Synthesis and photophysical properties of hyperbranched polyfluorenes containing 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine as the core

A series of new hyperbranched polymers containing a 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine core unit and polyfluorene chain arms have been synthesized via Suzuki coupling, and characterized by NMR, IR and GPC. All the polymers exhibit good thermal stability with a high decomposition temperature. By changing the 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine/fluorene ratio the UV-vis absorption and emission spectra can be partially tuned. It has been found that the polymers containing a low ratio of 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine units (P1-P3) have an absorption maximum around 385 nm, localized in the polyfluorene chain, and a shoulder around 425 nm ascribable to a charge transfer state involving the fluorene and the 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine core. Increasing the molar ratio of the 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine unit enhances the charge transfer band which becomes dominant for P4. The LUMO level of these polymers is relatively low due to the electron affinity of the triazine group. The polymers show dual emission, with a structured band in the blue (410-440 nm), attributed to the polyfluorene, and a broad band in the red (470-500 nm) associated with the charge transfer state. All the polymers exhibit two-photon absorption activity in the range of 660 to 900 nm with the maximum two-photon absorption (TPA) cross-section red-shifted from the corresponding linear absorption. The values of the TPA cross-sections vary from 1000 to 5000 GM, following the 2,4,6-tris(thiophen-2-yl)-1,3,5-triazine/fluorene ratio.     

基于1-(4-己氧)苯和2,4,6-三苯基-1,3,5-三嗪功能化芴单元的聚合物蓝光材料的合成与表征

以聚(9,9-二己烷芴)(1)和聚(9,9-二(1-(4-己氧)苯)芴)(2)作为参照物,通过Suzuki偶联反应合成了侧链9位碳含有4-己氧基苯和2,4,6-三苯基-1,3,5-三嗪单元的芴共聚物3.聚合物1,2和3固体粉末的5%质量热损失温度分别是274,318和401℃,玻璃化转变温度分别是91,120和139℃.聚合物1,2和3在甲苯溶液中的最大吸收峰和荧光发射峰分别在380和435 nm.从聚合物1到聚合物3,薄膜的荧光发射最大半峰宽逐渐降低.大体积刚性吸电子2,4,6-三苯基-1,3,5-三嗪基团的引入,使聚合物1,2和3的热稳定性、蓝光发射的色纯度和光谱稳定性逐渐提高,不同工作电压驱动下聚合物3稳定的电致发光光谱进一步证明了这一点.聚合物1,2和3的最高占有轨道能级分别为-5.72,-5.95和-5.96eV,最低未占有轨道能级分别为-2.70,-2.39和-2.43 eV.聚合物1,2和3的三线态能级分别为2.82,2.81和2.97 eV.聚合物1,2和3的单线态-三线态能级差分别是0.32,0.32和0.15 eV.4-己氧基苯的引入使聚合物的能隙变宽,而吸电子的2,4,6-三苯基-1,3,5-三嗪的引入使聚合物单线态-三线态能级差依次减少.聚合物1,2和3粉末均易于形成非晶薄膜.聚合物3粉末的有序性介于聚合物1和2之间,聚合物2侧链的烷氧基苯有助于提高固体粉末有序形态的多样化.综合结果表明,侧链含有刚性4-己氧基苯和2,4,6-三苯基-1,3,5-三嗪基团的无规共聚物3具有更佳的综合光电性质.     

聚-1,3,5-三嗪的合成及性能

将联苯二脒与苯甲醛或其盐酸盐与乙酸酐进行缩聚反应,合成了两种新的聚-1,3,5-三嗪,用元素分析、红外光谱、差热分析及热重分析进行了表征,聚合物的η_(比粘)为0.46—0.56分升/克(1％硫酸,25℃),具有良好的耐温性和耐水解性,也有一定的溶解性,利用这种聚-1,3,5-三嗪和二氯化钯反应,可以制成新的高分子络合物。     

New polynitrogen hyperbranched polymers

A method for the preparation of new representatives of polynitrogen hyperbranched polymers of heterocyclic series was developed involving polymerization of monomeric 2,4-diazido-6-propynyloxy-1,3,5-triazine by 1,3-dipolar cycloaddition. Kinetics of polymerization of diazidoacetylene monomer was compared with the kinetic data of polymerization of its closest analog, 2-azido-4,6-bis(propynyloxy)-1,3,5-triazine monomer. Properties of hyperbranched poly(1,2,3-triazole-1,3,5-triazine)s with terminal azide groups and terminal triple bonds were compared, as well.     

