Organic Inorganic Hybrid Crystal Research Articles

2,4,6-Trimethylpyridinium perchlorate: Polar properties and correlations with molecular structure of organic–inorganic hybrid crystal

[ ( CH 3 ) 3 C 5 H 2 NH ] [ ClO 4 ] has been synthesized and characterized by X-ray (at 344, 245, 180 and 115 K), calorimetric, dilatometric, dielectric and pyroelectric measurements. At room temperature the crystal structure is polar, space group Pmn 2 1 . It consists of discrete disordered [ ClO 4 ] - anions and ordered trimethylpyridinium cations giving the 3D network of hydrogen bonds. The compound reveals a rich polymorphism in the solid state. It undergoes four solid–solid phase transitions: from phases I to II at 356/327 K (heating/cooling), II → III at 346/326, III → IV at 226 K and IV → V at 182/170 K. [ ( CH 3 ) 3 C 5 H 2 NH ] [ ClO 4 ] reveals a strong pyroelectric response over a wide temperature region (phases III, IV and V) with the spontaneous polarization changes ( Δ P s ) of the order of 1.5 – 8 × 10 - 3 C / m 2 . The spontaneous polarization is irreversible over all the polar phases, however, the magnitude of the Δ P s in the vicinity of the phase transitions is characteristic of compounds with the ferroelectric order. The molecular mechanism of the successive phases transitions in the studied crystal is proposed.

Coordinated NH3-Removal-Induced Hydrogen Adsorption of Cu-Complex Crystals

We synthesized a discrete type of organic-inorganic hybrid crystal [Cu(ina)2(NH3)2(H2O)2] (ina = isonicotinate). The monomer units connect to each other with hydrogen bonds and pi-pi interactions, forming a three-dimensional network. Removal of ammonia and water molecules by vacuum heating treatment induced a substantial change from nonporous to porous crystals. The resultant porous crystals can predominantly adsorb supercritical hydrogen rather than nitrogen vapor at 77 K.

Theoretical investigation of organic-inorganic hybrid crystal: Optical transparency and quadratic harmonic coefficients of 2-Amino-5-Nitropyridinium chloride

The IR and UV absorption cut-offs (λ$_{IR}$ and λ$_{UV})$ of an organic-inorganic hybrid nonlinear optical (NLO) crystal, 2-amino-5-nitropyridinium chloride (2A5NPCl), were investigated in the framework of density functional theory. The macroscopic quadratic NLO coefficients of the crystal were evaluated at the MP2/6-31+G** level coupled with the oriented-gas model. The calculated results reveal that the λ$_{IR}$ and λ$_{UV}$ are governed by the asymmetric N-H stretch of NH$_{2}$ group and the charge transfer (CT) transition from Cl$^{-}$ to 2A5NP$^{+}$, respectively. The optical transparency has been determined in the region 407-1415 nm. The analyses of the electronic absorption spectrum show that the CTs of both Cl$^{-}→$ 2A5NP$^{+}$ and π → p* within 2A5NP$^{+}$ moiety make dominant contributions to the β values. The studies of the oriented-gas model show that the crystal has large NLO coefficients.

Theoretical studies on vibrational spectra and nonlinear optical property of l-arginine phosphate monohydrate crystal

Linear and nonlinear optical properties of the organic–inorganic hybrid crystal, l-arginine phosphate monohydrate crystal have been investigated by the first-principles calculation as well as the electronic and vibrational properties. The calculated nonlinear optical coefficients agreed well to the experimental data. The results showed both organic and inorganic structural building blocks contribute to the large nonlinear optical activities of this crystal and the significant contribution of the intermolecular hydrogen bonds. The absorption-edges on both IR and UV sides of LAP crystal have been estimated and the structure–property relationship has been discussed. The study is helpful to the further development of l-arginine phosphate monohydrate crystal analogs with improved nonlinear optical properties.

Theoretical investigation of organic-inorganic hybrid crystal: Optical transparency and quadratic harmonic coefficients of 2-Amino-5-Nitropyridinium chloride

The IR and UV absorption cut-offs ($_{IR}$ and $_{UV})$ of an organic-inorganic hybrid nonlinear optical (NLO) crystal, 2-amino-5-nitropyridinium chloride (2A5NPCl), were investigated in the framew...

Preparation and characterization of a layered perovskite-type organic–inorganic hybrid compound (C 8NH 6–CH 2CH 2NH 3) 2CuCl 4

The organic–inorganic hybrid compound (C 8NH 6–CH 2CH 2NH 3) 2CuCl 4 (AEI–CuCl 4) was synthesized from ethanol solution containing copper chloride and 3-2-(aminoethyl) indole hydrochloride (AEI–HCl). High order diffraction peaks corresponding to (0 0 l; l = 2, 4, 6, …) observed in the X-ray diffraction profile of AEI–CuCl 4 indicated the formation of hybrid crystal with layered perovskite structure. The organic–inorganic hybrid crystal thin film can be easily prepared by spin-coating method from the ethanol solution of the AEI–CuCl 4 perovskite and it showed characteristic absorptions of CuCl-based layered perovskite centered at 288 and 388 nm, as well as the photoluminescence peak at around 420 nm. The unaided-eye-detectable blue fluorescence emission comes from the cooperation of AEI–HCl and AEI–CuCl 4 perovskite, in which protonized aminoethyl indole dominates the shape of the spectrum and the enhancement of emission intensity is due to the formation of the perovskite structure. The thermal analysis presented that the AEI–CuCl 4 perovskite started to melt at 182 °C, together with the beginning of the decomposition of the hybrids. Compared with the organic–inorganic perovskite hybrids reported previously, the AEI–CuCl 4 perovskite shows a novel stepwise decomposition behavior.

A New Organic-Inorganic Hybrid Crystal Prepared from 1-Methyl-4-Carbamoylpyridinium Iodide and Cadmium Iodide

Although 4-substituted pyridinium derivatives studied so far form the 2:1 complexes with cadmium iodide, an exceptional 1:1 complex was found for 1-methyl-4-carbamoylpyridinium iodide. Its X-ray crystallographic analysis revealed that its inorganic portion has a unique structure with corner-sharing one-dimensional tetrahedral chains of (CdI 3 − ) n .

A New Organic-Inorganic Hybrid Crystal Prepared from 1-Methyl-4-Carbamoylpyridinium Iodide and Cadmium Iodide

Although 4-substituted pyridinium derivatives studied so far form the 2:1 complexes with cadmium iodide, an exceptional 1:1 complex was found for 1-methyl-4-carbamoylpyridinium iodide. Its X-ray crystallographic analysis revealed that its inorganic portion has a unique structure with corner-sharing one-dimensional tetrahedral chains of (CdI 3 − ) n .

A New Organic-Inorganic Hybrid Crystal Prepared from 1-Methyl-4-Carbamoylpyridinium Iodide and Cadmium Iodide

Although 4-substituted pyridinium derivatives studied so far form the 2:1 complexes with cadmium iodide, an exceptional 1:1 complex was found for 1-methyl-4-carbamoylpyridinium iodide. Its X-ray crystallographic analysis revealed that its inorganic portion has a unique structure with corner-sharing one-dimensional tetrahedral chains of (CdI 3 − ) n .