Supporting Information Stabilization of a Reactive Polynuclear Silver Carbide Cluster through the Encapsulation within Supramolecular Cage Cai-Yan Gao, Liang Zhao,* and Mei-Xiang Wang* The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China zhaolchem@mail.tsinghua.edu.cn; wangmx@mail.tsinghua.edu.cn Synthesis All commercially available chemicals were used without further purification. Methylazacalix[6]pyridine (Py6) was synthesized according to the literature method by the [3+3] fragment coupling protocol between terminal dibrominated and diaminated linear tetramers. 1 The silver carbide complexes Ag 2 C 2 and Ag 2 C 4 were synthesized by previously reported methods. 2 The solvents used in this study were processed by standard procedures. All reactions were carried out under a nitrogen atmosphere unless otherwise noted. CAUTION! Ag 2 C 2 and Ag 2 C 4 are potentially explosive and should be handled with care and in small amounts. [(CF 3 SO 3 ) 1.5 Ag 3.5 ( t BuC C)(Py6)(CH 3 OH) 0.5 ](CF 3 SO 3 ) (H 2 O) 0.5 (1). In a 10 ml round-bottom flask, AgSO 3 CF 3 (50.8 mg, 0.2 mmol) was dissolved in CH 3 OH (1 ml) at room temperature. Then [ t BuC CAg] n (18.9 mg, 0.1 mmol) solid was added to the solution under stirring. After 10 min, a CH 2 Cl 2 solution (1 ml) of methylazacalix[6]pyridine (Py6, 12.0 mg, 0.02 mmol) was added stepwisely. The mixture was further stirred for one hour and the suspension changed into clear. The solution was filtered and the filtrate was diffused by diethyl ether in the dark. After a day, pale yellow crystals of 1 were obtained in 74% yield based on Py6 ligand. Elemental analysis for 1 (CH 2 Cl 2 ) 4 : C 49 H 56 Ag 3.5 Cl 8 F 7.5 N 12 O 8.5 S 2.5 (after remove solvent under vacuum), found (calcd): C 31.80 (32.11); H 2.84 (3.08); N 9.35 (9.17). Electrospray ionization mass spectrometry (ESI-MS): m/z = 1189.06 for the [(CF 3 SO 3 )Ag 3 ( t BuC C)(Py6)] +. S1
[(CF 3 SO 3 ) 4 Ag 8 (C C C C)(Py6) 2 ](CF 3 SO 3 ) 2 (2). The method for the synthesis of 2 was similar to that for complex 1, but employed Ag 2 C 4 instead of AgC C t Bu. Orange red crystals of complex 2 were obtained in 45% yield based on Py6 ligand. Elemental analysis for 2 (Et 2 O) 2 : C 90 H 92 Ag 8 F 18 N 24 O 20 S 6, found (calcd): C 33.61 (33.50); H 2.75 (2.87); N 11.17 (10.42). Electrospray ionization mass spectrometry (ESI-MS): m/z = 2414.93 for the [(CF 3 SO 3 ) 3 Ag 6 (C C C C)(Py6) 2 ] +, and 1132.99 for the [(CF 3 SO 3 ) 2 Ag 6 (C C C C)(Py6) 2 ] 2+. {[Ag 5 (C C)(Py6) 2 ](CF 3 SO 3 ) 3 } 0.7 {[Ag 6 (C C)(Py6) 2 ](CF 3 SO 3 ) 4 } 0.3 (3). A synthetic procedure similar with 1 was applied in the synthesis of complex 3 with Ag 2 C 2 in place of Ag 2 C 4. Yellow crystals of 3 were deposited in the dark by the envaporation of pale yellow filtrate. Yield: 30% (based on Py6). The elemental analysis results of complex 3 varied in different measurements, which may be due to mutable ratios between the two encapsulated silver cluster: C 2 @Ag 5 and C 2 @Ag 6 in bulk material. Electrospray ionization mass spectrometry (ESI-MS): m/z = 993.08 for the {[Ag 5 (C C)(Py6) 2 ](CF 3 SO 3 )} 2+. X-ray Crystallographic Analysis Data for complexes 1-3 were collected at 173K with Mo-Kα radiation (λ = 0.71073 Å) on a Rigaku Saturn 724+ CCD diffractometer with frames of oscillation range 0.5º. All structures were solved by direct methods, and non-hydrogen atoms were located from difference Fourier maps. All non-hydrogen atoms were subjected to anisotropic refinement by full-matrix least-squares on F 2 by using the SHELXTL program unless otherwise noticed. All figures are drawn by using X-seed program. 