基于四硫富瓦烯衍生物Langmuir-Blodgett膜的研究进展

在简要介绍了Langmuir-Blodgett (LB)膜的基础上, 主要依据制备LB膜的四硫富瓦烯(TTF)衍生物化学结构的不同, 概括了基于两亲性TTF衍生物、非两亲性TTF衍生物、TTF电荷转移(CT)复合物或盐、以及TTF金属络合物LB膜的制备、结构表征与性能研究进展. 介绍了基于TTF衍生物的LB膜在导电、化学及生物传感器、光学以及磁性方面的应用, 并对基于TTF衍生物LB膜的发展进行了展望.     

非两亲性四硫代富瓦烯导电LB膜的研究

近年来，利用LB技术制备电活性的有机超薄膜受到广泛的关注．导电LB膜的膜材料主要是含有受体化合物7，7’，8，8’-四氰基二亚甲基苯醌（TCNQ）的电荷转移复合物[1~3]以及给体分子[4，5]，特别是四硫代富瓦烯（TTF）衍生物[6~8]．尽管LB膜多由带长链的两亲性分子组装而成，但是对非两亲性TTF衍生物LB膜的研究[9~11]结果表明，引入长链烷基并非制备TTF类电荷转移复合物LB膜的先决条件．该结果极大地拓展了LB膜材料的研究范围．本文报道非两亲性TTF衍生物与花生酸混合导电LB膜的制备、结构表征与导电性能研究．1实验部分利用亚磷…     

四硫富瓦烯及其衍生物在分子开关领域的研究进展

四硫富瓦烯(TTF)及其衍生物由于具有特殊的结构和性质, 在分子开关、分子传感器、光信息存储和非线性光学等领域显示出诱人的应用前景. 综述了近几年TTF及其衍生物在分子开关领域的最新研究进展.     

四硫富瓦烯衍生物/硬脂酸LB膜的表征

研究了四（苄硫基）四硫富瓦烯／硬脂酸（TBT－TTF／SA）（1：1）LB膜、二（亚乙二硫基）四硫富瓦烯／硬脂酸（BEDT－TTF／SA）（1：1）LB膜和四（十六烷硫基）四硫富瓦烯／硬脂酸（THT－TTF／SA）（1：1）LB膜的结构．从X射线衍射结果得到了LB膜的层间距离．X射线衍射图显示了TBT－TTF／SALB膜和BEDT－TTF／SALB膜的层间结构由硬脂酸控制．从偏振红外结果计算出硬脂酸和四硫富瓦烯衍生物在LB膜中的取向角．根据分子取向角确定了LB膜的层间结构．用分子长度和分子取向角得到的层间距离与从X射线衍射得到的层间距离相吻合．     

胆红素及其两亲衍生物的Langmuir-Blodgett膜研究

研究了亚相酸度和金属离子对胆红素(1)及其两个两亲衍生物胆红素二(十八烷基)酯(2)和胆红素二(十八烷基)酰胺(3)的单分子膜和LB膜性能的影响.通过π-A等温线、X射线光电子能谱、紫外-可见光谱等方法,研究了它们在有序分子膜中的分子伸展及与金属离子的配位方式.胆红素及其两亲衍生物与金属离子在有序分子膜中的配位(生成1:1型配合物)明显不同于其在本体溶液中的配位(1:1,1:2或2:1型配合物).小角X射线衍射表明1,2和3形成双层膜间距分别为2.15,5.55和5.65nm的Y型LB膜.     

2,3-二硫甲基-6,7-二硫十六烷基四硫代富瓦烯的合成

Langmuir-Blodgett(简称LB)法作为分子水平的成膜技术,能制备纳米级几乎无缺陷的单分子层或多分子层膜,在微电子学,分子器件,磁性有序材料,生物膜等方面有广泛的应用前景。目前,四硫富瓦烯类衍生物作为导电LB膜材料的研究,引起人们极大的兴     

2-烷基-苯并咪唑在硝酸银亚相上的Langmuir膜及LB膜

对不同链长的2-烷基-苯并咪唑衍生物（BzCn,烷基链长从C5到C15）在硝酸银亚相上的成膜行为及形成的LB膜的结构进行了研究.表面压－面积曲线的结果表明，短链(C5～C9)的2-烷基-苯并咪唑可在银离子亚相上形成稳定的单分子膜，而长链(C13和C15)衍生物则形成多层膜.利用LB技术可将上述Langmuir膜转移到固体基板上形成LB膜，其吸收光谱的结果说明了苯并咪唑和银离子配位.利用AFM、XRD及FT-IR等技术研究了烷基链长对LB膜结构的影响.实验结果表明,除了BzC15，其余的衍生物都可形成规整的层状结构.短链衍生物的单层LB膜具有均一、平整的形貌；而对于BzC15，观察到多层结构.     

