Structural Odd–Even Effect Impacting the Dimensionality of Transport in BTBT‐CnOH Organic Field Effect Transistors

The synthesis and characterization of a series of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) molecules disubstituted by hydroxy aliphatic chains in positions 2 and 7 (BTBT-CnOH), where the intralayer molecular stacking alternates between a classical and an inverted herringbone mode as a function of whether the alkyl sides chains have an even or an odd number of carbon atoms are reported. This odd–even effect does not only affect the interlayer distance of the lamellar structures and the melting points, but also the electronic properties. The BTBT-CnOH odd series develops a classical herringbone pattern with edge-to-edge S⋯S interaction chains linked together by face-to-edge S⋯S interaction chains with 2D mobility. However, the even series has only edge-to-edge interactions in an inverted herringbone organization and thus only a 1D conducting character. These two types of herringbone patterns have different field effect transistor characteristics and mobilities, those of the odd members being systematically higher than their even neighbors. This is the first example of an odd–even effect impacting the electronic properties of an organic semiconductor.Modules solaires photovoltaïques organiques de grande surface à hauts rendements stabilisé

Crystal structure of tris(binol)cyclotriphosphazene. A new clathration system

International audienceThe crystal structure of inclusion compound constituted by chiral tris(binol)cyclotriphosphazene ((S,S,S)-TBP) host and o-xylene guest has been determined. It has an orthorhombic unit cell with space group P212121 (no. 19) and unit cell dimensions a = 10.9265(4) Å, b = 17.8959(8) Å, and c = 30.3964(1) Å. Guest free (S,S,S)-TBP is an amorphous material according to the literature (Chem. Eur. J. 2001, 7, 1486–1494) and crystal structure has not been reported so far. Formation of inclusion adduct with o-xylene guests acting as a molecular glue allowed to determine the structural features. (S,S,S)-TBP has a propeller-like shape with binol units considered as paddles. Naphthalene units are twisted at 51° in those paddles. Effects of this twist on spirocyclic seven-membered ring and on cyclotriphosphazene ring are discussed. © 2016 Elsevier Lt