Synthesis of new chiral organosulfur donors with hydrogen bonding functionality and their first charge transfer salts

Abstract

Abstract.The syntheses of a range of enantiopure organosulfur donors with hydrogen bonding groups are described including TTF related materials with two, four, six and eight hydroxyl groups and multiple stereogenic centres and a pair of chiral N-substituted BEDT-TTF acetamides. Three charge transfer salts of enantiopure poly-hydroxysubstituted donors are reported, including a 4:1 salt with the meso stereoisomer of the dinuclear [Fe2(oxalate)5 ] 4-anion in which both cation and anion have chiral components linked together by hydrogen bonding, and a semiconducting salt with triiodide.

Enantiopure and racemic radical-cation salts of bis(2′-hydroxylpropylthio)(ethylenedithio)TTF with polyiodide anions

“…10 60 We have recently reported the synthesis of a novel enantiopure donor molecule which has the potential to form hydrogen bonds via its 2-hydroxypropylthio side chains. 11 Through electrocrystallisation with the anion BF4 -the enantiopure R,R or S,S salts were obtained which were both 1:1 semiconducting salts 65 with activation energies of 0.19-0.24 eV, whilst the racemate has a smaller activation energy of 0.15-0.17 eV. 12 This is in contrast to previous observations in TTF-oxazoline-PF6 and BEDT-TTF4[(NH4)Fe(oxalate)3].sec-phenethyl alcohol where the structural disorder had the effect of reducing the conductivity in 70 the racemate.…”

“…6,9 We report here the synthesis of a series of radical-cation salts of enantiopure or racemic bis(2'-hydroxylpropylthio) (ethylenedithio)TTF (BHPT-EDT-TTF, Scheme 1) with polyiodide anions prepared by diffusion and electrocrystallisation 75 methods Experimental Donor synthesis: Enantiopure (S,S)-BHPT-EDT-TTF and (R,R)-BHPT-EDT-TTF were synthesized using the method described previously. 11 rac-BHPT-EDT-TTF was prepared by making a 50:50 mixture of (S,S)-BHPT-EDT-TTF and (R,R)-BHPT-EDT- 5 …”

New semiconducting radical-cation salts of chiral bis(2-hydroxylpropylthio)ethylenedithio TTF

“…7 Chirality can also be introduced into the donor molecule, and a range of enantiopure donors based on EDT-TTF or BEDT-TTF such as 1-5 have been prepared and studied (Scheme 1). [8][9][10][11][12][13] Scheme 1. Structures of chiral organosulfur donor molecules 1-5.…”

“…10 We have previously reported the synthesis of the novel chiral donor molecule bis(2-hydroxylpropylthio) ethylenedithiotetrathiafulvalene (BHPT-EDT-TTF 1) in the enantiopure R,R or S,S form, and also the meso/rac form which contains a mixture of R,R, S,S and R,S-1. 8 This donor has proven to be fruitful at forming radical-cation salts with a variety of anions owing, in part, to the flexibility and the hydrogen-bonding ability of the 2-hydroxypropylthio side-chains. 14,15 In the first examples of radical-cation salts from this donor we have observed a multitude of donor packing motifs with the anions I3 -, I8 -, Fe2(oxalate)5 4-, BF4 -or TCNQ-F4.…”

“…14,15 In the first examples of radical-cation salts from this donor we have observed a multitude of donor packing motifs with the anions I3 -, I8 -, Fe2(oxalate)5 4-, BF4 -or TCNQ-F4. 8,14,15 We report here a series of new 1:1 radical-cation salts prepared by electrocrystallisation of the enantiopure donor S,S-BHPT-EDT-TTF (S,S)-1 with bromide, chloride, perchlorate and hexafluorophosphate anions, along with their R,R and meso/rac analogues for the latter two anions.…”