J. Appl. Cryst.の発刊に際して

The control of luminous radiation has extremely important implications for modern and future technologies as well as in medicine. In this Review, we detail chemical structures and their relevant photophysical features for various groups of materials, including organic dyes such as metalloporphyrins and metallophthalocyanines (and derivatives), other common organic materials, mixed metal complexes and clusters, fullerenes, dendrimeric nanocomposites, polymeric materials (organic and/or inorganic), inorganic semiconductors, and other nanoscopic materials, utilized or potentially useful for the realization of devices able to filter in a smart way an external radiation. The concept of smart is referred to the characteristic of those materials that are capable to filter the radiation in a dynamic way without the need of an ancillary system for the activation of the required transmission change. In particular, this Review gives emphasis to the nonlinear optical properties of photoactive materials for the functi...

Nonlinear Optical Materials for the Smart Filtering of Optical Radiation.

Luminogenic molecules [(TPE)3 (1), TPE-C = C-TPE-C = C-TPE (2), and TPE-C≡C-TPE-C≡C-TPE (3)] and their polymers P1–P3 are constructed from tetraphenylethene (TPE) building blocks in high yields by Suzuki, Witting, and Sonogashira coupling reactions. All the compounds are soluble and enjoy high thermal stability, losing little of their weights when they are heated to 290–528 °C under nitrogen or 288–436 °C in air. Analyses by UV spectroscopy and cyclic voltammetry as well as theoretical calculations show that the conjugation of the luminophores is in the order of 2 > 3 > 1, P2 > P3 > P1, and P1–P3 > 1–3. All the molecules and polymers are weakly emissive in solutions. They, however, become strong emitters in the aggregate state with fluorescence quantum yields up to 90%. Both 1–3 and P1–P3 exhibit the feature of aggregation-enhanced two-photon excited fluorescence. Large two-photon absorption cross sections (up to ∼900 GM) are observed in the nanoaggregates of the polymers. Thin solid films of the polymers show high refractive indices (RI = 1.7649 − 1.6873) in a wide wavelength region of 400–1700 nm, high modified Abbe numbers (vD′ up to 3436), and low optical dispersions (D′ down to 2.9 × 10−4). The light emissions of the polymers can be quenched exponentially by picric acid with large quenching constants, suggesting that they can be utilized as efficient chemosensors for explosive detection.

Luminogenic materials constructed from tetraphenylethene building blocks: Synthesis, aggregation-induced emission, two-photon absorption, light refraction, and explosive detection

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Crystal structure, Hirshfeld surfaces and DFT computation of NLO active (2E)-2-(ethoxycarbonyl)-3-[(1-methoxy-1-oxo-3-phenylpropan-2-yl)amino] prop-2-enoic acid.

Proceeding from quantum mechanical predictions, a high shear piezoelectric constant of 178 pm V−1 was measured for the amino acid crystal beta glycine. This originates from the efficient packing of the molecules of the amino acid.

Control of piezoelectricity in amino acids by supramolecular packing.

Structural, thermal, linear and nonlinear optical studies of an organic optical limiter based on reverse saturable absorption

Synthesis, growth and characterization of second-order nonlinear optical crystal: 5-Br-2-thienyl-4′-methoxychalcone

This paper deals with the studies on synthesis, characterization, nonlinear absorption, and optical-limiting property of a new organic crystal 3-(3-fluorophenyl)-1-[4-(methylsulfanyl) phenyl] prop-2-en-1-one (FMP). Primary characterization of FMP samples were performed using FTIR, UV-Visible, and NMR Spectroscopy techniques. FMP crystallizes in monoclinic system with centrosymmetric space group P21/n. UV-Visible spectrum shows minimum absorption in the entire visible region. From the thermo gravimetric and differential scanning calorimetry, melting point of FMP was found to be 96°C and there was no phase transition below this temperature. Open aperture Z scan experiment of FMP showed a good nonlinear absorption and optical-limiting property.

Structural, Nonlinear Absorption, and Optical Limiting Properties of a New Organic Crystal 3-(3-fluorophenyl)-1-[4-(methylsulfanyl) phenyl] prop-2-en-1-one

We report here on the optical and structural characteristics carried out on strontium doped calcium tartrate tetrahedral single crystalline materials obtained by diffusing calcium and strontium ions through silica gel impregnated with optically active tartaric acid. Linear optical properties of this material such as refractive index, birefringence and transmission characteristics were measured in the wavelength range 200 nm <λ<1500 nm. No dispersion of the birefringence was observed within the experimental accuracy. The packing of tartrate molecules remained unaltered with 12% of the strontium doping.

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S. M. Dharmaprakash

Papers

Structural, thermal, linear and nonlinear optical studies of an organic optical limiter based on reverse saturable absorption

Synthesis, growth and characterization of second-order nonlinear optical crystal: 5-Br-2-thienyl-4′-methoxychalcone

Structural, Nonlinear Absorption, and Optical Limiting Properties of a New Organic Crystal 3-(3-fluorophenyl)-1-[4-(methylsulfanyl) phenyl] prop-2-en-1-one

Optical and structural characteristics of strontium doped calcium tartrate crystals

Crystal growth, characterization, structural characteristics and second harmonic generation in N-benzoyl glycine crystals