Radical cation and dication of a 4H-dithieno[2,3-b:3',2'-e][1,4]thiazine

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1 Electronic Supplementary Material (ESI) for Organic Chemistry Frontiers. This journal is the Partner Organisations 2017 Radical cation and dication of a 4H-dithieno[2,3-b:3',2'-e][1,4]thiazine Arno Schneeweis, a Andreas Neidlinger, b Guido J. Reiss, c Walter Frank, c Katja Heinze, b and Thomas J. J. Müller*,a a Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D Düsseldorf, Germany b Institut für Anorganische Chemie und Analytische Chemie, Johannes-Gutenberg-Universität Mainz, Duesbergweg 10-14, D Mainz, Germany c Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, D Düsseldorf, Germany ThomasJJ.Mueller@hhu.de Table of contents 1 General Considerations Preparation of starting materials Bis(phenylsulfonyl)sulfide ,3 -Dibromo-2,2 -dithienylsulfide (3) H, 13 C and HSQC NMR spectra of 4-(4-(tert-butyl)phenyl)-4H-dithieno[2,3-b:3',2'-e][1,4]thiazine (5) H NMR of [SbCl 6 ] Crystal Structure determination of UV/Vis spectra of 5 + and Computed xyz-coordinates and computed UV/Vis spectra of TD-DFT calculated structures XYZ-coordinates for of the S 0 state of the intra conformer of 5 (RB3LYP/6-311G(d)) XYZ-coordinates for of the S 0 state of the intra conformer of 5 (RB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) XYZ-coordinates for of the S 0 state of the extra conformer of 5 (RB3LYP/6-311G(d)) XYZ-coordinates for of the S 0 state of the extra conformer of 5 (RB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) XYZ-coordinates for of the S 0 state of the extra conformer of 5 and TD DFT calculation (RB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) XYZ-coordinates for of the D 0 state of 5 + and TD DFT calculation (UB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) XYZ-coordinates for of the S 0 state of 5 2+ (UB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) XYZ-coordinates for of the T 0 state of 5 2+ (UB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM)... 40

2 1 General Considerations All reactions were conducted in heat gun-dried glassware under an argon atmosphere. Solvents for reactions were directly used from a MB-SPS 800 solvent drying system (Firma MBraun) or dried according to literature. Commercially available reagents and catalysts were purchased and employed without further purification. All reactions were monitored by TLC (silica gel 60, F254, Merck KGaA). The spots were detected with UV light at λ max,exc = 254 nm and treated with iodine vapour. The crude mixtures were absorbed on Celite 545 ( mm, Carl Roth GmbH Co.KG) prior to chromatographic purification. Preparative flash column chromatography was conducted with silica gel (0.04 to mm, Macherey-Nagel) and a pressure of 1.0 bar (nitrogen) was employed. 1 H, 13 C and 135-DEPT NMR spectra were recorded on Bruker Avance III 600, Bruker Avance DRX 500, or Bruker Avance III 300 in acetone-d 6 ( 1 H δ 2.05, 13 C δ 29.8) and in CDCl 3 ( 1 H δ 7.26, 13 C δ 77.0). As an internal standard for the 1 H NMR the signal of the remaining protons of the deuterated solvent was used. As internal standard for the 13 C NMR the signal of CDCl 3 (δ 77.0) or acetone-d 6 (δ 29.8) was used. The conventional abbreviations were used as follows: s (singlet), d (doublet), t (triplet), q (quartet), dd (doublet of doublets), m (multiplet). The EI mass spectra were recorded on a Finnigan MAT 8200 apparatus and ESI mass spectra on a Finnigan TSQ 7000 apparatus. IR spectra were recorded on a Shimadzu IRAffinity-1 apparatus (ATR). The intensities of the absorption bands are indicated by s (strong), m (medium), and w (weak). UV/VIS spectra were recorded with a Hewlett-Packard HP8452 diode array. Melting points were measured by using a Büchi B545 apparatus. Elemental analyses were carried out with Elementar vario MICRO cube at the Institut für Pharmazeutische und Medizinische Chemie at the HHU Düsseldorf. Cyclic voltammetry experiments (EG & G potentiostatic instrumentation) were performed under argon in dry and degassed CH 2 Cl 2 at room temperature and at scan rates of 100, 250, 500 and 1000 mvs -1. The electrolyte was n Bu 4 NPF 6 (0.1 M). The working electrode was a 1 mm platinum disk, the counter electrode was a platinum wire, and the reference electrode was an Ag/AgCl electrode. The potentials were corrected to the internal standard of 0/+1 decamethylferrocene in CH 2 Cl 2 (E 0 = -95 mv vs. ferrocene E 0/+1 0 = 450 mv). 1 Spectroelectrochemistry measurements were done with a quartz cuvette of the company GAMEC Analysentechnik (thickness: 1 mm). The cell was equipped with a platinum net working electrode, a platinum counter electrode and an Ag/AgNO 3 reference electrode. As electrolyte 0.1 M solution of [ n Bu 4 N][B(C 6 F 5 ) 4 ] in CH 2 Cl 2 was used. All potentials are stated 1 P. Zanello, Ferrocenes, eds. A. Togni, T. Hayashi, VCH, Weinheim, 1995,

