Supplemental Information. Nano-sized I 12 L 6 Molecular Capsules. Based on the [N,,,I +,,,N] Halogen Bond

Transcription

1 Chem, Volume 3 Supplemental Information Nano-sized I 12 L 6 Molecular Capsules Based on the [N,,,I +,,,N] Halogen Bond Lotta Turunen, Ulrike Warzok, Christoph A. Schalley, and Kari Rissanen

2 1. General Information Reagents were purchased from commercial suppliers and used without further purification. C 6 - Resorcinarene 1,2, iodinated C 6 -resorcinarene 3 and iodinated ethylenecavitand 4 were prepared according to reported procedures. 1 H, 13 C, 1 H DOSY and 1 H, 15 N-HMBC NMR spectra were recorded on a Bruker Avance III 500 or Avance 400 spectrometers. All signals are given as δ values in ppm using residual solvent signals as the internal standard. Coupling constants are given in Hz. External 15 N reference used was 90% 15 N enriched nitromethane (δ N = 0.0 ppm) in a sealed tube. Melting points were determined with melting point apparatus SMP3. Positive-mode electrospray ionisation quadrupole-time-of-flight high resolution mass spectrometry (ESI-Q-TOF-HRMS) measurements were performed with a micromass LCT ESI-TOF instrument for analysis of cavitand 1 and its precursors as well as a Synapt G2-S HDMS (Waters Co., Milford, MA, USA) for capsule formation studies. For the latter, the following parameters were used to record mass spectra: Flowrate 10 µl min -1, spray voltage 3.0 kv, sample-cone voltage 24 V, source offset 81 V, source temperature 85 C, desolvation temperature 220 C, nebuliser gas 6 bar, desolvation gas flow 500 L h -1. To determine exact masses, recorded MS spectra were recalibrated using Leucin-enkephalin lockspray (m/z ). 2. Synthesis and characterization of ethylene-bridged tetrakis(4-pyridyl)cavitand 1 Scheme S1. Synthesis of ethylene-bridged tetrakis(4-pyridyl)cavitand 1. Ethylene-bridged tetrakis(4-pyridyl)cavitand 1 was synthesized according to a reported procedure. 5 To the flask containing iodoethylenecavitand (600 mg, 420 µmol), pyridyl-4-boronic acid (260 mg, 2.1 mmol), [Pd(PPh 3 ) 4 ] (120 mg, 105 µmol) and Cs 2 CO 3 (2.0 g, 6.3 mmol), degassed 1,4-dioxane (117 ml) and water (2.5 ml) were added under argon. The reaction mixture was degassed three times, then refluxed at 110 C for 2 d. The mixture was cooled to room temperature and the solvent was evaporated under reduced pressure. The residue was dissolved in DCM (50 ml) and water (50 ml) was added. After the phases were separated, the aqueous phase was extracted with DCM (2 x 50 ml). The combined organic phases were dried over MgSO 4. The solvent was removed under reduced pressure to give the crude product, which was purified by column chromatography (SiO 2, DCM/MeOH 9:1). The cavitand 1 was obtained as a white solid (240 mg, 46 %). m.p. >270 o C (decomposition); 1 H NMR (500 MHz, CDCl 3, 298 K) δ (ppm): 0.90 (t, J = 6.9 Hz, 12H, CH 3, ), (m, 32H, CH 2chain ), (m, 8H, CH 2chain ), (m, 8H, CH 2in ), (m, 8H, CH 2out ), 5.25 (t, J = 8.1 Hz, 4H, CH), 7.10 (d, J = 5.9 Hz, 8H, H b ), 7.62 (s, 4H, H c ), 8.61 (d, J = 5.9 Hz, 8H, H a ). 13 C NMR (126 MHz, CDCl 3, 298 K) δ (ppm): 14.0, 22.6, 27.8, 29.3, 31.8, 33.8, 34.7, 72.3, 124.9, 124.9, 128.7, 136.3, 143.7, 149.5, 151.2; LCT ESI-TOF: m/z = Found [M + 2H] 2+, Calc [M + 2H] 2+ (-1.5 mda).

3 Figure S1. 1 H NMR spectrum of ethylene-bridged tetrakis(4-pyridyl)cavitand (CDCl 3, 303K, 500 MHz). Figure S2. 13 C NMR spectrum of ethylene-bridged tetrakis(4-pyridyl)cavitand 1 (CDCl 3, 303 K, 126 MHz). 3. NMR measurements For the NMR measurements, a 1 mm solution of capsule 2 was prepared by stirring cavitand 1 (1.0 eq.) and AgOTs (2.0 eq.) in CDCl 3 at room temperature for 10 min. 5 A 1 mm solution of capsule 3 was prepared by adding I 2 (2.3 eq.) into the 1 mm solution of capsule 2 in CDCl 3 and stirring the mixtures at room temperature for 30 min. Before measurements, the precipitated AgI was filtered off.

4 The average diffusion coefficients for Ag + and I + -capsules were derived from the 1 H NMR signals of the hexamer cavitand protons. The hydrodynamic radii are calculated by using the Stokes-Einstein equation: k B T D c π η r where k b is the Boltzmann constant, T is the temperature, c = 6, η is the viscosity of the medium, and D is the diffusion coefficient of the species in the given medium. Figure S3. 1 H NMR spectrum of hexameric capsule 2 (CDCl 3, 298 K, 500 MHz). Figure S4. 1 H NMR spectrum of hexameric capsule 3 (CDCl 3, 298 K, 500 MHz).

