Electronic Supplementary Information. Trigonal prismatic Cu(I) and Ag(I) pyrazolato nanocage hosts: encapsulation of S 8 and hydrocarbon guests

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1 Electronic Supplementary Information Trigonal prismatic Cu(I) and Ag(I) pyrazolato nanocage hosts: encapsulation of S 8 and hydrocarbon guests Peng-Cheng Duan, a Zhao-Yang Wang, a Jing-Huo Chen, a Guang Yang, a * and Raphael G. Raptis b * a College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, China b Department of Chemistry and the Institute for Functional Nanomaterials University of Puerto Rico, San Juan, PR , USA. Table of Contents Measurements and instruments 2 Experiments 2-6 X-ray crystallography 7 Thermal analyses 8-10 Luminescence spectra 11 Figs. S8-S10 Molecular structure and intermolecular interactions for complexes 1-3 Table S1 Crystallographic data 15 Table S2 Selected bond distances and angles 16 Table S3 Elemental analysis data 16 1

2 Measurements and instruments All reagents were commercially available and were used as received. IR spectra were recorded on a Nicolet Impact 420 FT-IR spectrometer as KBr pellets in the range of cm -1. C, H, N microanalyses were determined on a Flash EA 1112 elemental analyzer. 1 H NMR spectra were recorded on a Bruker DPX-400 spectrometer. Thermal analyses were conducted on a NETZSCH STA 409 PC system under air with a flow rate of 60 ml min -1 at a scanning rate of 10 C min -1. Luminescence spectra were measured on a PTI Fluorimeter utilizing a photomutiplier to measure light intensity and Xe-lamp as radiation source. The MS spectra for the Ag 6 L 3 cage were recorded on a Bruker ultraflextreme MALDI-TOF/TOF mass spectrometer; the matrix used was HCCA. Experiments Preparation of 2,7-bis(4 -methylene-1h-3,5 -diphenylpyrazole)-naphthalene (H 2 L) Step A A mixture of N-bromosuccinimide (2.50 g, 14.1 mmol), 2,7-dimethylnaphthalene (1.00 g, 6.4 mmol), AIBN (0.10 g, 0.58 mmol) in CCl 4 (100 ml) was stirred at reflux for 10 min after which the mixture was cooled to 0 C, the precipitated succinimide was filtered off and the filtrate evaporated under reduced pressure. The residue was recrystallized from anhydrous ether to give 2,7-di(bromomethyl)naphthalene as a white solid. Yield: 85%. 1 H NMR (400MHz, CDCl 3 ): δ = 4.67 (s, 4H, -CH 2 Br), (m, 6H, -naphthyl). Step B: Potassium (0.19 g, 4.9 mmol) was dissolved in tert-butyl alcohol (50 ml), to this solution, dibenzoylmethane (1.19 g, 5.3 mmol), 2,7-di(bromomethyl)naphthalene (0.77 g, 2.45 mmol) and KI (0.5 g) were added successively. The mixture was refluxed for 72 h under nitrogen. White precipitate was obtained after tert-butyl alcohol was removed with rotary evaporation, which was then dissolved in CHCl 3, and washed with water for several times to remove inorganic salts. The resulted CHCl 3 solution, containing the intermediate bis-diketone, was dried by anhydrous magnesium sulfate. Then the residue was recrystallized from THF-methanol to give the desired product as blocks. Yield: 75%. 2

3 1 H NMR (400MHz, CDCl 3 ): δ = (d, 4H, -CH 2 -), (t, 2H, -CH-), (m, 26H, -Ph and naphthyl) Step C To the above-obtained CHCl 3 solution (50 ml) of bis-diketone was added slowly a methanol solution (8 ml) of hydrazine (80% N 2 H 4 H 2 O, 0.8 ml). The mixture was refluxed for 12 h and then the solvent was removed off, the residue was recrystallized from THF-methanol to afford the bipyrazole as needles. Yield: 70 %. Anal. calcd. for C 42 H 32 N 4 1/2(CH 3 OH): C 83.84; H 5.63; N 9.21%. Found C 83.72; H 5.70; N 9.55%. IR (KBr, cm -1 ): 3205s, 3049s, 2923m, 1633w, 1604m, 1494s, 1445s, 1292w, 1264w, 1220m, 1171m, 974s, 916m, 837m,763s, 696s. 1 H NMR (400 MHz, DMSO): δ = 4.19 (s, 4H, -CH 2 -), (m, 26H, -Ph and naphthyl). 1 H NMR (400 MHz, CDCl 3 ): δ = 4.27 (s, 4H, -CH 2 -), (m, 26H, -Ph and naphthyl). 13 C NMR (400 MHz, CDCl 3 ): δ = , , , , , , , , , MS: m/z = [M+H] +. Scheme S1. Synthetic route for the bipyrazole H 2 L. Preparation of Cu 6 L 3 Method A: A solution of CuBr 2 (4.4 mg, 0.02 mmol) in ammonia (1 ml) was mixed with a solution of H 2 L (6.0 mg, 0.01 mmol) in THF (2 ml), ethanol (2 ml) and water (1 ml). The mixture was heated in a sealed tube at 160 C for 72 h, after cooling to the room temperature, colorless blocks were obtained. Yeild: 60 %. Anal. calcd. for C 126 H 90 Cu 6 N 12 4H 2 O: C 68.00; H 4.44; N 7.55%. Found C 68.10; H 4.44; N 3