3 versus the oxidation potential of ferrocene. The potentiostat/galvanostat was a BioLogic SP- 50 apparatus. The UV-Vis-NIR spectra were measured with a Varian Cary 5000 spectrometer. The X-band CW-ESR spectra were measured with a Miniscope MS 300 at room temperature. The corresponding settings were as follows: center field = G; sweep = G; modulation amplitude = 100 mg; receiver gain = 0.5; microwave attenuation = 10 db; sweep time = 120 s. As a reference Mn 2+ in ZnS was used (g = 2.118, 2.066, 2.027, 1.986, 1.946, 1.906). The simulation was done with EasySpin (v ) 2 for MatLab (R2007b). 2 S. Stoll and A. Schweiger, J. Magn. Reson., 2006, 178, 42. 3

4 2 Preparation of starting materials 2.1 Bis(phenylsulfonyl)sulfide 3 28 g (170 mmol) sodium benzenesulfinate were suspended in 250 ml dry diethyl ether. A solution of 9.3 g (90 mmol) sulfur dichloride 4 and 50 ml diethyl ether was added dropwise. After that the reaction mixture was heated to 40 C and stirred for 3 h. Then after a short rest without heating water was added and the colourless solid was filtered of. The solid was washed several times with water and recrystallized from acetone to give colourless crystals (20 g, 65 mmol, 72%). Mp 133 C. 1 H-NMR (300 MHz, CDCl 3 ): δ (m, 4 H), (m, 2 H), (m, 4 H). 13 C-NMR (75 MHz, CDCl 3 ): δ (CH), (CH), (CH), (C quart ). EI-MS (m/z (%)): 250 ([C 12 H 10 S 3 ] +, 14), 141 ([C 6 H 5 O 2 S] +, 78), 125 ([C 6 H 5 OS] +, 16), 109 ([C 6 H 5 S] +, 9), 77 ([C 6 H 5 ] +, 100) ,3 -Dibromo-2,2 -dithienylsulfide (3) 5 90 ml dry toluene and 9.0 ml (64 mmol) diisopropylamine were filled in a dry Schlenk vessel with septum. The solution was cooled to -78 C and then 39 ml (62 mmol) of a 1.6 M n- butyllithium solution in n-hexane were added. The reaction mixture was stirred for 2 h at 0 C. In the meantime a second dry Schlenk vessel was prepared by filling it with 10 g (61 mmol) 3-bromthiophene and dry toluene. The content was also cooled to 0 C. After the time is up the 3-bromthiophene solution is transferred to the reaction vessel and the stirring continues for 2 h. Then the reaction mixture was cooled to -78 C before 9.2 g (29 mmol) of bis(phenylsulfonyl)sulfide was added. The suspension was stirred for additional 8 h at -78 C. The reaction was concluded by the addition of water at -78 C. After reaching room temperature the organic phase was extracted three times with diethyl ether. The combined organic layers were dried with anhydrous magnesium sulfate and the solvent was removed under vacuum. The crude product was absorbed on Celite and purified chromatographically 3 F. Allared, J. Hellberg and T. Remonen, Tetrahedron Lett., 2002, 43, Synthesized according to: G. Brauer (ed.): Handbuch der Präparativen Anorganischen Chemie, Stuttgart: Ferdinand-Enke Verlag, 3rd revised edition 1954, p M. Miyasaka and A. Rajca, J. Org. Chem., 2006, 71,

