Supporting Information. Copyright Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 2008

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1 upporting Information Copyright Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim, 2008

2 1 Mono- and Bis-Tetrathiafulvalene-1,3,5-Triazines as Covalently Linked Donor-Acceptor ystems: tructural, pectroscopic and Theoretical Investigations François Riobé, Philippe Grosshans, Helena idorenkova, Michel Geoffroy,* and arcis Avarvari* [a] Université d'angers, CR Laboratoire de Chimie et Ingénierie Moléculaire, CIMA UMR 6200 UFR ciences, Bât. K, 2 Bd. Lavoisier, Angers (France) [b] Department of Physical Chemistry, University of Geneva, 30 Quai Ernest Ansermet, 1211 Geneva (witzerland)

3 2 Experimental section General comments. Dry CH 2 Cl 2 and CH 3 C were obtained by distillation over P 2 O 5 and THF and diethylether were distilled over sodium and benzophenone. uclear magnetic resonance spectra were recorded on a Bruker Avance DRX 500 spectrometer operating at MHz for 1 H. Chemical shifts are expressed in parts per million (ppm) downfield from external TM. The following abbreviations are used: s, singlet; d, doublet. EI M spectrum was recorded on Thermo Electron Corporation TRACE-DQ apparatus, with direct introduction probe at 70 ev, while MALDI-TOF M spectrum was recorded on Bruker Biflex-IIITM apparatus, equipped with a 337nm 2 laser Elemental analyses were performed by the "ervice d'analyse du CR" at Gif/Yvette, France. tarting material: 2,4,6-trichloro-1,3,5-triazine Method A To a solution of tetrathiafulvalene (TTF) (409 mg, 2 mmol) in diethylether (15 ml) LDA (2.4 mmol, 1.2 ml, 2M in hexanes) was added at -78 C under magnetic stirring. The mixture was stirred for 45 min and a yellow precipitate appeared. Then a solution of cyanuric chloride (74 mg, 0.4 mmol, 0.2 eq) in THF (30 ml) was added drop wise. The colour turned immediately to blue, and then to black when the solution was allowed to warm at RT. Then, MeOa (65 mg, 1.2 mmol) in methanol (10 ml) was added and the colour slowly changed to red. The mixture was filtered onto celite, concentrated under vacuum and chromatographed. Two main products 1 (red powder) and 2 (purple powder) could be separated on silica gel (DCM:cyclohexane 1:1 as eluant), with the later eluted first. Most of the unreacted TTF could be also recovered by chromatography. A very small amount of the C 3 -symmetric tris-ttftriazine was also isolated with this procedure: -1 mg of 2,4,6-tris(tetrathiafulvalene)-1,3,5-triazine (blue powder) (compound 3) M (MALDI-TOF) m/z: (M th =686.74); 2,4-Bis(tetrathiafulvalene)-6-methoxy-1,3,5-triazine (2) (10 mg, 3%). 1 H MR (THF-d8): δ = 4.06 (s, 3H, CH 3 O), 6.54 (d, 3 J HH = 6.2 Hz, 1H, CH=CH), 6.57 (d, 3 J HH = 6.2 Hz, 1H, CH=CH), 8.07 (s, 2H, CH=C-C=); M (MALDI-TOF) m/z: (M th =514.85); Anal. calcd for C 16 H 9 3 O 8 : C, 37.26; H, 1.76;, Found: C, 36.91; H, 1.95;, Unfortunately, because of the sparing solubility of 2 in all deuterated solvents, including THF-d8, we were not able to record a 13 C MR spectrum.

