Structural,Computational and 3D Interaction Energy Calculations of the Compound 2-chloro-3-(1-napthyl)-5,5-dimethyl-2-cyclohexenone

Crystallography Reports - The molecular structure of 2-chloro-3-(1'-napthyl)-5,5-dimethyl-2- cyclohexenone was determined by single crystal X-ray diffraction. The compound crystallized in a...     

Regeneration of Carbonyl Compounds from Oximes and Hydrazones Using Peroxymonosulfate on Silica gel under Solvent-free Conditions

In an environmentally benign solvent-free system, oximes and hydrazones are rapidly transformed into parent carbonyl compounds using peroxymonosulfate on silica gel under microwave irradiation in good to excellent yields.     

Templated‐Assembly of CsPbBr3 Perovskite Nanocrystals into 2D Photonic Supercrystals with Amplified Spontaneous Emission

Perovskite nanocrystals (NCs) have revolutionized optoelectronic devices because of their versatile optical properties. However, controlling and extending these functionalities often requires a light‐management strategy involving additional processing steps. Herein, we introduce a simple approach to shape perovskite nanocrystals (NC) into photonic architectures that provide light management by directly shaping the active material. Pre‐patterned polydimethylsiloxane (PDMS) templates are used for the template‐induced self‐assembly of 10 nm CsPbBr₃ perovskite NC colloids into large area (1 cm²) 2D photonic crystals with tunable lattice spacing, ranging from 400 nm up to several microns. The photonic crystal arrangement facilitates efficient light coupling to the nanocrystal layer, thereby increasing the electric field intensity within the perovskite film. As a result, CsPbBr₃ 2D photonic crystals show amplified spontaneous emission (ASE) under lower optical excitation fluences in the near‐IR, in contrast to equivalent flat NC films prepared using the same colloidal ink. This improvement is attributed to the enhanced multi‐photon absorption caused by light trapping in the photonic crystal.     

Size and nonlinear optical effects of ferroic organic nanocomposites

The third harmonic generation of ferroic (NH₂(C₂H₅)₂)₂CuCl₄ diethylammonium cuprate chlorate (DEACC) single crystals and nanocrystals (NCs) incorporated into polymethyl methacrylate (PMMA) polymer matrices was investigated. It was established that the crystal field spectra of Cu²⁺ ion determines the observed size dependence effect. The role of nanocrystallite size and content and the symmetry of the THG at ambient and nitrogen temperatures were studied.     

Photoluminescence and energy transfer in Tb/Mn co-doped ZnAl2O4 glass ceramics

We report on Tb³⁺ as efficient sensitizer for red photoemission from Mn²⁺-centers in ZnO-B₂O₃-Al₂O₃-Si₂O-Na₂O-SrO glasses and corresponding gahnite glass ceramics. In comparison to singly or co-doped glasses, the glass ceramics exhibit significantly increased emission intensity. Structural considerations, ESR, and dynamic luminescence spectroscopy indicate partial incorporation of Mn²⁺ as well as Tb³⁺ into the crystalline phase, the former on octahedral Zn²⁺-sites. Interionic distance and charge transfer probability between both species depend on crystallization conditions. This enables control of the energy transfer process and, hence, tunability of the color of photoemission by simultaneous emission from Tb³⁺ and Mn²⁺ centers. Concentration quenching in Mn²⁺-singly doped materials was found at a critical dopant concentration of about 1.0 mol%. The energy transfer process was studied in detail by dynamic as well as static luminescence spectroscopy. Spectroscopic results suggest the application of the studied materials as single or dual-mode emitting phosphor for luminescent lighting.     

Structural Conformation of a Novel Piperidine-4-One Derivative: 1-Acryloyl-3-Methyl-2,6-Dip-Tolylpiperidine-4-One

Abstract  

The novel 3-methyl-2,6-dip-toylpiperidine-4-one was acylated by 3-chloropropanoychloride and subjected for dehydrohalogenation. The synthesized compound was characterized by spectroscopic techniques and finally confirmed by X-ray diffraction studies. The molecule crystallizes in the monoclinic crystal class in the space group C ₂/c with cell parameters a = 18.538(2) ?, b = 9.9050(1) ?, c = 22.954(2) ?, β = 94.486(8)° and Z = 8. The piperidine ring adopts a twist boat conformation.     

Laser induced effects in PbO-Bi2O3-Ga2O3-BaO: Eu glasses

We have observed a several times enhancement of the optical second harmonic generation in newly synthesized Europium doped PbO-Bi₂O₃-Ga₂O₃-BaO glasses for the fundamental wavelength 1320 nm during optical treatment by coherent fundamental and doubled frequency beams with a pulse duration about 15 ns. We have found that the maximal optical second harmonic generation was achieved for the Eu content of about 1.4% at fundamental beam average power equal to about 3 GW/cm² , temperature of about 300 K and intensity ratio between the fundamental and doubled frequency beams of about 9. Frequency repetition of the optical pulses was equal to about 10 Hz. It was shown that doping by other rare earth ions, particularly by Dysprosium does not give a sufficient contribution to the effect.     

Blue-to-Orange Tunable Luminescence from Europium Doped Yttrium--Silicon--Oxide--Nitride Phosphors

Europium-doped yttrium-silicon-oxide-nitride phosphors are synthesized by carbothermal reduction and nitridation method. The crystal structure of the phosphors changed gradually from oxide Y2Si2O7 to nitride YSi3N5 state with increasing dosage of Si3N4 and carbon powder. The Y2Si2O7：Eu phosphor shows a blue emission at 465 nm with 300 nm excitation and a characteristic red emission of Eu^3＋ at 612 nm with 230 nm excitation. The YSi3N5：EU phosphor shows a broad emission band centred at 595nm with some sharp peaks of Eu^3＋ with 325nm excitation. The absorption of the studied phosphors increases from 450 to 700hm with an increment in nitrogen content. Blue-to-orange tunable luminescence is observed with 390 nm excitation.