5 on silica gel with n-hexane as mobile phase. On this way product 3 was obtained as a colorless to pale yellow solid (6.9 g, 19 mmol, 66%). Mp 53 C. 1 H-NMR (300 MHz, CDCl 3 ): δ 7.00 (d, 3 J = 5.5 Hz, 2 H), 7.34 (d, 3 J = 5.5 Hz, 2 H). 13 C-NMR (75 MHz, acetone-d 6 ): δ (C quart ), (C quart ), (CH), (CH). EI-MS (m/z (%)): 358 ([C 8 H 81 4 Br 2 S 3 ] +, 12), 356 ([C 8 H 79 4 Br 81 BrS 3 ] +, 21), 354 ([C 8 H 79 4 Br 2 S 3 ] +, 10), 196 ([C 8 H 4 S 3 ] +, 100), 82 ([C 4 H 2 S] +, 5). 5

6 3 1 H, 13 C and HSQC NMR spectra of 4-(4-(tert-butyl)phenyl)-4Hdithieno[2,3-b:3',2'-e][1,4]thiazine (5) 1 H NMR spectra of 5 (acetone-d 6 /CS 2, 300 MHz, 293 K). 6

7 1 H-NMR spectra of 5 (acetone-d 6, 300 MHz, 293 K). 13 C NMR spectra of 5 (acetone-d 6 /CS 2, 75 MHz, 293 K). 7

8 HSQC spectra of 5 (benzene-d 6, 300/75 MHz, 293 K). 8

9 4 1 H NMR of [SbCl 6 ] - 1 H NMR spectra of [SbCl 6 ] - (acetone-d 6, 300 MHz, 293 K). 9

10 5 Crystal Structure determination of 5 Identification code 5 (exp_1123) Empirical formula C 18 H 17 N S 3 Formular weight [g/mol] Crystal description and colour needle, yellow Crystal size x x Crystal system triclinic Space group 1 Unit cell dimiensions a = (3) Å α = (2) b = (3) Å β = (2) c = (3) Å γ = (18) Volume [Å 3 ] (8) Formula units Z 4 Calculated density [Mg/m 3 ] Temperature [K] 295 Measurment device type Xcalibur (Oxford Diffraction) Radiation and wavelength [Å] Mo-Kα, λ = Absorption coefficient [1/mm] F (000) Teta range for data collection [ ] to Index ranges -15 h k l 17 Reflections collected Independent reflections 6998 [R int = 0.107] Observed reflections [I > 2σ(I)] 4740 Refinement method Full matrix least square on F 2 Absorption correction multi scan : T min = 0.616, T max : 1.000: Data / restraints / parameters 6998 / 0 / 407 Final R indices [I > 2σ(I)] [a,b] R 1 = , wr 2 = Goodness-of-fit on F 2[c] Largest diff. Peak and hole (max.,min.) [e.ǻ -3 ] 0.54 und Completeness [%] 99.9 [a] R 1 = Σ F 0 - F c / Σ F 0 [b] wr 2 = {Σ[w(F 0 2 -F c 2 ) 2 ] / Σ[w(F 0 2 ) 2 ]} 1/2, w = 1/(σ 2 (F 0 2 )+(a P) 2 +b P) (P = [max(0,f 0 2 )+2F c 2 ] 1/3 [c] GooF = S = {[Σw(F 0 2 -F c 2 ) 2 ] / (m-n)} 1/2, m = number of reflections, n = number of parameters 10

11 Ellipsoid plot 11

12 6 UV/Vis spectra of 5 + and 5 2+ UV/Vis spectrum of 5 + in dichloromethane (c = mol/l; T = 293 K) UV/Vis spectrum of 5 + in acetone (T = 293 K) 12

13 UV/Vis spectrum of 5 2+ in acetone (c = mol/l; T = 293 K) 13

14 7 Computed xyz-coordinates and computed UV/Vis spectra of TD- DFT calculated structures 7.1 XYZ-coordinates for of the S 0 state of the intra conformer of 5 (RB3LYP/6-311G(d)) C C N C C S C C S S C C C C C C C C C C C C H

