High-quality crystal growth and characterization of organic nonlinear optical crystal: 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST)

High quality 4-dimethylamino-N-methyl-4-stilbazolium tosylate (DAST) crystal has been successfully grown from saturated methanol solution by a slow cooling method in a Teflon vessel. The full width at half maximum (FWHM) of (001) X-ray diffraction (XRD) rocking curve depends on the growth rate, and the FWHM could be decreased to 15·8 arcsec. Close relation was observed between the mechanical property and crystallinity. The Vickers hardness increased up to 49 on decreasing FWHM.     

非线性光学晶体MnHg(SCN)4(C2H6SO)2的热学和光学性质的测定

制备了一种新型非线性光学晶体二甲亚砜合硫氰酸汞锰(分子式MnHg(SCN)4(C2H6SO)2,简称MMTD).用热重法、差热分析法、差示扫描量热法、热机械分析法、分光光度法和红外光谱研究了它的热学和光学性质.MMTD晶体具有较好的物理化学稳定性.在27℃时,它的比热为699.5 J/mol·℃.晶体的热膨胀系数为α1=5.33×10-5/℃,α2=4.51×10-5/℃,α3=3.10×10-5/℃.MMTD晶体的截止波长为375nm;透光波段为375-2560 nm.MMTD晶体在标准紫光波长404nm的透过率为44.18%,高于硫氰酸汞锰(MMTC)晶体.     

Second-harmonic generation of a novel transparent material: N,N-diphenyl-8-[2-(4-pyridinyl)ethenyl]-dibenzofuran-2-ylamine

N,N-diphenyl-8-[2-(4-pyridinyl)ethenyl]-dibenzofuran-2-ylamine has been synthesized as a novel second-harmonic generation (SHG) material. From reflection measurement in powder form, the SHG of the titled compound is found to be nine times as intense as that of urea. An effective d coefficient by means of second-harmonic wave generated with the evanescent wave (SHEW) method is estimated to be 3 pm/V. The cutoff wavelength of the compound is 370 nm.     

Synthesis,crystal growth and characterization of novel semiorganic nonlinear optical crystal: Dichlorobis(l-proline)zinc(II)

Single crystals of the semiorganic material, dichlorobis(l-proline)zinc(II) (DCBPZ), were grown from aqueous solution. The grown crystals were tested by single crystal X-ray diffraction, energy-dispersive spectrometry, FT-IR, UV–vis and TG–DTA. The structural prefection of the grown crystals has been analyzed by high-resolution X-ray diffraction (HRXRD) rocking curve measurements. The dielectric and mechanical behavior of the specimen was also studied. The SHG efficiency of DCBPZ is three times greater than that of KDP. Measuring transmittance of DCBPZ permitted the calculation of the refractive index n, the extinction coefficient K and both the real ?_r and imaginary ?_i components of the dielectric constant as functions of photon energy. The optical band gap of DCBPZ is 4.8 eV.     

Materials synthesis,crystal growth and third nonlinear optical properties of semiorganic crystal: 4-dimethylaminopyridine lithium nitrate (DMAPLN) crystal

4-dimethylaminopyridine lithium nitrate crystal (4-DMAPLN) was synthesized by the slow evaporation solution growth technique. The titular crystal was subjected to various studies to recognize its physicochemical properties. The crystalline nature and orthorhombic crystal system were revealed by single crystal and powder XRD. FTIR spectroscopy study confirms the various modes of vibrations available in the titular crystal. Linear optical studies show the lower cut-off wavelength of 280 nm with an optical bandgap value (E_g) of 4.3 eV. The electrical behavior of the 4-DMAPLN crystal was studied using dielectric studies. The mechanical behavior of the grown crystal was analyzed using the Vicker’s microhardness study, revealing that the grown crystal belongs to the hard category. The second-order nonlinear optical (NLO) behavior of 4-DMAPLN crystal was measured using Kurtz–Perry powder techniques and it was found to be 1.17 times higher than reference KDP. Z-scan analysis reveals 4-DMAPLN is a suitable candidate for optical limiting applications.

     

Preparation, characterization, and optical properties of disulfide-comprising oligo[2,5-bis(thiomethyl)-1,4-dithiane] and its poly[S-alkylcarbamate]

Novel poly[S-alkylcarbamate]s were prepared by polyaddition of oligo [2,5-bis(thiomethyl)-1,4-dithiane] (oligo[BMMD]) with isocyanate for optical polymers having high refractive indices (nD) and Abbe's numbers (D). Oxidation of 2,5-bis(mercaptomethyl)-1,4-dithiane (BMMD) with ferric chloride or methylsulfoxide gave oligo[BMMD] in a mixture of n-mers (typically n = 1–6) by disulfide-forming propagation. The use of the former oxidant giving mainly BMMD dimer appeared to be preferable for the subsequent preparation of transparent poly[S-alkylcarbamate]. With 1,3-bis(isocyanatomethyl)cyclohexane, 1,6-diisocyanatohexane, or 1,3,5-tris(isocyanatomethyl)cyclohexane, nD:D values of poly[S-alkylcarbamate]s ranging from 1.609:38.0 to 1.659:35.6 were comparable to those of flint glasses. Copoly[S-alkylcarbamate]s were prepared using 2-mercaptoethylsulfide or 2-mercaptoethylether for modification of nD and D. Contribution of the disulfide bond and the 1,4-dithiane ring in oligo[BMMD] to increase nD is discussed in terms of molar refraction. Suppressed UV absorption of the polymer, which caused high D, was attributed to the trans-gauche-trans conformation around the disulfide bond. This work shows that oligo[BMMD] serves as a useful material for the preparation of polymers having high nD and high D and that poly[S-alkylcarbamate]s thus obtained are promising optical materials.     

