Syntheses of Novel Triphenylene-Aminoanthraquinone Dimers and Studies on Their Mesomorphic and Fluorescence Properties

Two novel triphenylene-aminoanthraquinone dimers 4a and 4b were synthesized by reacting triphenylene carboxyl derivatives 3a or 3b with 2-aminoanthracene-9,10-dione in yields of 80% and 78%, respectively. Their structures were confirmed by ¹H NMR, electrospray ionization (ESI-MS), and elemental analysis. Their mesomorphic properties were studied by diffraction scanning calorimetry (DSC), polarizing optical microscopy (POM), and x-ray diffraction (XRD). The mesomorphic results suggested that they possess excellent mesophase properties. The investigation of fluorescence properties indicated that the strong cooperating fluorescence actions exist between two structural units. The fluorescence of dimers 4a and4b are seriously quenched due to the electron transfer from donor (triphenylene unit) to acceptor (aminoanthraquinone unit).     

Synthesis,complexation, and mesomorphism of novel calixarene-linked discotic triphenylene based on click chemistry

The novel calixarene-linked discotic triphenylene 5a and 5b were synthesized in good yields via click chemistry. Structural and conformational characterization of new compounds had been achieved by NMR, MS, and elemental analysis. Their liquid crystalline behaviors before and after complexation were studied by polarizing optical microscopy, differential scanning calorimetry, and X-ray diffraction. The neat compounds 5a and 5b showed mesophase but the complexes of 5a and 5b with metallic salts exhibited no liquid crystal behaviors.     

Synthesis and characterization of novel imidazolium-based ionic discotic liquid crystals with a triphenylene moiety

Two novel triphenylene-tethered imidazolium salts were synthesized either by the quaternization of 1-methylimidazole with an ω-bromo-substituted triphenylene or by the quaternization of a triphenylene-substituted imidazole with methyl iodide. Their chemical structures were determined by ¹H NMR, ¹³C NMR, IR, UV spectroscopy and elemental analysis. The thermotropic liquid crystalline properties of these salts were investigated by polarizing optical microscopy and differential scanning calorimetry. These triphenylene-based imidazolium salts with bromide or iodide as counterion show columnar mesophase properties over a wide temperature range.     

Synthesis and mesomorphic properties of calix[4]resorcinarene–triphenylene oligomers

By controlling the mol ratios of reactants, novel calix[4]resorcinarene–triphenylene monomer, dimer and tetramer were designed and synthesised in yields of 50–60% via Click chemistry. Their structures were characterised by NMR and MS. Their liquid crystalline behaviours were studied by differential scanning calorimetry, polarising optical microscopy and X-ray diffraction analysis. The more triphenylene units on calix[4]resorcinarene resulted in the wider temperature scopes of mesophase and higher phase transition temperatures. The monomer 6 and dimer 7 showed the mixed columnar mesophase with hexagonal columnar structure and disordered lamellar columnar structure, and compound 8 possessed only disordered lamellar columnar mesophase. These research results suggest that calix[4]resorcinarene was a good platform to construct columnar liquid crystal and the mesomorphic properties were greatly influenced by the substituted numbers of mesogen units on calix skeleton.     

苯丙炔酸和苯丙烯酸酯苯并菲盘状液晶的合成及介晶性

合成了7个含苯丙炔酸和苯丙烯酸酯链的苯并菲盘状液晶化合物C₁₈H₆(OC_nH_2n＋1)₅O₂CR' [R'＝C≡CC₆H₅, n＝4～9 (1a～1f); R'＝CH＝CHC₆H₅, n＝6 (1g)]. 该系列化合物结构通过¹H NMR, IR和元素分析表征. 液晶性通过差示扫描量热法和偏光显微镜进行了研究, 结果显示: 化合物均为六方柱状相热致型液晶; 含苯丙炔酸酯链苯并菲盘状液晶化合物1a～1f, 随着烷氧链的增长, 清亮点呈现逐渐下降的趋势; 对于含苯丙烯酸酯链苯并菲化合物1g与具有同样软链长度的炔基酯链苯并菲化合物1c比较, 具有更低的熔点和结晶点, 而它们的清亮点几乎一致, 因而化合物1g有更宽的介晶性温度范围.     

