Isolation of an Antiaromatic Singlet Cyclopentadienyl Zwitterion

Transcription

1 Isolation of an Antiaromatic Singlet Cyclopentadienyl Zwitterion Paolo Costa, Iris Trosien, Joel Mieres-Perez, and Wolfram Sander* Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, Bochum, Germany Contents Figures (S1-S10) and Tables (S1-S5)... S1 - S13 Cartesian coordinates of optimized structures... S14 - S19 References... S20 S1

2 Figures Figure S1. Comparison of annealing experiments between an argon matrix containing T-4 (blue line) and an argon matrix doped with 1% of H 2O containing T-4 (black line). a) T-4 in an Ar matrix doped with 1% water at 3 K. b) Same matrix showing difference after annealing for 10 min at 25 K. Bands pointing downwards assigned to T-4 are disappearing and bands pointing upwards assigned to the dimer of 4 are appearing. c) T-4 in an Ar matrix at 3 K. d) Same matrix showing difference after annealing for 10 min at 25 K. Bands pointing downwards assigned to T-4 are disappearing and bands pointing upwards assigned to the dimer of 4 are appearing. *signals are caused by water. S2

3 Figure S2. IR spectra in the range cm -1 showing the interaction between tetrachlorocyclopentadienylidene T-4 and BF 3. a) IR spectrum of T-4 in argon doped with 1% of BF 3 at 3 K generated by 450 nm photolysis of 7. b) IR spectrum of the same matrix showing the difference between IR spectrum recorded at 20 K and the one recorded after irradiation of 7 at 3 K. c) IR spectrum of the same matrix showing the difference between IR spectrum recorded at 25 K and the one recorded after irradiation of 7 at 3 K. d) IR spectrum of the same matrix showing the difference between IR spectrum recorded at 30 K and the one recorded after irradiation of 7 at 3 K. e) IR spectrum of the same matrix showing the difference between IR spectrum recorded at 30 K and the one recorded after at 20 K. Bands pointing downwards in b), c), d) and e) assigned to T-4 and BF 3 are disappearing, and bands pointing upwards assigned to S-1e, S-1e BF 3 and oligomers of BF 3 are appearing. The transparent yellow and blue areas denote the IR bands assigned to the C- C-C str. vibration of S-1e and S-1e BF 3 respectively. For simplicity, the IR bands disappearing and appearing are labelled only in the difference spectrum d). S3

4 Figure S3. IR spectra showing the shift of the C-C-C str. vibration of S-1e and S-1e BF 3. a) IR spectra of 1c (black line) and S-1e BF 3 (red line) calculated at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. b) Difference IR spectrum showing the disappearance of S-1e upon irradiation with λ = 650 nm (black line). Difference IR spectrum showing the disappearance of S-1e BF 3 upon irradiation with λ = 365 nm (red line). S4

5 Figure S4. IR spectra showing the photochemistry of S-1e... BF 3. a) IR spectrum of S-1e... BF 3 calculated at the M06-2X/ G(d)/IEF-PCM(argon) level of theory considering the natural abundance of boron 11 (multiplied by 0.8, red line), IR spectrum of S-1e... BF 3 calculated at the M06-2X/ G(d)/IEF- PCM(argon) level of theory considering the natural abundance of boron 10 (multiplied by 0.2, blue line), IR spectrum of S-1e... BF 3 calculated at the M06-2X/ G(d)/IEF-PCM(argon) level of theory considering the natural abundance of boron 10 (multiplied by 0.2, green line). b) Difference IR spectrum showing changes after 365 nm irradiation an argon matrix at 3 K containing S-1e... BF 3. Bands pointing downwards are assigned to S-1e... BF 3. Bands pointing upwards indicate formation of an unknown species. * IR bands assigned to T-4, IR bands assigned to 8. S5

6 Figure S5. IR spectra showing the interaction between tetrachlorocyclopentadienylidene T-4 and BF 3 in xenon matrix. a) IR spectrum of T-4 in xenon doped with 1% of BF 3 at 3 K generated by 450 nm photolysis of 7. b) IR spectrum of the same matrix showing the difference between IR spectrum recorded at 35 K and one recorded after irradiation of 7 at 3 K. c) IR spectrum of the same matrix showing the difference between IR spectrum recorded at 40 K and the one recorded at 35 K. d) IR spectrum of the same matrix showing the difference between IR spectrum recorded at 45 K and the one recorded at 40 K. Bands pointing downwards in b), c) and d) assigned to T-4 and BF 3 are disappearing, and bands pointing upwards assigned to S-1e, S-1e BF 3 and oligomers of BF 3 are appearing. S6

