Distorted Tetrahedral Nickel-Nitrosyl Complexes: Spectroscopic Characterization and Electronic Structure

Transcription

1 Submitted to Journal of Biological Inorganic Chemistry as a Full article Distorted Tetrahedral Nickel-Nitrosyl Complexes: Spectroscopic Characterization and Electronic Structure Shoko Soma, Casey Van Stappen, Mercedesz Kiss, Robert K. Szilagyi, Nicolai Lehnert, Kiyoshi Fujisawa Electronic supplementary material The online version of this article (doi:xxxx/xxx) contains supplementary material, which is available to authorized users. S. Soma, K. Fujisawa ( ) Department of Chemistry, Ibaraki University, Mito, , Ibaraki, Japan kiyoshi.fujisawa.sci@vc.ibaraki.ac.jp M. Kiss, R. K. Szilagyi ( ) Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, United States and MTA-ELTE Chemical Structure & Function Momentum Laboratory, Budapest, Hungary szilagyi@montana.edu C. Van Stappen, N. Lehnert ( ) Department of Chemistry and Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan, 48109, United States lehnertn@umich.edu C. Van Stappen (current address) Max-Planck Institute for Chemical Energy Conversion Stiftstraße 34-36, Mülheim an der Ruhr, Germany casey.van-stappen@cec.mpg.de SUP - 1

2 Experimental details This complex has been reported before, but was prepared and crystallized here by a modified method. [NiCl2(PPh3)2] (9 g, 1.67 mmol), PPh3 (41 g, 1.68 mmol), and NaNO2 (1.89 g, 27.4 mmol) were dissolved in tetrahydrofuran (30 ml). The resulting brown suspension was stirred and refluxed under an argon atmosphere for 1 h. The suspension was allowed to cool to room temperature and filtrated through Celite, followed by drying of the solution in vacuo. Recrystallization from dichloromethane / heptane at room temperature gave dark purple crystals. Yield: g, 34 mmol (50%). Anal. Calcd for C36H30ClNNiOP2: C, 66.65; H, 4.66; N, Found: C, 66.43; H, 4.59; N, IR (KBr, cm 1 ): 3053 m, 1966 w, 1889 w, 1817 w, 1715 vs, 1482 s, 1434 s, 1308 w, 1183 w, 1156 w, 1095 s, 1027 m, 997 m, 747 s, 693 s, 521 s. Far IR (CSI, cm 1 ): 618 w, 573 m, 521 vs, 508 vs, 494 s, 448 m, 424 m, 380 w, 280 m, 253 w. UV vis (CH2Cl2, λ, nm) (ε, M 1 cm 1 ): 265 (21000), 382 (310), 504 (580), 631 (710). DR(solid, λ, nm): 382, 512, H-NMR (CDCl3, δ, ppm, 500 MHz): 7.23 (dd, J = 7.5 Hz, 12H, o PhH), 7.34 (m, J = 7.0 Hz, 18H, m,p PhH). 13 C-NMR (CDCl3, δ, ppm, 125 MHz): (3,5 PhC), (4 PhC), (1 PhC), (2,6 PhC). 31 P-NMR (CDCl3, δ, ppm, 200 MHz): 37.4 (s). [Ni(NO)(Br)(PPh 3 ) 2 ] This complex has been reported before, but was prepared and crystallized here by a modified method. [NiBr2(PPh3)2] (2.01 g, 2.70 mmol), PPh3 (0.733 g, 2.79 mmol), and NaNO2 (3.23 g, 46.8 mmol) were dissolved in tetrahydrofuran (40 ml). The resulting brown suspension was stirred and refluxed under an argon atmosphere for 1 h. The suspension was allowed to cool to room temperature and filtrated through Celite, followed by drying of the solution in vacuo. Recrystallization from dichloromethane / heptane at room temperature gave dark purple crystals. Yield: 1.39 g, 2.01 mmol (74%). Anal. Calcd for C36H30BrNNiOP2: C, 62.39; H, 4.36; N, Found: C, 62.44; H, 4.38; N, IR (KBr, cm 1 ): 3438 w, 3049 m, 1966 w, 1895 w, 1822 w, 1731 vs, 1479 s, 1432 s, 1310 m, 1180 m, 1159 m, 1095 s, 1027 m, 997 m, 742 s, 695 s, 506 s. Far IR (CSI, cm 1 ): 618 w, 571 m, 521 vs, 508 vs, 494 s, 447 m, 435 m, 424 m, 398 w, 374 w, 252 w, 208 m, 195 w, 163 w. UV vis (CH2Cl2, λ, nm) (ε, M 1 cm 1 ): 265 (17000), 385 (390), 517 (600), 620 (680). DR(solid, λ, nm): 388, 514, H-NMR (CDCl3, δ, ppm, 500 MHz): 7.24 (dd, J = 8.0 Hz, 12H, o PhH), 7.34 (m, J = 6.3 Hz, 18H, m,p PhH). 13 C-NMR (CDCl3, δ, ppm, 125 MHz): (3,5 PhC), 13 (4 PhC), (1 PhC), (2,6 PhC). 31 P-NMR (CDCl3, δ, ppm, 200 MHz): 35.0 (s). [Ni( 15 NO)Br(PPh 3 ) 2 ] The 15 N-labeled complex was prepared by the same method as the corresponding unlabeled complex using Na 15 NO2. IR (KBr, cm 1 ): 3049 m, 1965 w, 1894 w, 1826 w, 1698 vs, 1480 s, 1433 s, 1309 w, 1180 w, 1159 w, 1095 s, 1027 m, 997 m, 743 s, 695 s, 521 s. Far IR (CSI, cm 1 ): 618 w, 562 m, 521 vs, 507 vs, 495 s, 446 m, 435 m, 424 m, 398 w, 367 w, 252 w, 208 m, 194 w, 163 w. SUP - 2