不对称苯并菲盘状液晶的合成及取代基对介晶性的影响

合成了一系列新型含间位二硝基苯甲酸酯不对称苯并菲盘状液晶化合物2-(3,5-二硝基苯甲酰氧基)-3,6,7,10,11-五烷氧基苯并菲(3a～3f). 通过偏光显微镜(POM)和差示扫描量热计(DSC)对其介晶性进行了研究. 结果显示: 此类化合物有高的清亮点, 稳定的六方柱状相以及较宽的介晶相范围, 且随着软链碳原子数的增加, 化合物的熔点和清亮点均出现下降趋势, 但六方柱状相的有序性却没有发生很明显的变化. 同时通过与其它三类苯并菲盘状液晶2-苯甲酰氧基-3,6,7,10,11-五烷氧基苯并菲(4a～4f), 2-二茂铁甲酰氧基-3,6,7,10,11-五烷氧基苯并菲(5a～5f), 2,3,6,7,10,11-六烷氧基苯并菲(6a～6f)的对比研究, 探讨了酯基, 强吸电子基团, 以及取代官能团体积对介晶性的影响. 证实了苯并菲化合物中分子结构小的变化将引起介晶性大的改变.     

Ionic discotic liquid crystals: synthesis and characterization of pyridinium bromides containing a triphenylene core

Five novel pyridinium salts tethered with hexaalkoxytriphenylene molecules were synthesized by the quaternization of pyridine with ω-bromo-substituted triphenylene derivatives. Their chemical structures were determined by ¹H NMR, ¹³C NMR, IR, UV spectroscopy and elemental analysis. The thermotropic liquid crystalline properties of these salts were investigated by polarizing optical microscopy and differential scanning calorimetry. These triphenylene-based pyridinium salts with bromide as counterion were found to be mesomorphic over a wide temperature range.     

Novel room-temperature perylene liquid crystals: synthesis of 1,7-dibrominated cholesterol–perylene bisimides with different ester-bridging chains and their mesomorphic properties

Three novel 1,7-dibrominated cholesterol–perylene liquid crystals 6a, 6b and 6c with different ester-bridging chains were designed and synthesised in yields of 30–40%. Their structures were characterised by FT-IR, ¹H NMR and HR-MS spectra. Their mesomorphic behaviours were studied by differential scanning calorimetry (DSC), polarising optical microscopy (POM) and X-ray diffraction (XRD). Compounds 6a, 6b and 6c exhibit hexagonal columnar liquid crystalline phase at room temperature. Their mesomorphic temperature ranges are as wide as 140–162°C. Their fluorescence spectra suggested that they possess good fluorescence properties in solution. The soft ester-bridging chains are more favourable for room-temperature mesophase and high fluorescence than the rigid ester-bridging chain.     

Effect of orientation of extra fused benzene ring and lateral methyl substituent on the mesophase behaviour of three-ring azo/ester molecules

ABSTRACT

Two homologous series of the three-ring azo/ester compounds 2-(or1-) naphthyl 4?-(4?’-alkoxy phenylazo) benzoates (In_a and IIn_a) were synthesised. A lateral methyl group was introduced in different positions of the alkoxy phenyl moiety, in position-2 to give series In_b and IIn_b and in position-3 to give series In_c and IIn_c. Molecular structures were characterised via elemental analyses, infrared and ¹H-NMR. Their mesophase characteristics were investigated by differential scanning calorimetry (DSC) and their phases identified via polarised light microscopy (PLM). Transition temperatures were correlated with the alkoxy-chain length (n) that varies between 6, 8, 10, 12, 14, and 16 carbons. Comparative studies were first made to investigate the effect of including the extra fused benzene ring, and its orientation, into the previously investigated three-ring compounds, 4-phenyl 4?-(4′′-alkoxyphenylazo) benzoates (IIIn_a). Investigation of the mesophase behaviour was extended to cover the effect of introducing the lateral methyl group and its position. The comparison between the present six series and their corresponding phenyl analogues IIIn_a,b,c, indicated that the 2-naphthyl analogues, In_a,b,c, exhibit the highest mesophase stability. Whereas, the steric effect of the protruded naphthalene group destabilises all mesophases and appear only monotropically. The results were discussed in terms of polarisability effect.     

Heptasubstituted triphenylene 2,3-dicarboxylic esters discotic liquid crystals with three different types of peripheral substitution

Hexasubstituted triphenylene (1a) containing four alkoxy and two adjacent methoxycarbonyl tails can be smoothly brominated or nitrated at its α-position(s) of two electron-rich rings to give a series of bromides and nitro compounds through electrophilic aromatic substitutions. Positions of bromo or nitro groups in target compounds were unambiguously established by combined analysis of 2D nuclear magnetic resonance experiments including nuclear Overhauser effect and heteronuclear multiple-bond correlation which indicated that monobromination or mononitration occurred preferentially at position 8 or 5 of 1a, respectively. Calculations of molecular geometry on 2a–e reveal that the α-Br or α-NO₂ group(s) would induce different degrees of helical deformation in the triphenylene core and the degree of non-planarity decrease in the following order: 2c > 2b > 2e > 2a > 2d. In contrast to highly twisted 2b–c and 2e, which did not form a mesophase, the formation of a hexagonal columnar phase at room temperature even down to ?50°C was observed and confirmed by polarising optical microscopy and X-ray diffraction for sterically less hindered, monosubstituted 2a and 2d.     

