The advantage of "self-assembly" (strong covalent binding to substrates) was combined with the advantage of Langmuir-Blodgett (LB) or Langmuir-Schaefer (LS) transfer to a solid substrate (quantitative transfer of monolayers to the substrate). The electrical rectification (asymmetric conduction) by a monolayer of thioacetylalkylquinolinium tricyanoquinodimethanide was critically compared when these molecules had been transferred, by such competing techniques, onto gold electrodes, and then covered by a "cold gold" pad electrode. Unimolecular rectification was observed in the expected directions in the LB and LS monolayers. The Self-Assembled Monolayers (SAMs) were disordered; macroscopic measurements of rectification were unsuccessful for the SAMs, but successful for the down-stroke LB and LS monolayers, whose orientation and potential bonding to the Au surface should be identical to that of an ideal SAM.

The Chemistry of several condensed selenophenes, and tellurophenes (1–4) will be presented. The synthesis of mixed selenium-tellurium fulvenes (5) and generation of 2,4-bis-methyleneditelluretane (6) will be discussed.

New electron-donor (D)-electron-acceptor (A) TTF architectures are presented in which two electron-donating 1,3-dithiole moieties are connected by a pi bridge to the weak electron-accepting quinoxaline moiety (D-pi-A compounds 9a and 9b and also two 1,3-dithiole-2-ylidene moieties are connected by a pi bridge to the electron-accepting thieno[3,4-b]quinoxaline bridge (D-pi-A-pi-D compounds 12a-c). There are through-bond intramolecular charge-transfer (ICT) interactions, predicted in theoretical calculations, and confirmed by UV-vis spectroscopy and cyclic voltammetry measurements. This work constitutes the first use of quinoxalines as electron-accepting moieties in D-pi-A compounds.

[reaction: see text] The synthesis of stable methylthio-capped biisothianaphthene and biisoselenophene derivatives has been achieved using DMF-mediated sodium reduction of cyclic thiocarbonyl compounds.

AbstractFor Abstract see ChemInform Abstract in Full Text.

[reaction: see text] The preparation of 1,3,5,7-tetramethyl-4,8-dihydrobenzo[1,2-c:4,5-c']dithiophene-4,8-dione and its conversion to the corresponding mono- and dithione are described.

Abstract 4,5‐dibenzoyl‐1,3‐dithiole‐2‐thione product: 4,5‐Dibenzoylthio‐1,3‐dithiole‐2‐thione (3) intermediate: 16 g (0.0223 mol) of tetraethylammonium bis(1,3‐dithiole‐2‐thione‐4,5‐dithio) zincate (2)

ChemInformVolume 34, Issue 38 Heterocyclic Compounds Thiophene Isosteres of 9,10-Dithioanthraquinone. Yvette A. Jackson, Yvette A. Jackson Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorDesikan Rajagopal, Desikan Rajagopal Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorJackie Bendolph, Jackie Bendolph Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorMelanie Guillory, Melanie Guillory Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorM. V. Lakshmikantham, M. V. Lakshmikantham Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorJongtae Yang, Jongtae Yang Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorMichael P. Cava, Michael P. Cava Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this author Yvette A. Jackson, Yvette A. Jackson Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorDesikan Rajagopal, Desikan Rajagopal Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorJackie Bendolph, Jackie Bendolph Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorMelanie Guillory, Melanie Guillory Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorM. V. Lakshmikantham, M. V. Lakshmikantham Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorJongtae Yang, Jongtae Yang Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this authorMichael P. Cava, Michael P. Cava Dep. Chem., Univ. Ala., Tuscaloosa, AL 35487, USASearch for more papers by this author First published: 27 August 2003 https://doi.org/10.1002/chin.200338086Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume34, Issue38September 23, 2003 RelatedInformation

[reaction: see text] Benzo[c]selenophene has been generated via facile bromination-dehydrobromination as well as oxidation of the 1,3-dihydrobenzo[c]selenophene. Benzo[c]selenophene thus generated has been lithiated in situ and treated with ClCOOEt to give the first functionalized derivative subject to X-ray crystallographic analysis.

[reaction: see text]. The unstable seleno[2,3-b]quinoxoline was generated and functionalized in situ to give the stable dialdehyde and diester derivatives. The dicyano compound was made in several steps from biscyanomethyl selenide and was found to be very stable.

A novel four-membered 1,3-ditelluretane dialdehyde 8/9 was synthesized from trimethylsilylethynyl tellurolate. The dialdehyde was transformed into extended tetrathiafulvalenes (14 and 15). These are the first examples of ditelluretane spaced TTF derivatives.

Rectification by a monolayer of (acetylthioundecyl)quinolinium tricyanoquinodimethanide, 6, sandwiched or physisorbed or chemisorbed on gold electrodes, was studied by scanning tunneling microscopy and scanning tunneling spectroscopy, and also by macroscopic "gold \ monolayer \ gold" pads, using either physisorption (Langmuir-Blodgett deposition, followed by partial chemisorption) onto a Au substrate or chemisorption ("self-assembly"onto Au surface). Rectification ratios of 5 to 7 were seen by scanning tunneling spectroscopy of individual molecules, as expected, but the macroscopic films are too disordered to show dramatic rectification ratios.

3,4-Cyanomethyl substituted thiophenes reacted with thionyl chloride in the presence of base to give dicyano substituted thieno(3,4-c)thiophenes. The use of selenium oxychloride furnished the corresponding cyano substituted seleno(3,4-c)thiophene. 1,2-Phenylenediacetonitriles gave the corresponding cyano substituted benzo(c)thiophenes and benzo(c)selenenophenes, respectively, upon reaction with thionyl chloride and selenium oxychloride in the presence of base.

[reaction: see text] The first synthesis of dendralene-type TTF derivatives bearing a 1,3-ditellurole ring has been achieved. Preliminary electrochemical results are presented.

Rectification was observed across a monolayer of 2,6-di [dibutylamino-phenylvinyl]- 1-butylpyridinium iodide, (Bu(2)NphiV)(2)BuPy+I-, 1 sandwiched between gold electrodes. The current is enhanced at a forward bias above 0.5 to 1.0 V, as electrons flow preferentially from the iodide ions to the pyridinium ring, and is as high as 100 000 electrons molecule(-1) s(-1), with a rectification ratio of up to 90.