3 Fig. S1 Molecular structures of (left) and [Ni(NO)(Br)(PPh 3 ) 2 ] (right) showing 50% thermal ellipsoids and the atom-labeling scheme. Hydrogen atoms are omitted for clarity. Relevant bond lengths (Å) and angles ( ): : Ni1 N1, (14); Ni1 Cl1, (6); Ni1 P1, (6); Ni1 P2, (6); N1 O1, 1.160(2); N1 Ni1 Cl1, (6); N1 Ni1 P1, (5); N1 Ni1 P2, 105(5); Cl1 Ni1 P1, (19); Cl1 N41 P2, (17), P1 Ni1 P2, 127(2); Ni1 N1 O1, (15). [Ni(NO)(Br)(PPh 3 ) 2 ]: Ni1 N1, 1.672(3); Ni1 Br1, (7); Ni1 P1, (11); Ni1 P2, (10); N1 O1, 1.167(4); Ni2 N2, 1.684(3); Ni2 Br2, (7); Ni2 P3, (11); Ni2 P4, (10); N2 O2, 1.161(4); N1 Ni1 Br1, (10); N1 Ni1 P1, (11); N1 Ni1 P2, (10); Br1 Ni1 P1, (3); Br1 Ni1 P2, 98.67(3), P1 Ni1 P2, (4); Ni1 N1 O1, 152.5(3); N2 Ni2 Br2, (10); N2 Ni2 P3, (12); N2 Ni2 P4, (10); Br2 Ni2 P3, (3); Br2 Ni2 P4, 99.14(3), P3 Ni2 P4, (4); Ni2 N2 O2, 15(3). In [Ni(NO)(Br)(PPh 3 ) 2 ], two crystallographically independent molecules are found in the unit cell whose structural features are essentially identical. Molecule 1 is presented here. SUP - 3