Synthesis of Aromatic Polythioethers Containing 1,3,5-Triazine Ring by Aromatic Nucleophilic Substitution Polymerization

Abstract

Reaction of 2,4-dichloro-6-phenyl-1,3,5-triazines with bis(4-mercaptophenyl) sulfide in the presence of a base in THF afforded the corresponding condensation polymer as a whole aromatic polythioether in moderate yield. The polymerization of several 2,4-dichloro-1,3,5-triazine derivatives with this dithiols also proceeded in the o-dichlorobenzene-water two-phase system by using phase transfer catalysts. The resulting polymers consisted of THF-soluble and -insoluble fractions. The x-ray diffraction pattern indicated that these THF-insoluble polymers have a highly crystalline nature. Further, the polymers obtained here showed high thermal stability.     

Coordination chemistry of 2,4,6-tri(pyridyl)-1,3,5-triazine ligands

This review covers the rich coordination chemistry of 2,4,6-tri(pyridyl)-1,3,5-triazine ligands. These polypyridyl derivatives have been coupled to transition metals and lanthanides, and the complexes obtained have been used in various fields such as luminescent materials, for the preparation of coordination polymers and networks as well as for the synthesis of discrete metalla-assemblies. The synthetic and structural aspects of the different isomers of 2,4,6-tri(pyridyl)-1,3,5-triazine are presented, and a survey of their coordination chemistry is given.     

Photocured thiol-ene based optical fluorescence sensor for determination of gold(III)

This study describes the preparation and the characterization of a new thiol-ene based polymeric fluorescence sensor by photo initiated polymerization of trimethylolpropane tris(3-mercaptopropionate), 2-hydroxyethylacrylate, and 2,4,6-triallyloxy-1,3,5-triazine which are used as monomers and also a photo initiator (2,2-dimethoxy-2-phenylacetophenone) for its usage as optical sensor for gold ions. The thiol-ene based polymeric membrane sensor was characterized by using attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). The response characteristics of the sensors including dynamic range, pH effect, response time, and the effect of foreign ions were investigated. Fluorescence spectra showed that the excitation/emission maxima of the membrane were at 379/425 nm, respectively     

Hyperbranched Poly([1,2,3]-triazole-[1,3,5]-triazine)s: An Unusual High Degree of Branching as an Effect of a Polyaddition Kinetics

The results of the kinetic study of melt and solution polymerization at the 1,3-dipolar cycloaddition reaction of the AB₂ monomer – 2-azido-4,6-bis(prop-2-yn-1-yloxy)-[1,3,5]-triazine (ABPOT) are presented in this work as well as the results of the ¹³C-NMR characterization of the obtained hyperbranched poly([1,2,3]-triazole-[1,3,5]-triazine)s. It is established, that the first-shell substitution effect during polyaddition process and unusual high degree of branching (up to 0.9) of polymers synthesized in melt are held.     

Preparation of poly(2,4-dichloro-6-vinyl-1,3,5-triazine-co-styrene)s as polymer supports containing two replaceable groups in monomer unit

Poly(2,4-dichloro-6-vinyl-1,3,5-triazine-co-styrene)s were prepared by the reaction of poly(2,4-diamino-6-vinyl-1,3,5-triazine-co-styrene)s with hydrochloric acid, and followed by treatment with thionyl chloride and N,N-dimethylformamide. The chlorine atoms in the resulted polymers were replaced readily by several nucleophiles such as amide, alkoxide, and mercaptide to afford the corresponding polymers in moderate yields. Among these, polymers containing oligo (oxyethylene) groups at both 2 and 4 positions of 1,3,5-triazine ring worked effectively as phase transfer catalysts for the reaction of n-octyl bromide with alkali metal thiocyanates in toluene–water systems. However, polystyrenes containing only one oligo (oxyethylene) group in monomer unit scarcely exhibited the activity under these conditions although the degree of loading of the functional group was almost the same. The activity depended on the number of oxyethylene units, and the selectivity to alkali metal ions was also observed. © 1992 John Wiley & Sons, Inc.     

