Materials. 2-Hydroxypyrimidine HCl was purchased from Aldrich. [Cu(2-pymo) 2 ] nh 2 O (1 R ) was

Transcription

1 Dr. Jorge A. R. Navarro Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Granada Av. Fuentenueva S/N, Granada, SPAIN Tel Fax: Mineralomimetic Sodalite and Muscovite Type Coordination Frameworks. Dynamic Crystal to Crystal Interconversion Processes Sensitive to Ion Pair Recognition Elisa Barea, a Jorge A. R. Navarro, a, * Juan M. Salas, a, * Norberto Masciocchi, b, * Simona Galli b and Angelo Sironi c a) Departamento de Química Inorgánica, Universidad de Granada, Av. Fuentenueva S/N, E Granada, Spain; b) Dipartimento di Scienze Chimiche, Fisiche e Matematiche, Università degli Studi dell Insubria, via Valleggio 11, I Como, Italy; c) Dipartimento di Chimica Strutturale e Stereochimica Inorganica, Università di Milano, and ISTM-CNR, via G. Venezian 21, I Milano, Italy. Experimental Section Materials. 2-Hydroxypyrimidine HCl was purchased from Aldrich. [Cu(2-pymo) 2 ] nh 2 O (1 R ) was prepared as previously reported. 1 Note: Apart from the evacuated 1 C, all species host, in their MOF channels, a number of water molecules. 1 Tabares, L. C.; Navarro, J. A. R.; Salas, J. M. J. Am. Chem. Soc. 2001, 123, 383. S1

2 Preparation of [Cu(2-pymo) 2 ] (M(NO 3 ) m ) 1/3 (M(NO 3 ) C ), (M = NH + 4, Li +, Na +, K +, Rb +, Tl +, La 3+ ). Microcrystalline purple M(NO 3 ) C clathrates were obtained by suspending 1 R in 0.05 M water:methanol (1:4) solutions of the corresponding nitrate salts at room temperature. When M = NH + 4, Li + the thermodynamic equilibrium for the solid-liquid sorption process is reached after 1 week, giving the corresponding [Cu(2-pymo) 2 ] (MNO 3 ) 1/3 clathrates. However, it should be noted that for M = Na +, K +, Rb +, Tl +, La 3+ the cubic M(NO 3 ) C systems are intermediate phases prior to the formation of the thermodynamically stable orthorhombic M(NO 3 ) O ones (see below). The intermediate M(NO 3 ) C phases can be isolated after optimal sorption periods ranging from 6 hours for M = La 3+, 48 hours for M = Na + to 72 hours for M = K +, Rb +, Tl +. These systems have been characterised by EA, IR and XRPD methods confirming their M(NO 3 ) C nature. Crystals of NH 4 NO C and LiNO C were grown from an ammonia:water:methanol (2:11:7) solution (25 ml) containing Cu(NO 3 ) 2 3H 2 O (2 mmol), 2-hydroxypyrimidine HCl (4 mmol) and MNO 3 (1 mmol). Dark purple crystals of NH 4 NO C and LiNO C were isolated within one day. Elemental analyses: NH 4 NO C. Yield 85 %. C 8 H 7.33 CuN 4.67 O 3 1.5(H 2 O): C, 33.20; H, 2.90; N, Found: C, 33.5; H, 3.1; N, UV-vis (nm): 295 vs, 330 vs, sh, 535 s. LiNO C. Yield 87 %. Anal. Calcd. For C 8 H 6 CuLi 0.33 N 4.33 O (H 2 O): C, 31.37; H, 3.05; N, Found: C, 31.4; H, 3.1; N, UV-vis (nm): 290 vs, 340 vs, 540 s NaNO C. Yield 100 %. Anal. Calcd. For C 8 H 6 CuNa 0.33 N 4.33 O 3 2(H 2 O): C, 30.21; H, 3.17; N, S2

