新型I型五聚四硫富瓦烯衍生物的合成和性质

利用2,3-二(2'-氰乙基硫基)-6,7-二烷硫基四硫富瓦烯在甲醇钠的作用下消除一个保护基团生成四硫富瓦烯单钠盐,与1,4-二(氯甲基)苯反应,形成单桥-双(四硫富瓦烯)衍生物,生成的单桥-双(四硫富瓦烯)衍生物再次在甲醇钠的作用下消除剩下的保护基团,形成单桥-双(四硫富瓦烯)衍生物二钠盐,最后与四(3'-碘丙硫基)四硫富瓦烯反应形成新型I型五聚TTF衍生物,并通过循环伏安法和化学氧化法分别对其氧化还原性质和紫外光谱进行了研究.     

新型I型五聚四硫富瓦烯衍生物的合成和性质

利用2,3-二(2'-氰乙基硫基)-6,7-二烷硫基四硫富瓦烯在甲醇钠的作用下消除一个保护基团生成四硫富瓦烯单钠盐,与1,4-二(氯甲基)苯反应, 形成单桥-双(四硫富瓦烯)衍生物, 生成的单桥-双(四硫富瓦烯)衍生物再次在甲醇钠的作用下消除剩下的保护基团, 形成单桥-双(四硫富瓦烯)衍生物二钠盐, 最后与四(3'-碘丙硫基)四硫富瓦烯反应形成新型I型五聚TTF衍生物, 并通过循环伏安法和化学氧化法分别对其氧化还原性质和紫外光谱进行了研究.     

新型四四硫富瓦烯环蕃的合成和性质

利用2,3-二(2-氰基乙硫基)-6,7-二烷硫基四硫富瓦烯在甲醇钠的作用下消除一个保护基团生成四硫富瓦烯单钠盐, 与1,4-二氯甲基苯反应, 形成“单桥”-双(四硫富瓦烯)衍生物, 生成的“单桥”-双(四硫富瓦烯)衍生物再次在甲醇钠的作用下消除剩下的保护基团, 形成“单桥”-双(四硫富瓦烯)衍生物二钠盐, 最后与二溴代烷反应形成新型四四硫富瓦烯环蕃, 并通过循环伏安法和化学氧化法分别对其氧化还原性质和紫外光谱进行了研究.     

一种合成插烯式四硫富瓦烯衍生物的新方法

插烯式四硫富瓦烯(tetrathiafulvalene vinylogues,TTFV)化合物由于其优良的供电子性质在有机电子学研究中引人关注.TTFV类化合物的合成通常是利用烯键键链的二硫富瓦烯(diathiafulvalene,DTF)化合物通过I2以及Ag BF4等氧化偶联反应来制备,其存在产率较低、毒性较大等局限.鉴于萘基团的荧光性质以及硫代丙腈基的衍生化反应特点,以亚磷酸三甲酯为偶联剂,含丙腈基硫酮化合物1与1-萘醛发生偶联反应生成二硫富瓦烯化合物2.在四氯苯醌(chloranil,CA)/甲磺酸(methanesulfonic acid,MSA)催化条件下,化合物2氧化偶联得到插烯式四硫富瓦烯化合物3.初步优化了四氯苯醌-甲磺酸(CA-MSA)催化反应条件.优化的反应条件为:1.5 equiv.的CA催化剂,甲磺酸与二氯甲烷的体积比为1∶10,氮气保护下室温反应2 h,化合物3的产率可达86.7%.通过1H NMR,~(13)C NMR,FT-IR,MS方法对插烯式四硫富瓦烯衍生物3分别进行了表征分析,同时用X射线衍射法确认了化合物3的晶体结构.与传统的I2氧化偶联反应进行了实验比较,结果表明在甲磺酸存在下,以四氯苯醌为有机氧化剂合成插烯式四硫富瓦烯衍生物的新方法简便有效.     