15 H H H H H H H H H H H H H H H H SCF Done: E(RB3LYP) = A.U. after 1 cycles E(RB3LYP) = kj/mol Sum of electronic and zero-point Energies= Sum of electronic and thermal Energies= Sum of electronic and thermal Enthalpies= Sum of electronic and thermal Free Energies= XYZ-coordinates for of the S 0 state of the intra conformer of 5 (RB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) C C N C C S C C S

16 S C C C C C C C C C C C C H H H H H H H H H H H H H H H H H SCF Done: E(RB3LYP) = A.U. after 1 cycles E(RB3LYP) = kj/mol Sum of electronic and zero-point Energies= Sum of electronic and thermal Energies= Sum of electronic and thermal Enthalpies= Sum of electronic and thermal Free Energies=

17 7.3 XYZ-coordinates for of the S 0 state of the extra conformer of 5 (RB3LYP/6-311G(d)) N S C C C C C C C C S S C C C C C C C C C

18 C H H H H H H H H H H H H H H H H H SCF Done: E(RB3LYP) = A.U. after 1 cycles E(RB3LYP) = kj/mol Sum of electronic and zero-point Energies= Sum of electronic and thermal Energies= Sum of electronic and thermal Enthalpies= Sum of electronic and thermal Free Energies= ΔE intra-extra = kj/mol 7.4 XYZ-coordinates for of the S 0 state of the extra conformer of 5 (RB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) N S C C

19 C C C C C C S S C C C C C C C C C C H H H H H H H H H H H H H H

20 H H H SCF Done: E(RB3LYP) = A.U. after 1 cycles E(RB3LYP) = kj/mol Sum of electronic and zero-point Energies= Sum of electronic and thermal Energies= Sum of electronic and thermal Enthalpies= Sum of electronic and thermal Free Energies= ΔE intra-extra = -3.3 kj/mol 7.5 XYZ-coordinates for of the S 0 state of the extra conformer of 5 and TD DFT calculation (RB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) N S C C C C C C C C S

21 S H H H H C C C C C C H H H H C C H H H C H H H C H H H SCF Done: E(RB3LYP) = A.U. after 1 cycles After PCM corrections, the SCF energy is a.u. Sum of electronic and zero-point Energies= Sum of electronic and thermal Energies= Sum of electronic and thermal Enthalpies= Sum of electronic and thermal Free Energies= HOMO ev LUMO ev 21

22 Relevant excitation energies and oscillator strengths: Excited State 1: Singlet-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 State 2: Singlet-A ev nm f= > Excited State 3: Singlet-A ev nm f= > > Excited State 4: Singlet-A ev nm f= > > > > > Excited State 5: Singlet-A ev nm f= > > > > > > Excited State 6: Singlet-A ev nm f= > > > > > Excited State 7: Singlet-A ev nm f=

23 88 -> > > > > Excited State 8: Singlet-A ev nm f= > > > XYZ-coordinates for of the D 0 state of 5 + and TD DFT calculation (UB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) N S C C C C C C C C S S H

24 H H H C C C C C C H H H H C C H H H C H H H C H H H SCF Done: E(UB3LYP) = A.U. after 1 cycles After PCM corrections, the SCF energy is a.u. Sum of electronic and zero-point Energies= Sum of electronic and thermal Energies= Sum of electronic and thermal Enthalpies= Sum of electronic and thermal Free Energies=

25 The percentage contributions of a transition to the excited state were calculated by using the following equation 6 : % 100 Relevant excitation energies and oscillator strengths: Excited State 1:?Spin -A ev nm f= B -> 90B This state for optimization and/or second-order correction. Copying the excited state density for this state as the 1-particle RhoCI density. Excited State 2:?Spin -A 90A -> 91A B -> 90B B -> 90B B -> 90B Excited State 3:?Spin -A 90A -> 91A B -> 90B B -> 90B B -> 90B B -> 90B Excited State 4:?Spin -A 85B -> 90B B -> 90B B -> 90B Excited State 5:?Spin -A 86A -> 92A A -> 91A B -> 91B B -> 90B B -> 90B B -> 93B B -> 90B Excited State 6:?Spin -A 90A -> 91A B -> 90B B -> 90B Excited State 7:?Spin -A 81A -> 92A A -> 91A A -> 99A A -> 92A A -> 92A B -> 90B ev nm f= ev nm f= ev nm f= ev nm f= ev nm f= ev nm f= R. A. Vogt, T. G. Gray, C. E. Crespo Hernández, J. Am. Chem. Soc. 2012, 134,

