TY - JOUR

T1 - Toward Redox-Active Indenofluorene-Extended Tetrathiafulvalene Oligomers-Synthesis and Studies of Dimeric Scaffolds

AU - Broløs, Line

AU - Kilde, Martin Drøhse

AU - Hammerich, Ole

AU - Nielsen, Mogens Brøndsted

PY - 2020/3/6

Y1 - 2020/3/6

N2 - The promotion of mixed-valence interactions between redox-active, π-conjugated scaffolds is of interest when developing new conducting or electrochromic materials as well as in the construction of redox-controlled supramolecular assemblies. In this work, dimeric structures of the redox-active indenofluorene-extended tetrathiafulvalene (IF-TTF) unit were synthesized in a stepwise protocol. The synthesis relied on the development of a new unsymmetrical IF-TTF building block by a combination of phosphite-mediated and Horner-Wadsworth-Emmons reactions for introduction of the dithiafulvene units. The redox properties were studied by cyclic voltammetry, where it was observed that a first one-electron oxidation, corresponding to a mixed-valence state, occurs at a significantly lower potential when the IF-TTF unit is incorporated into a dimer, compared to a monomer analogue. This result indicates that locking the redox-active IF-TTF units in close proximity promotes intramolecular mixed-valence interactions. A computational study was also conducted, supporting the involvement of intramolecular interactions.

AB - The promotion of mixed-valence interactions between redox-active, π-conjugated scaffolds is of interest when developing new conducting or electrochromic materials as well as in the construction of redox-controlled supramolecular assemblies. In this work, dimeric structures of the redox-active indenofluorene-extended tetrathiafulvalene (IF-TTF) unit were synthesized in a stepwise protocol. The synthesis relied on the development of a new unsymmetrical IF-TTF building block by a combination of phosphite-mediated and Horner-Wadsworth-Emmons reactions for introduction of the dithiafulvene units. The redox properties were studied by cyclic voltammetry, where it was observed that a first one-electron oxidation, corresponding to a mixed-valence state, occurs at a significantly lower potential when the IF-TTF unit is incorporated into a dimer, compared to a monomer analogue. This result indicates that locking the redox-active IF-TTF units in close proximity promotes intramolecular mixed-valence interactions. A computational study was also conducted, supporting the involvement of intramolecular interactions.

U2 - 10.1021/acs.joc.9b03118

DO - 10.1021/acs.joc.9b03118

M3 - Journal article

C2 - 31984743

VL - 85

SP - 3277

EP - 3286

JO - Journal of Organic Chemistry

JF - Journal of Organic Chemistry

SN - 0022-3263

IS - 5

ER -