双（亚烷二硫基)四硫富瓦烯衍生物的合成及其电化学性质

以四(氰乙硫基)四硫富瓦烯为原料经醇钠消去氰乙基生成四硫富瓦烯四硫盐， 再与二元卤代烷烃化反应，除了得到三种文献报道的双(亚烷二硫基)四硫富瓦烯衍 生物外，还得到三种新的“四桥”双—四硫富瓦烯衍生物，为“桥式”双—四硫富 瓦烯衍生物的合成提出了一种新的方法．并研究了它们的循环伏安图、电化学性质 和紫外—可见光光谱．     

新型三(四硫富瓦烯)环蕃的合成和性质

利用四(3'-碘丙硫基)四硫富瓦烯和四硫富瓦烯二钠盐反应合成新的三(四硫富瓦烯)环蕃, 并通过循环伏安法和化学氧化法分别对其氧化还原性质和紫外光谱进行了研究.     

不对称四硫富瓦烯衍生物合成新方法及其电化学性质的研究

以2,3－二（2′－氰乙硫基）－6,7－亚烷硫基四硫富瓦烯为原料,在醇钠的作用下消去氰乙基生成的二元硫负离子与对－二（氯甲基）苯反应除了生成两种新的不对称四硫富瓦烯衍生物外,还得到两种新的“二桥”－双四硫富瓦烯衍生物,为四硫富瓦烯衍生物的合成提供了一种新的方法。并对不对称四硫富瓦烯衍生物和“二桥”－双四硫富瓦烯衍生物的循环伏安图、电化学性质和UV－Vis光谱进行了研究。     

新型非对称四硫富瓦烯环状冠醚衍生物的合成及其对碱金属离子的响应性能

在Cs OH的CH3OH/DMF溶液中,4,5-二(氰乙硫基)乙二硫撑四硫富瓦烯(1a),4,5-二(氰乙硫基)甲基乙二硫撑四硫富瓦烯(1b),4,5-二(氰乙硫基)丙二硫撑四硫富瓦烯(1c)和4,5-二(氰乙硫基)苯基四硫富瓦烯(2)分别与五(乙二醇醚)二-对甲苯磺酸盐经偶联反应合成了4个新型的非对称四硫富瓦烯环状冠醚衍生物(3a~3c和4),其结构经1H NMR,~(13)C NMR,ESI-MS和元素分析表征。用循环伏安法研究了3a~3c和4对碱金属离子(Na+,Li+,K+和Rb+)的响应性能。结果表明:2,3-二硫-(3',6',9',12'-四氧冠醚)-6,7-丙二硫代四硫富瓦烯(3c)和2,3-二硫-(3',6',9',12'-四氧冠醚)-6,7-苯基四硫富瓦烯(4)对Na+响应较明显,其△E1/21分别为30 m V和45 m V。     

四硫富瓦烯和联萘基构建的新型多功能氧化还原荧光开关

利用3-溴甲基-2,2'-二甲氧基亚甲氧基-1,1'-联萘和四硫富瓦烯四硫盐反应合成新的联萘基四硫富瓦烯衍生物, 通过电化学氧化还原法发现其荧光能够可逆地增强和减弱, 因此它是一个新的氧化还原荧光开关. 并通过循环伏安法发现这种氧化还原荧光开关可以选择性地识别和跟踪Fe^3＋.     

新型四硫代富瓦烯衍生物的合成及其性质的研究

合成了3个新的含有卤素取代基的四硫代富瓦烯衍生物及6个新的相关化合物。利用溶液的电子吸收光谱对四硫代富瓦烯衍生物的性质进行了研究。研究结果表明, 四硫代富瓦烯衍生物的分子中π轨道之间的能级差较小, 因而分子具有较高的稳定性。     

Synthesis and electrochemical properties of a chiral silyl-substituted tetrathiafulvalene derivative

A new chiral tetrathiafulvalene(TTF) derivative and related silyl-substituted 1,3-dithiole-2-(thi)one compounds were synthesized and characterized by ~1H NMR,~(13)C NMR,MS and IR spectra.Single crystal structure of the silyl-substituted 1,3-dithiole-2-one revealed the high degree of conjugation of the fivemembered ring moiety in the compound.The electrochemical properties of the new TTF derivative were studied by cyclic voltammetry and the results indicated that the electron-donating ability of the chiral TTF derivative was similar to that of BEDT-TTF.The △E value for the new TTF derivative was smaller than those for TTF and BEDT-TTF,indicative of decreased Coulombic repulsion in the dicationic redox state.Formation of charge-transfer(CT) complex between the new donor and electron acceptor 2,3-dichloro-5,6-dicyano-l,4-benzoquinone(DDQ) was demonstrated.     