Generation and photoreactions of 2,4,6-trinitreno-1,3,5-triazine, a septet trinitrene

We have studied the matrix photolysis of 2,4,6-triazido-1,3,5-triazine (cyanuric triazide, 1). Stepwise generation of the corresponding mononitrene, dinitrene, and trinitrene was observed by matrix IR and electron paramagnetic resonance (EPR) spectroscopy. The generated species were identified by comparison of their matrix IR spectra with density functional theory (DFT) computational results. The generation of 2,4,6-trinitreno-1,3,5-triazine with a septet ground state was confirmed for the first time by matrix EPR spectroscopy. The trinitrene readily decomposed into three NCN molecules upon further photoirradiation. This process was also confirmed by matrix EPR spectroscopy.     

SYNTHESIS AND PROPERTIES OF POLY-1,3,5-TRIAZINES

Two new polytriazines: poly[2-methyl-4, 6-(4,′4″-diphenylene)-1, 3, 5-triazine] (Ⅰ) and poly[2-phenyl-4, 6-(4′, 4″-diphenylene)-1, 3, 5-triazine] (Ⅱ) were synthesized from the solution condensation of biphenyl-4, 4′-diamidine dihydrochloride with acetic anhydride and biphenyl-4, 4′-diamidine with benzaldehyde respectively. These two polymers were characterized by TGA, DTA, elemental analysis and IR spectroscopy. They exhibited good thermal oxidative stability as shown by the fact that the powders of these polymers suffered 5.4%, 2.4% weight loss after isothermal aging in air at 300℃for 200 hours. The decomposition temperature of (Ⅱ) was 583℃in air and 590℃in N_2. These linear poly-1, 3, 5-triazines were soluble in concentrated sulfuric acid, phosphoric acid and trifluoroacetic acid whereas the erosslinked poly-1, 3, 5-triazines reported in the literature were insoluble and infusible.It is interesting that these polymers can form complexes with metal halides as determined by X-ray photoelectron spectroscopy (XPS). The polymer metal complex (Ⅲ). PdCl_2 possesses catalytic activity for hydrogenation.     

Thiol-ene reactions of 1,3,5-triacryloylhexahydro-1,3,5-triazine (TAT): facile access to functional tripodal thioethers

Efficient syntheses of tripodal thioethers have been achieved by ionic thiol-ene reactions of 1,3,5-triacryloylhexahydro-1,3,5-triazine (TAT) with a variety of commercially available thiols. The reactions are complete within minutes and give the products in high yields (63−96%) and high purity without a complex workup. The thiol-ene reactions tolerate a wide range of functionality, including hydroxy, amino, carboxylate, and trimethoxylsilyl groups. The amino acid cysteine is also an excellent substrate for this reaction.     

Extraction and analysis of trace amounts of cyclonite (RDX) and its nitroso-metabolites in animal liver tissue using gas chromatography with electron capture detection (GC-ECD)

