Nonlinear optical properties of novel H-shaped chromophores

Novel and effective H-shaped chromophores were doped into polymethyl methacrylate (PMMA) to form guest-host polymer thin films.The measurement results of Maker fringe method show that the polymer thin films containing the H-shaped chromophores as a guest exhibit high second harmonic coefficients (d33) compared with other two-dimensional chromophores.     

Synthesis of chiral polybinaphthyls with novel conjugated chromophores

An efficient strategy has been developed to incorporate new chromophores into chiral binaphthyl polymers. The repeating units of these polymers are made of conjugated structures with strongly electron-donating amino groups at the both ends. These optically active materials contain the highest possible density of chromophores in a polymer chain since every repeating unit in these polymers is a chromophore. They are soluble in common organic solvents and can be easily processed. The spectroscopic properties of these polymers are studied. The structural similarity of the chromophores in these chiral conjugated polymers with those of two-photon absorbing molecules may lead to interesting optical properties.     

Synthesis and characterization of novel bifunctional hemithioindigo chromophores

[structure: see text] General methods for the synthesis of novel bifunctional hemithioindigo (HT) compounds, e.g., omega-amino acid derivatives, are presented. The photochromic properties of the photoswitches have been characterized by UV-vis and (1)H NMR spectroscopy.     

Synthesis of novel rigid-rod and tripodal azulene chromophores

Two novel azulene chromophores 1 and 2 were synthesized to study dynamics of ultrafast electron injection at the interface of TiO₂ semiconductor nanoparticles. Fluorescence quenching was observed upon binding.     

Synthesis and photophysical properties of novel pyrimidine-based two-photon absorption chromophores

Three new two-photon absorption chromophores based on a pyrimidine core were synthesized by Aldol condensation in the absence of any organic solvents. Their single-photon spectroscopic characterization as well as their two-photon absorption properties is reported. In addition, strong modulation of single-photon and two-photon fluorescent spectra of these molecules by (de)protonation is also discussed.     

Synthesis and properties of novel C3-symmetric coplanar chromophores

New synthetic pathways for novel C(3)-symmetric molecules featured with a thiophene-fused six-five-five carbon-bridged coplanar core structure have been established. The incorporation of thiophene as the constituent of a C(3)-symmetric core provides effective modulation of the physical properties and imparts extra flexibility for π-conjugated functionalization stemming from either the embedded thiophene or pendant aryl substitutions.     

Synthesis and photoluminescence properties of novel polyarylates bearing pendent naphthylamine chromophores

A new series of blue photoluminescent aromatic polyesters (polyarylates) were synthesized from 1-[N,N-di(4-carboxyphenyl)amino]naphthalene with various bisphenols by the diphenylchlorophosphate (DPCP) activated direct polycondensation in a medium of pyridine and lithium chloride. The synthesis, basic characterizations, photoluminescence and electrochemical properties of this series of novel polyarylates bearing pendent naphthylamine chromophores were investigated. All polymers not only had good solubility in many polar aprotic solvents and excellent thin-film-forming ability, but also exhibited high T_g values, good thermal stability and lower highest occupied molecular orbital (HOMO) level. Thus, these naphthylamine-containing polyarylates may be widely applied in P-LED as hole-transporting layer and blue light-emitting materials due to their proper HOMO level, excellent thermal stability and fluorescence quantum efficiency.     

Synthesis and characterizations of novel spindle-like terphenyl-type chromophores for non-linear optical materials

A series of novel spindle-like terphenyl-type chromophores, based on 2,5-diphenyl-1,4-distyrylbenzene π-conjugating bridge, N,N-dimethyl and triphenyl amino donors, and Tricyanovinyldihydrofuran(TCF), 1,3,3-trimethyl-5-dicyanovinyl-1-cyclohexene (TDC) acceptors, have been synthesized successfully for the first time. And the non-linear optical properties were evaluated by using the finite-field (FF) method. The results show that, the first-order hyperpolarizability of the chromophores increase with the increase of the withdraw ability of the substituent group on the π-conjugating bridge.     