7 Figure S6. IR spectra showing the photochemical rearrangement from S-1e to 8 in argon and in xenon matrix. a) Difference IR spectrum showing changes after irradiation with λ = 650 nm of a xenon matrix containing S-1e. Bands pointing downwards are assigned to S-1e and bands pointing upwards are assigned to 8. b) Difference IR spectrum showing changes after irradiation with λ = 365 nm of an argon matrix containing S-1e. Bands pointing downwards are assigned to S-1e and bands pointing upwards are assigned to 8. S7

8 Figure S7. IR spectra showing the photochemistry of S-1e BF 3 in xenon and in argon matrices. a) Difference IR spectrum showing changes after irradiation with λ = 365 nm a xenon matrix containing S-1e BF 3. Bands pointing downwards are assigned to S-1e BF 3 and bands pointing upwards are due to the formation of unknown ring-opening product. b) Difference IR spectrum showing changes after irradiation with λ = 365 nm an argon matrix containing S-1e BF 3. Bands pointing downwards are assigned to S-1e BF 3 and bands pointing upwards are due to the formation of unknown ring-opening product. *Asterisks denote IR bands of T-4. S8

9 Figure S8. Characteristic IR vibrations of the BF 3 fragment. The experimental frequencies of the degenerate, E symmetrical BF and FBF stretching vibrations (black), A 1 symmetrical BF 3 stretching vibrations (red) of the cation BF 3+, 1 of the anion BF 3-1 and for the neutral BF (three lower traces) are compared to those of S-1e, S-1e BF 3 and 5 (upper traces). S9

10 Figure S9. (A) UV-vis spectra showing the generation and annealing processes of an argon matrix doped with 1% of BF 3 containing T-4. a) UV-vis spectrum of tetrachlorodiazocyclopentadiene 7 in argon matrix doped with 1% of BF 3 at 8 K. b) UV-vis spectrum of the same matrix after photolysis of 7 by 450 nm showing the generation of T-4. c) UV-vis spectrum of the same matrix after annealing at 20 K d) UV-vis spectrum of the same matrix after annealing at 25 K. e) UV-vis spectrum of the same matrix after annealing at 30 K. (B) UVvis spectra showing the irradiation process of the matrix annealed to 30 K. a) Same UV-vis spectrum of panel (A) e). b) UV-vis spectrum of the same matrix after irradiation for 40 min with 650 nm. c) UV-vis spectrum of the same matrix after irradiation with 365 nm. (C) The panel C shows the most intense spectral transitions calculated with TD-DFT method. a) Spectral transitions of S-1e, S-1e BF 3, T-1e and 8 calculated by TD-DFT at the (U)M06-2X/ G(d)/IEF-PCM(argon) level of theory. f) Spectral transitions of S-1e, S-1e BF 3, T-1e and 8 calculated by TD-DFT at the ωb97x-d/ g(d)/ief-pcm(argon) level of theory. S10

11 Figure S10. S-T gaps (kcal mol -1 ) of 4 and its most stable complexes with BF 3 calculated at the (U)ωB97X-D/ G(d)/IEF-PCM(argon) level of theory. Table S1. Adiabatical gap ( E A) corrected with zero point vibrational energy ( E ZPVE) for 4. All values in kcal/mol. (U)M06-2X/ G(d)/IEF-PCM(argon) (U)ωΒ97X-D/ G(d)/IEF- PCM(argon) E A E A Table S2. Stabilization energies ( E) corrected with zero point vibrational energy ( E ZPVE) for the complex of 4 with BF 3. All values in kcal/mol. (U)M06-2X/ G(d) /IEF-PCM(argon) (U)ωΒ97X-D/ G(d) /IEF-PCM(argon) Complex E ZVPE E ZVPE T S-1e T-1e S11

12 Figure S11. ACID isosurface of S-1e BF 3 (isosurface value 0.05). Current density vectors in the ACID isosurfaces indicate the direction of ring current. Clockwise currents are diatropic and indicate aromatic character, while anti-clockwise currents are paratropic and indicate antiaromatic character. Table S3. Assignment of the IR vibrations of S-1e. Mode Calculated [a] Argon [b] Xenon [c] ν/cm -1 (I abs) ν/ cm -1 (Ι rel) ν/ cm -1 (Ι rel) Assignment (99) (7) (7) BF 3 str (10) (3) (4) C-C rocking (132) (8) (9) Skel vibr (295) (18) (21) C-B str (276) (16) (19) C-B str (343) (25) (22) B-F str (233) (8) (6) B-F str (150) (6) (5) C-C-C def (1529) (100) (100) C-C-C str. + C-B def. [a] Calculated at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. [b] Argon matrix at 3 K. [c] Xenon matrix at 3 K. S12

