We compare the conductance of 1,4-bis(methylthio)benzene with that of 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']dithiophene and the conductance of 1,4-bis(methylseleno)benzene with that of 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']diselenophene and show explicitly that the orientation of an Au-S or Au-Se bond relative to the aromatic TT system controls electron transport through conjugated molecules. Specifically, we have found that the conduction pathway connects the Au electrodes to the aromatic pi-system via the chalcogen p lone pairs, and greater overlaps among these components lead to higher conductivity through the molecular junction.
One-pot Synthesis of Benzo[<i>b</i>]thiophenes and Benzo[<i>b</i>]selenophenes from <i>o</i>-Halo-Substituted Ethynylbenzenes: Convenient Approach to Mono-, Bis-, and Tris-Chalcogenophene-Annulated Benzenes
procedure for the synthesis of benzo[b]thiophenes and selenophenes from readily available o-halo-ethynylbenzene precursors is described. Regardless of the substituent on the acetylene terminus or the number of cyclization moieties on the precursors, various benzo[b]thiophenes and selenophenes, including not only the parent, alkyl-, and phenyl-substituted derivatives but also benzo[1,2-b:4,5-b′]dithiophenes
描述了一种方便的一锅法,用于从容易获得的邻卤代乙炔基苯前体合成苯并[ b ]噻吩和硒代苯。不论乙炔末端上的取代基或前体上的环化部分数量如何,各种苯并[ b ]噻吩和硒代苯不仅包括母体,烷基和苯基取代的衍生物,而且还包括苯并[1,2- b]可以高产率地制备: 4,5- b ′]二噻吩和二硒吩和苯并[1,2- b: 3,4- b ′:5,6 - b ′′]三噻吩和三硒吩。
A general and convenient synthesis of benzo[1,2-b:4,5-b']-dichalcogenophenes including the thiophene (BDT, 1), selenophene (BDS, 2), and tellurophene (BDTe, 3) homologues is developed. Thus synthesized heterocycles are structurally characterized by single-crystal X-ray analysis, and all three homologues are isostructural with one another. They all have completely planar molecular structures packed in a herringbone arrangement. Their physicochemical properties were also elucidated by means of cyclic voltammetry (CV) and LTV-vis spectra.
Borylation on Benzo[1,2-<i>b</i>:4,5-<i>b</i>′]- and Naphtho[1,2-<i>b</i>:5,6-<i>b</i>′]dichalcogenophenes: Different Chalcogene Atom Effects on Borylation Reaction Depending on Fused Ring Structure
The direct borylation reactions of two types of alpha-silyl-protected acenedichalcogenophenes, i.e., benzo[1,2-b:4,5-b']- and naphtho[1,2-b:5,6-b']dichalcogenophenes, were examined, and it was observed that the reaction efficiency largely depends on the fused ring structure and chalcogenophene ring.