苯并噻吩类稠环化合物的合成及其在有机场效应晶体管中研究的进展

总结了苯并噻吩类稠环化合物半导体材料的最新研究进展,对其合成方法及结构与性能进行了归纳,介绍了它们在有机场效应晶体管中的应用,并对其研究和应用前景进行了展望。     

Ab initio study of ladder-type polymers: Polythiophene and polypyrrole

An ab initio study of four polymers, polythiophene, polypyrrole, ladder-type polythiophene, and ladder-type polypyrrole is presented. Upon an analysis of the variation of the band gap when comparing the non-ladder and the ladder-type polymers, a discrepancy is found between the thiophene and the pyrrole polymer families. For polythiophene, the ladder-type polymer has a larger band gap than the non-ladder polymer whereas the opposite is found for the pyrrole polymers. This difference is explained in terms of the competition between the bond length alternation and the effect of the charge density distribution in the carbon backbone.     

On-surface synthesis and atomic scale characterization of unprotected indenofluorene polymers

Polycyclic hydrocarbons with nonzero radical character have attracted enormous interest as potential active media for organic electronics and spintronics. In this context, indenofluorenes are an intriguing class of formally antiaromatic, biradical materials with a radical character that depends on the connectivity of their six- and five-membered rings. Synthesis of indenofluorene polymers and related compounds, first achieved in the early ‘90s with the production of ladder-type chains, represents a major step toward incorporation of these systems into devices. However, solution-based synthetic protocols require bulky protecting groups to stabilize the most reactive sites and, at the same time, to improve solubility and processability of such compounds. The preparation of various pristine – that is, unprotected—indenofluorene polymers has recently become possible via the on-surface synthesis approach, where the resulting nanostructures are supported and efficiently stabilized by the underlying substrate in ultrahigh vacuum conditions. Here, an overview of these recent works is given, with a focus on synthetic challenges, structural details and electronic properties.     

Direct assembly of polyarenes via C-C coupling Using PIFA/BF3·Et2O

Direct oxidative Kita-type coupling between naphthalene and substituted benzenes was found to proceed via four-component coupling, leading to a linear tetraarene with a binaphthalene core. The methodology was extendable to the coupling of unfunctionalized 1,1'-binaphthalene with mesitylene to give a linear hexaarene product in a remarkably chemoselective manner in 87% yield. The method represents an attractive alternative to the traditional syntheses of related oligonaphthalene products via a sequence of metal-catalyzed cross-coupling steps.     

Self-assembling and photophysical properties of the organogelators based on cyanostyryl-substituted carbazoles

Four cyanostyryl-substituted carbazole derivatives (CN-ODEC1, CN-ODEC2, CN-DDEC1, and CN-DDEC) were synthesized and their self-assembly properties have been studied. It was found that they could form organogels especially in aromatic solvents. Scanning electron microscopy and light microscopy images show that the xerogels formed from monosubstituted derivatives (CN-O/DDEC1) gave well-organized tapes, and those from disubstituted derivatives (CN-O/DDEC2) exhibited heavy entangled three-dimensional structures. The UV–vis absorption and fluorescence emission spectra, as well as X-ray diffraction patterns, suggest that carbazole derivatives underwent J-type π-stacking. Meanwhile, we suggested that strong H-bonding and moderate π–π interactions were the key driving force for the gelation of the monosubstituted derivatives, and head-to-tail “ladder-type” J-aggregates were formed in the gel state. On the other hand, strong π–π interaction might be considered as the main driving force for the gelation of disubstituted derivatives, and J-aggregates with no well-organized packing mode of molecules were obtained in the gel phase. It should be noticed that aggregation-induced emission was observed during the gelation processes.     