Synthesis,growth, structural,physicochemical, linear,and nonlinear optical properties of new hybrid [2(C10H20O5) Ba] [Co (SCN)4] single crystal

Journal of Materials Science: Materials in Electronics - A novel organometallic single crystal of Bis(15-Crown-5-k5O) barium tetrakis (isothiocynato-kN) cobalt (II) [BCBCTC] was synthesized by slow...     

Investigation of optical,thermal and mechanical studies on semi organic nonlinear optical diaquabis(L-lactato)magnesium (DLLM) single crystal for optoelectronic devices applications

Journal of Materials Science: Materials in Electronics - The Diaquabis(L-lactato)magnesium (DLLM) single crystals have been grown by slow evaporation solution growth technique. The lattice...     

Efficient deep-blue organic light-emitting diodes with a 1,4-(dinaphthalen-2-yl)-naphthalene

Deep-blue organic light-emitting diodes (OLEDs) with nearly 5% external quantum efficiency were demonstrated using a 1,4-(dinaphthalen-2-yl)-naphthalene (DNN) host. The 4,4'-bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl (BCzVBi) dopant that was used in this experiment effectively accepted energy from the DNN host via F?rster energy transfer because the photoluminescence spectrum of the DNN host showed better spectra overlap with the ultraviolet-visible (UV-vis) absorption spectrum of the BCzVBi dopant than the photoluminescence spectrum of the 2-methyl-9,10-bis(naphthalen-2-yl)anthracene host did. Moreover, the DNN host had a higher energy bandgap (3.5 eV) than the BCzVBi dopant did (3.0 eV), while the MADN host had the same energy bandgap as the BCzVBi dopant. The optimized deep-blue device also had ETL of bis-(2-methyl-8-quinolinolate)-4-(phenylphenolato)aluminium which showed smoother sigma of 0.6 nm and higher Tg of 92 degrees than those of 4,7-diphenyl-1,10-phenanthroline (14.8 nm and 62 degrees C). The deep-blue device exhibited a peak current efficiency of 5.68 cd/A, a peak external quantum efficiency of 4.89%, and Commission Internationale d' Eclairage coordinates of (0.15, 0.13).     

Studies on optical and mechanical properties of new organic NLO crystal: Guanidinium 4-aminobenzoate (GuAB)

Organic nonlinear optical crystal of guanidinium 4-aminobenzoate (GuAB) has been successfully grown by slow evaporation solution growth technique. The grown crystal is up to the dimension of 36 × 8 × 6 mm³. The crystal is characterized by single crystal XRD for obtaining unit cell parameters. Optical properties of the grown crystal have been studied by means of UV–Vis–NIR transmission and absorption spectra in the range of 200 to 1000 nm. The refractive index and band gap energy of the GuAB crystal are obtained as 1.68 and 3.73 eV respectively. Mechanical hardness has been carried out on the grown crystal.     

Efficient orange-red organic light-emitting diodes using 9,10-bis[4-(di-4-tert-butylphenylamino)styryl] anthracene as a fluorescent orange-red emitter

The authors have demonstrated efficient orange-red organic lighting diodes (OLEDs) using a new fluorescent orange-red material, 9,10-bis[4-(di-4-tert-buthylphenylamino)styryl]anthracene (ATBTPA). The optimized orange-red OLED using ATBTPA achieved a maximum external quantum efficiency (EQE) of 3.78%, a current efficiency (CE) of 9.47 cd/A, and Commision Internationale de L'Eclairage (CIE_x,y) coordinates of (0.51, and 0.48) at 1.61 mA/cm² in comparison with orange-red OLED using (5,6,11,12)-tetraphenyl-naphthacene (rubrene) which showed a maximum EQE of 1.65%, CE of 4.94 cd/A, and CIE_x,y coordinates of (0.50, and 0.49) at 0.61 mA/cm², respectively. The optimized orange-red device using ATBTPA showed higher efficiency of two times the orange-red device using rubrene due to the efficient Förster singlet energy transfer from MADN to ATBTPA in comparison with that from MADN to rubrene. This study clearly suggests that ATBTPA is an excellent fluorescent orange-red material for efficient WOLEDs.     

