Chiral 2D Cu(I) Halide Frameworks

Abstract

Hybrid multifunctional materials have great potential in a wide variety of applications due to their flexible combination of organic and inorganic components. Introducing chiral organic modules into the metal halide frameworks can effectively generate multifunctional materials, achieving new functionalities with noncentrosymmetric structures. Here, by incorporating (R)-or (S)-piperidine-3-carboxylic acid (R/S-PCA) as the templating cation, we report the synthesis and characterization of three pairs of new 2D chiral hybrid Cu(I) halides, namely, (R/S-PCA)CuBr 2 , (R/S-PCA)CuBr 2 •0.5H 2 O, and (R/S-PCA)CuI 2 . These chiral Cu(I) halides crystallize in the noncentrosymmetric space group C2 and belong to a new structural type similar to layered silicates. The optical absorption edges of these chiral materials can be tuned by changing the halide or upon the absorption of water and range from 2.70 to 3.66 eV. A dynamic conversion between (R/S-PCA)CuBr 2 and (R/S-PCA)CuBr 2 •0.5H 2 O occurs through exposure to moisture or vacuum drying along with changes in the reversible bandgap and photoluminescence. Chiroptical properties such as circular dichroism, circular polarized light emission, and second harmonic generation are investigated. Density functional theory calculations (DFT) show the indirect and direct bandgap natures of these Cu(I) halides and reveal the mechanism for the broadband self-trapped exciton emission at the excited state. The fascinating structural type, chiroptical properties, and reversible hydrochromic behavior of these Cu(I)-based halides make them viable candidates for next-generation multifunctional optoelectronic materials.

Two-dimensional semiconducting Cu(i)/Sb(iii) bimetallic hybrid iodides with a double perovskite structure and photocurrent response

“…The bond length of Cu 1 –I 9 (3.763 Å), Cu 1 –I 11 (4.304 Å), Cu 2 –I 2 (4.071 Å) and Cu 2 –I 16 (4.482 Å) in CuSbI-2 are much longer than several reported complexes containing Cu–I bonds, such as 2.61–2.72 Å in (R/S-PCA)CuI 2 . 46 Therefore, bonding characteristics of complexes CuSbI-1 and CuSbI-2 were investigated through the interaction region indicator (IRI) analysis 47 via Multiwfn program, 48 which can distinguish the strengths and features of intra- or inter-molecular interactions in different regions. Reasonable fragments of both molecules were considered and their atomic coordinates were directly extracted from single crystal structures without geometry optimization (Fig.…”

Resonant Second Harmonic Generation in Proline Hybrid Lead Halide Perovskites

“…These chiral hybrid perovskites exhibit unique chiroptoelectronic properties such as circularly polarized light (CPL), [ 32,53,54 ] circular dichroism (CD), [ 33,55 ] ferroelectricity, [ 40,56,57 ] and second harmonic generation (SHG). [ 35–37,41,52,58,59 ]…”

“…These chiral hybrid perovskites exhibit unique chiroptoelectronic properties such as circularly polarized light (CPL), [32,53,54] circular dichroism (CD), [33,55] ferroelectricity, [40,56,57] and second harmonic generation (SHG). [35][36][37]41,52,58,59] Natural amino acids, as the fundamental components of proteins, make pivotal contribution to the growth and metabolism of living organisms. [60] These amino acids are essentially chiral and abundant in nature.…”

1D Chiral Lead Bromide Perovskite with Superior Second‐Order Optical Nonlinearity, Photoluminescence, and High‐Temperature Reversible Phase Transition

“…Since the composition of low‐dimensional organic‐inorganic hybrid perovskites can be harmonized with flexible crystal structure, chiral groups can be reasonably introduced into the inorganic metal framework as ligands, so as to realize the construction of multifunctional materials [22–24] . The chiral transfer from organic to inorganic groups can be effectively achieved not only through the formation of chemical bonds, but also through spatial interactions [25–27] . The intrinsic chirality introduced in metallic hybrid materials often breaks the symmetry, resulting in novel photoelectric properties associated with chirality, such as circular dichroism (CD), circularly polarized luminescence (CPL), second harmonic generation (SHG), pyroelectric, piezoelectric, and ferroelectric properties [28–33] .…”

“…[22][23][24] The chiral transfer from organic to inorganic groups can be effectively achieved not only through the formation of chemical bonds, but also through spatial interactions. [25][26][27] The intrinsic chirality introduced in metallic hybrid materials often breaks the symmetry, resulting in novel photoelectric properties associated with chirality, such as circular dichroism (CD), circularly polarized luminescence (CPL), second harmonic generation (SHG), pyroelectric, piezoelectric, and ferroelectric properties. [28][29][30][31][32][33] The most prominent in the field of hybrid perovskites is the lead halide perovskite.…”