TY - JOUR
T1 - Electron acceptors of the fluorene series. Part 13.19-(5-Nitrofuran-2-ylidene)- and 9-(5-nitro-2-thienylidene)-2,4,5,7-tetranitrofluorenes
T2 - Novel π-extended electron acceptors. Synthesis, cyclic voltammetry and X-ray crystal structures for the acceptor and its 4,5-dimethyltetrathiafulvalene complex, and a theoretical study
AU - Perepichka, Igor F.
AU - Perepichka, Dmitrii F.
AU - Lyubchik, Svetlana B.
AU - Bryce, Martin R.
AU - Batsanov, Andrei S.
AU - Howard, Judith A.K.
PY - 2001
Y1 - 2001
N2 - Two novel polynitrofluorene acceptors π-extended with 5-nitrofuran and 5-nitrothiophene moieties (2 and 3), have been synthesised. Cyclic voltammetry experiments show single electron reduction peaks at ca. −0.66–0.67 V (vs. Fc/Fc+); however, this process (probably due to substantial changes in geometry of reduced species) is electrochemically irreversible and re-oxidation of the derived radical anions is observed at +0.05 and −0.04 V, for 2 and 3, respectively. Electronic absorption spectroscopy confirms charge transfer complexation of the studied acceptor with 4,5-dimethyltetrathiafulvalene (Me2TTF) in solution. The X-ray crystal structure of the 1:1 charge transfer complex (CTC) of acceptor 2 with Me2TTF shows mixed A ċD ċA ċD stacking, and its comparison with the structure of the acceptor itself indicates a neutral ground state of this CTC. Theoretical HF/6-31G(d) calculations for the acceptor 2 and its radical anion and dianion states are in agreement with this conclusion. Intramolecular hydrogen bonding in 2 between the oxygen of the furan ring and C(8)-H hydrogen of the fluorene moiety is observed in both solution (1H NMR) and solid state (X-ray) and also supported by theoretical calculations.
AB - Two novel polynitrofluorene acceptors π-extended with 5-nitrofuran and 5-nitrothiophene moieties (2 and 3), have been synthesised. Cyclic voltammetry experiments show single electron reduction peaks at ca. −0.66–0.67 V (vs. Fc/Fc+); however, this process (probably due to substantial changes in geometry of reduced species) is electrochemically irreversible and re-oxidation of the derived radical anions is observed at +0.05 and −0.04 V, for 2 and 3, respectively. Electronic absorption spectroscopy confirms charge transfer complexation of the studied acceptor with 4,5-dimethyltetrathiafulvalene (Me2TTF) in solution. The X-ray crystal structure of the 1:1 charge transfer complex (CTC) of acceptor 2 with Me2TTF shows mixed A ċD ċA ċD stacking, and its comparison with the structure of the acceptor itself indicates a neutral ground state of this CTC. Theoretical HF/6-31G(d) calculations for the acceptor 2 and its radical anion and dianion states are in agreement with this conclusion. Intramolecular hydrogen bonding in 2 between the oxygen of the furan ring and C(8)-H hydrogen of the fluorene moiety is observed in both solution (1H NMR) and solid state (X-ray) and also supported by theoretical calculations.
UR - http://www.scopus.com/inward/record.url?scp=0034824505&partnerID=8YFLogxK
U2 - 10.1039/b103392c
DO - 10.1039/b103392c
M3 - Article
AN - SCOPUS:0034824505
SN - 0300-9580
VL - 1
SP - 1546
EP - 1551
JO - Journal of the Chemical Society. Perkin Transactions 2
JF - Journal of the Chemical Society. Perkin Transactions 2
IS - 9
ER -