A Redox-Fluorescent Molecular Switch Based on a. Heterobimetallic Ir(III) Complex with a Ferrocenyl. Azaheterocycle as Ancillary Ligand.

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1 Supporting Information (SI) A Redox-Fluorescent Molecular Switch Based on a Heterobimetallic Ir(III) Complex with a Ferrocenyl Azaheterocycle as Ancillary Ligand. Fabiola Zapata, Antonio Caballero, Arturo Espinosa, Alberto Tárraga* and Pedro Molina* Departamento de Química Orgánica. Facultad de Química. Universidad de Murcia. Campus de Espinardo, E Murcia, Spain. pmolina@um.es atarraga@um.es Table of contents General comments... S3 Computational details... S3 Figure SI 1. Relative energies for all possible stereoisomers of model complex 3... S3 Synthesis and relevant spectral and characterization data... S4 Figure SI 2. 1 H- and 13 C-MR spectra of complex S5 Figure SI 3. Cyclic voltammograms of 2 at different scan rates.... S6 Figure SI 4. Anodic (left) and cathodic (right) current intensities versus the S1

2 square root of the scan rates.... S6 Figure SI 5. Evolution of the LSW during the course of the monooxidation of S7 Figure SI 6. Evolution of UV-Vis-IR spectra during the course of the oxidation of compound S7 Figure SI 7. Calculated HOMO, HOMO-2 and LUMO surfaces for complex S8 Figure SI 8. Calculated MO diagrams for 2 and S9 Calculated structures. Cartesian coordinates and energies of 2, 2 + and S10 References.... S15 S2

3 General comments.- Melting points were determined on a hot-plate melting point apparatus and are uncorrected. 1 H- and 13 C-MR spectra were recorded at 300 MHz. Chemical shifts refer to signals of tetramethylsilane in the case of 1 H and 13 C spectra. Quantum yield values were measured with respect to anthracene as standard (Φ = 0.27±0.03), 1 using the equation Φ x /Φ s = (S x /S s ) [(1-10 -As )/(1-10 -Ax )], 2 where x and s indicate the unknown and standard solution, respectively, Φ is the quantum yield, S is the area under the emission curve and A is the absorbance at the excitation wavelength (λ exc = 250 nm) Computational details.- Calculated geometries for complex 2, its oxidized derivative 2 +, as well as the 2- unsubstituted derivative were fully optimized in the gas-phase with tight convergence criteria and using ultrafine grids for integrals (pruned grids consisting on 99 radial shells and 590 angular points per shell around every nuclear position) at the DFT level with the Gaussian 03 package. 1 The B3LYP 2 functional and the 6-31G* basis set, augmented with diffuse functions at atoms (denoted as aug6-31g*), were used for all atoms - except Ir, for which SDD-ecp was employed. All PF 6 counteranions were systematically omitted in all calculated cationic structures. Reported energies do not include the ZPE (zero-point energy) correction. In order to demonstrate the expected preference exhibited by the ppy C donor atoms to occupy trans-positions with respect to the phenanthroline donor atoms, a preliminary study was performed on a 2- unsubstituted model complex 3 (Figure SI 1), in the potential energy surface at either the working level of theory (method A) or the higher B3LYP/aug6-311G**/SDDecp level (method B) H Ir H Ir H Ir 3 2eq/2ax 3 3eq/1ax 3 4eq Method A [0.00] [1.22] [10.96] Method B [0.00] [1.20] [11.28] S3

4 Figure SI 1. Possible stereoisomers of model complex 3. In brackets their relative energies (in Kcal/mol) using method A (black) or B (gray). Synthesis and characterization data of complex 2.- A solution of [Ir(ppy) 2 Cl] 2 (160 mg) and 2-ferrocenyl-imidazo[4,5-f]-1,10- phenanthroline 1 (120,6 mg) in CH 2 Cl 2 -MeOH (30 ml, 2:1, v/v) was heated to reflux. After 4 h, the yellow solution was cooled to room temperature, and then a 10-fold excess of potassium hexafluorophosphate was added. The suspension was stirred for 2 h and then was filtered to remove insoluble inorganic salts. The solution was evaporated to dryness under reduced pressure. The solid residue was recrystallized from CH 2 Cl 2 - ether to give 2 (215 mg) in 68 % yield. S4

