SUPPLEMENTARY INFORMATION

Transcription

1 SUPPLEMENTARY INFORMATION SUPPLEMENTARY INFORMATION for Photochemistry in a 3-D Metal Organic Framework. Alexander J. Blake, Neil R. Champness*, Timothy L. Easun, David R. Allan, Harriott Nowell, Michael W. George*, Junhua Jia and Xue-Zhong Sun. Synthesis of Re(2,2 -bipyridine-5,5 -dicarboxylic acid)(co) 3 Cl (C 2 H 5 OH): 2,2'-bipyridine-5,5'-dicarboxylic acid 33 (0.024 g, 0.1 mmol) and Re(CO) 5 Cl (0.036 g, 0.1 mmol) were mixed in a 10 ml dry ethanol/toluene (1:1) solution and added to a 50 ml test tube. The tube was sealed and heated at 80 º C for two days. The sealing film was then removed and red orange crystals formed while the solvent was evaporated at 80 º C. The product was filtered, washed with toluene and collected as red orange crystals. Yield: 0.045g, 81%. 1 H NMR (d-acetone, 300 MHz): 9.56 (s, 2H), 8.95 (d, 2H), 8.82 (dd, 2H). Elemental analysis: Calculated for [C 12 H 8 N 2 O 4 Re(CO) 3 Cl] (C 2 H 5 OH): C, 34.26; H, 2.37; N, 4.70 %. Found: C, 34.76; H, 2.00; N, 4.45 %. Synthesis of Mn(2,2 -bipyridine-5,5 -dicarboxylic acid)(co) 3 Br 2,2 -bipyridine-5,5 -dicarboxylic acid 33 (0.6 mmol, g) and Mn(CO) 5 Br (0.5 mmol, g) were dissolved in 100 ml of tetrahydrofuran and toluene (1:1). The solution was transferred to a 250 ml two-neck round bottom flask and heated at 90 o C under N 2 for 2h maximum. Dark red crystalline solid was filtered and washed by toluene. Yield: 0.132g, 57.2%. IR (!(CO), ATR-IR): 2031, 1939, 1911 cm H NMR was attempted in d-dmso and d-methanol but the sample decomposed before spectra could be recorded. Elemental analysis: Calculated for {C 12 H 8 N 2 O 4 Mn(CO) 3 Br}! : C, 38.90; H, 1.74; N, 6.05%. Found: C, 38.68; H, 1.62; N, 6.25 %. nature chemistry 1

2 supplementary information To establish the effect of the carboxylic acid substituents on the photophysics of the Re(diimine)(CO) 3 Cl moiety, the TRIR spectra of MOF precursor Re(bpy(CO 2 H) 2 )(CO) 3 Cl were recorded in a KBr disc in the same way as for 1. Figure S1 demonstrates that the principal excited state formed is MLCT in nature (" = 450 ps) and no evidence for MLCT to #$#* energy transfer is observed.!abs Wavenumber / cm -1 Figure S1: The TRIR difference spectra of Re(bpy(CO 2 H) 2 )(CO) 3 Cl in a KBr disc recorded at 10 ps (black line); 200 ps (red line) and 850 ps (green line) laser irradiation. Single crystal X-ray diffraction data for 1 were collected at 150 K using Bruker SMART CCD area detector diffractometer equipped with an Oxford Cryosystems open flow cryostat, using graphite-monochromated Mo-K% radiation (& = Å). Absorption corrections based on symmetry equivalent reflections were applied to the data using SADABS (Bruker AXS, Madison, WI, USA, 2004). Single crystal X-ray diffraction date for 2a and 2b were collected at 150 K. Single crystal X-ray diffraction data for 2a and 2b were collected at 150 K using a Rigaku Saturn 724+ CCD detector on a Crystal Logic 4-circle kappa goniometer, mounted on Beamline I19 at the UK Diamond Light Source where the synchrotron X-ray wavelength was Å. 2 nature chemistry

3 supplementary information Absorption corrections based on symmetry equivalent reflections were applied using CrystalClear. S1 The structures were solved by direct methods using SHELXS97 and refined by full-matrix least squares on F 2 using SHELXL97. S2 Further details of the refinement process including treatment of disorder are given in the CIF. Due to weak diffraction data for the structure of compound 1 a number of distance restraints were applied to during refinement, Re-Cl [2.49(1) Å], Re-C3C [1.92(1) Å], C3C-O3C [1.15(1) Å], Re1...O3C [3.07(1)Å]. Similarly, C-C and N-C distances were restrained. All atoms of the coordinated DMF molecule, the disordered O1, O1' atoms of the carboxylate group and C5 of the pyridyl ring were refined isotropically. Several high residual Q peaks were attributed to features in the data which could not be modelled: these have no structural or chemical significance. The best refinement model was obtained in Pnna although other space groups which were investigated (P2 1 /n, Pnn2) give essentially the same structure. For compound 2a in the asymmetric unit there are five atoms directly bond to Mn1 atom. N1 and its symmetry-equivalent are from the pyridyl rings of the ligand. The coordinated chloride ligand Cl1 is disordered with one of the carbonyls (C2C, O2C) by rotation about the two-fold rotation axis - symmetry operation (x, 1/2-y, 3/2-z). This symmetry operation generates one N,N-bipyridyl, one chloride and three carbonyls per Mn. Cl1 and C2C-O2C were each modelled as half-occupied and similarity restraints were applied to the Mn-C(carbonyl) distances. The carboxylate O atoms, O1 and O2, are each disordered over two orientations with a major occupancy (for O1' and O2') refined to 0.69(3) [minor occupancy 0.31(3) for O1 and O2]. Similarity restraints were applied to the C6-O1, C6-O1', C6-O2 and C6-O2' distances within the carboxylate groups. Disorder in the coordinated DMF molecules were modelled by two components with occupancies 0.525(15) and 0.475(15) and separate similarity restraints were applied to the C=O, C-N and O-N distances. Atoms O1, O2, N1N, C2C and O2C were refined with isotropic displacement parameters. A cutoff was applied at 2" = 52 degrees because of the weakness of higher-angle diffraction data. nature chemistry 3

