Combination of N-Arylstilbazolium Organic Nonlinear Optical Chromophores with Iodoargentates: Structural Diversities and Optical Properties

Abstract

A combination of N-arylstilbazolium organic nonlinear optical chromophores with iodoargentates results in five new hybrids, i.e., [(DAST)­(Ag2I3)] n (1), [(DMAQS)­(Ag2I3)] n (2), [(DPAS)­(Ag2I3)] n (3), [(DPTAS)2­(Ag5I7)] n (4), and [(CEMAS)2­(Ag5I7)] n (5). Among them, the former four are centrosymmetric, and 5 is non-centrosymmetrical (space group Pna21) with the introduction of a cyano group in an organic chromophore. The (Ag5I7) n 2n– chains in 4 and 5 are special, in which that of 4 is constructed from Ag5I10 building blocks with a μ6-I σ-bonding to six Ag ions, and that in 5 is the connection of a cubane-like Ag4I4 core with bridged AgI4 tetrahedra. UV/vis/near-IR adsorptions and near-IR photoluminescences have been observed. All the organic chromophores are stacked as head-to-tail arrangements, resulting in second harmonic generation (SHG) inactive in 1–4. But 5 is SHG active without J-aggregation of organic chromophore, whose symmetry break was driven by the formation of hydrogen bonds around the cyano group. The SHG activity of 5 originates from the polarizations of the asymmetric contribution of Ag5I9 4– unit mixing with non-centrosymmetrical (CEMAS)2 2+ pair. Theoretical calculations were carried out to disclose their electronic structures.

Tuning the photocurrent responsive and resistive switching performances of stilbazolium/iodoargentate hybrids by modulating the aggregation mode among chromophores

“…Stilbazolium-type π-delocalized molecules possess unique D–π–A structures and the larger molecular hyperpolarizability ( β ), which contain an electron acceptor linked to an electron donor group via a π-conjugated bridge. 19,20 It has been proved that the polarities can be tuned by introducing different electron-donating or withdrawing groups. 21 They are good candidates for the investigation of the aggregation mode on RS behaviors because they can aggregate as offset J-aggregation or face-to-face H-aggregation, 22,23 which will greatly affect the charge mobility behavior in molecular devices.…”

“…26–28 The iodine-involved hydrogen bonds will help to realize the modulation of the aggregation type of organic stilbazolium-type molecules. 20 Herein, we designed three stilbazolium-type molecules (Scheme 1), and their substituent groups were introduced on the ortho -position of the acceptor moiety, which can lower the electronic deficiency degree and enhance the intramolecular charge transfer performance. 19,29 Based on the X-ray single crystal structural analysis, the aggregation mode can be tuned by the hydrogen bonds with iodoargentates, and the device bearing head-to-tail H-aggregated stilbazolium can produce better photocurrent responsive and RS behavior with an energy-saving property.…”

Construction of Iodoargentates with Diverse Architectures: Template Syntheses, Structures, and Photocatalytic Properties

“…Various connection modes of the I – ion could adopt a μ 2 - to μ 8 -bridging/chelating fashion, making the structures of iodoargentates exceptionally unpredictable. Functionally, iodoargentates are usually equipped with remarkable physical and chemical properties, including thermo­(photo)­chromism, photocatalytic degradation of organic dye pollutants, nonlinear optical properties, and so on. − With the assistance of either organic cations or metal–organic complex cations as structure-directing agents (SDAs) or templates, a large amount of silver–iodine hosts have been successfully prepared up to now. − For instance, Yue reported a series of iodoargentates with diverse architectures by employing metal–organic complexes as the SDAs, exhibiting an effective visible light-driven photocatalytic behavior . Templated by flexible or rigid organic amines, Fu et al constructed a large number of functional iodoargentate hybrids with reversible thermochromism or photochromic properties .…”

<p>Multifunctional Quaternary Phosphorus/Bromoargentate Hybrids: The Achievement of Greenish Blue Luminescence, Repeatable Photocurrent Responses and Durable Antimicrobial Activities with Enhanced Water Stability</p>

“…In the past decades, halometallate-based functional materials have attracted great attention due to their versatile structure and unique properties, based on which many novel applications have emerged, such as perovskite solar cells, 1,2 luminescence, 3 molecular switches, 4 nonlinear-optic devices 5 and chromisms. 6 Among the halometallate hybrids, d 10 silver(I) halides have captured special interest for the following reasons: first, various anion dimensionalities based on rich coordination geometries of the Ag(I) ion (from linear MX 2 , triangular MX 3 , tetrahedral MX 4 , and octahedral AgX 6 ) and variable connection modes; 7 second, unique physical properties of electron-rich halo-argentates.…”