Solution-Processable Copper Halide Based Hybrid Materials Consisting of Cationic Ligands with Different Coordination Modes

Abstract

Using cationic ligands containing both aromatic and aliphatic coordination sites, we have synthesized and structurally characterized five new CuX-based hybrid materials consisting of anionic inorganic motifs that also form coordinate bonds with the cationic organic ligands. As a result of the unique bonding nature at the inorganic/organic interfaces, these compounds demonstrate strong resistance toward heat and can be readily processed in solution. They emit light in the visible region ranging from cyan to yellow color, with the highest photoluminescence quantum yield (PLQY) reaching 71%. The influence of the different coordination modes of the ligands on their emission behavior was investigated employing both experimental and theoretical methods, which have provided insight in understanding structure–property relationships in these materials and guidelines for tuning and enhancing their chemical and physical properties.

Making coordination networks ionic: a unique strategy to achieve solution-processable hybrid semiconductors

“…17 Since the success in systematic construction of the first group of the AIO-type structures in 2017, 14 great efforts by us and others have been devoted to the design of new AIO structures and 60+ AIO compounds have been synthesized to date. 13,14,[16][17][18][19][20][21][22][23][24][25][26] Their structures range from molecular (zerodimensional, 0D) species to one-dimensional (1D) chains and two-dimensional (2D) layers. A variety of inorganic anionic modules from the smallest CuI 2 À monomer to an infinite 2D network of Cu 8 I 10 2À have been identified, revealing excellent structural diversity of this interesting material class.…”

“…To gain insight into the ligand effects in these structures, which is crucial to guide the structure modification and property optimization, comprehensive studies have been carried out on different aspects, including coordination affinity, 13,23 steric effect, 20,22 connectivity 19 and hybridization. 21 The structure formation of AIO-type compounds may also be influenced by the synthesis conditions. By controlling the ratios of the reagents, different types of AIO structures may result even with the same ligand.…”

“…15,31,32 The dissolved species were identified as anionic CuX clusters which remain coordinated to the cationic ligands via dative bonds by NMR and mass spectrometry. 20,21…”

Dual-Emissive γ-[Cu4I8]4– Enables Luminescent Thermochromism in an Organic–Inorganic Hybrid Copper(I) Halide

“…2,4,6,7 The unsaturated nature of the coordination sites (sp 2 ) is also emphasized in some dual-emissive all-in-one type compounds. 52 Since the band intensity of dual emission varies with temperature, luminescent thermochromism is consequently realized. Does this apply to the organic− inorganic hybrid Cu(I) halide of an ionic type?…”

Assembly of One-, Two-, and Three-Dimensional Cu(I)-Based Coordination Frameworks for Tunable White Light Emission and Effective Fluorescence Sensing

“…Luminescent coordination polymers (CPs) have received huge attention by virtue of their diverse topologies and broad applications in optics, display, bioimaging, sensing, and detection. − Of particular interest is the family of d 8 /d 10 transition-metal compounds, which is regarded as an emerging class of excellent luminescent solids benefiting from the presence of noncovalent metal···metal interactions in such complexes. − In particular, the copper­(I) halide-based coordination compounds, owing to not only the diverse coordination styles of Cu + (linear, trigonal, and tetrahedral geometry) and halide anions (from μ 2 - to μ 8 -linking) but also their unique photophysical or photochemical properties, have attracted huge interest. − Consequently, great efforts are being made in the pursuit of Cu-X-based (X = I, Br, Cl) networks with diverse structural motifs varying from discrete CuX or CuX 2 , Cu 2 X 2 dimers, Cu 3 X 3 , Cu 4 X 4 , or Cu 6 X 6 clusters, to zigzag [CuX] n or double-stranded [Cu 2 X 2 ] n chains and even to 2D Cu-X-based layers or 3D intricate frameworks. − Thanks to these various building blocks in the self-assembly process, numerous copper­(I) halide-based coordination frameworks have been fabricated in recent years with the assistance of diverse bridging ligands, which have a large possibility to exhibit vivid luminescence rooted in cluster-centered interactions or intracluster metal-halide charge transfer. , For example, Zang and co-workers reported a copper iodide cluster-based metal–organic framework (MOF) scintillator, which presents a high X-ray excited luminescence efficiency and can be used for X-ray flexible imaging …”