Synthesis,structure and nonlinear optical properties of two novel two-photon absorption chromophores

Two triphenylamine-based derivatives that can be used as two-photon absorption chromophore,tris{4-[4-(3-trifluoromethyl-3-oxopanoyl)]phenyl}amine (1) and tris{4-[4-(3-phenyl-3-oxopanoyl)] phenyl} amine (2) were successfully synthesized and fully characterized by elemental analysis,IR,1H NMR and MS. The single crystal X-ray diffraction analysis showed that the molecules possess D-(π-A)3 structures. One-and two-photon absorption and fluorescence in various solvents were experimentally investigated. A data rec...     

Synthesis and near-infrared characteristics of novel perylene bisimide dyes bay-functionalized with naphthalimide chromophores

Novel perylene bisimide dyes bay-functionalized with naphthalimide chromophores have been prepared conveniently by coupling of 1,8-naphthalimide and dibromoperylene bisimides. Their optical properties were investigated by UV-vis and fluorescence spectroscopy. The absorption spectra of these compounds showed wide spectral responses from 300 to 700 nm,which would be potentials for application as organic solar cells.     

Synthesis of novel polyarylate with elecrooptical chromophores as side chain as electro-optic host polymer

Two novel soluble polyarylates with different nonlinear optical chromophores as the side chains were prepared and characterized by UV–visible spectra, nuclear magnetic resonance, and infrared spectroscopy. The titled polymers show us good thermal stability; the thermal decomposition temperature values were 201 and 253?°C, respectively, for polymer sPAR-CTCF and sPAR-CTCP. The glass transition temperatures were 139 and 122?°C for sPAR-CTCF and sPAR-CTCP, respectively. Chromophore FTC-wl was doped in these polymers as a guest chromophore to form binary chromophore electro-optic (EO) system. And super large EO coefficients (124?pm/V) were found from FTC-wl-doped sPAR-CTCP binary chromophore system at high chromophore loading density.     

Synthesis of silicon-bridged benzocrown ethers as novel ion-sensing chromophores based on the σ–π system

Compounds having two benzocrown ether units bridged by an organosilicon bridge were prepared by the reactions of lithiated benzocrown derivatives with dichloromono- and disilanes in THF, and the ionochromic effects on their optical properties were studied. Of those, disilanylene-bridged benzocrown ethers exhibited clear ionochromism in the emission spectra and the intensity of the original emission band at about 320 nm decreased and a new broad band centered at 400 nm appeared, when selected alkali or alkali-earth metal ions were added into the acetonitrile solutions. In contrast to this, no significant changes were observed in the UV absorption spectra on addition of the metal ions.     

Synthesis of pyridinium betaine azo chromophores

New chromophores have been synthesized and investigated containing as acceptor a quaternized pyridine unit with mobile bromine in the structure conjugated with two donor units – the indan-1,3-dione anion and the dihydroxyethylamino group through a π-conjugated spacer.     

Synthesis and self-assembly of reactive H-shaped block copolymers

The H-shaped block copolymers (PTMSPMA)₂-PEG(PMPSTMSPMA)₂ with two compositions, (EG)₉₁-b-(TMSPMA)₉₂ and (EG)₄₅₅-b-(TMSPMA)₁₇₆ have been successfully synthesized by atom transfer radical polymerization (ATRP) of tri(methoxylsilyl)propyl methacrylate (TMSPMA) at room temperature in methanol. The initiation system applied was composed of 2,2-bis(methylene α-bromoisobutyrate)propionyl terminated poly(ethylene glycol) (Br₂PEGBr₂) with M _n = 4000 or 2000, CuBr and 2,2′-bipyridine. The macroinitiator, Br₂PEGBr₂, was prepared by the reaction of two hydroxyl groups terminated PEG with 2,2-bis(methylene α-bromoisobutyrate)propionyl chloride. The NMR spectroscopy and GPC measurements were used to characterize the structure and molecular weight and molecular weight distribution of the resultant copolymers. The H-shaped block copolymers Sam 1 and Sam 2 were self-assembled in DMF/water mixtures and then the trimethoxysilyl groups in PTMSPMA were cross-linked by condensation reaction in the presence of triethylamine. Stable large-compound vesicles with 10 nm diameter of cavities were formed for Sam 1 which contains a short PEG chain. However, the self-assembling of the Sam 2 in the selective solvents resulted in big vesicles aggregates. These two different morphologies of aggregates are attributed to their relative chain length of water soluble PEG. The vesicles formed from Sam1 with short PEG chains have big surface energy which will lead them to self-assemble further, forming large-compound vesicles. __________ Translated from Acta Polymerica Sinica, 2007, 10: 974–978 [译自: 高分子学报]     