3 Found: C, 30.1; H, 2.9; N, KNO C. Yield 100 %. Anal. Calcd. For C 8 H 6 CuK 0.25 N 4.25 O (H 2 O): C, 31.40; H, 2.96; N, Found: C, 31.6; H, 3.1; N, RbNO C. Yield 100 %. Anal. Calcd. For C 8 H 6 CuRb 0.25 N 4.25 O (H 2 O): C, 30.25; H, 2.86; N, Found: C, 30.5; H, 2.9; N, TlNO C. Yield 100 %. Anal. Calcd. For C 8 H 6 CuTl 0.29 N 4.29 O (H 2 O): C, 27.02; H, 2.51; N, Found: C, 27.2; H, 2.6; N, La(NO 3 ) C. Yield 100 %. Anal. Calcd. For C 8 H 6 CuLa 0.25 N 4.75 O (H 2 O): C, 27.05; H, 2.34; N, Found: C, 27.1; H, 2.3; N, Preparation of [Cu(2-pymo) 2 ] (M(NO 3 ) m ) 1/2 (MeOH) 1/2 (M(NO 3 ) O ), M = Na +, K +, Rb +, Tl +, Ba 2+, La 3+ ). These brown microcrystalline solids were obtained by stirring a suspension of 1 R (150 mg) in a 0.05 M solution of the corresponding nitrate salt in 25 ml of water:methanol (1:4) mixture. The thermodynamic equilibrium is reached at different periods of time ranging from 24 h for M = La 3+ to 7 days for M = Tl + and K +. To ensure that the thermodynamic equilibrium was achieved, we have exposed all the samples to the salt solution during 1 week at room temperature. In the case of M = Ba 2+ it should be noted that no previous formation of a cubic phase of type (Ba(NO 3 ) C ) is observed. Crystals of (RbNO O ) suitable for X-ray analysis were grown from an ammonia:water:methanol (2:11:7) solution (25 ml) containing Cu(NO 3 ) 2 3H 2 O (2 mmol), 2-hydroxypyrimidine HCl (4 mmol) and RbNO 3 (1 mmol). Brown crystals of RbNO O were obtained after 3 days. Elemental analyses: S3

4 NaNO O : Yield 100 %. Anal. Calcd. for C 8 H 6 CuNa 0.50 N 4.50 O (CH 3 OH) 1(H 2 O): C, 31.78; H, 2.82; N, Found: C, 31.4; H, 2.5; N, KNO O. Yield 100 %. Anal. Calcd. For C 8 H 6 CuK 0.50 N 4.50 O (CH 3 OH) 0.5(H 2 O): C, 31.00; H, 2.75; N, Found: C, 31.2; H, 2.8; N, UV-vis (nm): 295 vs, 330 vs, sh, 500 s, 640 s, sh. RbNO O. Yield 100 %. Anal. Calcd. For C 8 H 6 CuRb 0.50 N 4.50 O (CH 3 OH) 1(H 2 O): C, 28.97; H, 2.57; N, Found: C, 29.0; H, 2.6; N, UV-vis (nm): 290 vs, 335 vs, sh, 500 s, 640 s, sh. TlNO O. Yield 100 %. Anal. Calcd. For C 8 H 6 CuTl 0.40 N 4.40 O (CH 3 OH) 0.4(H 2 O): C, 26.53; H, 2.49; N, Found: C, 26.1; H, 3.5; N, Ba(NO 3 ) O. Yield 100 %. Anal. Calcd. For C 8 H 6 CuBa 0.50 N 4.50 O (CH 3 OH) 0.5(H 2 O): C, 26.98; H, 2.40; N, Found: C, 26.5; H, 2.6; N, La(NO 3 ) O. Yield 100 %. Anal. Calcd. For C 8 H 6 CuLa 0.50 N 5.50 O (CH 3 OH) 0.25(H 2 O): C, 23.16; H, 2.04; N, Found: C, 23.1; H, 1.8; N, Preparation of orthorhombic [Cu(2-pymo) 2 ] n (1 O ). The microcrystalline empty orthorhombic phase can be obtained by refluxing 150 mg of KNO O in 25 ml in MeOH in the presence of an excess of 18-crown-6-ether (150 mg) under Ar atmosphere during 6 days. The elemental analysis shows the presence of some CuO impurity which may be attributed to partial decomposition due to the prolonged heating of the sample. Yield 95 %. Anal. Calcd. for 1 O, [Cu(C 4 H 3 N 2 O) 2 ] (CuO) H 2 O: C, 31.07; H, 3.39; N, Found: C, 31.0; H, 3.1; N, UV-vis (nm): 290 vs, 535 s. Characterisation and physical measurements. Elemental (C,H,N) analyses were obtained at a S4