Synthesis,Recognition of Metal Ions of Salicylidenimine Functionalized p-tert-Butylcalix[n]arene-core Dendrimers

A series of salicylidenimine functionalized p-tert-butylcalix[n]arene-core dendrimers 7a–b were synthesized in higher yields by divergent method from the corresponding ethyl p-butylcalix[n]arylacetates 2a–b (n = 6, 8). 2a–b were first treated with excess of 1,6-diaminohexane to give amide derivatives with free amine terminal groups 3a–b, which in turn reacted with salicylaldehyde in alcohol to yield the first generation of Schiff bases 4a–b. 3a–b reacted with ethyl acrylate, ammonolized with 1,6-diaminohexane and condonsated with salicylaldehyde successfully to give the second generation of Schiff bases 7a–b. The extraction and binding properties of the dentritic Schiff bases 4a–b and 7a–b for several kinds of metal ions were studied with UV–Vis spectroscopy and atomic absorption spectroscopy. In which they showed a great affinity for soft Cu^2 +  ions and formed 1:1 or 1:2 stoichiometric complexes.     

Novel discotic liquid crystal oligomers: 1,3,5-triazine-based triphenylene dimer and trimer with wide mesophase

Series of novel 1,3,5-triazine-based triphenylene oligomers 7, 10 and 12 with large bridging polyaromatic core were designed and synthesised by simple procedures in high yields. Their structures were confirmed by FTIR, ¹H NMR, ESI-MS and elemental analyses. Their mesomorphic behaviours were studied by differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. 1,3,5-triazine-based triphenylene monomer 7 has no mesomorphic property, but 1,3,5-triazine-based triphenylene dimer 10 and 1,3,5-triazine-based triphenylene trimer 12 possess excellent mesomorphic properties. The mesomorphic temperature range of compound 12 was as wide as 180°C. These studies indicated that the mesomorphic properties were determined by the numbers of triphenylene units. More units of triphenylene in the oligomers resulted in better mesomorphic properties.     

无膦钯催化Heck反应合成新型芳维A酸类化合物

考察了以二环己基胺作配体的无膦钯催化Heck反应条件, 建立起一种新型的无膦钯催化Heck反应体系. 应用该体系可高收率(72%～84%)、高立体选择性(83%～95%)合成二取代和三取代二苯烯类化合物. 以2,4,5-三甲氧基苯乙烯、α-细辛脑为原料, 合成了4个尚未见文献报道的新型二苯烯类芳维A酸甲酯(3a, 3b, 4a, 4b), 并且在温和的水解体系[LiOH, V(THF)∶V(H₂O)＝5∶1]下顺利得到了它们的水解产物芳维A酸(5a, 5b, 6a, 6b), 产物通过¹H NMR, ¹³C NMR, IR和MS进行了结构确认.     

Synthesis and Spectroscopic Properties of S-,O-Substituted Naphthoquinone Dyes

New S-,O-substituted naphthoquinone compounds (3a, 4b, 6, 7c, 9d, 10, 12, 13c, 14d, 15) were synthesized via vinilic substitution. 2,3-Dichloro-1,4-naphthoquinone gave 3a and 4b with 4,4′-thiobisbenzenethiol, respectively. Compounds 6 and 7c were obtained from the reaction of 2,3-dichloro-1,4-naphthoquinone with cyclohexylmercaptane. The compounds 9d and 10 were prepared from the reaction of 2,3-dichloro-1,4-naphthoquinone with 6-mercapto-1-hexanol. Compounds 12, 13c, 14d, and 15 were synthesized from the reaction of 2,3-dichloro-1,4-naphthoquinone with 1,6-hexanedithiol. Their structures were characterized by micro analysis, FT-IR, ¹H NMR, ¹³C NMR, MS, UV-Vis, and fluorescence spectroscopy.     