26 81B -> 93B B -> 91B B -> 93B Excited State 8:?Spin -A 78A ->107A A -> 91A A -> 94A A -> 95A A -> 93A A -> 94A B -> 91B B -> 94B B -> 95B B -> 92B B -> 94B Excited State 9:?Spin -A 85A -> 92A A -> 92A A -> 91A A -> 99A A -> 91A B -> 93B B -> 93B B -> 91B B -> 99B Excited State 10:?Spin -A 90A -> 93A A -> 94A A -> 95A A -> 98A Excited State 11:?Spin -A 85A -> 91A A -> 91A A -> 91A A -> 92A A -> 92A B -> 90B B -> 90B B -> 90B B -> 91B B -> 91B B -> 91B B -> 93B Excited State 12:?Spin -A 85A -> 91A A -> 91A A -> 92A A -> 92A B -> 90B B -> 90B B -> 90B B -> 91B B -> 91B B -> 93B ev nm f= ev nm f= ev nm f= ev nm f= ev nm f=

27 Excited State 13:?Spin -A 90A -> 92A B -> 90B B -> 90B B -> 91B Excited State 14:?Spin -A 90A -> 93A A -> 94A A -> 95A A -> 98A Excited State 15:?Spin -A 90A -> 96A Excited State 16:?Spin -A 87A -> 93A A -> 91A A -> 95A B -> 90B B -> 92B B -> 91B B -> 94B B -> 95B Excited State 17:?Spin -A 89A -> 91A A -> 95A B -> 90B B -> 91B B -> 95B Excited State 18:?Spin -A 85A -> 91A A -> 91A A -> 91A A -> 94A A -> 95A A -> 93A A -> 94A A -> 92A B -> 90B B -> 90B B -> 91B B -> 91B B -> 91B B -> 94B B -> 95B B -> 92B B -> 94B B -> 93B Excited State 19:?Spin -A 85A -> 91A A -> 91A A -> 91A A -> 94A A -> 95A ev nm f= ev nm f= ev nm f= ev nm f= ev nm f= ev nm f= ev nm f=

28 88A -> 92A A -> 93A A -> 94A A -> 95A A -> 92A B -> 90B B -> 91B B -> 91B B -> 92B B -> 94B B -> 95B B -> 92B B -> 95B B -> 93B Excited State 20:?Spin -A 78B -> 90B B -> 90B Excited State 21:?Spin -A 88A -> 91A A -> 94A A -> 95A A -> 99A B -> 91B Excited State 22:?Spin -A 87A -> 93A A -> 94A A -> 95A A -> 91A A -> 94A A -> 95A B -> 92B B -> 95B B -> 91B B -> 94B B -> 95B Excited State 23:?Spin -A 86A -> 92A A -> 91A A -> 99A A -> 95A A -> 99A B -> 93B B -> 91B ev nm f= ev nm f= ev nm f= ev nm f=

29 7.7 XYZ-coordinates for of the S 0 state of 5 2+ (UB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) N S C C C C C C C C S S H H H H C C C C C C H

30 H H H C C H H H C H H H C H H H SCF Done: E(UB3LYP) = A.U. after 1 cycles After PCM corrections, the SCF energy is a.u. Sum of electronic and zero-point Energies= Sum of electronic and thermal Energies= Sum of electronic and thermal Enthalpies= Sum of electronic and thermal Free Energies= HOMO ev LUMO ev Excitation energies and oscillator strengths: Excited State 1: Triplet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B This state for optimization and/or second-order correction. Copying the excited state density for this state as the 1-particle RhoCI density. 30

31 Excited State 2: Triplet-A ev nm f= A -> 90A B -> 90B Excited State 3: Triplet-A ev nm f= A -> 90A A -> 90A A -> 90A B -> 90B B -> 90B B -> 90B Excited State 4: Singlet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B Excited State 5: Triplet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B Excited State 6: Singlet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B Excited State 7: Singlet-A ev nm f= A -> 90A

32 87B -> 90B Excited State 8: Triplet-A ev nm f= A -> 90A B -> 90B Excited State 9: Singlet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B Excited State 10: Singlet-A ev nm f= A -> 90A A -> 90A A -> 91A A -> 91A B -> 90B B -> 90B B -> 91B B -> 91B Excited State 11: Triplet-A ev nm f= A -> 90A B -> 90B Excited State 12: Singlet-A ev nm f= A -> 90A B -> 90B Excited State 13: Triplet-A ev nm f= A -> 90A

