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Tetrathiafulvalene‐Based Macrocycles Formed by Radical Cation Dimerization: The Role of Intramolecular Hydrogen Bonding and Solvent
Author(s) -
Wang WeiKun,
Chen YuanYuan,
Wang Hui,
Zhang DanWei,
Liu Yi,
Li ZhanTing
Publication year - 2014
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201301729
Subject(s) - chemistry , intramolecular force , tetrathiafulvalene , dimer , hydrogen bond , dichloromethane , non covalent interactions , cyclic voltammetry , photochemistry , acetonitrile , solvent , amide , crystallography , molecule , stereochemistry , organic chemistry , electrochemistry , electrode
Compounds 1 a and 1 b were prepared by appending two tetrathiafulvalene (TTF) units to an aromatic amide segment that is driven by six or two intramolecular NH⋅⋅⋅O hydrogen bonds to adopt a folded conformation. UV/Vis absorption experiments revealed that if the TTF units were oxidized to TTF .+ radical cations, the two compounds could form a stable single molecular noncovalent macrocycle in less polar dichloromethane or dichloroethane or a bimolecular noncovalent macrocycle in a binary mixture of dichloromethane with a more polar solvent owing to remarkably enhanced dimerization of the TTF .+ units. The stability of the (TTF .+ ) 2 dimer was evaluated through UV/Vis absorption, electron paramagnetic resonance, and cyclic voltammetry experiments and also by comparing the results with those of control compound 2 . The results showed that introduction of the intramolecular hydrogen bonds played a crucial role in promoting the stability of the (TTF .+ ) 2 dimer and thus the noncovalent macrocyclization of the two backbones in both uni‐ and bimolecular manners.