5 FISONS-CARLO ERBA EA 1008 analyser; thermogravimetric analyses were performed on a Schimadzu-TGA-50H equipment in the presence of a dinitrogen atmosphere and electronic spectra on microcrystalline samples were carried out on a Varian Cary UV-vis-NIR spectrophotometer (all these instruments are in Centre of Scientific Instrumentation of the University of Granada). IR spectra were recorded on a ThermoNicolet IR 200 spectrometer by using KBr pellets. X-ray Powder Diffraction Characterisation. Analytical measurements. Powder X-ray diffractograms of 1 R, MNO C, M(NO 3 ) O and 1 O were performed on a Philips PW1000 using CuK α radiation and λ = Å. Thermodiffractometry. XRPD data (CuK α, λ = Å) were collected on a θ:θ Bruker AXS D8 diffractometer equipped with a zero-background Si(111) monocrystal sample holder located in a remotely-controlled heating stage assembled by Officine Elettrotecniche di Tenno, Italy. Nominal thermal stability: ±0.1 C. Ab-initio XRPD structural analysis of 1 R. The powders were gently ground in an agate mortar, then cautiously deposited in the hollow of an aluminium holder 0.3 mm deep. Diffraction data (CuK α, λ = Å) were collected on a θ:θ Bruker AXS D8 diffractometer equipped with primary and secondary Soller slits (2.3 ), divergence, antiscatter and receiving slits (0.5, 0.5 and 0.2 mm, respectively), secondary beam curved graphite monochromator, Na(Tl)I scintillation detector and pulse height amplifier discrimination. The generator was operated at 40 kv and 40 ma. Nominal resolution for the present set-up is θ (FWHM of the α 1 component) as measured from the Si(111) peak at S5

6 28.44 (2θ). A long step-scan with 2θ = 0.02 was performed in the 5 < 2θ < 105 range with t = 30 s. Indexing by TREOR90 2 [M(18) = 13, F(18) = 31(0.013, 45)]; 3 systematic absences indicated, among others, R-3m as the probable space group, later confirmed by successful structure solution and refinement. Whole profile structure solution using simulated annealing 4 was performed with TOPAS 2.0 suite of programs 5. 2-pymo ligands were treated as rigid bodies, assigning them average literature bond distances and angles (C-C and C-N distances = 1.40 Å; C-O distance = 1.25 Å; C-H distances = 0.95 Å; ring bond angles = ). Convergence to a chemically significant model was supported by imposing soft restraints on the independent Cu-N bond distances (2.00 Å). The final refinements were performed by the Rietveld method using TOPAS, maintaining the rigid body and soft restraints described above (statistically significant standard deviations for fractional atomic coordinates are thus not available). Peak shapes were described by the fundamental parameters approach 6. Experimental background was fit by a polynomial description. Systematic errors were modelled with a sampledisplacement angular shift and a preferred orientation correction in the March-Dollase formulation (with [001] pole 7 ); copper metal atoms were given a refinable, isotropic displacement parameter (B M ), while lighter atoms were assigned a common B = B M Å 2 value. Scattering factors, corrected for real and imaginary anomalous dispersion terms, were taken from the internal library of TOPAS. Crystal data for 1 R C 8 H 8 CuN 4 O 3, fw g mol -1, trigonal, R-3m, a = (2), c = (2) Å, V = (2) Å 3, Z = 36; ρ = g cm -3 ; R wp, R p and R Bragg 0.057, and 0.022, for 3150 data collected in the θ range. 2 Werner, P. E.; Eriksson, L.; Westdahl, M. J. Appl. Crystallogr. 1985, 18, a) De Wolff, P. M. J. Appl. Crystallogr. 1968, 1, 108. b) Smith, G. S.; Snyder, R. L. J. Appl. Crystallogr. 1979, 12, Coelho, A. A. J. Appl. Crystallogr. 2000, 33, Bruker AXS 2000: Topas V2.0: General profile and structure analysis software for powder diffraction data. 6 Cheary, R. W.; Coelho, A. A. J. Appl. Crystallogr. 1992, 25, a) March, A. Z. Kristallogr.,1932, 81, 285. b) Dollase, W. A. J. Appl. Crystallogr. 1987, 19, 267. S6