4 oscillator strength x [Ni(Cl)(L3)] excitation/photon energy, ev XAS intensity oscillator strength x [Ni(NO)(L3)] excitation/photon energy, ev XAS Intensity oscillator strength x XAS Intensity oscillator strength x [Ni(NO)(Br)(PPh 3 ) 2 ] XAS Intensity excitation/photon energy, ev excitation/photon energy, ev oscillator strength x XAS Intensity oscillator strength x [Ni(Br) 2 (PPh 3 ) 2 ] XAS Intensity excitation/photon energy, ev excitation/photon energy, ev oscillator strength x [Ni(I) 2 (PPh 3 ) 2 ] XAS Intensity excitation/photon energy, ev Fig. S2 Simulated Ni K-edge spectra with lines representing each excited state with significant oscillator strength. The envelope spectrum was generated by pseudo-voigt line shape broadening with 2.2 ev line widths. Dashed line represents the experimental spectrum. SUP - 4

5 oscillator strength x [Ni(Cl)(L3)] XAS intensity oscillator strength x XAS Intensity excitation/photon energy, ev excitation/photon energy, ev oscillator strength x XAS intensity excitation/photon energy, ev Fig. S3 Simulated Cl K-edge spectra with lines representing each excited state with significant oscillator strength. The envelope spectrum was generated by pseudo-voigt line shape broadening with 1.2 ev line widths. Dashed line represents the experimental spectrum. SUP - 5

6 oscillator strength x excitation/photon energy, ev 1.2 XAS intensity oscillator strength x [Ni(NO)(Br)(PPh 3 ) 2 ] TD DFT excitation energy, ev 1.2 XAS intensity oscillator strength x excitation/photon energy, ev XAS Intensity oscillator strength x [Ni(Br) 2 (PPh 3 ) 2 ] excitation/photon energy, ev 1.2 XAS Intensity oscillator strength x [Ni(I) 2 (PPh 3 ) 2 ] excitation/photon energy, ev Fig. S4 Simulated P K-edge spectra with lines representing each excited state with significant oscillator strength. The envelope spectrum was generated by pseudo-voigt line shape broadening with 1.6 ev line widths. Dashed line represents the experimental spectrum XAS Intensity SUP - 6

7 [Ni(NO)(Cl)(PPh3)2] [Ni( 14 NO)(Br)(PPh3)2] Transmittance [Ni( 15 NO)(Br)(PPh3)2] [Ni(Cl)(L3)] [Ni(NO)(L3)] Wavenumber / cm / cm 1-1 Fig. S5 IR spectra of all of the complexes. [Ni( 14 NO)(Br)(PPh3)2] Transmittance [Ni( 15 NO)(Br)(PPh3)2] [Ni( 14 NO)(L3)] [Ni( 15 NO)(L3)] Wavenumber / cm/ cm -1 1 Fig. S6 Far-IR spectra of the NO complexes. SUP - 7

8 [Ni(NO)(Cl)(PPh3)2] Transmittance [Ni(NO)(Br)(PPh3)2] Wavenumber / cm 1-1 Fig. S7 Far-IR spectra of the NO complexes. SUP - 8

9 2.5 X X 10 4 [Ni(NO)(Cl)(PPh 3 ) 2 ] [Ni(NO)(Br)(PPh 3 ) 2 ] [Ni(Cl)(L3)] [Ni(NO)(L3)] Epsilon / M -1 cm X 10 4 X Wavelength / nm Fig. S8 UV-Vis spectra of all complexes in dichloromethane solution ( nm region). Absorbance Wavelengh / nm Fig. 9 UV-Vis spectral comparison of [Ni(Cl)(L3)] (red line) and [Ni(Br)(L3)] (blue line) (unpublished results). SUP - 9

10 [Ni(NO)Cl(PPh 3 ) 2 ] [Ni(NO)Br(PPh 3 ) 2 ] [Ni(NO)(L3)] [NiCl(L3)] Relative reflectivity (arbitrary unit) Wavelength / nm Fig. S10 Diffuse reflectance spectra of all complexes (solid, nm). SUP - 10