Synthesis,crystal growth,structural, spectral,thermal, mechanical,linear and nonlinear optical studies of organic single crystal 4-Iodo 4-nitrostilbene (IONS): A potential NLO material

An organic nonlinear optical material 4-Iodo 4-nitrostilbene (IONS) has been synthesized and good optical quality single crystal was grown from ethyl methyl ketone solvent by the solution growth technique. Single and powder X-ray diffraction analyses reveals that the grown crystal belongs to monoclinic crystal system with noncentrosymmetric space group ‘P2₁’ and it has good crystalline nature. Functional groups and molecular structure of the title compound were confirmed by FTIR and ¹H NMR respectively. The UV–Vis–NIR absorption study reveals no absorption in the visible region and the cut-off wavelength was found to be at 412.84 nm, TG/DTA, mass spectral analysis, photoluminescence and microhardness studies have been carried out for the grown crystals and results are discussed in detail. The second harmonic efficiency of the IONS was determined by Kurtz–Perry powder technique which reveals that the IONS crystal (3.1 V) has greater efficiency i.e., 143 times to that of KDP (21.7 mV).     

Synthesis and crystal structure of chlorate-enclathrated in aluminogermanate sodalite Na8[AlGeO4]6(ClO3)2

Encapsulation of chlorate in sodalite with aluminogermanate host framework has been obtained by one pot hydrothermal synthesis at 393 K. The crystal structure of Na₈[AlGeO₄]₆(ClO₃)₂; sodalite was refined from X-ray powder data in the space group P $\bar 4$ 3n: a = 9.169 Å, where Al-O-Ge angle is 137.6°. The ²⁷Al MAS NMR study confirmed alternate Ge and Al ordering of the sodalite framework, while ²³Na gave insight into the structure and dynamics of the cage fillings. Infrared spectrum confirmed the encapsulation of chlorate as well as the framework formation of aluminogermanate sodalite. SEM study showed the retention of cubical morphology of the aluminogermanate sodalite. Thermogravimetric analysis provided information on the extent of chlorate entrapment, stability within the sodalite cages and decomposition properties.     

[Cu(1,4-C4H12N2)2(ClO4)2]n(H2O)2n,a novel butane-1,4-diamine-bridged two-dimensional copper(II) square network: Synthesis,structure, and magnetic properties

A novel butane-1,4-diamine-bridged copper(II) compound was synthesized via solvent diffusion route with high yield. Each copper is coordinated by four butane-1,4-diamine ligands, each of which in turn links with two copper atoms to form a two-dimensional (2D) square network. Interestingly, the title compound features a cross-linking rhombic channel (ca. 5.06 × 14.73 Å) parallel to the crystallographic b axis. And magnetic result measured indicates the presence of localized unpaired electrons in the structure and thus the cupric Cu(II) state.     

4-(p-N,N-Diarylphenyl)substituted 1H-pyrazolo[3,4-b]quinolines as novel luminophors for organic light emitting diode—synthesis, electroluminescent devices

We have synthesized 4-(p-N,N-diarylphenyl)substituted 1H-pyrazolo[3,4-b]quinolines 6–9. The principal novelty of these materials consists in N,N-aryl substituents in the 4-positioned phenyl ring. We have explored their spectral properties, in particularly absorption, photoluminescence and electroluminescence to obtain a possibility to tune the emission with the varied substituents in the visible spectral range. Quantum chemical simulations were done and the origin of the observed spectra is discussed. Role of the surrounding matrices on the observed absorption, photoluminescent and electroluminescent spectra is discussed.     

Studies on the nonlinear optical single crystal: Ammonium d,l-tartrate (C4H9NO6)

The organic nonlinear optical material ammonium d,l-tartrate single crystal has been successfully grown by slow evaporation solution technique (SEST). The grown crystals were characterized by single crystal XRD and the lattice parameters have been confirmed. The structural perfection of the grown crystal was analyzed by high-resolution X-ray diffraction measurement. The optical transmittance spectrum shows that the material has a good optical transparency in the entire visible region with the UV cut-off wavelength at 234 nm. Thermogravimetric and differential scanning calorimetric measurements were performed to study the thermal properties of the grown crystal. Chemical etching studies were attempted to determine the dislocation density of the grown crystal. Mechanical behavior was assessed using Vickers hardness testing carried out on (0 0 1) crystallographic plane. The Kurtz–Perry powder SHG technique confirms the NLO property of the grown crystal and the efficiency of AMT crystal was found to be 1.3 times that of standard KDP crystal.     

聚(2,5-二羟基-1,4-苯撑吡啶并二咪唑)纤维的性能与应用

介绍了[聚(2,5-二羟基-1,4-苯撑吡啶并二咪唑)](PIPD)纤维的制备、性能及应用,PIPD纤维的强度和模量高,具有耐热、阻燃和耐化学稳定性等优良性能,尤其具有良好的压缩和扭曲性能,高电阻特性以及与树脂基体优良的粘结性能,PIPD纤维可作为耐热材料、增强材料、防弹冲击材料、电绝缘材料而广泛应用于航空军事等领域.