Disclosing the complex structure of UiO-66 Metal Organic Framework: a synergic combination of experiment and theory

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1 Supporting Information for Disclosing the complex structure of UiO-66 Metal Organic Framework: a synergic combination of experiment and theory Loredana Valenzano, 1 Bartolomeo Civalleri, 1 Sachin Chavan, 1 Silvia Bordiga, 1 Merete H. Nilsen, 2 Søren Jakobsen, 2 Karl Petter Lillerud, 2* Carlo Lamberti 1 1 Department of Inorganic, Physical and Material Chemistry, NIS Centre of Excellence, and INSTM reference center, University of Turin, Via P. Giuria 7, I Torino, Italy 2 ingap centre of Research-based Innovation, Department of Chemistry, University of Oslo, Sem Saerlandsvei 26, N Oslo, Norway S1. Adsorption isotherm. The adsorption of nitrogen was measured volumetrically with a BELSORP-mini II instrument and the specific surface area was obtained by the BET method. The sample was heated to 250 C and kept at this temperature under continuous evacuation for 6 hours prior to adsorption measurement. The adsorption of nitrogen follows a type I isotherm with no hysteresis (figure S16), and with a BET surface area of 1069 m 2 /g V/cm 3 (STP)/g P/P 0 Figure S1: BET nitrogen adsorption (filled squares) and desorption (open squares) isotherms of Zr-BDC (UiO-66) at 77 K. Corresponding authors: C. Lamberti Tel: Fax: ; carlo.lamberti@unito.it K.-P Lillerud: Tel: ; k.p.lillerud@kjemi.uio.no S1

2 S2. Remarkable structure stability upon interaction with solvents and chemicals. The XRPD studies, reported in Figure S2 indicate that UiO-66 framework is stable in water, benzene, acetone, ethanol, and, obviously, DMF. As some reactions run at ph values significantly different from neutrality, we also checked the stability in presence of a strong acid (HCl) and a strong base (NaOH). The patterns reported in Figure S2 indicate that UiO-66 is well stable in HCl solution and that it still maintains an appreciable degree of crystallinity in NaOH solution. (a) Si(111) (b) DMF Benzene C 2 H 5 OH Acetone HCl Water As-synthesized H 2 O NaOH θ θ Figure S2: Part (a): XRPD pattern of desolvated UiO-66 treated with various solvents at room temperature for 24 h in stirred suspension. Part (b): XRPD pattern of desolvated UiO-66 after interaction at room temperature for 2 hours in stirred suspension with, from top to bottom: ethanol, HCl, H 2 O and NaOH. The arrow in part (a) indicates the Si(111) reflection at 2θ = 28.4 used for calibration. λ = Å. S2

3 S3. Failure of XRPD in determining the local distortion of Zr 6 -clusters upon dehydroxylation. Figure S3a shows superimposed images of 7-coordinated Zr 6 -clusters oriented along different directions. The effect of this random orientation in the Rietveld refinement, made in a cubic space group, is the systematic average of Zr and O atomic coordinates. This effect is evidenced in Figure S3b, where the cluster in the middle is obtained by averaging two Zr 6 O 6 clusters oriented along two perpendicular directions. The Zr atoms are drawn with 0.3 Å spheres, the maximum deviation in Zr positions is approximately 0.15 Å. The change in the zirconium coordination is not visible in the XRPD refinement, where only a change in the occupancy of the µ 3 -oxygen from 1 to 0.75 and an increase in the thermal parameters of all atoms are observed (see Figure 4a in the main text). The changes are however clearly illustrated by the EXAFS data presented in Figure 4c in the main text. Figure S3. Part (a): superimposed images of 7-coordinated Zr 6 -clusters oriented along different directions simulating the statistically disorder undergone by the structure in dehydroxylation process. Part (b): top and bottom show two Zr 6 O 6 clusters oriented along two different directions; their superimposition is reported in the middle, describing the average situation observed by XRPD. Note that the averaging process restores the cubic symmetry lost in the dehydroxylation process. S3

4 S4. CRYSTAL input file: UiO-66 hydroxylated. UiO-66 hydroxylated optimized structure - space group F-43m CRYSTAL E E E E E E E E E E E E E E E E E E E E E E E E E E E-03 ENDG S4

5 D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D ENDB DFT B3LYP XLGRID END SCFDIR BIPOSIZE EXCHSIZE SHRINK 2 2 S5

6 TOLINTEG FMIXING 90 BROYDEN TOLDEE 8 ENDSCF S6

7 S5. CRYSTAL input file: UiO-66 dehydroxylated. UiO-66 dehydroxylated optimized structure - space group R-3 CRYSTAL E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E E-01 END S7

8 D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D D ENDB DFT B3LYP XLGRID END SCFDIR S8

9 BIPOSIZE EXCHSIZE SHRINK 2 2 TOLINTEG FMIXING 90 BROYDEN TOLDEE 8 ENDSCF S9

10 S6. Adopted Zirconium Basis-Set. Zr_all_electron_dovesi_unpub S10