Remarkable interplay of redox states and conformational changes in a sterically crowded, cross-conjugated tetrathiafulvalene vinylog

被引:7
作者
Amriou, Samia
Perepichka, Igor F.
Batsanov, Andrei S.
Bryce, Martin R. [1 ]
Rovira, Concepcio
Vidal-Gancedo, Jose
机构
[1] Univ Durham, Dept Chem, Durham DH1 3LE, England
[2] Univ Durham, Ctr Mol & Nanoscale Elect, Durham DH1 3LE, England
[3] CSIC, Inst Ciencia Mat Barcelona, Bellaterra 08193, Catalonia, Spain
[4] Natl Acad Sci Ukraine, Inst Phys Organ & Coal Chem, UA-83114 Donetsk, Ukraine
基金
英国工程与自然科学研究理事会;
关键词
charge transfer; cross-conjugation; dendralene; electrochemistry; sulfur heterocycles;
D O I
10.1002/chem.200600244
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Derivatives of 9-[2-(1,3-dithiol-2-ylidene)ethylidene]thioxanthene have been synthesized using Horner-Wadsworth-Emmons reactions of (1,3-dithiol-2-yl)phosphonate reagents with thioxanthen-9-vlidene-acetaidehyde. (5). Further reactions lead to the sterically crowded cross-conjugated "vinylogous ietrathiafulvalene" derivative 9[2,3-bis -(4.5-dimethyl-1,3-dithiol-2-ylidene)-propylidene]thioxanthene (10). X-ray crystallography, solution electrochemistry optical spectroscopy, spectroelectrochemistry and simultaneous electrochemistry and electron paramagnetic resonance spectroscopy, combined with theoretical calculations performed at the B3LYP/6-31G(d) level, eluciclare the interplay of the electronic and structural properties in these molecules. For compound 10, multistage redox behavior is observed: the overall electrochemical process can be represented by 10 -> 10(.+->)10(2+)-> 10(4+) with good reversibility for the 10 -> 10(.+)-> 10(2+) transformations. At the tetracation stage there is the maximum gain in aromaticity at the dithiolium and thioxanthenium rings. Theory predicts that for 10, 10(.+), and 10(2+) the trans isomers are more stable than the cis isomers (by ca. 2-18 kJmol(-1)), whereas for 104, the cis isomer becomes more stable than the trans isomer (by ca. 25 kJ mol(-1)) [trans and cis refer to the arrangement of the two dithiole moieties with respect to the central =C(R)C(H) fragment]. These data explain the detection in cyclic voltammograms of both trans and cis isomers of 10 and 10(.+) during the reduction of 10(4+) at fast scan rates (> 100 mVs(-1)) when the cis-trans isomerization is not completed within the timescale of the experiment. The X-ray structure of the charge-transfer complex (CTC) of 10 with 2,4,5,7-tetranitrofluorene-9-dicyanomethylenefluorene (DTeF) [stoichiometry: 10(.+).(DTeF)(2)(.-).2PhCl] reveals a twisted conformation of 10(.+) (driven by the bulky thioxanthene moiety) and provides a very rare example of segregated stacking of a fluorene acceptor in a CTC.
引用
收藏
页码:5481 / 5494
页数:14
相关论文
共 64 条
[1]   TABLES OF BOND LENGTHS DETERMINED BY X-RAY AND NEUTRON-DIFFRACTION .1. BOND LENGTHS IN ORGANIC-COMPOUNDS [J].
ALLEN, FH ;
KENNARD, O ;
WATSON, DG ;
BRAMMER, L ;
ORPEN, AG ;
TAYLOR, R .
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2, 1987, (12) :S1-S19
[2]   Dendralene-type TTF vinylogs containing a 1,3-diselenole ring [J].
Amaresh, RR ;
Liu, DZ ;
Konovalova, T ;
Lakshmikantham, MV ;
Cava, MP ;
Kispert, LD .
JOURNAL OF ORGANIC CHEMISTRY, 2001, 66 (23) :7757-7764
[3]   The interplay of inverted redox potentials and aromaticity in the oxidized states of new π-electron donors:: 9-(1,3-dithiol-2-ylidene)fluorene and 9-(1,3-dithiol-2-ylidene)thioxanthene derivatives [J].
Amriou, S ;
Wang, CS ;
Batsanov, AS ;
Bryce, MR ;
Perepichka, DF ;
Ortí, E ;
Viruela, R ;
Vidal-Gancedo, J ;
Rovira, C .
CHEMISTRY-A EUROPEAN JOURNAL, 2006, 12 (12) :3389-3400
[4]  
Batsanov AS, 2001, J MATER CHEM, V11, P2181, DOI 10.1039/b101866n
[5]   DENSITY-FUNCTIONAL EXCHANGE-ENERGY APPROXIMATION WITH CORRECT ASYMPTOTIC-BEHAVIOR [J].
BECKE, AD .
PHYSICAL REVIEW A, 1988, 38 (06) :3098-3100
[6]   Controlling the conformation changes associated to electron transfer steps through chemical substitution: Intriguing redox behavior of substituted vinylogous TTF [J].
Bellec, N ;
Boubekeur, K ;
Carlier, R ;
Hapiot, P ;
Lorcy, D ;
Tallec, A .
JOURNAL OF PHYSICAL CHEMISTRY A, 2000, 104 (43) :9750-9759
[7]   NEW VINYLOGOUS TETRATHIAFULVALENE PI-ELECTRON DONORS WITH PERIPHERAL ALKYLSELENO SUBSTITUTION [J].
BRYCE, MR ;
COFFIN, MA ;
CLEGG, W .
JOURNAL OF ORGANIC CHEMISTRY, 1992, 57 (06) :1696-1699
[8]  
Bryce MR, 2000, CHEM-EUR J, V6, P1955, DOI 10.1002/1521-3765(20000602)6:11<1955::AID-CHEM1955>3.3.CO
[9]  
2-2
[10]  
Bryce MR, 2000, EUR J ORG CHEM, V2000, P51