7 Figure S.1. Rietveld refinement plot for the XRPD analysis of pristine (hydrated) [Cu(2-pymo) 2 ] n, 1 R ; the insert shows the XRPD trace of the evacuated 1 C cubic phase obtained upon gentle heating. Single crystal X-ray Analysis. Single crystal X-ray intensity data for NH 4 NO C, LiNO C and RbNO O were collected with a BRUKER SMART APEX (Mo Kα, λ= Å, graphite monochromator) (Centre of Scientific Instrumentation of the University of Granada). In all cases, the whole sphere reciprocal space was covered by measurements of 360 frames. Preliminary orientation matrices and unit cell parameters were obtained from the peaks of the first 10 frames and were refined using the whole data set. Frames were integrated and corrected for Lorentz and polarization effects using DENZO. 8 The scaling and the global refinement of crystal parameters were performed by SCALEPACK. 8 Reflections that were partly measured on previous and following frames were used to mutually scale these frames. The crystals were corrected from absorption by multiscan method. Structure solution and refinements. The single crystal structures were solved by standard direct methods 9 and refined by full-matrix least squares methods based on F 2 using the SHELXTL-PLUS 10 and SHELXL-97 programs. 11 The atom scattering factors were taken as those given in the SHELXTL- PLUS program. Transmission factors were calculated using SHEXL For RbNO O all nonhydrogen atoms were refined anisotropically. In the case of LiNO C and NH 4 NO C crystal 8 Otwinowsky, Z.; Minor, W. Processing of X-ray Diffraction Data Collected in Oscillation Mode, Methods in Enzymology (Eds.: C. W. Carter, Jr., R. M. Sweet), Academic Press, 1996, p Sheldrick, G. M. Acta Crystallogr. 1990, A46, Sheldrick, G. M. SHELXTL-PLUS (VMS). Siemens Analytical X-ray Instruments, Inc. Madison WI, Sheldrick, G. M. SHELXL-97, Program for the refinement of Crystal structures, University of Göttingen (Germany), S7

8 structures, the [Cu(2-pymo) 2 ] n frameworks are well defined while the [Li(H 2 O) 4 ]NO 3 and NH 4 NO 3 2H 2 O guests appear disordered as a result of the high symmetry of the recognition sites. In the crystal structure of LiNO C, the two nitrates and two [Li(H 2 O) 4 ] + groups included in the sodalite type β-cages are distributed in four equivalent positions. This results in a close contact between the O1N atom of the nitrate group and the water molecule O2w coordinated to the lithium atom. Therefore, the nitrate group has been treated as a rigid body and the Li-O2w distance was constrained. Likewise, in NH 4 NO C, the two nitrate groups are distributed in four equivalent positions while the water molecules and ammonium ions are found to be distributed respectively in 12 and 6 equivalent positions near a 3m symmetry site. Crystallographic data (excluding structure factors) for the structures reported in this paper have been deposited with the Cambridge Crystallographic Data Centre supplementary publication no. CCDC Copies of the data can be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB21EZ, UK (Fax: (+44) ; deposit@ccdc.cam.ac.uk). S8