4 3 2 2) Cl 1) 2 LDA Cl Cl Cl MeOa OMe

5 1 H MR spectrum: 4

6 5 2-Tetrathiafulvalene-4,6-dimethoxy-1,3,5-triazine (1) (20 mg, 3%). 1 H MR (CDCl 3 ): δ = 4.06 (s, 6H, CH 3 O), 6.32 (d, 3 J HH = 6.2 Hz, 1H, CH=CH), 6.34 (d, 3 J HH = 6.2 Hz, 1H, CH=CH), 7.81 (s, 1H, CH=C-C=); 13 C MR (CDCl 3 ): 55.4; 108.3; 113.2; 118.7; 119.3; 134.9; 167.8; 172.3; M (EI + -DQ) m/z: (M th =342.96); Anal. calcd for C 11 H 9 3 O 2 4 : C, 38.47; H, 2.64;, Found: C, 38.71; H, 2.44;, ) Cl 1) LDA Cl Cl Cl Cl MeOa MeO OMe

7 1 H MR spectrum: 6

8 13 C MR spectrum: 7

9 8 Method B 2,4-TTF-6-methoxy-1,3,5-triazine (2) To a solution of TTF (306 mg, 1.5 mmol) in Et 2 O (15 ml), LDA (1,65 mmol) freshly prepared (0.23 ml of diisopropylamine and 1 ml of BuLi (1,6M in hexanes)) in ether (10 ml) was added at -78 C. After one hour, a solution of cyanuric chloride (69 mg, 0.38 mmol) in THF (50 ml) was added drop wise. Then, the mixture was allowed to warm slowly (5h). At -15 C, MeOa (30 mg, 0.57 mmol) in methanol (15 ml) was added and the colour turned to purple. The mixture was treated at RT as previously to obtain 2 (80 mg, 21%). tarting material: 2,4-dichloro-6-methoxy-1,3,5-triazine 2-TTF-4,6-dimethoxy-1,3,5-triazine (1) To a solution of 1 mmol of lithium-tetrathiafulvalene in 15 ml of ether, prepared in situ as previously, 2,4-dichloro-6-methoxy-1,3,5-triazine (180 mg, 1 mmol) in THF (50 ml) was added at -78 C. The mixture was allowed to warm to -10 C. Then, 108 mg (2 mmol) of MeOa in 15 ml of methanol were added. The colour turned immediately to red. After one night at RT, the mixture was filtered onto celite, concentrated under vacuum and the resulting mixture purified by chromatography on silica gel (DCM:cyclohexane 1:1) to afford 1 as a red powder (37 mg, 11%). 1) LDA 2) Cl Cl OMe Cl OMe MeOa MeO OMe

10 9 X-ray structure of 1. Fig. 1 Molecular structure of 1 along with the numbering scheme (left). ide view of the molecule (right). Fig. 2 Packing diagram of 1 along the b axis. hortest intrastack distance 3.95 Å; shortest interstack distances Å (highlighted in red dotted line). Bond Lengths (Å) 1 C (11) 1 C (9) 2 C (11) 2 C (9) 3 C (11) 3 C (9) 4 C (11) 4 C (10) 1 C (13) 1 C (11) 2 C (13) 2 C (11) 3 C (13) 3 C (13) O1 C (12) O1 C (9) O2 C (12) O2 C (10) C1 C (12) C1 C (13) C3 C (12) C5 C (12) Bond Angles ( ) C3 1 C1 94.1(5) C2 2 C3 94.1(5) C5 3 C4 94.3(5) C6 4 C4 95.7(5) C9 1 C (11) C8 2 C (10) C8 3 C (12) C9 O1 C (9) C8 O2 C (10) C2 C1 C (11) C2 C (10) C7 C (9) C1 C (9) C4 C (8) C4 C (9) 1 C (6) C3 C (9) C3 C (8) 3 C (6) C6 C (10) C5 C (11) 2 C (12) 2 C7 C (11) 1 C7 C (12) 3 C (12) 3 C8 O (13) 2 C8 O (13) 3 C (12) 3 C9 O (13) 1 C9 O (13)