11 o-phh m,p-phh TMS o-phh m,p-phh [Ni(NO)(Br)(PPh 3 ) 2 ] TMS Grease C(CH 3 ) 3 [Ni(NO)(L3)] 4-pzH CH(CH 3 ) 2 CH(CH 3 ) 2 TMS Fig. S11 1 H-NMR spectra of the NO complexes in CDCl3 solution at room temperature. 4-pzH CH(CH 3 ) 2 BH CH(CH 3 ) 2 C(CH 3 ) 3 Fig. S12 1 H-NMR spectra of [Ni(Cl)(L3)] in CDCl3 solution at room temperature. SUP - 11

12 First Derivative of XAS intensity A Ni K-edge [Ni(Cl)(L3)] [Ni(NO)(L3)] [Ni(NO)(Br)(PPh 3 ) 2 ] [Ni(Br) 2 (PPh 3 ) 2 ] [Ni(I) 2 (PPh 3 ) 2 ] [NiF 2 ] Ni foil Second Derivative of XAS intensity -15 Photon Energy, ev B [Ni(Cl)(L3)] [Ni(NO)(L3)] [Ni(NO)(Br)(PPh 3 ) 2 ] [Ni(Br) 2 (PPh 3 ) 2 ] [Ni(I) 2 (PPh 3 ) 2 ] [NiF 2 ] Ni foil -03 Photon Energy, ev Fig. S13 First (A) and second (B) derivative spectra at the Ni K-edge for reference materials (Ni foil and [NiF2]), formally Ni(II) complexes ([Ni(X)2(PPh3)2], X = Cl, Br, I; [Ni(Cl)(L3)]) and the NO complexes investigated here. The derivative spectra were generated using 5% Savitzky-Golay filter. SUP - 12

13 First Derivative of XAS intensity (EY/I0) Photon Energy, ev [Ni(NO)(Br)(PPh 3 ) 2 ] A Ni L 3 -edge [Ni(Cl)(L3)] [Ni(NO)(L3)] [Ni(Br) 2 (PPh 3 ) 2 ] [Ni(I) 2 (PPh 3 ) 2 ] [NiF 2 ] First Derivative of XAS intensity (EY/I0) Photon Energy, ev B Ni L 2 -edge [Ni(Cl)(L3)] [Ni(NO)(L3)] [Ni(NO)(Br)(PPh 3 ) 2 ] [Ni(Br) 2 (PPh 3 ) 2 ] [Ni(I) 2 (PPh 3 ) 2 ] [NiF 2 ] Second Derivative of XAS intensity (EY/I0) [Ni(NO)(Br)(PPh ) 2 ] C [Ni(Cl)(L3)] [Ni(NO)(L3)] Photon Energy, ev [Ni(Br) 2 (PPh 3 ) 2 ] [Ni(I) 2 (PPh 3 ) 2 ] [NiF 2 ] Second Derivative of XAS intensity (EY/I0) 0.1 [Ni(NO)(Cl)(PPh ) 2 ] [Ni(NO)(Br)(PPh 3 ) 2 ] D Photon Energy, ev [Ni(Cl)(L3)] [Ni(NO)(L3)] [Ni(Br) 2 (PPh 3 ) 2 ] [Ni(I) 2 (PPh 3 ) 2 ] [NiF 2 ] Fig. S14 First (A and B) and second (C and D) derivative spectra at the Ni L3 and L2-edges, respectively, for reference materials (Ni foil and [NiF2]), formally Ni(II) complexes ([Ni(X)2(PPh3)2], X = Cl, Br, I; [Ni(Cl)(L3)]) and the NO complexes investigated here. The derivative spectra were generated using 5% Savitzky-Golay filter. SUP - 13