Multiredox tetrathiafulvalene-modified oxide-free hydrogen-terminated Si(100) surfaces

Tetrathiafulvalene (TTF) monolayers covalently bound to oxide-free hydrogen-terminated Si(100) surfaces have been prepared from the hydrosilylation reaction involving a TTF-terminated ethyne derivative. FTIR spectroscopy characterization using similarly modified porous Si(100) substrates revealed the presence of vibration bands assigned to the immobilized TTF rings and the Si-C═C- interfacial bonds. Cyclic voltammetry measurements showed the presence of two reversible one-electron systems ascribed to TTF/TTF(.+) and TTF(.+)/TTF(2+) redox couples at ca. 0.40 and 0.75 V vs SCE, respectively, which compare well with the values determined for the electroactive molecule in solution. The amount of immobilized TTF units could be varied in the range from 1.7 × 10(-10) to 5.2 × 10(-10) mol cm(-2) by diluting the TTF-terminated chains with inert n-decenyl chains. The highest coverage obtained for the single-component monolayer is consistent with a densely packed TTF monolayer.     

Effects of protonation and metal coordination on intramolecular charge transfer of tetrathiafulvalene compound

A protonated bifunctional pyridine-based tetrathiafulvalene (TTF) derivative (DMT-TTF-pyH)NO3 and a copper(II) complex Cu(acac)2(DMT-TTF-py)2 have been obtained and studied. Electronic spectra of the protonated compound show a large ICT (intramolecular charge transfer) band shift (Deltalambda=136 nm) compared with that of the neutral compound. Cyclic voltammetry also shows a large shift of the redox potentials (DeltaE1/2(1)=77 mV). Theoretical calculation suggests that the pyridium substituent is a strong pi-electron acceptor. Crystal structures of the protonated compound and the metal complex have been obtained. The dihedral angle between least-squares planes of the pyridyl group and the dithiole ring might reflect the intensity of the ICT effect between the TTF moiety and the pyridyl group. It is also noteworthy that the TTF moiety could be oxidized to TTF2+ dication by Fe(ClO4)(3).6H2O when forming a metal complex, while the protonated TTF derivative can only be oxidized to the TTF*+ radical cation by Fe(ClO4)(3).6H2O even with an excess amount of the Fe(III) salt, which can be used to control the oxidation process to obtain neutral TTF, TTF*+ radical cation, or TTF2+ dication.     

New crown annelated tetrathiafulvalenes: synthesis, electrochemistry, self-assembly of thiol derivatives, and metal cation recognition

The synthesis of new S(2)O(4)-crown annelated tetrathiafulvalene (TTF) derivatives substituted with one terminal thiol group is described. Self-assembled monolayers (SAMs) of these compounds have been assembled on gold and platinum surfaces, the latter substrate giving improved quality films. SAMs of TTF derivative 16b are the most stable of those we have studied. Electrochemical data for SAMs of 5a, 5b, 8, 16a, and 16b in acetonitrile reveal two reversible one-electron waves, typical of the TTF system; the current increased linearly with scan rate, indicating a surface wave response. SAMs of 8, 16a, and 16b exhibited an electrochemical response in aqueous electrolytes, which was observed between 50 and 100 cycles. Moreover, if the potential scanned was limited to the first TTF oxidation, the cyclic voltammetry response was observed for at least 1000 cycles. Metal complexation by the crown ionophore of the SAMs in acetonitrile has been monitored by a positive shift in the first oxidation potential of the TTF unit (maximum DeltaE(1)(1/2) = 80 mV for Ag(+)). We also report the X-ray crystal structure of TTF-crown derivative 21 bearing two hydroxymethyl substituents, synthesized during the course of this work. The structure is characterized by infinite chains of molecules linked by strong intrachain hydrogen bonds between the terminal hydroxy groups.     