4 7.19%. IR (KBr, cm -1 ): 3451m, 3048m, 2907m, 1636m, 1604m, 1577m, 1529w, 1465s, 1442m, 1323m, 1302w, 1235m, 1156m, 1072m, 1016m, 944m, 833m, 744m, 696s. Method B: A CH 3 CN solution (6 ml) of CuI (3.8 mg, 0.02 mmol) was mixed with a THF solution (2 ml) of H 2 L (6.0 mg, 0.01 mmol), and then Et 3 N (0.02 mmol) in 2 ml of MeOH was added. The solution was stirred for 1 h and then MeOH was added. The supernatant was removed and the residue was washed with MeOH and Et 2 O successively. Colorless crystals were obtained by slow diffusion of cyclohexane into a CHCl 3 solution of Cu 6 L 3 within two days. Yield: 80 %. Anal. calcd. for C 126 H 90 Cu 6 N 12 C 6 H 12 4H 2 O: C 68.64; H 4.80; N 7.28%. Found C 68.92; H 4.41; N 7.45%. IR (KBr, cm -1 ): 3415m, 3048m, 2097m, 1636m, 1604m, 1577m, 1529w, 1465s, 1442m, 1323m, 1302w, 1235m, 1156m, 1072m, 1016m, 944m, 833m, 774m, 696s. 1 H NMR (400 MHz, CDCl 3 ): δ = 4.02 (s, 4H, -CH 2 ), (m, 26H, Ph and naphthyl). Preparation of Ag 6 L 3 C 6 H 12 To Ag(PhCOO) (4.6 mg, 0.02 mmol) in THF (5 ml) was added H 2 L (6 mg, 0.01 mmol). The clear reaction mixture was stirred for 18 h, the solvent was reduced to approximately 1/5 of its volume, and MeOH (5 ml) was added. The supernatant was removed and the product was washed with CH 3 OH and Et 2 O, successively. Colorless crystals were obtained by slow diffusion of cyclohexane into a CHCl 3 solution of Ag 6 L 3 within two days. Yield: 80 %. Anal. calcd. for C 126 H 90 Ag 6 N 12 C 6 H 12 6H 2 O: C 60.71; H 4.40; N 6.44%. Found C 60.80; H 4.04; N 6.42%. IR (KBr, cm -1 ): 3048w, 2922w, 1636m, 1604m, 1510m, 1464s, 1443m, 1413w, 1321w, 1272m, 1234m, 1158w, 1073m, 1008m, 944w, 773m, 698s. 1 H NMR (400 MHz, CDCl 3 ): δ = 4.05 (s, 4H, -CH 2 ), (m, 26H, -Ph and naphthyl). Encapsulation of sulfur by Ag 6 L 3 -cage (Ag 6 L 3 S 8 ) The powder sample of Ag 6 L 3 (7.2 mg, mmol) and S 8 (25.7 mg, 0.1 mmol) were dissolved in CHCl 3, and the solution was stirred for 2 h. The single crystals of the clathrate complex in block habit, appropriate for X-ray diffraction study, were grown by layering cyclohexane on the surface of the resulted CHCl 3 solution of Ag 6 L 3 and sulfur. Yield: 75 %. 4

5 Anal. calcd. for C 126 H 90 Ag 6 N 12 S 8 6H 2 O: C 54.47; H 3.70; N 6.05; S 9.21%. Found C 54.60; H 3.39; N 6.20; S 9.61%. IR (KBr, cm -1 ): 3047w, 2903w, 1635m, 1603m, 1509m, 1492s, 1463s, 1442m, 1412w, 1319m, 1234m, 1174m, 1072m, 1008m, 942w, 832m, 772m, 756m, 697s. 1 H NMR (400 MHz, CDCl 3 ): δ = 4.04 (s, 4H, -CH 2 ), (m, 26H, Ph and naphthyl). Fig. S1 1 H NMR spectra of the Ligand (1), Ag 6 L 3 (2) and Ag 6 L 3 S 8 (3) Mass spectrum of Ag 6 L 3 The MALDI MS of Ag 6 L 3 does not show the signal of the molecular ion, possibly due to the fact that the cage is neutral and it is impossible to charge such compound without breaking its structure. However, the signals appeared can be assigned reasonably to the molecular fragments as [Ag 5 L 2 ] + (m/z: 1721), [Ag 4 L 2 H] + (m/z: 1613), [Ag 3 L 2 (H) 2 ] + (m/z: 1507), [Ag 3 L] + (m/z: 913), [Ag 2 LH] + 5