14 First Derivative of XAS intensity (FY/I0) A Photon Energy, ev Cl K-edge [Ni(Cl)(L3)] Cs 2 [CuCl 4 ] NaCl Second Derivative of XAS intensity (FY/I0) B Photon Energy, ev [Ni(Cl)(L3)] Cs 2 [CuCl 4 ] NaCl Fig. S15 First (A) and second (B) derivative spectra at the Cl K-edge for the free ligand salt (NaCl), the reference compound (Cs2[CuCl4]), formally Ni(II) complexes ([Ni(Cl)2(PPh3)2]; [Ni(Cl)(L3)]) and the NO complex with a chloride ligand. The derivative spectra were generated using 5% Savitzky-Golay filter. SUP - 14

15 First Derivative of XAS intensity (FY/I0) A P K-edge [Ni(NO)(Br)(PPh 3 ) 2 ] [Ni(Br) 2 (PPh 3 ) 2 ] [Ni(I) 2 (PPh 3 ) 2 ] PPh 3 PCy 3 Second Derivative of XAS intensity (FY/I0) B Photon Energy, ev Photon Energy, ev [Ni(NO)(Br)(PPh 3 ) 2 ] [Ni(Br) 2 (PPh 3 ) 2 ] [Ni(I) 2 (PPh 3 ) 2 ] PPh 3 PCy 3 Fig. S16 First (A) and second (B) derivative spectra at the P K-edge for the free ligands (PR3, R=Ph, Cy), formally Ni(II) complexes ([Ni(X)2(PPh3)2], X=Cl, Br, I) and the NO complexes with phosphane ligands. The derivative spectra were generated using 5% Savitzky-Golay filter. SUP - 15

16 calculated oscillator strength x A [Ni(NO)(L3)] [Ni(Cl)(L3)] [Ni(NO)(Br)(PPh 3 ) 2 ] [Ni(I) 2 (PPh 3 ) 2 ] 0.1 [Ni(Br) 2 (PPh 3 ) 2 ] calculated Ni 1s excitation energies calculated oscillator strength x B [Ni(Cl)(L3)] calculated Cl 1s excitation energies calculated oscillator strength x C [Ni(NO)(Br)(PPh 3 ) 2 ] 2.0 [Ni(I) 2 (PPh 3 ) 2 ] [Ni(Br) 2 (PPh 3 ) 2 ] calculated P 1s excitation energies Fig. S17 Calculated core-level excited state spectra at the Ni K (A), Cl K (B), and P K (C) edges for the first 100 excited states at BP86/TZVP level of theory. Fig. S18 Comparison of the experimental [Ni(NO)(L3)] Ni K-edge XAS with that calculated by TD-DFT using the broken-symmetry formalism. The first 100 calculated states were calculated using the B3LYP/decontracted def2-tzvp functional-basis combination. A shift of ev was applied to the calculated spectrum. The generated spectra utilize a 1.5 ev linewidth. SUP - 16

17 Fig. S19 Comparison of the experimental [Ni(NO)(L3)] Ni K-edge XAS with that calculated by TD-DFT using the closed-shell formalism. The first 100 calculated states were calculated using the B3LYP/decontracted def2-tzvp functional-basis combination. A shift of ev was applied to the calculated spectrum. The generated spectra utilize a 1.5 ev linewidth. Fig. S20 Comparison of the experimental [Ni(NO)(L3)] Ni K-edge XAS with that calculated by TD-DFT using the broken-symmetry (red) and closed-shell (blue) formalisms. The first 100 calculated states were calculated using the B3LYP/decontracted def2-tzvp functional-basis combination. A shift of ev was applied to the calculated spectra. The generated spectra utilize a 1.5 ev linewidth. SUP - 17

18 Fig. S21 Cyclic voltammetry of a 2 mm solution of [Ni(NO)(L3)] in THF at various scan rates with 0.1 M TBAP as supporting electrolyte. A glassy carbon working electrode was used along with a platinum working electrode and Ag wire reference electrode. SUP - 18