Synthesis and biological evaluation of amide derivatives of (6-Chloro-2,3-dihydro-1H-inden-1-yl)acetic acid as potential anti-inflammatory agents with lower gastrointestinal toxicity

A variety of amide derivatives of (6-chloro-2,3-dihydro-1H-inden-1-yl)acetic acid were synthesized and screened for their anti-inflammatory and related biological activities. These compounds were found to be longer acting and showed residual activity exceeding that of standard indomethacin. The studies with SKF-525A, a standard hepatic microsomal enzyme inhibitor showed that probably the test compound per se is the active species. The compound 6y showed best activity profile with ED30 of 6.45 mg/kg however this compound was found to be toxic at 100 mg/kg p.o. Though these compounds exhibited appreciable analgesic and antipyretic activities but they failed to prevent the development of secondary inflammation in adjuvant induced arthritis assay. The compound 6x showed 94% inhibition of acetic acid induced writhing. Studies showed that antagonism of TNF-alpha is not possibly involved in the mechanism of action of these compounds. However these compounds were found to have only mild ulcerogenic potential at the tested dose level of 100 mg/kg p.o. in comparison to indomethacin.     

Synthesis and characterization of electron-deficient and highly soluble (Bis)indenofluorene building blocks for n-type semiconducting polymers

New electron-deficient and soluble indenofluorene-based and bisindenofluorene-based ladder-type building blocks embedding carbonyl and dicyanovinylene functionalities were synthesized, and their optical and electrochemical properties were characterized. These derivatives exhibit optical band gaps of 1.83 to 2.44 eV and low LUMO energies of -3.24 to -4.30 eV, representing a promising new building block class for n-type polymeric electronic materials.     

2,3,6,7-Tetraamino-9,9-bis(2-ethylhexyl)fluorene: new multifunctional monomer for soluble ladder-conjugated molecules and polymers

2,3,6,7-Tetraamino-9,9-bis(2-ethylhexyl)fluorene (TABEF), as a new multifunctional monomer for ladder-type conjugated molecules and polymers, was efficiently synthesized via a six-step procedure with an overall yield of 30%. Two isomeric ladder compounds based on TABEF building blocks were also synthesized and preliminarily studied.     

HPLC-DAD-qTOF Compositional Analysis of the Phenolic Compounds Present in Crude Tomato Protein Extracts Derived from Food Processing

The conversion of raw fruits and vegetables, including tomatoes into processed food products creates side streams of residues that can place a burden on the environment. However, these processed residues are still rich in bioactive compounds and in an effort to valorize these materials in tomato by-product streams, the main aim of this study is to extract proteins and identify the main phenolic compounds present in tomato pomace (TP), peel and skins (TPS) by HPLC-DAD-ESI-QTOF. Forty different phenolic compounds were identified in the different tomato extracts, encompassing different groups of phenolic compounds, including derivatives of simple phenolic acid derivatives, hydroxycinnamoylquinic acid, flavones, flavonones, flavonol, and dihydrochalcone. In the crude protein extract (TPE) derived from tomatoes, most of these compounds were still present, confirming that valuable phenolic compounds were not degraded during food processing of these co-product streams. Moreover, phenolic compounds present in the tomato protein crude extract could provide a valuable contribution to the required daily intake of phenolics that are usually supplied by consuming fresh vegetables and fruits.     

Can cyclodextrins really improve the selectivity of extraction of BTEX compounds?

Solubility of BTEX compounds was determined in aqueous solutions of natural CDs (α-, β-, γCD) as well as of some industrial βCD derivatives (RAMEB, HPBCD, AcβCD) measured by UV photometry. From the phase solubility diagrams the complex association constants were determined. The βCD derivatives increased the solubility of individual monoaromatic compounds, depending on the structure of the guest molecule. We have found that RAMEB (randomly methylated βCD) and AcβCD (partially acetylated βCD) are the most effective solubilizers while the effect of natural CDs is not significant because the complexes precipitate from the solutions. Extraction experiments were performed to see how the complexation of components influences the extraction using a mixture modeling the composition of these pollutants in soil. We have found that although the soluble CD derivatives are not as selective as expected based on complex association constants, they increased the efficacy of extraction by 4–6 times. The reason of the low selectivity is that the concentration ratio of certain BTEX compounds in CD solutions is smaller than in water. CD derivatives seem to have an equalizing effect: the solubility of the least soluble p-xylene is improved in the highest extent, but that of benzene the least. This result, however, is an advantage in the application of these CD derivatives in soil remediation (the availability of each BTEX compounds will be enhanced).     

