An efficient synthesis of substituted 2-iminothiazolidin-4-one and thiadiazoloquinazolinone derivatives

A convenient synthesis of functionalized 2-iminothiazolidin-4-ones and thiadiazoloquinazolinones has been achieved by the reaction of dialkyl acetylenedicarboxylates (DAAD) with 1-pheny-3-pyridin-2-yl-thiourea (1) and 3-amino-2-mercapto-3H-quinazolin-4-one (8), respectively. The starting materials for these processes were prepared from phenyl isothiocyanate, 2-aminopyridine for (1) and anthranilic acid, carbon disulfide, hydrazine for (8). Treatment of these compounds with DAAD resulted in the formation of an intermediate that readily underwent intramolecular cyclization to afford functionalized five membered heterocyclic rings was formed.     

Regiospecific iodocyclization of S-allyl dithiocarbamates: synthesis of 2-imino-1,3-dithiolane and 2-iminium-1,3-dithiolane derivatives

4-Alkyl-2-imino-1,3-dithiolanes and 4-alkyl-2-iminium-1,3-dithiolanes were prepared in excellent yields with complete regiospecificity under mild conditions by the iodocyclization of S-allyl dithiocarbamates. Dehydrohalogenation of the 4-alkyl-2-imino-1,3-dithiolanes gave 4-alkylidene-2-imino-1,3-dithiolanes in excellent yields.     

Synthesis and Crystal Structure of Ethylenediammonium bis iodate tetra iodic Acid: [C<Subscript>2</Subscript>H<Subscript>10</Subscript>N<Subscript>2</Subscript>] (IO<Subscript>3</Subscript>)<Subscript>2</Subscript>·4HIO<Subscript>3</Subscript>

Abstract  

The synthesis and crystal structure are presented for the ethylenediammonium bis iodate tetra iodic acid. An X-ray investigation has shown that this compound crystallizes in a centrosymmetric monoclinic system, space group P2₁/c with the lattice parameters: a = 7.2536(2) ?, b = 18.5351(5) ?, c = 7.5685(2) ?, β = 107.937(1)°, V = 968.10(3) ?³. The structure was solved from 5281 independent reflections with R ₁ = 0.0229 and wR ₂ = 0.0428, and refined with 156 parameters. The structure is built up of [(CH₂)₂(NH₃)₂]²⁺ cations connected to the one-dimensional [HIO₃]_n chains and to the [H₂I₄O₁₂]²⁻ clusters by a weak N–H···O hydrogen bonds.     

Nanostructure dependence of field-effect mobility in regioregular poly(3-hexylthiophene) thin film field effect transistors

Low polydispersity regioregular polythiophenes with number average molecular weights ranging from 2 to 13 kDa were cast under the same conditions from solution to form a series of field effect transistors (FETs). Tapping mode AFM and grazing incidence small-angle X-ray scattering revealed that in all cases the polymers formed regular nanofibrillar morphologies with the width of nanofibrils proportional to the weight average contour length of polymer chains, indicating that conjugated backbones were oriented perpendicular to the nanofibril axes. FET charge carrier mobilities exhibited exponential dependence on nanofibril width, pointing to the decisive role of extended conjugated pathways in charge transport.     

A combining rule calculation of the ground-state van der Waals potentials of the magnesium rare-gas complexes

The potential energy curves and spectroscopic constants of the ground-state of the Mg–Rg (Rg = He, Ne, Ar, Kr, and Xe) van der Waals complexes are generated by the Tang–Toennies potential model and a set of derived combining rules. The parameters of the model are calculated from the potentials of the homonuclear magnesium and rare-gas dimers. The predicted spectroscopic constants are comparable to other available theoretical and experimental results, except in the case of Mg–He, we note that there are large differences between various determinations. Moreover, in order to reveal relative differences between species more obviously we calculated the reduced potential of these five systems. The curves are clumped closely together, but at intermediate range the Mg–He reduced potential is clearly very different from the others.     

Performance of SLS/MWCNTs/PANI capacitor electrodes in a physiological electrolyte and in serum

We report a stainless steel/multi walled carbon nanotubes/polyaniline (SLS/MWCNTs/PANI) capacitor electrode capable of operating in a physiological electrolyte and in serum. The specific capacitance of SLS/MWCNTs/PANI reaches 401 F g(-1) in the physiological electrolyte and 326 F g(-1) in serum. The capacity loss at 6.4 μA mm(-2) over 2000 cycles is 10% in the physiological electrolyte and 21% in serum.     

Synthesis of 3,7-diiodo-2,6-di(thiophen-2-yl)benzo[1,2-b:4,5-b']difurans: functional building blocks for the design of new conjugated polymers

3,7-Diiodo-2,6-di(thiophen-2-yl)benzo[1,2-b:4,5-b']difurans are efficiently prepared by an iodine-promoted double cyclization. This new heterocyclic core is readily modified by the attachment of alkyl chains for improved solubility. The use of these compounds for the synthesis of new conjugated polymers is also reported.     

嵌入式PC／104主板在惯性导航系统中的应用

提出了用嵌入式PC／104主板为核心的新型结构对原有系统进行改造,在提高系统性能的同时确保与原有接口的兼容,使原有系统软件以最小的代价移植到新的系统中。详细叙述了改造中的关键技术及具体实现方法,并对系统的应用技术提出展望。