Binuclear aluminum complexes with amine–imine type ligands derived from 1,3-benzenedialdehyde: synthesis,structures and their catalytic properties in ring-opening polymerization

Reaction of 1,3-bis(imino)benzenes with a stoichiometric amount of LiAlH₄ in THF yields iminoaminobenzenes L1 and L2. Further reaction of iminoaminobenzenes L1 and L2 with an equivalent of AlR₃ in toluene affords macrocyclic binuclear aluminum complexes 1a, 1b, and 2a. These macrocyclic aluminum complexes were characterized by ¹H NMR, ¹³C NMR, and IR spectroscopy. The molecular structures of 1a, 1b, and 2a were further confirmed by X-ray crystallography. X-ray diffraction analysis revealed that 1a, 1b, and 2a adopted a distorted tetrahedral geometry around aluminum. These complexes have efficient activities toward ring-opening polymerization of ε-caprolactone in the presence of benzyl alcohol.     

Synthesis of New Benzoxazaphosphinine/Benzoxazaphosphole/Diazaphosphaphenalene‐2‐sulfides using Lawesson's Reagent

Synthesis of new benzoxazaphosphinine/benzoxazaphosphole/diazaphosphaphenalene 2‐sulfides were accomplished by the reaction of Lawesson's reagent (LR) with 4‐bromo‐2‐[(phenylamino) methyl]phenol (1a), 4‐bromo‐2‐[(4‐chloro/bromo/methoxy/methylphenyl‐amino)methyl]phenol (1b–e), 4‐bromo‐2‐[(benzylamino)methyl]phenol (1f), 2‐amino‐4‐chlorophenol (2a)/2‐amino‐4‐methylphenol (2b), 1,8‐diaminonaphthalene (3) respectively in anhydrous toluene. Products 4a–f, 5a–b and 6 were characterized by IR, ¹H, ¹³C, ³¹P NMR and Mass spectra.     

Antiproliferative activities of 2-hydroxyethyl substituted benzimidazolium salts and their palladium complexes against human cancerous cell lines

Abstract

Benzimidazolium salts (1a and 1b) and respective palladium complexes (2a and 2b) were prepared and characterized with ¹H and ¹³C NMR, IR, elemental analysis as well as HRMS (for 2a). All target compounds were screened as potential anticancer agents against human cell lines for assessing their cytotoxicity. Heterocyclic organic compounds (1a and 1b) showed more cytotoxic activity than their complexes (2a and 2b) in the tested two cell lines. Particularly, a benzimidazolium salt including a 4-methylbenzyl group had a high cytotoxic potency towards MDA-MB-231 and DLD-1 cell lines with IC₅₀ values comparable to a well-known anticancer drug cisplatin, which is generally used in clinical studies. Furthermore, a compound namely 1-(2-hydroxyethyl)-3-(2,3,4,5,6-pentamethylbenzyl)-1H-benzo[d]imidazol-3-ium bromide was found to be more cytotoxic activity in MDA-MB-231 cell line compared to cisplatin with following IC₅₀ value of 7.59?±?0.68?μM.     

具有纳米尺寸的四聚四硫富瓦烯大环冠醚的合成

以二(碘乙基)醚和2,3-二氰乙硫基四硫富瓦烯衍生物作为起始原料, 采用腈乙基保护与脱保护技术, 通过多步反应以较好的收率合成了两个纳米结构的大环四硫富瓦烯冠醚5a～5b. 通过循环伏安法(CV)研究了化合物4b和5b的电化学性质, 并用¹H NMR谱研究了5b与[60]富勒烯之间的相互作用. 结果表明: 5b存在环结构效应, 与[60]富勒烯有一定程度的电荷转移相互作用.     

Asymmetric N-heterocyclic carbene benzimidazolium salts and their silver(I) complexes: potential as ionic liquid crystals

The synthesis and characterisation of a homologous series of monodentate benzimidazolium salts, 1–4 and their mononuclear silver(I)–NHC (where NHC = N-heterocyclic carbene) complexes, 5–8, are reported. The benzimidazolium salts were prepared from the N-alkylation of 1-methyl-benzimidazole with alkyl halides of varying carbon chain lengths. The mono silver(I)-NHC complexes, 5–8, were prepared by the reaction of the benzimidazolium salts with Ag₂O. All the synthesised compounds were fully characterised by ¹H-nuclear magnetic resonance (¹H-NMR), ¹³C-NMR and fourier-transform infrared (FTIR) spectroscopy. The molecular structures of compounds 3·PF₆, 4·PF₆, 7 and 8 were elucidated through single-crystal X-ray diffraction analyses. We postulate that the attachment of long alkyl chains to the heterocyclic core of 1-methyl benzimidazole could induce mesophase formation. The liquid crystalline behaviour of the benzimidazolium salts was investigated by polarised optical microscope and differential scanning calorimetry. Salts 3 and 4 were found to be thermotropic liquid crystals which exhibited a smectic A phase. However, upon complexation with silver(I) ions, all the Ag(I)–NHC complexes are found to be non-mesogenic.