9 Table S.1. Crystallographic data of compounds NH 4 NO C, LiNO C and RbNO O. Compound NH 4 NO C LiNO C RbNO O Empirical formula Cu(2-pymo) 2 Cu(2-pymo) 2 Cu(2-pymo) 2 (NH 4 NO 3 2H 2 O) 1/3 (Li(H 2 O) 4 NO 3 ) 1/3 (Rb(H 2 O)NO 3 ) 1/2 FW Crystal system Cubic Cubic Orthorhombic Space group Pn-3m Pn-3m Pna2 1 a [Å] 15.67(5) 15.65(5) 18.78(2) b [Å] 15.67(5) 15.65(5) 11.02(1) c [Å] 15.67(4) 15.65(5) 11.45(1) α [º] β [º] γ [º] V [Å 3 ] (2) (2) (2) Z (Cu) V/Z Cu...Cu [Å 3 ] ρ calcd [Mg/m -3 ] µ (Mo-K α ) [mm -1 ] T (K) 298(2) 298(2) 298(2) Crystal size [mm] θ max [º] Reflns. Collected Independent rflns Reflns. Obs Parameters refined [a] R [b] WR Goodness of fit Residuals [eå -3 ] 0.063/ / / [a] R 1 = F o - F c / F o. [b] wr 2 = [ w(f 2 o F 2 c ) 2 / w(f 2 o ) 2 ] 1/2. S9

10 Figure S.2. Packing diagram for (hydrated) 1 R. Hydrogen atoms are omitted for clarity. Cu (pale red), N (blue), C (black), water molecules (yellow). Figure S.3. View of the supramolecular recognition pattern of the [NH 4 (H 2 O) 2 ]NO 3 ion pair in the crystal structure of NH 4 NO C. Cu (green), N (blue), O (red), C (grey). S10

11 Figure S.4. View of the [Cu(2-pymo) 2 ] n framework in the crystal structures of isomorphous MNO C systems. For sake of clarity, guest ions and molecules are omitted. Cu (green), N (blue), O (red), C (grey). Figure S.5. Packing diagram of RbNO O. Cu (green), N (blue), O (red), C (grey), Rb (purple). S11

12 Figure S.6. Schematic interconversion processes sensitive to ion pair recognition taking place in the [Cu(2-pymo) 2 ] n framework upon exposition to KNO 3. IR spectra (left) and XRPD (right) of the different steps in the sequential sorption process. -n/2 MNO 3 H 2 O [Cu(2-pymo) 2 ] n (1 O ) -n/2 MNO 3 +n/2 MNO crownether 3 H MeOH 2 O:MeOH [Cu(2-pymo) 2 ] n (KNO 3 ) n/2 (KNO3@1 O ) +n/6 MNO 3 H 2 O:MeOH [Cu(2-pymo) 2 ] n (KNO 3 ) n/3 (KNO3@1 C ) +n/3 MNO 3 H 2 O:MeOH -n/3 MNO 3 H 2 O [Cu(2-pymo) 2 ] n (1 R ) cm θ S12

13 Figure S.7. XRPD diagrams of the layered [Cu(2-pymo) 2 ] n (M(NO 3 ) m ) n/2 (M(NO 3 ) O ). The 200 reflection was used to estimate the effect of M(NO 3 ) m guest incorporation on the a parameter. 1 O La(NO 3 ) O Ba(NO 3 ) O TlNO O RbNO O KNO O θ NaNO O S13