BBr3-promoted cyclization to produce ladder-type conjugated polymer

A novel chemical cyclization method using BBr₃ has been successfully developed to prepare ladder-type conjugated systems. The cyclized ladder compounds revealed an extended conjugation due to planarization of the structures. The extended ladder polymer can also be easily prepared by our chemical cyclization method using a soluble precursor.     

Synthesis of novel ladder bis-silicon-bridged p-terphenyls

The tetralithiation reaction of 2,2',5',2' '-tetrabromo-p-terphenyl followed by a double silacyclization produces bis-silicon-bridged p-terphenyls. On the basis of this convenient method, a series of new ladder-type p-terphenyl derivatives have been synthesized. Their crystal structures and photophysical properties are described.     

Gas chromatographic and spectral properties of pentafluorobenzyl derivatives of 2,4-dichlorophenoxyacetic acid and phenolic pesticides and metabolites

Eleven phenols and 2,4-dichlorophenoxyacetic acid, compounds that may be found in body fluids of humans exposed to pesticides, are derivatized with pentafluorobenzyl bromide and characterized by gas chromatography with electron capture detection. These derivatives are further characterized by positive and negative chemical ionization mass spectrometry, nuclear magnetic resonance spectroscopy, and gas chromatography-Fourier transform infrared spectroscopy. Negative chemical ionization mass spectra of all derivatives have an anionic base peak derived from the parent analyte. In the positive mode the nonchlorinated derivatives have base peaks indicative of the analyte, while chlorinated derivatives are cleaved to give the pentafluorobenzyl cation as base peak. The possibility is explored that ortho-substituted phenols might be formed as byproducts in these derivatizations.     

Synthesis,Anti-Proliferative Evaluation and Mechanism of 4-Trifluoro Methoxy Proguanil Derivatives with Various Carbon Chain Length

Among the known biguanide drugs, proguanil has the best antiproliferative activity. In contrast, newly synthesized biguanide derivatives containing fluorine atoms have excellent biological activity, among which trifluoromethoxy compounds show the strongest ability. Preliminary work in our laboratory exhibited that n-heptyl containing proguanil derivatives on one alkyl chain side have better biological activity than those with a shorter carbon chain. However, the relationship between the length of the carbon chain and the activity of the compounds is unknown. In this study, we synthesized 10 new trifluoromethoxy-containing proguanil derivatives with various carbon chain lengths. The phenyl side is fixed as the trifluoromethoxy group with change of carbon chain length in alkyl chain side. It was found that the anti-cancer abilities of 5C–8C with n-pentyl to n-octyl groups was significantly better than that of proguanil in the five human cancer cell lines. The colony formation assay demonstrated that 6C–8C at 0.5 to 1.0 μM significantly inhibited the colony formation of human cancer cell lines, much stronger than that of proguanil. Pharmacologically, 8C activates AMPK, leading to inactivation of the mTOR/p70S6K/4EBP1 pathway. Thus, these novel compounds have a great potential for developing new anti-cancer candidates.     

Beta-N-cyanoethyl acyl hydrazide derivatives: a new class of beta-glucuronidase inhibitors

Eight new beta-N-substituted acyl hydrazides along with their corresponding acyl derivatives were synthesized and screened for in vitro beta-glucuronidase inhibition and found to be active against the enzyme. All of these compounds were found to be noncompetitive inhibitors except for N'-(2-cyanoethyl)-4-hydroxy benzohydrazide (10), which was found to be an uncompetitive inhibitor. Structure-activity relationship studies indicated that the benzyloxy group present in compounds 12 and 13 is responsible for the beta-glucuronidase inhibition activity.     