11 10 X-ray structure of 2. Fig. 3 Molecular structure of 2, along with a side view of the molecule. Bond Lengths (Å) Fig. 4 Packing diagram of 2. 1A C4A 1.760(5) 1A C6A 1.764(6) 2A C5A 1.720(4) 2A C6A 1.763(7) 3A C8A 1.712(5) 3A C7A 1.755(7) 4A C9A 1.728(5) 4A C7A 1.761(5) 1B C4B 1.754(4) 1B C6B 1.769(7) 2B C5B 1.736(7) 2B C6B 1.762(4) 3B C8B 1.706(7) 3B C7B 1.752(4) 4B C9B 1.749(6) 4B C7B 1.750(7) 1 C (7) 1 C (5) 2 C (7) 2 C (5) 3 C (5) 3 C (5) O1 C (5) O1 C (7) C1 C4A 1.465(6) C2 C4B 1.453(7) C4A C5A 1.328(7) C6A C7A 1.337(6) C8A C9A 1.317(8) C4B C5B 1.337(6) C6B C7B 1.337(6) C8B C9B 1.312(7) Bond Angles ( ) C4A 1A C6A 94.4(3) C5A 2A C6A 95.0(3) C8A 3A C7A 94.6(3) C9A 4A C7A 93.9(3) C4B 1B C6B 95.0(2) C5B 2B C6B 95.1(2) C8B 3B C7B 95.7(3) C9B 4B C7B 93.7(3) C1 1 C (4) C3 2 C (4) C3 3 C (4) C3 O1 C (4) 1 C (4) 1 C1 C4A 115.8(4) 3 C1 C4A 117.5(4) 2 C (4) 2 C2 C4B 117.0(4) 1 C2 C4B 117.6(4) 3 C (4) 3 C3 O (4) 2 C3 O (4) C5A C4A C (4) C5A C4A 1A 117.1(4) C1 C4A 1A 117.5(4) C4A C5A 2A 118.8(4) C7A C6A 2A 122.6(3) C7A C6A 1A 123.3(4) 2A C6A 1A 114.1(3) C6A C7A 3A 122.9(3) C6A C7A 4A 123.1(4) 3A C7A 4A 114.0(3) C9A C8A 3A 118.4(4) C8A C9A 4A 118.2(4) C5B C4B C (4) C5B C4B 1B 117.0(4) C2 C4B 1B 116.5(3) C4B C5B 2B 118.5(4) C7B C6B 2B 124.5(3) C7B C6B 1B 121.4(4)

12 2B C6B 1B 114.0(2) C6B C7B 4B 124.2(4) C6B C7B 3B 121.8(3) 4B C7B 3B 114.0(2) C9B C8B 3B 117.4(5) C8B C9B 4B 118.6(4) 11

13 12 Theoretical Calculations The optimized geometries have been obtained with the Gaussian03 1 package at the DFT level of theory. The B3LYP functional 2 with the 6-31+G* basis set has been used. Vibrations frequency calculations performed on the optimized structures at the same level of theory yielded only positive values. Time dependent DFT calculations have been performed at the B3LYP/6-31G* level on the equilibrium geometry corresponding to the conformation found in the crystal structure. Hyperfine coupling constants were calculated at the DFT/B3LYP/augcc-pPVDZ level. Theoretical calculations on TTF-dimethoxy-triazine 1 and its radical cation [1] + Equilibrium geometries and energies for neutral and radical cation forms of (1) min1 min2 min3 min4 neutral sym. C 1 cation sym. C s E = 0.92 kcal E = 1.05 kcal DE = 0.00 kcal E = 0.45 kcal (X-ray) DE = 0.00 kcal E = 4.47 kcal E = 1.61 kcal E = 1.09 kcal eutral C 1 symmetry Radical cation [1] C s symmetry 1 J. A. Pople et al., Gaussian03, Revision B.03; Gaussian, Inc.: Wallingford CT, (a) C. Lee, W. Yang and R. G. Parr, Phys. Rev. B, 1988, 37, 785; (b) A. D. Becke, J. Chem. Phys., 1993, 98, 5648.