新型双光子吸收化合物的合成、光物理及其在固态分散体系中的性质

通过多步反应制备了三个新型的双光子吸收化合物,测试了它们的光物理性质,发现该系列化合物具有较大的双光子吸收截面,并且随温度降低其双光子吸收截面增大.尤其是化合物TMVDB,其量子效率为0.83,常温时的双光子吸收截面达到1164GM,其双光子吸收截面除以分子量为2.08,表现出了优良的双光子吸收发光性能.进一步将TMVDB掺杂到固体材料中,得到强双光子诱导发光的固体材料.     

Synthesis of triphenylamine-cored dendritic two-photon absorbing chromophores

[structure: see text]. A new series of dendritic two-photon absorbing chromophores containing triphenylamine moiety as a core or branching points have been synthesized through a convergent synthetic strategy. One-photon and two-photon optical properties of these molecules were characterized. In the nanosecond time domain, these molecules exhibited large two-photon absorption (TPA) cross sections up to 7.56-12.2 x 10(-44) s cm(4) at 800 nm, indicating that these molecular structures were viable candidates for various two-photon related applications.     

Synthesis and two-photon absorption of triphenylbenzene-cored dendritic chromophores

The synthesis and the characterization of triphenylbenzene-cored dendrimers of first- and second-generation are described. Their absorption, photoluminescence as well as their two-photon absorption properties have been investigated and compared to a quadrupolar counterpart. These molecules combine wide transparency in the visible range and high two-photon absorption cross-sections that increase with the generation, making these dendrimers promising systems for optical power limiting applications.     

Synthesis of novel poly(meth)acrylates containing tetracyanocyclopropyl groups as piezoelectric chromophores and their properties

p‐(2,2,3,3‐Tetracyanocyclopropyl)phenoxyethyl acrylate ( 5a ) and p‐(2,2,3‐tetracyanocyclopropyl)phenoxyethyl methacrylate ( 5b ) were prepared by the reactions of bromomalononitrile with p‐(2‐acryloyloxyethoxy)benzylidenemalononitrile and p‐(2‐methacryloyloxyethoxy)benzylidenemalononitrile, respectively. Monomers 5a and 5b were polymerized with free‐radical initiators to obtain polymers with multicyanocyclopropane functionalities in the pendant group. The resulting polymers were soluble in acetone, and the inherent viscosities were 0.25–0.30 dL/g. Solution‐cast films showed thermal stability up to 300 °C with glass‐transition temperatures of 140–156 °C. The dipole moments of 5a and 5b , calculated by the atom superposition and electron delocalization molecular orbital method, were 7.58–7.30 D. Piezoelectric coefficients (d₃₁) of the poled polymer films were 1.8–1.9 pC/N, acceptable values for piezoelectric device applications. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 379–384, 2002     

Synthesis and characterization of fluoronitroaryl azo diaminobenzene chromophores

The novel fluoronitroaryl azo diaminobenzene chromophores for potential NLO applications were synthesized and the effects of the position of the fluorine group on the properties of the chromophores were investigated. These chromophores exhibit high decomposition temperatures whilst keeping molecular hyperpolarizabilities similar to those of the non-fluorinated analogues. The chromophore 2,4-diamino-4′-fluoro-3′-nitroazobenzene (2R-4F-3N-DIAMINE) shows a significant UV blue shift and a combination of good transparency, high thermal stability and nonlinearity in comparison with 2,4-diamino-2′-fluoro-5′-nitroazobenzene (2R-2F-5N-DIAMINE) and its non-fluorinated analogue 2,4-diamino-3′-nitroazobenzene (2R-3N-DIAMINE).