33 83A -> 90A B -> 90B B -> 90B Excited State 14: Singlet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B Excited State 15: Triplet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B Excited State 16: Singlet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B Excited State 17: Triplet-A ev nm f= A -> 90A A -> 92A A -> 91A A -> 92A A -> 91A A -> 91A B -> 90B B -> 92B B -> 91B

34 86B -> 92B B -> 91B B -> 91B Excited State 18: Triplet-A ev nm f= A -> 90A A -> 92A A -> 90A A -> 91A A -> 91A A -> 92A A -> 91A A -> 92A B -> 90B B -> 92B B -> 90B B -> 91B B -> 91B B -> 92B B -> 91B B -> 92B Excited State 19: Triplet-A ev nm f= A -> 90A A -> 90A A -> 90A A -> 91A A -> 91A A -> 91A A -> 96A A -> 93A A -> 95A

35 70B -> 90B B -> 90B B -> 90B B -> 91B B -> 91B B -> 91B B -> 96B B -> 93B B -> 95B Excited State 20: Triplet-A ev nm f= A -> 90A A -> 90A A -> 91A A -> 91A A -> 94A A -> 96A A -> 93A A -> 94A A -> 95A B -> 90B B -> 90B B -> 91B B -> 91B B -> 94B B -> 96B B -> 93B B -> 94B B -> 95B Excited State 21: Singlet-A ev nm f= A -> 91A

36 89B -> 91B Excited State 22: Triplet-A ev nm f= A -> 91A A -> 91A B -> 91B B -> 91B Excited State 23: Triplet-A ev nm f= A -> 90A A -> 91A A -> 92A A -> 91A A -> 93A A -> 95A B -> 90B B -> 91B B -> 92B B -> 91B B -> 93B B -> 95B Excited State 24: Singlet-A ev nm f= A -> 91A B -> 91B Excited State 25: Triplet-A ev nm f= A -> 90A A -> 90A A -> 90A A -> 90A A -> 91A

37 77B -> 90B B -> 90B B -> 90B B -> 90B B -> 91B Excited State 26: Singlet-A ev nm f= A -> 90A B -> 90B Excited State 27: Triplet-A ev nm f= A -> 90A A -> 90A A -> 90A A -> 90A A -> 90A A -> 90A A -> 91A A -> 91A B -> 90B B -> 90B B -> 90B B -> 90B B -> 90B B -> 90B B -> 91B B -> 91B Excited State 28: Singlet-A ev nm f= A -> 90A A -> 90A B -> 90B

38 80B -> 90B Excited State 29: Triplet-A ev nm f= A -> 90A A -> 90A A -> 90A A -> 91A A -> 91A A -> 92A A -> 91A A -> 92A A -> 95A B -> 90B B -> 90B B -> 90B B -> 91B B -> 91B B -> 92B B -> 91B B -> 92B B -> 95B Excited State 30: Triplet-A ev nm f= A -> 90A A -> 90A A -> 90A A -> 91A A -> 92A A -> 91A A -> 96A B -> 90B B -> 90B

39 81B -> 90B B -> 91B B -> 92B B -> 91B B -> 96B Excited State 31: Singlet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B Excited State 32: Triplet-A ev nm f= A -> 90A A -> 90A B -> 90B B -> 90B Excited State 33: Singlet-A ev nm f= A -> 90A A -> 90A A -> 90A B -> 90B B -> 90B B -> 90B Excited State 34: Singlet-A ev nm f= A -> 90A A -> 90A A -> 91A A -> 91A B -> 90B

40 80B -> 90B B -> 91B B -> 91B Excited State 35: Singlet-A ev nm f= A -> 91A B -> 91B XYZ-coordinates for of the T 0 state of 5 2+ (UB3LYP/6-31G(d,p), SCRF(IEFPCM, DCM) N S C C C C C C C C S S

41 H H H H C C C C C C H H H H C C H H H C H H H C H H H Sum of electronic and zero-point Energies= Sum of electronic and thermal Energies= Sum of electronic and thermal Enthalpies= Sum of electronic and thermal Free Energies=