新型偶氮苯自组装一LB组合有序膜的构造与表征

偶氮兹及其衍生物具有独特的光致异构化和电化学反应机制,其LB单分子膜作为一种高度有序的分子组装体系,以其诱人的应用前景引起了人们的极大兴趣．然而在这方面的研究中,LB膜通常是沉积在SnO。或镀金的基片上,其结构的相对木稳定性限制了实际应用的可能性．我们利用自组装技术,在金基底表面组装了具有特定末端基团的自组装单分子膜,然后利用LB技术构造偶氮苯衍生物的单分子膜,以期得到稳定而有序的偶氮苯LB膜,且不影响其光化学和电化学活性．本文报道了这种新型偶氮苯自组装一LB组合股的结构表征及其电化学行为．亚实验部分偶…     

四硫富瓦烯(TTF)衍生物的配位组装

四硫富瓦烯（tetratiafulvalenc,TTF)衍生物和二硫纶（dithiolene)化合行等有机富硫分子作为有机光电磁的功能化合物,一直受到了人们的重视,近年来一类融合了TTF和二硫纶结构的扩展TTF衍生物引起人们很大的兴趣,这类八硫共轭体系具有较好的电子授受特性,展示出潜在的应用价值。有目的地利用它与与金属离子间较强的配位能力对这些化合物进行晶体或分子设计已成为配位化学在富硫有机配合物研究中的一个热点。本文重点介绍这方面的研究的最新进展。主要包括以卤化亚铜基本骨架为基础的四烷基硫取代四硫富瓦烯（[(RS)2TTF(SR)2])的配位组装;二烷基硫取代的TTF融合二硫纶离子（[(RS)2TTF(S2)]^2-)和TTF融合双二硫纶离子（[(S)2TTF(S)]^4-金属配位衍生物的分子设计和空间构筑。通过配位修饰或组装,这类TTF金属衍生物显示了多变的结构,有的已发展具有较好的物理性质。     

四(十六烷硫基)四硫富瓦烯/硬脂酸混合LB膜的结构研究

我们考察了四(十六烷硫基)四硫富瓦烯/硬脂酸(THT-TTF:SA=1:n)在气一液界面的聚集状态及在LB膜中的排列.当n=1时,THT-TTF分子在气-液界面形成了双分子膜;当n>6时,THT-TTF分子形成了单分子膜;1相似文献   

High-performance organic field-effect transistors based on pi-extended tetrathiafulvalene derivatives

Aromatic ring-condensed TTF derivatives exhibited excellent p-type FET performances in thin films. Introduction of fused benzene and pyrazine rings to the TTF skeleton was effective to enhance the intermolecular interactions and stability to oxygen. Ordered molecular alignment was confirmed by XRD studies. A pi-stacking structure was observed in the single crystal of diquinoxalinoTTF.     

New Concepts in Tetrathiafulvalene Chemistry

Tetrathiafulvalene (TTF) and its derivatives were originally prepared as strong electron-donor molecules for the development of electrically conducting materials. This Review emphasizes how TTF and its derivatives offer new and in some cases little-exploited possibilities at the molecular to the supramolecular levels, as well as in macromolecular aspects. TTF is a well-established molecule whose interest goes beyond the field of materials chemistry to be considered an important building block in supramolecular chemistry, crystal engineering, and in systems able to operate as machines. At the molecular level, TTF is a readily available molecule which displays a strong electron-donor ability. However, its use as a catalyst for radical-polar crossover reactions, thus mimicking samarium iodide chemistry, has only recently been addressed. Important goals have been achieved in the use of TTF at the macromolecular level where TTF-containing oligomers, polymers, and dendrimers have allowed the preparation of new materials that integrate the unique properties of TTF with the processability and stability that macromolecules display. The TTF molecule has also been successfully used in the construction of redox-active supramolecular systems. Thus, chemical sensors and redox-switchable ligands have been prepared from TTF while molecular shuttles and molecular switches have been prepared from TTF-containing rotaxanes and catenanes. A large synthetic effort has been devoted to the preparation of the so-called organic ferromagnets, many of which are derived from TTF. The main task in these systems is the introduction of ferromagnetic coupling between the conduction electrons and localized electrons. TTF has also played a prominent role in molecular electronics where TTF-containing D-sigma-A molecules have allowed the preparation of the first confirmed unimolecular rectifier. Recently, it has been confirmed that TTF can display efficient nonlinear optic (NLO) responses in the second and third harmonic generation as well as a good thermal stability. These findings can be combined with the redox ability of TTF as an external stimuli to provide a promising strategy for the molecular engineering of switchable NLO materials. Fullerenes endowed with TTF exhibit outstanding photophysical properties leading to charge-separated (CS) states that show remarkable lifetimes.     

Crown-tetrathiafulvalenes attached to a pyrrole or an EDOT unit: synthesis, electropolymerization and recognition properties

A crown-tetrathiafulvalene electroactive receptor has been covalently linked to electropolymerizable pyrrole or 3,4-ethylenedioxythiophene monomers. The synthetic route to the monofonctionalized tetrathiafulvalene (TTF) ligand has been optimized. Two derivatives of pyrrole (N- and 3-substituted) were synthesized. The various substituted monomers have been electropolymerized to produce polypyrrole (PP) and poly(ethylenedioxothiophene) (PEDOT) films bearing the electroactive TTF moiety. The electroactivity of the polymer films is efficiently controlled by the well-defined two-step redox behavior of the TTF unit. In the case of PEDOT, an alternative post-polymerization derivatization strategy has been used, involving the grafting of the crown-TTF ligand on the previously grown PEDOT backbone. Though chemical derivatization is realized under heterogeneous conditions, in the bulk of the film, this strategy proved to be particularly efficient. These electrodes constitute the first examples of conducting polymer-based modified electrodes incorporating a TTF electrochemical probe, able to interact with a guest ion, such as Ba2+. The cation recognition properties of these various electrodes have been analyzed by cyclic voltammetry and their electroactivity in water as well as their regeneration capability have been investigated.     