An efficient extraction and cleanup technique, and an instrumental detection method suitable for determination of trace amounts of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and its nitroso-metabolites in animal liver tissue were developed and validated in this paper. The method includes the extraction of explosives from liver tissue samples using accelerated solvent extraction (ASE) followed by cleanup using florisil and styrene-divinyl benzene (SDB) cartridges to remove interfering naturally endogenous compounds. The instrumental analysis was conducted using a capillary column gas chromatograph coupled with an electron capture detector (GC-ECD). High recoveries (58.9-106.8%) of RDX, hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX), hexahydro-1,3-dinitroso-5-nitro-1,3,5-triazine (DNX), and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) were achieved at all concentrations studied. RDX, MNX, and TNX gave higher recoveries than DNX at all three tested concentrations (50, 250, 1250 ng/g). Overall recoveries of RDX, MNX, DNX, and TNX from 1 g beef liver samples containing 50, 250, and 1250 ng/g were 80.1, 82.8, 68.9, and 80.4%, respectively. The optimal injection port temperature range was 160-170 °C for analysis of RDX and its nitroso-metabolites. Higher or lower temperatures than 160-170 °C decreased signal amplitudes. RDX was unstable in the liver extraction matrix; as much as 50% of RDX was degraded 10 days after extraction if keeping the liver sample extracts at room temperature. Degradation of RDX to MNX, DNX, or TNX was not detected during the sample storage, extraction, or instrument analysis processes. Other optimized extraction and GC conditions are also discussed.     

Distinctive structural features of hydroxyamino-1,3,5-triazine ligands leading to enhanced hydrolytic stability of their titanium complexes

Three bis(homoleptic) titanium complexes of hydroxyamino-1,3,5-triazine ligands were synthesized and characterized, and their kinetic behavior in THF-water solutions was studied at various pH conditions using UV-vis, based on the characteristic Ti-O band at 380 nm. One of these complexes, , was analyzed by X-ray crystallography. Due to the characteristic electronic structure of the triazine rings, high electron density on the nitrogen atoms leads to strong N-Ti bonds, as indicative by the 2.0 A coordinative bond lengths in the X-ray structure. Consequently, these complexes exhibit high hydrolytic stability over a wide pH range, where hydrolysis was observed to be promoted by basic conditions. At neutral pH, t(1/2) was estimated to be >200 h, whereas at pH = 5.5, no hydrolysis was observed for a period of at least three days.     

基于1,3,5-三嗪的具有力致变色性质的聚集诱导荧光化合物的合成及性质

以1,3,5-三嗪为核, 四苯基乙烯为端基, 合成了两种新型的星状结构分子2,4,6-三(4-(1,2,2-三苯基乙烯基)苯基)-1,3,5-三嗪(TTPE-Tr)和2,4,6-三(4-(1,2,2-三苯基乙烯基)-4-联苯基)-1,3,5-三嗪(TTPE-Ph-Tr), 并利用核磁共振(NMR)、离子化质谱(MALDI-MS)及元素分析等对其进行了结构表征. 通过混合溶剂四氢呋喃(THF)/水析出实验显示, 化合物TTPE-Tr和TTPE-Ph-Tr在纯THF溶剂中无荧光, 而在THF/水混合溶剂中, 当水体积分数增加时呈现荧光增强现象. 通过紫外-可见(UV-Vis)光谱、荧光(PL)光谱、扫描电子显微镜(SEM)证实荧光量子效率的提高是由于分子内电子旋转受限(RIR)导致的. 同时发现化合物TTPE-Tr具有力致变色性质, 简单的研磨使其发光颜色(蓝绿光到黄绿光)及发光强度(Φ_F, 24.4%到14.7%)发生了明显的改变. UV-Vis光谱、PL光谱、X射线衍射(XRD)、荧光寿命和荧光量子效率等测试结果显示, 这种现象是由于力刺激改变了TTPE-Tr的分子堆积形式导致的. 热分析结果显示化合物TTPE-Tr和TTPE-Ph-Tr的热分解温度分别为464和385℃, 具有良好的热稳定性.     

Synthesis and properties of polyurethanes containing s-triazine rings in the main chain

Eight new diisocyanate monomers containing s-triazine ring have been prepared from the parent diacids via the Curtius rearrangement of the corresponding diacyl azides. The parent diacids were synthesised by the reaction of p- and m-hydroxybenzoic acid with 6-methoxy-2,4-dichloro-s-triazine, 6-phenoxy-2,4-dichloro-s-triazine, 6-phenyl-2,4-dichloro-s-triazine, and 2-diphenylamino-4,6-dichloro-s-triazine respectively. Polyurethanes have been synthesised by solution polymerization of these diisocyanates with ethylene glycol in N,N-dimethylacetamide (DMAC). The resulting polymers were characterized by IR spectroscopy, viscosity measurement, solubility tests, and softening points.     