6 (m/z: 807) and [AgL(H) 2 ] + (m/z: 701), respectively (Fig. S2). The isotopic distribution modelling further supported our assignments (Fig. S3a and b). Intens. [a.u.] m/z Fig. S2 MALDI mass spectrum of Ag 6 L 3. Intens. [a.u.] m/z Fig. S3a The isotopic distribution of the species [Ag 5 L 2 ] + in the MALDI-MS of Ag 6 L 3. 6

7 intensity Electronic Supplementary Material (ESI) for Dalton Transactions m/z Fig. S3b The calculated isotopic distribution of the species [Ag 5 L 2 ] +. X-ray crystallography Diffraction intensities were collected on an Oxford Xcalibur CCD diffractometer (Cu 6 L 3 ), or a Rigaku Saturn 724+ CCD diffractometer (Cu 6 L 3 C 6 H 12, Ag 6 L 3 C 6 H 12, Ag 6 L 3 S 8 ) with graphite-monochromated Mo-Kα radiation ( A). Absorption corrections were applied using the multiscan program. The structures were solved by direct methods and refined by least squares techniques using the SHELXS-97 and SHELXL-97 programs. [1] All non-hydrogen atoms and disorder solvents were refined with anisotropic displacement parameters; hydrogen atoms were generated geometrically. SQUEEZE subroutine in PLATON was used in the refinement of Cu 6 L 3 (prepared hydrothermally) to cope with unidentifiable solvent molecules. [2] Crystal data are summarised in Table S1. CCDC , and contain the crystallographic data for the complexes reported in this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via The structure of Cu 6 L 3 C 6 H 12 was provided here for comparison (with that of Cu 6 L 3 ). 1 G. M. Sheldrick, Acta Crystallogr., Sect. A 2008, 64, A. L. Spek, PLATON, a multipurpose crystallographic tool. Utrecht University, Utrecht,

8 Thermal analyses Fig. S4 TG/DSC curves of Cu 6 L 3 4H 2 O. The thermal analysis on Cu 6 L 3 4H 2 O was conducted from 20 C to 700 C under air. From 110 C to 250 C, the complex experienced a weight loss of 3.8 %, corresponding to loss of lattice water molecules (Calcd. 3.2 %). Starting from 340 C and ending at 510 C, the observed large weight loss (70.4 %) accords with an exothermic decomposition of the complex. The final residue accounts for 25.8 % of the total mass, which is tentatively assigned as CuO (Calcd %). 8

9 Fig. S5 TG/DSC curves of Ag 6 L 3 C 6 H 12 2H 2 O. The thermal analysis on Ag 6 L 3 C 6 H 12 2H 2 O was scanned from 30 C to 740 C under air. A slight weight loss of 4.8 % in the range of 90 C to 240 C can be ascribed to the loss of two lattice water molecules and a cyclohexane molecule per formula (Calcd. 4.7 %). The second weight loss was observed from 347 C to 550 C with a weight loss of 68.4 %, corresponding to the decomposition of the complex. The final residue, accounting for 26.8 % of the total mass, might be assigned as Ag 2 O, based on the calculated residual percentage of 27.3 %. 9

10 Fig. S6 TG/DSC curves of the clathrate complex Ag 6 L 3 S 8 (Ag 6 L 3 S 8 6H 2 O) The thermal analysis on Ag 6 L 3 S 8 was conducted from 30 C to 820 C under air (Fig. S4). The first weight loss in the range of 100 C to 300 C accounts for ca. 3.8 % of the total mass, corresponding to the loss of lattice water molecules (Calcd. 3.9 %). From that point to 660 C, the complex experienced two successive weight losses, amounting to 67.2 % of the total mass, which may correspond to the combustion of S 8 and decomposition of the complex. The final residue is estimated to be mainly Ag 2 S (observed, 28.9 %; Calcd %). It is noteworthy that sulfur encapsulated in the cage shows a decreased reactivity to O 2, considering the auto-ignition temperature of sulfur in the range of 248 C to 266 C. 10