A novel strategy to prepare conducting LB films based on TTF derivatives

A new method is described for the preparation of conducting Langmuir-Blodgett films based on tetrathialfulvalene (TTF) derivatives without long alkyl chain substitution. The mixed molecular system of behenic acid (BA) and oxygen-substituted TTF-type donor molecules such as 4,5-ethylenedioxy-4′,5′-ethylenedithio-tetrathiafulvalene (EOET) or bis-ethylenedioxy-tetrathiafulvalene (BO) provides a stable bilayer film at the air/water interface. In the LB films prepared by Y-type deposition, the donor molecules form mixed-valence dimers such as D⁺ D⁰, without secondary treatments. The maximum conductivities of the LB films reached 1.0S cm⁻¹ (EOET + BA) and 25 S cm⁻¹ (BO + BA) at room temperature. The surface pressure/area isotherms and Fourier transform infra-red spectra are also reported with regard to, respectively, film formation on the water surface and the mixed-valence dimer state under different molar ratios of the donors to B A.     

Tetrathiafulvalene: A Paradigmatic Electron Donor Molecule

Abstract

Tetrathiafulvalene (TTF) and its derivatives are exceptional building blocks in many areas of organic, supramolecular, and materials chemistry. Since the discovery ca. 30 years ago of the first “organic metal” tetrathiafulvalene-tetracyano-p-quinodimethane (TTF-TCNQ), a huge number of TTF derivatives have been synthetized.

Although initial efforts were directed to enhance the electron-donating ability of TTF analogues to improve the conductivities of salts and charge-transfer (CT) complexes derived from them, the developments in synthetic TTF chemistry have made it possible to incorporate TTF into more sophisticated structures such as materials exhibiting intramolecular charge-transfer and nonlinear optical properties, sensors, molecular shuttles and devices.

Compounds in which TTF and electron-accepting molecules, especially C ₆₀ , are covalently tethered exhibit outstanding photophysical properties leading, upon photoexcitation, to charge-separated (CS) states showing remarkable lifetimes. In these systems, the gain of aromaticity upon oxidation of the TTF moiety has been used as a new concept for improving the stability of the charge-separated state, and, therefore, are of interest for the preparation of artificial photosynthetic systems as well as photovoltaic devices.     

TTF[Ni(dmit)2]2: Now as Thin Films and Nanowires

Thin films and nanowires of the molecular superconductor TTF[Ni(dmit)₂]₂ (TTF = tetrathiafulvalene, dmit²⁻=2-thioxo-1,3-dithiol-4,5-dithiolato) are obtained by dipping process on stainless-steel and silicon conversion coatings and on a microrough silicon surface. The deposits are characterized by SEM, Raman spectroscopy and conductivity measurements.     

Application of conversion coatings to the growth of TTF–TCNQ thin films by CVD and conducting nanowires by dipping process

Thin films of the molecular conductor TTF–TCNQ are grown using chemical vapour deposition (CVD) on stainless steel conversion coating (SSCC) substrates. The fractal-like morphology and high adsorption properties of SSCC improve the surface coverage in CVD-grown thin films. 1 μm thick, oriented, conductive deposits are obtained and studied by SEM, IR, XRD and conductivity measurements. Additionally, an unexpected ability of SSCC to induce nanowire formation is shown. By successively dipping SSCC in TTF and TCNQ solutions, typically 20 nm×20 μm conducting wires and ribbons, and occasionally loops, form on the substrates. They could be separated from the surface and were studied by TEM, AFM and current–voltage measurements.     

Binding studies between tetrathiafulvalene derivatives and cyclobis(paraquat-p-phenylene)

The complexation between a number of different pi-electron donating TTF derivatives and the pi-electron accepting tetracationic cyclophane cyclobis(paraquat-p-phenylene) (CBPQT(4+)) has been studied by (1)H NMR and UV-vis spectroscopy. The results demonstrate that the strength of association between the donors (TTF derivatives) and acceptor (CBPQT(4+)) is strongly dependent on the pi-electron donating properties (measured by the first redox potential ) of the TTF derivatives. However, the first redox potential () is not the only factor of importance. The extended pi-surface of the TTF derivatives also exerts a stabilizing influence upon complexation. The kinetics for the complexation-decomplexation were studied using (1)H NMR spectroscopy and are related to the bulkiness of the TTF derivatives. These effects may serve to improve the design of interlocked molecular systems, especially (bistable) molecular switches, in which CBPQT(4+) and a derivatized TTF unit are incorporated.