Synthesis and evaluation of novel α-aminoamides with substituted benzene scaffold for the treatment of neuropathic pain

Small molecule sodium ion channel blockers with a pharmacophore of α-aminoamide have exhibited anti-allodynia effects on neuropathic pain. A library of new α-aminoamide derivatives containing a scaffold of substituted benzene were designed and synthesized. These compounds were evaluated in mice formalin model and they exhibited significant analgesic activities. However, the anti-allodynia mechanism of these compounds remains unclear; some of the target compounds can only moderately inhibit the sodium ion channel, Nav1.7, in a whole-cell patch clamp assay. These results suggest that introduction of the moiety of substituted benzene to α-aminoamide derivatives can improve their bioactivity and further study is warranted.     

Phosphorylation and cyclophosphorylation of 1,4-diacetoxyanthracene and dianthrone

Phosphorylation and cyclophosphorylation of 1,4-dihydroxyanthracene and dianthrone by hexaalkylphosphorous triamides in pyridine was effected for the first time. The phosphorylation rate is found depending on the type of the alkyl fragment in the amido group of the phosphorylating agent. Cyclic phosphoramidites derived from anthracene were prepared both by molecular assembling and direct cyclophosphorylation. Thio and oxo derivatives of these cyclic compounds were obtained. Dianthrone derivatives undergo intramolecular cycloaddition at only one anthracene fragment to form an interesting bulky structure containing the phospholane ring.     

Synthesis and Anti-tumor Activity of Novel Amide Derivatives of Ursolic Acid

Ursolic acid was modified at C3 and C28 position to obtain fourteen derivatives including twelve novel compounds, and their chemical structures were characterized by IR, ^1H NMR and MS. Cell growth inhibitory effects of the derivatives against Hela cell were evaluated by MTT assay. All these derivatives were found to have stronger cell growth inhibitory than their parent compound, ursolic acid. The derivatives with a substituted acetyl group at C3 hydroxyl group show better activities than those with an unsubstituted hydroxyl group.     

Trimethylene-bridged Tetraorganodistannoxanes {[Me3SiCH2(RCOO)Sn(CH2)3Sn(OOCR)CH2SiMe3]O}n (R = Ph, 2,4-Me2C6H3): Control of Structure by Variation of R

The synthesis of trimethylene-bridged carboxylate-substituted tetraorganodistannoxanes {[Me₃SiCH₂(RCOO)Sn(CH₂)₃Sn(OOCR)CH₂SiMe₃]O} _n (1, R = Ph; 2, R = 2,4-Me₂C₆H₃) is reported. Depending on the structure of R, in the solid state these compounds are either dimers (1, n = 2, cis-isomer) with a ladder-type structure or tetramers (2, n = 4) with a double ladder-type structure.     

Fulvalene-Based Polycyclic Aromatic Hydrocarbon Ladder-Type Structures: Synthesis and Properties

Polycyclic aromatic hydrocarbons (PAHs) have found strong interest for their electronic properties and as model systems for graphene. While PAHs have been studied intensively as single units, here PAHs were constructed in ladder-type arrangements using cross-conjugated fulvalene and dithiafulvalene motifs as connecting units and moving forward a convenient synthetic approach for dimerizing (thio)ketones into olefins by the action of Lawesson's reagent. Some of the PAHs can also be regarded as “super-extended” tetrathiafulvalenes (TTFs) with some of the largest cores ever explored, being multi-redox systems that exhibit both reversible oxidations and reductions. Concomitant absorption redshifts were observed when expanding the ladder-type structures from one to two to three indenofluorene units, and optical and electrochemical HOMO-LUMO gaps were found to correlate linearly. Various conformations (and solid-state packing arrangements) were studied by X-ray crystallography and computations.