo -1-CB 11 H 12 ] − (CB 11 – ), first synthesized by Knoth at DuPont in 1967, has been scarcely used in the development of phosphorescent emitters, − and most reports are concerned largely with exploring its synthetic methodologies. − CB 11 – is isoelectronic with C 2 B 10 and can, in theory, serve many of the same roles. Although both of these two clusters possess fascinating features such as icosahedral geometries, large steric hindrance, and remarkable chemical and thermal stabilities, CB 11 – is distinguished by its singly negative charge. , In 2019, we utilized this weakly coordinating anion as a building block to synthesize copper clusters with complex structures . This work demonstrated the important role of carborane acetylene anions in regulating the structure and optical properties of copper complexes.…”

Excellent Blue Emissive Neutral Cu(I) Complexes: Structural Analysis, Thermochromic Luminescent Properties, and Terahertz Spectrum Research

“…Recently, Cu­(I)-based complexes have been widely studied in luminescent materials, such as fluorescent probes, chemical sensors, bioimaging agents, and organic light-emitting diodes (OLEDs). − Not only their fantastic photophysical properties but also their relatively inexpensive cost, low toxicity, and rich abundance in earth make Cu­(I) ions a potential alternative for traditional noble metals such as iridium and platinum . Due to the effects of heavy atom effects, many Cu­(I) complexes have pure phosphorescent emission, and the others exhibit typical thermally activated delayed fluorescence (TADF) characteristics. ,− Thus, the theoretical value of internal quantum efficiency can easily reach 100%. − Benefitting from the above advantages, many devices of Cu­(I) complexes have been synthesized in recent years, and their luminescent color covers the whole visible region. − …”