5 Ir H + Fe PF 6-1 H MR 2 13 C MR Figure SI 2. 1 H- and 13 C-MR spectra of complex 2 (in DMSO-d 6 ). S5

6 Figure SI 3. Cyclic voltammograms of 2 (1 mm) in CH 2 Cl 2 with [(n-bu) 4 ]PF M as supporting electrolyte, Ag/AgCl, as the reference electrode. Different scanning rates were used to check the reversibility of the system. Figure SI 4. Plots showing the anodic (left) and cathodic (right) current intensities versus the square root of the scan rates, obtained from the CV of 2 (1 mm) in CH 2 Cl 2 with [(n-bu) 4 ]PF M as supporting electrolyte. S6

7 Figure SI 5. Evolution of the LSW during the course of the monooxidation of 2 (1mM in CH 2 Cl 2 ) at V with [(n-bu) 4 ]PF M as supporting electrolyte, obtained using a rotating disk electrode at 100 mv/s and 1000 rpm. Figure SI 6. Evolution of UV-Vis-IR spectra during the course of the oxidation of compound 2 (1 mm) in CH 2 Cl 2 with [(n-bu) 4]PF 6 (0.15 M) as supporting electrolyte when 1 electron is removed. Arrows indicate absorptions that increase or decrease during the experiment. S7

8 S8

9 Figure SI 7. Calculated (a) HOMO, (b) HOMO-2 and (c) LUMO (0.04 isovalue) surfaces for complex 2. S9

10 Electronic Supplementary Information for Dalton Transactions Figure SI 8. Calculated MO diagrams for 2 (black and gray) and 2 + (blue). Energies, in ev, are quoted relative to the highest Ir-based HOMO (HOMO-2 for 2, or degenerated α-homo or β-homo for 2 +). S10

11 Calculated structures.- Cartesian coordinates (Å) and energies (au) for 2, 2 + and 3.- Compound 2 (singlet): E = au C C C C C H H H H Fe C C C C C H H H H H C H C C C C C C C C C C C C H H H H H H Ir C C C C C C H H H H C C C C C H H H H C C C C C C H H H H C C S11

12 C C C H H H H Compound 2 + : E = au C C C C C H H H H Fe C C C C C H H H H H C H C C C C C C C C C C C C H H H H H H Ir C C C C C C H H H H C C C C C H H H H C C C C C C H S12

13 H H H C C C C C H H H H Compound 3 2eq/2ax (singlet): E = au E = au (method B) H C H C C C C C C C C C C C C H H H H H H Ir C C C C C C H H H H C C C C C H H H H C C C C C C H H H H C C C C C S13

14 H H H H Compound 3 3eq/1ax (singlet): E = au E = au (method B) H C H C C C C C C C C C C C C H H H H H H Ir C C C C C C H H H H C C C C C H H H H C C C C C C H H H H C C C C C H H H H S14

15 Compound 3 4eq (singlet): E = au E = au (method B) H C H C C C C C C C C C C C C H H H H H H Ir C C C C C H H H H C C C C C C H H H H C C C C C H H H H C C C C C C H H H H S15

16 References Gaussian 03, Revision B.03, Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, Jr., J. A.; Vreven, T.; Kudin, K..; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.; Scalmani, G.; Rega,.; Petersson, G. A.; akatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; akajima, T.; Honda, Y.; Kitao, O.; akai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Bakken, V.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; anayakkara, A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; and Pople, J. A.; Gaussian, Inc., Wallingford CT, Bartolottiand, L. J.; Fluchick, K. In Reviews in Computational Chemistry, Lipkowitz. K. B; Boyd, B. D., Eds.; VCH, ew York, 1996; Vol. 7, pp S16