4 supplementary information For compound 2b particularly weak diffraction data were collected, due to some loss of crystallinity following irradiation to initiate the photoisomerisation process. Thus various restraints were applied during modelling of data. Similarity restraints were applied to Mn-Cl, Mn- C, C-O and Mn...O distances, and to all 1,2 distances within the DMF components. Significant electron density attributable to a partially-occupied chloride ligand was observed in a difference electron density map lying close to and disordered with carbonyl group C1C-O1C in the equatorial plane. The DMF molecule was found to be disordered over two orientations, with occupancies of 0.64(5) and 0.36(5). With the exception of the aromatic H atoms, hydrogen atoms were not included in the refinement model and extensive restraints were applied to the displacement parameters. Even with the use of synchrotron radiation, the small size of the crystal and the pervasive disorder precluded further refinement. Powder diffraction data for 2 were collected over the 2" range 4-50 o on a Philips X pert diffractometer using Cu K# radiation ($ = Å, 40 kv/40ma) over a period of 4 hours. The simulated powder pattern of the fac-isomer was generated from the crystal structure of 2a. Intensity ! 4 nature chemistry

5 supplementary information Figure S2: Powder diffraction pattern of 2 (bottom) and simulated powder diffraction pattern for the fac-isomer of 2a (top). Small variations in peak positions can be attributed in part to halide scrambling in the single crystal structure of 2a. Figure S3: Electron density map for 2b illustrating electron density (circled) assigned as an equatorially positioned chloride ligand. The equipment used for ps-trir measurements has been described in detail previously. S3 IR spectra were probed with IR pulses generated by difference-frequency generation (ca. 200 cm-1 wide). Pumping was achieved using 1 khz 355 nm pulses (1 ns) and the time delay between the pump and probe pulses was achieved using a electronic delay. nature chemistry 5

6 supplementary information The instrumentation used to record the low-temperature KBr disc spectra has previously been described elsewhere. S4 Briefly, each KBr disc was cut to fit a copper cell with CaF 2 windows, the cell sealed, purged with N 2 gas, evacuated, attached to a cold finger inside a vacuum shroud and cooled to 200 K for photolysis. Photolysis was achieved using a Philips HPK medium pressure 125 W mercury arc lamp and infrared spectra were recorded on a Thermo Nicolet Avatar 360 spectrometer (with 2 cm -1 resolution). Infrared mapping was performed using a Thermo Nicolet Continuµm XL Infrared Microscope with 15X magnification. The in situ ATR-FTIR experiment was performed using a Nicolet Nexus 870 Rapid-scan FTIR spectrometer (spectrum collected every 60 ms with 8 cm -1 resolution) fitted with a Nicolet Smart Golden Gate ZnSe ATR. The powder sample was placed on the ZnSe surface and compressed using the ATR screw press. The press was then removed and the ground-state spectrum was recorded (4 cm -1 resolution). The sample was photolysed using two seconds of 10 Hz pulses of a 355 nm Spectraphysics GC12 Nd:YAG laser, directed onto the sample via an Oriel Visible Liquid Light Guide (~ 3 mw per pulse measured at the sample). The spectrum was then re-recorded and the ground-state subtracted to give the difference spectrum shown in Figure 3. Supporting Information References S1. CrystalClear. Rigaku Corporation, Tokyo, Japan (2008). S2. Sheldrick, G. M. A short history of SHELX. Acta Crystallogr., Sect. A 64, (2008). S3. Alamiry A. H.; Boyle, N. M.; Brookes, C. C.; George, M. W.; Long, C.; Portius, P.; Pryce, M. T.; Ronayne, K. L.; Sun, X. -Z.; Towrie, M.; Vuong, K. Q. Unusually Slow Photodissociation of CO from ( h 6 -C 6H 6)Cr(CO) 3 (M = Cr or Mo): A Time-Resolved Infrared, Matrix Isolation, and DFT Investigation. Organometallics, 28, (2009) 6 nature chemistry

7 supplementary information S4. Cooper, A. I. and Poliakoff, M. High-pressure reactions in polyethylene films, a new development in matrix isolation. The photochemical reaction of Fe(CO) 5 with N 2 and the thermal reaction of Fe(CO) 4 (N 2 ) with H 2. Chem. Phys. Lett., 212, (1993) nature chemistry 7