5 4. DOSY spectrum of capsule 2 Figure S5. 1 H DOSY NMR spectrum of capsule 2 (CDCl 3, 400 MHz, 298K) H, 15 N-HMBC Figure S6. 1 H, 15 N-HMBC spectrum of 1 (CDCl 3, 500 MHz, 298K). δ ( 15 N) = ppm

6 Figure S7. 1 H, 15 N-HMBC spectrum of 3 (CDCl 3, 500 MHz, 298K). Only one set of NMR signals are present belonging to the pyridines participating in halogen bonding. δ ( 15 N) = ppm 6. VT 1 H NMR spectra of capsule 3 Figure S8. VT 1 H NMR spectra of capsule 3 (CDCl 3, 500 MHz).

7 7. ESI-MS Experiments Figure S9. ESI-Q-TOF-HRMS spectrum of ethylene-bridged tetrakis(4-pyridyl)cavitand 1 (100 μm in CH 2 Cl 2 /MeOH 10:1). Capsule 2 for ESI-MS measurements was obtained by mixing cavitand 1 (1 eq.) and AgOTs (2 eq.) in CHCl 3 (1 mm solution) and stirring the mixture for 2 hours at room temperature. Capsule 3 for ESI-MS measurements was obtained by addition of iodine (3 eq.) to a solution of capsule 2 (1 mm in CHCl 3 ). The mixture was stirred at room temperature for at least 10 min and centrifuged to separate the red solution from the precipitated AgI. Prior to ESI-MS measurements, all samples were diluted using CHCl 3 (100 μm solutions) and additional 10% of MeCN were added. In the MS spectra of capsules 2 and 3, signals are also present of monomeric and dimeric complexes. The presence of these species is very likely due to some fragmentations during the ionization or minor fluctuations during the preparation. However, as they are of very low abundance and other oligomers are absent, it can be concluded that the formation of hexameric complexes is specific in both cases. Figure S10. ESI-Q-TOF-HRMS spectrum of capsule 2 ((90 μm in 9:1 v/v CHCl3/MeCN).

8 Table S1. Ions observed for capsule 2 with measured and calculated exact masses as well as stoichiometric assignments. m/z (exp.) m/z (cal.) Assignment [1 Ag] + /[1 2 Ag 2 ] [1 Ag MeCN] [1 2 Ag 3 OTs] [1 Ag H OTs] [1 Ag 2 OTs] + /[1 2 Ag 4 OTs 2 ] [1 6 Ag 9 OTs 5 ] [1 6 Ag 10 OTs 6 ] [1 6 Ag 11 OTs 7 ] [1 6 Ag 12 OTs 8 ] [1 6 Ag 8 OTs 5 ] [1 6 Ag 9 OTs 6 ] [1 6 Ag 10 OTs 7 ] Molecular modelling As both hexamers have a chemical formula of C 548 H 604 N 24 O 84 S 12 Z 12, Z = Ag or I, and thus huge in size, Ag FW = and I FW = , and as the ethylene-bridged tetrakis(4-pyridyl)cavitand 1 is rather rigid (only the hexyl chains at the lower rim of the cavitand have more degrees of freedom) the molecular modelling was done at the MM-level (Spartan16, MMFF force field). In both cases the structure was minimized without the tosylate anions as the capsule size is not affected by the anions. The Ag was minimized without any constraints starting from linear [N Ag + N] motif and remained linear with Ag-N bond distance of 2.13 Å, the same is observed in the single crystal X-ray structures of complexes with [N Ag + N] motif. Upon unconstrained I-N bond distance the Spartan MMFF force field gives I-N as 2.05 Å, clearly too short distance. The X-ray structures of complexes with [N I + N] motif have shown that the I-N bond distance is 2.25 Å. Thus, in the energy minimization for I the I-N distances were fixed to this value. Figure S11. The molecular modelled structures of Ag (left) and I (right). The Ag-N bond distance is 2.13 Å and the I-N 2.25 Å. The Ag is thus slightly smaller (diameter ca. 4.3 nm) than the I (diameter ca. 4.5 nm).

9 9. References 1. Tunstad, L.M., Tucker, J.A., Dalcanale, E., Weiser, J., Bryant, J.A., Sherman, J.C., Helgeson, R.C., Knobler, C.B., and Cram, D.J. (1989). Host-Guest Complexation. 48. Octol Building Blocks for Cavitands and Carcerands. J. Org. Chem. 54, Abis, L., Dalcanale, E., Du vosel, A., and Sperala, S. (1988). Structurally New Macrocycles from the Resorcinol- Aldehyde Condensation. Configurational and Conformational Analyses by Means of Dynamic NMR, NOE, and T1 Experiments. J. Org. Chem. 53, Gruppi, F., Boccini, F., Elviri, L., and Dalcanale, E. (2009). Self-assembly of a cavitand-based heteronuclear coordination cage. Tetrahedron 65, Turunen, L., Beyeh, N.K., Pan, F., Valkonen, a, and Rissanen, K. (2014). Tetraiodoethynyl resorcinarene cavitands as multivalent halogen bond donors. Chem. Commun. 50, Turunen, L., Warzok, U., Puttreddy, R., Beyeh, N.K., Schalley, C.A., and Rissanen, K. (2016). [N I+ N] Halogen-Bonded Dimeric Capsules from Tetrakis(3-pyridyl)ethylene Cavitands. Angew. Chem. Int. Ed. 55,