14 13 Fig. 5 Optimized geometry for 1 (minimum 4, corresponding to the conformation found in the X-ray structure) (DFT/B3LYP/6-31+G*). Fig. 6 HOMO (left) (E = ev).and LUMO (right) (E = ev).of 1 (minimum 4) (DFT/B3LYP/6-31+G*, (isovalue 0.05)). Orientation for 1 (minimum 4) Center Atomic Atomic Coordinates (Angstroms) umber umber Type X Y Z

15 Mode ymmetry A A A A A Frequencies ZPE = hartree Time dependent DFT calculations for 1 (DFT/B3LYP/6-31G*). Excitation energies and oscillator strengths: Excited tate 1: inglet-a ev nm f= > This state for optimization and/or second-order correction. Copying the excited state density for this state as the 1-particle RhoCI density. Excited tate 2: inglet-a 88 -> ev nm f= Excited tate 3: inglet-a 88 -> > ev nm f= Excited tate 4: inglet-a 88 -> > > ev nm f= Excited tate 5: inglet-a 87 -> > > > > ev nm f= Excited tate 6: inglet-a 87 -> > ev nm f=0.0056

16 > > > > Excited tate 7: inglet-a 87 -> ev nm f= Excited tate 8: inglet-a 83 -> > > ev nm f= Excited tate 9: inglet-a 87 -> > > ev nm f= Excited tate 10: inglet-a 86 -> > > > > ev nm f= Fig. 7 Optimized geometry with atom labeling and OMO (isovalue 0.05) for [1] + (minimum 1) (DFT/B3LYP/6-31+G*).

17 16 Optimized geometry of neutral molecule 1 and radical cation [1] + 1 (C 1 ) min3 [1] + (C s ) min1 d(c11-c12), Å d(c11-h13), Å d(c12-h14), Å d(c11-17), Å d(c12-18), Å d(17-c10), Å d(18-c10), Å d(c10-c6), Å d(c6-15), Å d(c6-16), Å d(15-c7), Å d(16-c8), Å d(c7-c8), Å d(c7-h9), Å d(c8-c3), Å d(c3-21), Å d(c3-2), Å d(21-c4), Å d(2-c1), Å d(c1-5), Å d(c4-5), Å d(c1-o19), Å d(c4-o20), Å d(o19-c26), Å d(o20-c22), Å d(c26-h27), Å d(c26-h28), Å d(c26-h29), Å d(c22-h23), Å d(c22-h24), Å d(c22-h25), Å d(21-h9), Å d(2-16), Å (C7-C8-C3), (C8-C3-21), di(17-c10-c6-15), di(h13-c11-c7-h9), di(h13-c11-c3-21), di(h9-c7-c3-21),

18 17 Calculated coupling constants (A iso, MHz) at DFT/B3LYP/aug-cc-pPVDZ level for [1] + H9 H13 H14 [1] + min min min min

19 18 Theoretical calculations on bis(ttf)-methoxy-triazine 2 tructure and energies for neutral and dication triplet forms of 2 min1 min2 min3 min4 neutral sym. C 1 E = 0.60 kcal E = 0.84 kcal E = 0.42 kcal (Xray) DE = 0.00kcal dication sym. C s DE = 0.00 kcal E = 2.83 kcal E = 0.76 kcal E = 1.29 kcal eutral C 1 symmetry Radical cation [2] C s symmetry Fig. 8 Optimized geometry for bis(ttf)-methoxy-triazine 2 (minimum 3 corresponding to the conformation found in the X-ray structure) (DFT/B3LYP/6-31+G*).

20 19 Fig. 9 HOMO 1 (E = ev), HOMO (E = ev) and LUMO (E = ev).of 2 (minimum 3) Orientation for 2 (minimum 3). (DFT/B3LYP/6-31+G*, isovalue 0.05) Center Atomic Atomic Coordinates (Angstroms) umber umber Type X Y Z Mode ymmetry A A A A A Frequencies ZPE = hartree

21 20 Time dependent DFT calculations (DFT/B3LYP/6-31G*). Excitation energies and oscillator strengths: Excited tate 1: inglet-a ev nm f= > > This state for optimization and/or second-order correction. Copying the excited state density for this state as the 1-particle RhoCI density. Excited tate 2: inglet-a 130 -> > ev nm f= Excited tate 3: inglet-a 130 -> > ev nm f= Excited tate 4: inglet-a 130 -> > ev nm f= Excited tate 5: inglet-a 130 -> > ev nm f= Excited tate 6: inglet-a 130 -> > ev nm f= Excited tate 7: inglet-a 130 -> > ev nm f= Excited tate 8: inglet-a 130 -> ev nm f= Excited tate 9: inglet-a 130 -> > > ev nm f= Excited tate 10: inglet-a 131 -> > > ev nm f=0.0048

