From Intercalation to Aggregation:  Nonlinear Optical Properties of Stilbazolium Chromophores−MPS₃ Layered Hybrid Materials

Abstract

A number of cationic chromophores derived from the stilbazolium skeleton have been synthesized and inserted into the transparent layered MPS 3 compounds (M ) Mn, Cd, Zn). The NLO properties of the intercalates have been studied. Some of the materials are found to be active for second harmonic generation. UV-visible spectroscopy shows that some of the chromophores, once inserted, undergo strong intermolecular interactions and form J-type aggregates along the inorganic galleries, whereas others do not. Moreover, we have found that only those intercalates which contain aggregates are NLO active. The results allow us to understand, at least partially, why the centrosymmetrical MPS 3 host lattice can yield noncentrosymmetrical intercalates. The host lattice appears not so much to impose specific orientations upon the guest species as to favor chromophore aggregation.

Layered Organic–Inorganic Materials: A Way towards Controllable Magnetism

“…In such systems, the formation of very large J-type aggregates of the chromophores explain their non-centrosymmetric arrangement in the galleries. [52] Unfortunately, no real coupling between magnetism and NLO properties has been evidenced to date. …”

Organic-MPS3 nanocomposites with large second-order nonlinear optical response

“…The synthesis of the intercalate MPS 3 derivatives has been described elsewhere [9]. It must be pointed out that cationic species do not penetrate easily into MPS 3 lattices; the interlamellar spacing usually needs to be pre-expanded using a solvated, highly mobile cation such as pyridinium or tetramethylammonium.…”

Synthesis, structure and properties of crystalline and nanocrystalline MnPS 3 -poly(phenylene vinylene) intercalates

“…The divalent metal thiohypophosphates are layer-structured compounds that have been studied by several research groups, mostly due to their ability to intercalate guest molecules, forming organic-inorganic materials with interesting magnetic and electronic properties [8][9][10][11]. In addition to their versatile intercalation chemistry, M II PS 3 materials are often quite transparent in the visible region, which makes them ideal hosts for luminescent polymers with optoelectronic applications [12].…”

“…MPS 3 compounds are usually prepared as macroscopic crystals by high-temperature techniques [8][9][10][11]; however, they can also be produced as colloidal nanoparticles in aqueous solution at room temperature. This was first done by Foot et al [13] by mixing a source of thiohypophosphate (P 2 S 6 ) 4-anions and a solution of M 2+ cations.…”