Synthesis of Conjugated Polymers via Transition Metal Catalysed C−H Bond Activation

Transition metal catalysed C−H bond activation chemistry has emerged as an exciting and promising approach in organic synthesis. This allows us to synthesize a wider range of functional molecules and conjugated polymers in a more convenient and more atom economical way. The formation of C−C bonds in the construction of pi-conjugated systems, particularly for conjugated polymers, has benefited much from the advances in C−H bond activation chemistry. Compared to conventional transition-metal catalysed cross-coupling polymerization such as Suzuki and Stille cross-coupling, pre-functionalization of aromatic monomers, such as halogenation, borylation and stannylation, is no longer required for direct arylation polymerization (DArP), which involve C−H/C−X cross-coupling, and oxidative direct arylation polymerization (Ox-DArP), which involves C−H/C−H cross-coupling protocols driven by the activation of monomers’ C(sp²)−H bonds. Furthermore, poly(annulation) via C−H bond activation chemistry leads to the formation of unique pi-conjugated moieties as part of the polymeric backbone. This review thus summarises advances to date in the synthesis of conjugated polymers utilizing transition metal catalysed C−H bond activation chemistry. A variety of conjugated polymers via DArP including poly(thiophene), thieno[3,4-c]pyrrole-4,6-dione)-containing, fluorenyl-containing, benzothiadiazole-containing and diketopyrrolopyrrole-containing copolymers, were summarized. Conjugated polymers obtained through Ox-DArP were outlined and compared. Furthermore, poly(annulation) using transition metal catalysed C−H bond activation chemistry was also reviewed. In the last part of this review, difficulties and perspective to make use of transition metal catalysed C−H activation polymerization to prepare conjugated polymers were discussed and commented.     

Synthesis,polarography and herbicidal activity of quaternary salts of 2-(4-pyridyl)-1,3,5-triazines, 5-(4-pyridyl)pyrimidine, 2-(4-pyridyl)pyrimidine and related compounds

2-(4-Pyridyl)-1,3,5-triazine, 2-(4-pyridyl)-4-methyl-1,3,5-triazine, 2-(4-pyridyl)-4,6-dimethyl-1,3,5-triazine and 2-(4-pyridyl)pyrimidine have been prepared by modification of established triazine and pyrimidine syntheses. These compounds and some of their relatives have been converted to quaternary pyridinium salts. The polarographic reduction potentials of the salts in aqueous solution are pH dependent. The activity of the salts as post-emergent herbicides is reported.     

Synthesis and structure of 6-azido-2,4-bis(2,2,2-trinitroethylamino)-1,3,5-triazine and its <Emphasis Type="Italic">N</Emphasis>-nitro derivatives

Methods were developed for the synthesis of 6-azido-2,4-bis(2,2,2-trinitroethylamino)- 1,3,5-triazine and its N-nitro derivatives (6-azido-2,4-bis(2,2,2-trinitroethyl)nitramino-1,3,5-triazine and 6-azido-2-(2,2,2-trinitroethylamino)-4-(2,2,2-trinitroethyl)nitramino-1,3,5-triazine) containing combinations of azido, trinitroethyl, and nitramine groups. These compounds are of interest as components of energetic composites. The molecular and crystal structures of 6-azido-2,4-bis(2,2,2-trinitroethylamino)-1,3,5-triazine and 6-azido-2,4-bis(2,2,2-trinitroethyl) nitramino-1,3,5-triazine were studied by X-ray diffraction and NMR spectroscopy.     

New hyperbranched poly([1,2,3]-triazole-[1,3,5]-triazines)

New hyperbranched polymers have been synthesized through the 1,3-dipolar polycycloaddition of the AB₂ monomer—2-azido-4,6-bis(propynyloxy)-[1,3,5]-triazine. The polymers contain conjugated heteroaromatic triazine and triazole cycles and terminal acetylene groups. The products have been characterized by exclusion liquid chromatography and IR and ¹H NMR studies.