Adsorption of n-butyl-substituted tetrathiafulvalene dodecanethiol on gold

Tetrathiafulvalene (TTF) derivative substituted with two butyl- and two dodecylthiol chains is adsorbed on polycrystalline gold. The TTF-derived thiol adsorbates were characterized by ellipsometry, contact angle goniometry, infrared and X-ray photoelectron spectroscopy and cyclic voltammetry. The molecule is strongly anchored on the gold surface through the sulfur terminating the alkylthiol chains. On the average, the TTF moiety is oriented extended away from the gold surface. The topmost layer of the film containing the dibutyl chains is disordered with gauche defects. The molecule was organized with majority of the alkylthiol chains bound to the gold surface. There are indications of pinholes in the monolayer due to steric hindrance of the bulky TTF rings. The molecular systems consisting of an electroactive pi-system such as TTF, are promising for thin-film field effect transistor application.     

Absolute stereochemistries and total synthesis of (+)-arisugacins A and B, potent, orally bioactive and selective inhibitors of acetylcholinesterase

In the current studies, we used the Kakisawa-Kashman modification of the Mosher NMR method to determine the complete absolute stereochemistry of arisugacins. We also report the convergent total synthesis of (+)-arisugacins A and B by a sequence including (i) ruthenium complex-catalyzed asymmetric reduction of the cyclohexenone derivative; (ii) stereoselective construction of the arisugacin skeleton by a Knoevenagel-type reaction of an α,β-unsaturated aldehyde derivative with production of a 4-hydroxy-2-pyrone derivative as a key reaction; and (iii) stereoselective dihydroxylation to give the diol derivative, followed by deoxygenation. Accordingly, we defined the absolute structures of arisugacins A and B as 4a-(R),6a-(R),12a-(R), and 12b-(S). Finally, we characterized the bioactivities of the synthetic intermediates to understand the structure-activity relationships of the arisugacins.     

Imidazole‐Annulated Tetrathiafulvalenes Exhibiting pH‐Tuneable Intramolecular Charge Transfer and Redox Properties

CT or not CT : Three imidazole‐annulated TTF derivatives 1 – 3 have been prepared and fully characterized. The influence of the TTF unit on the pK_a values of the acceptor units as determined by photometric titration has been discussed. The results reported here are part of an initial exploratory study to generate a range of well‐defined coordination networks.

     

Liquid-crystalline [60]fullerene-TTF dyads

[structure: see text] [60]Fullerene was functionalized with a TTF derivative and a bis-mesogenic fragment. The synthetic methodology was based on the addition of a malonate derivative to C60 (Bingel-type reaction). Both the malonate and dyad showed smectic B and A phases. The supramolecular organization within the smectic layers was of the monolayer type for the malonate and of the bilayer type for the fullerene derivative. In the latter case, the supramolecular organization was governed by the C60 unit.     

“A-C≡C-TTF-C≡C-A”型四硫富瓦烯衍生物的合成与性质研究

四硫富瓦烯及其衍生物是性能优良的电子给体.本文利用Sonogashira反应将吡啶基团连接在四硫富瓦烯单元上,合成了"A-C≡C-TTF-C≡C-A"型四硫富瓦烯共轭体系衍生物4,4′(5′)-二-(4-吡啶乙炔基)-四硫富瓦烯(TTF4N).吸收光谱、电化学和Pb2+配位键合研究表明,三键作为桥基能够有效实现分子内的电荷转移.金属Pb2+离子与吡啶基团的配位能够引起TTF4N的吸收光谱、核磁氢谱和电化学性质的显著变化.     

Bis(diamino-diamido)-tetrathiafulvalene, a redox active sensor for proton, anions, and cations

A bis(diamino-diamido) tetrathiafulvalene (TTF) derivative H(4)L(2) has been designed and synthesized. Experiments of pH titration reveal that integrating the redox active TTF unit with the diamino-diamido moiety adds new properties to the traditional ligand. Oxidation of the TTF moiety increases the acidity of the amido group, and the coordination of metal ions is also sensitive to the oxidation state of the ligand. This compound is capable of acting as a leaving or accepting ligand for proton and metal ions. The electrochemistry of the protonated TTF derivative of H(4)L(2) was studied in the presence of a series of oxo anions and metal cations. The results indicate that the redox potentials selectively respond to HC(2)O(4)(-) and SO(4)(2-) anions, and Ni(II) and Cu(II) cations. Solid-state structures of a cation-anion salt H(8)L(2)·2SO(4)·8H(2)O and a nickel coordination compound [Ni(2)L(2)]·2DMF have been characterized by means of X-ray crystallography which are helpful in understanding the inter-ion interactions.