11 Luminescence spectra Fig. S7 Luminescent spectra of H 2 L, Cu 6 L 3, Cu 6 L 3 C 6 H 12 and Ag 6 L 3 C 6 H 12 in the solid-state at room temperature. The solid state luminescent spectra were recorded for bipyrazole, Cu 6 L 3 C 6 H 12 and Ag 6 L 3 C 6 H 12 at room temperature under excitation at 355, 321, 353, 355 nm with the emission maxima located at ca 414, 338, 392, 388 nm, respectively. 11

12 (a) (b) Fig. S8 (a) Ball-and-stick diagram of a top-view of Cu 6 L 3. All H-atoms and solvents are omitted for clarity. (b) Packing diagram of Cu 6 L 3, showing the intermolecular C-H π interactions 12

13 (a) (b) Fig. S9 (a) Ball-and-stick diagram of Ag 6 L 3 C 6 H 12. The encapsulated cyclo-hexane molecule has been split to two parts due to the disorder it exhibits; (b) Packing diagram of Ag 6 L 3, showing the intermolecular C-H π interactions 13

14 (a) (b) Fig. S10 (a) Ball-and-stick diagram of Ag 6 L 3 S 8 ; (b) Packing diagram of Ag 6 L 3 S 8, showing the intermolecular C-H π interactions 14

15 Table S1. Crystallographic data of the complexes Complex Cu 6 L 3 Cu 6 L 3 C 6 H 12 Ag 6 L 3 C 6 H 12 Ag 6 L 3 S 8 Mr Crystal size (mm 3 ) Crystal system Monoclinic Monoclinic Monoclinic Triclinic Space group Cc Cc Cc P-1 a (Å) (6) (6) (6) (3) b (Å) (3) (3) (4) (4) c (Å) (5) (5) (5) (5) α ( ) (3) β ( ) (3) (3) (3) 71.00(3) γ ( ) (3) V (Å 3 ) 11732(4) 11552(4) 12284(4) 6039(2) Z T (K) 298(2) 153(2) 153(2) 153(2) D calcd (Mg/m 3 ) μ (mm -1 ) F(000) (e) Refl. Collected Refl. Unique (R int = ) 24969(R int = ) (R int = ) (R int = ) Param. Refined Restraints Final R indices R 1 = R 1 = R 1 = R 1 = [I >2σ(I)] wr 2 = wr 2 = wr 2 = wr 2 = GoF (F 2 ) Δρ fin (max,min), e Å , , , , CCDC

16 Table S2 Selected bond distances (Å) and angles ( )* Complex Cu 6 L 3 Cu 6 L 3 C 6 H 12 Ag 6 L 3 C 6 H 12 Ag 6 L 3 S 8 M-N(av)/Å M-N(range) Å 1.851(56)-1.872(58) 1.849(5)-1.872(6) 2.064(12) (11) 2.073(8)-2.099(8) N-M-N(av)/deg N-M-N(range)/Å 175.4(3)-177.5(2) 175.9(3)-178.3(3) 173.2(5)-178.7(5) 171.5(3)-177.5(3) M M(av intra)/å M M intra/å 3.188(1)-3.279(1) 3.204(1)-3.291(1) 3.462(2)-3.564(2) 3.387(2)-3.528(2) M M(av inter)/å M M inter/å (2)-7.919(3) 7.233(2)-7.908(3) 7.292(3)-8.071(3) 7.210(3)-7.520(3) * av = average; intra = intra-trimer; inter = inter-trimer. Table S3 Elemental analysis data Sample Cu 6 L 3 S 8 * Ag 6 L 3 S 8 * Ag 6 L 3 +S 8 ** Found1 Found2 Calc Found1 Found2 Calc Found1 Found2 Calc C H N S Formula Cu 6 L 3 (S 8 ) 0.3 (H 2 O) 4 Ag 6 L 3 (S 8 )(H 2 O) 6 Ag 6 L 3 (S 8 ) 0.4 (H 2 O) 4 Molar ratio (M 6 L 3 :S 8 ) Cu 6 L 3 :S 8 = 1:0.3 Ag 6 L 3 :S 8 = 1:1 Ag 6 L 3 :S 8 = 1:0.4 * Crystalline samples were prepared by layering of cyclohexane on the surface of a CHCl 3 solution containing M 6 L 3 and S 8 in 1:30 molar ratio. ** The sample was obtained by suspension of Ag 6 L 3 in a cyclohexane solution containing S 8 with Ag 6 L 3 :S 8 = 1:30. Table S4 1 HNMR data in CDCl 3 H 2 L Ag 6 L 3 Ag 6 L 3 C 6 H 12 Ag 6 L 3 S 8 1-naph (s, 1H) {7.233} ,6-naph (d, 1H) ,5-naph (d, 1H) { } CH 2 (s, 2H) o-ph (d, 4H) { } m-ph (ps-t, 4H) { } { } p-ph (t, 2H) { } { } Values in brackets indicate overlapping resonances. 16