22 21 Fig. 10 Optimized geometry for [2] 2+ triplet (minimum 1) (DFT/B3LYP/6-31+G*). Optimized geometry of neutral molecule 2 and radical cation [2] 2+ (triplet) 2 (C 1 ) min3 [2] 2+ (C s ) min1 2 (C 1 ) min3 [2] 2+ (C s ) min1 d(c11-c12), Å d(c34-c35), Å d(c11-h13), Å d(c34-h36), Å d(c12-h14), Å d(c35-h37), Å d(c11-17), Å d(c34-32), Å d(c12-18), Å d(c35-33), Å d(17-c10), Å d(32-c31), Å d(18-c10), Å d(33-c31), Å d(c10-c6), Å d(c30-c31), Å d(c6-15), Å d(c30-29), Å d(c6-16), Å d(c30-27), Å d(15-c7), Å d(29-c26), Å d(16-c8), Å d(27-c25), Å d(c7-c8), Å d(c26-c25), Å d(c7-h9), Å d(c26-h28), Å d(c8-c3), Å d(c25-c4), Å d(c3-20), Å d(c4-20), Å d(c3-2), Å d(c4-5), Å d(2-c1), Å d(5-c1), Å d(c1-o19), Å d(5(20)-h28), Å d(o19-c21), Å d(20(5)-27), Å d(c21-h22), Å (C26-C25-C4), d(c21-h23), Å (C25-C4-20), d(c21-h24), Å di(32-c31-c30-29), d(20-h9), Å di(h36-c34-c26-h28), d(2-16), Å di(h36-c34-c4-20), (C7-C8-C3), di(h28-c26-c4-20), (C8-C3-20), di(17-c10-c6-15), di(h13-c11-c7-h9), di(h13-c11-c3-20), di(h9-c7-c3-20),

23 22 Calculated coupling constants (A iso, MHz) at DFT/B3LYP/aug-cc-pPVDZ level for [2] 2+ (triplet) H9 H13 H14 H28 H36 H37 [2] 2+ min min min min

24 23 Electrochemical studies. Cyclic voltammetry measurements were performed in a glove box containing dry, oxygen-free (< 1 ppm) argon, using a three-electrode cell equipped with a platinum millielectrode of cm 2 area, an Ag/Ag + pseudo-reference and a platinum wire counter-electrode. The potential values were then re-adjusted with respect to the saturated calomel electrode (CE). The electrolytic media involved a 0.1 mol.l -1 solution of (n- Bu 4 )PF 6 in THF. All experiments have been performed at room temperature at 0.1 V.s 1. Experiments have been carried out with an EGG PAR 273A potentiostat with positive feedback compensation. For both compounds the reduction process is accompanied by a strong adsorption at the electrode, which can be avoided only at high speed voltage (5 V s 1 ). Fig. 11 Cyclic voltammetry of 1. Fig. 12 Cyclic voltammetry of 2.

25 24 UV-Visible pectroscopy. All solvents used for spectroscopic measurements were of spectroscopic grade and were used as commercially available. Electronic absorption spectra were recorded with a Lambda 950 UV/vis spectrophotometer from Perkin-Elmer. TTF-DMe-TZ l max = 492 nm TTF 2 -Me-TZ l max = 530 nm Fig. 13 UV-Vis spectra of TTF-DMe-TZ (1) (a) and TTF 2 -Me-TZ (2) (b). Fig. 14 UV-Vis spectra of TTF-DMe-TZ (1) (a), TTF 2 -Me-TZ (2) (b) and TTF 3 -TZ (3) (c) (λ max = 552 nm).

26 25 Fig. 15 UV-Vis spectra of TTF and a mixture of TTF and 2,4-dichloro-6-methoxy-triazine. The second curve represents the sum of the absorption curves of TTF and 2,4-dichloro-6-methoxy-triazine. o charge transfer band is observed.