Tetrathiafulvalene-hydroxyamides and -oxazolines: hydrogen bonding, chirality, and a radical cation salt
作者:Céline Réthoré、Marc Fourmigué、Narcis Avarvari
DOI:10.1016/j.tet.2005.08.104
日期:2005.11
Racemic and enantiopure ethylenedithio-tetrathiafulvalene (EDT-TTF) derivatives featuring beta-hydroxyamide or oxazoline (OX) groups bearing methyl or isopropyl substituents have been synthesized starting from the corresponding amino alcohols. Crystal structure analysis shows in the case of the racemic methyl-beta-hydroxyamide donor the development of a unique hydrogen bond network, characterized by short C=O center dot center dot center dot H-O and N-H center dot center dot center dot O-H intermolecular distances. The enantiopure (S)-EDT-TTF-methyl-OX crystallizes in the monoclinic non-centrosymmetric space group P2(1), whereas the isopropyl counterparts, (R)-and (S)-EDT-TTF-isopropyl-OX, crystallize in the orthorhombic non-centrosymmetric space group P2(1)2(1)2(1). All of them adopt a s-trans conformation in which TTF and oxazoline units are coplanar. Electrocrystallization experiments with the racemic EDT-TTF-methyl-OX, in the presence of (nBu(4))(2)Mo6Cl14 as supporting electrolyte, afford a radical cation salt, formulated as [(+/-)-EDT-TTF-methyl-OX](2)Mo6Cl14, in which the donors associate in strong dimers, which further stack along the b direction to form quasi-homochiral helix-like ribbons. (c) 2005 Elsevier Ltd. All rights reserved.