19 Table S1 X-ray crystallographic data for and [Ni(NO)(Br)(PPh 3 ) 2. [Ni(NO)(Br)(PPh 3 ) 2 ] CCDC deposit number Empirical Formula C36H30ClNNiOP2 C36H30BrNNiOP2 Formula Weight Crystal System monoclinic triclinic Space Group P21/a (#14) P 1 (#2) a / Å (2) 9.625(2) b / Å (3) (3) c / Å (2) (5) α / (4) β / (2) (6) γ / (7) V / Å 3 318(9) 319(12) Z 4 4 Dcalc / g cm μ(mo Kα) / cm θmax / Temperature / C Exposure Rate / sec Reflections collected Unique reflections R (int) No. of obserb. (All refl.) No. of variables R1 (I > 2.0 σ(i)) wr2 (All reflections) Good. of fit indicator Max/min peak, / e Å 3 9 / / 0.73 R1 = Σ Fo - Fc / Σ Fo ; wr2 = [(Σ w( (Fo 2 - Fc 2 ) 2 )/ Σ w( Fo 2 ) 2 ] 1/2 SUP - 19

20 Table S2 X-ray crystallographic data for [Ni(NO)(L3)] and [Ni(Cl)(L3)] [Ni(NO)(L3)] [Ni(Cl)(L3)] CCDC deposit number Empirical Formula C30H52BN7NiO C30H52BClN6Ni Formula Weight Crystal System orthorhombic monoclinic Space Group Cmc2 1 (#36) P21/n (#14) a / Å (3) (8) b / Å (17) (8) c / Å (3) 2069(13) α / β / (3) γ / V / Å (10) (4) Z 4 4 Dcalc / g cm μ(mo Kα) / cm θmax / Temperature / C Exposure Rate / sec Reflections collected Unique reflections R (int) No. of obserb. (All refl.) No. of variables R1 (I > 2.0 σ(i)) wr2 (All reflections) Good. of fit indicator Max/min peak, / e Å 3 9 / 1 93 / 0.73 R1 = Σ Fo - Fc / Σ Fo ; wr2 = [(Σ w( (Fo 2 - Fc 2 ) 2 )/ Σ w( Fo 2 ) 2 ] ½ SUP - 20

21 Table S3 BP86-optimized coordinates of [Ni(NO)(L3)]. x y z Ni O N N N N N N N C C C C C C C C C C C C C C B H H H H H H H H H H C H H H C H H H C H H H SUP - 21

22 C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C C H H H C H C H C H SUP - 22

23 Table S4 M06-L-optimized coordinates of [Ni(NO)(L3)]. x y z Ni O N N N N N N N C C C C C C C C C C C C C C B H H H H H H H H H H C H H H C H H H C H H H SUP - 23

24 C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H C H C H SUP - 24

25 Table S5 B3LYP-optimized coordinates of [Ni(NO)(L3)]. x y z Ni O N N N N N N N C C C C C C C C C C C C C C B H H H H H H H H H H C H H H C H H H C H H H SUP - 25

26 C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H C H C H SUP - 26

27 Table S6 B3LYP-D-optimized coordinates of [Ni(NO)(L3)]. x y z Ni O N N N N N N N C C C C C C C C C C C C C C B H H H H H H H H H H C H H H C H H H C H H H SUP - 27

28 C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H C H C H SUP - 28

29 Table S7 B3LYP-CAM-optimized coordinates of [Ni(NO)(L3)]. x y z Ni O N N N N N N N C C C C C C C C C C C C C C B H H H H H H H H H H C H H H C H H H C H H H SUP - 29

30 C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H H H C H C H C H SUP - 30

31 Table S8: Input keywords used for calculating core-level excited state spectra within ADF at BP86/TZ2P level #!/bin/csh ####################################################################### $ADFBIN/adf << eor title complex Charge 0 2 unrestricted atoms cartesian coords Ni x y z end integration 5.0 XC GGA BP86 END Basis Type TZ2P Core None End excitation allowed lowest 100 end relativistic scalar zora modifyexcitation UseOccupied <irred.rep> <MO number(s)> subend UseScaledZORA end eprint orbpoper end end input eor ###################################################################### SUP - 31