13 Table S4. Assignment of the IR vibrations of S-1e BF 3. Mode Calculated [a] Argon [b] Xenon [c] ν/cm -1 (I abs) ν/ cm -1 (Ι rel) ν/ cm -1 (Ι rel) Assignment (422) (21) (22) B-F asym. str. (on fluoride bridge) (110) (4) (6) Skel vibr (128) (10) (10) B-F sym. str. (on fluoride bridge) (334) (17) * C-B str (65) (3) * B-F str. (on the second BF 3 molecule) (636) (24) (26) B-F str. (on the second BF 3 molecule) (1743) (100) (100) C-C-C str. + C-B def (116) (7) (9) C-C str. [a] Calculated at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. [b] Argon matrix at 3 K. [c] Xenon matrix at 3 K *the corresponding IR bands could not be detected due to the broad IR vibration of T-4 in xenon matrix which covers them. Table S5. Assignment of the IR vibrations of 8. Mode Calculated [a] Argon [b] Xenon [c] ν/cm -1 (I abs) ν/ cm -1 (Ι rel) ν/ cm -1 (Ι rel) Assignment (23) (5) (4) F-B-F scissoring (56) (18) (17) C-B def. + C=C def (46) (20) (18) Skel vibr (50) (14) (12) C-B str. + C-C-C def (42) (20) (23) C-F str. + C-C-C def (117) (48) (51) C-C-C def (183) (29) (25) C-C str (332) (41) (38) C-B str (376) (100) (100) B-F str (107) (25) (23) C=C str. [a] Calculated at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. [b] Argon matrix at 3 K. [c] Xenon matrix at 3 K. S13

14 Table S6. Cartesian coordinates of T-4 at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. Single point energy at CCSD(T)/ G(d)//M06-2X/ G(d)/IEF-PCM(argon) represented as E CCSD(T). C C C C C Cl Cl Cl Cl E = ZPE = E CCSD(T)= Table S7. Cartesian coordinates of T-4 at the ωb97x-d/ g(d)/ief-pcm(argon) level of theory. C C C C C Cl Cl Cl Cl E = ZPE = Table S8. Cartesian coordinates of S-4 at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. Single point energy at CCSD(T)/ G(d)//M06-2X/ G(d)/IEF-PCM(argon) represented as E CCSD(T). C C C C C Cl Cl Cl Cl E = ZPE = E CCSD(T)= S14

15 Table S9. Cartesian coordinates of S-4 at the ωb97x-d/ g(d)/ief-pcm(argon) level of theory. C C C C C Cl Cl Cl Cl E = ZPE = Table S10. Cartesian coordinates of T-9 at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. Single point energy at CCSD(T)/ G(d)//M06-2X/ G(d)/IEF-PCM(argon) represented as E CCSD(T). B F F F C C C C C Cl Cl Cl Cl E = ZPE = E CCSD(T)= S15

16 Table S11. Cartesian coordinates of T-9 at the ωb97x-d/ g(d)/ief-pcm(argon) level of theory. B F F F C C C C C Cl Cl Cl Cl E = ZPE = Table S12. Cartesian coordinates of T-1e at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. Single point energy at CCSD(T)/ G(d)//M06-2X/ G(d)/IEF-PCM(argon) represented as E CCSD(T). C C Cl C Cl C Cl C Cl B F F F E = ZPE = E CCSD(T) = S16

17 Table S13. Cartesian coordinates of T-1e at the ωb97x-d/ g(d)/ief-pcm(argon) level of theory. C C Cl C Cl C Cl C Cl B F F F E = ZPE = Table S14. Cartesian coordinates of S-1e at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. Single point energy at CCSD(T)/ G(d)//M06-2X/ G(d)/IEF-PCM(argon) represented as E CCSD(T). C C Cl C Cl C Cl C Cl B F F F E = ZPE = E CCSD(T)= S17

18 Table S15. Cartesian coordinates of S-1e at the ωb97x-d/ g(d)/ief-pcm(argon) level of theory. C C Cl C Cl C Cl C Cl B F F F E = ZPE = Table S16. Cartesian coordinates of 8 at the M06-2X/ G(d)/IEF-PCM(argon) level of theory C C Cl C Cl C Cl C Cl B F F F E = ZPE = S18

19 Table S17. Cartesian coordinates of S-1e BF 3 at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. Single point energy at CCSD(T)/ G(d)//M06-2X/ G(d)/IEF-PCM(argon) represented as E CCSD(T). C C Cl C Cl C Cl C Cl B F F F B F F F E = ZPE = E CCSD(T)= Table S18. Cartesian coordinates of T-1e BF 3 at the M06-2X/ G(d)/IEF-PCM(argon) level of theory. Single point energy at CCSD(T)/ G(d)//M06-2X/ G(d)/IEF-PCM(argon) represented as E CCSD(T). C C Cl C Cl C Cl C Cl B F F F B F F F E = ZPE = E CCSD(T)= S19

20 References 1. Jacox, M. E.; Thompson, W. E., J. Chem. Phys. 1995, 102, Nxumalo, L. M.; Ford, T. A., Vibrational Spectroscopy 1994, 6, S20