3 Crystal data for [(CF 3 SO 3 ) 1.5 Ag 3.5 ( t BuC C)(Py6)(CH 3 OH) 0.5 ](CF 3 SO 3 ) (H 2 O) 0.5 (1): C 45 H 48 Ag 3.5 F 7.5 N 12 O 8.5 S 2.5, M = 1493.14, monoclinic, space group C2/c (No. 15), a = 20.150(4) Å, b = 15.922(3) Å, c = 33.605(7) Å, β = 90.57(3), V = 10781(4) Å 3, Z = 8, T = 173 K, D c = 1.838 g cm -3. The structure, refined on F 2, converged for 9855 unique reflections (R int = 0.0345) and 9272 observed reflections with I > 2σ(I) to give R 1 = 0.0608 and wr 2 = 0.1647 and a goodness-of-fit = 1.115. Silver atom Ag4, water molecule O1W, methanol molecule and triflate group S3 each has a set site-occupancy ratio of 0.5. All oxygen and fluorine atoms of a triflate group (S2) each are disordered at two positions with a refined siteoccupancy ratio of 0.51:0.49. The tert-butyl moiety of the tert-butylacetylide group was processed into two disordered parts in the ratio of 0.60:0.40. The water hydrogen atoms were not added in the structure model due to its absence in the Fourier difference map. The carbon atom C45 was refined isotropically. In the check cif report, atoms C41 and O7 have large ADP max/min ratios (7.1 and 5.1, respectively). This can be ascribed to the high disorder of the tert-butyl group and the triflate anion S3. The triflate anion S3 has an orientation disorder as shown below. S2
Crystal data for [(CF 3 SO 3 ) 4 Ag 8 (C C C C)(Py6) 2 ](CF 3 SO 3 ) 2 (2): C 41 H 36 Ag 4 F 9 N 12 O 9 S 3, M = 1539.45, monoclinic, space group C2/c (No. 15), a = 18.163(4) Å, b = 29.225(6) Å, c = 19.868(4) Å, β = 98.30(3), V = 10436(4) Å 3, Z = 8, T = 173 K, D c = 1.970 g cm -3. The structure, refined on F 2, converged for 9122 unique reflections (R int = 0.0714) and 8098 observed reflections with I > 2σ(I) to give R 1 = 0.1179 and wr 2 = 0.2949 and a goodness-of-fit = 1.236. Silver atom Ag3 is disordered over two closely separated positions in the ratio of 0.57:0.43. The trifluoromethyl group of triflate group S2 is disordered at two positions with a refined site-occupancy ratio of 0.50:0.50. The oxygen atom O8 on triflate group S3 has two disordered positions in a set ratio of 0.70:0.30 while the trifluoromethyl group on S3 can be processed into two disordered parts in the ratio of 0.54:0.46. The fourth triflate group S4 is highly disordered and thus can not be refined properly to give specific coordinates for each atom. Several disordered atoms including C40, F21, F23, C40, O8, C41, F32, F33, F41, F42 and O11 were refined isotropically. In the check cif report, atom O7 has a high Ueq value compared to neighbors while atom S3 has a low Ueq. This is also because of the disorder of triflate anion S3. Crystal data for {[Ag 5 (C C)(Py6) 2 ](CF 3 SO 3 ) 3 } 0.7 {[Ag 6 (C C)(Py6) 2 ](CF 3 SO 3 ) 4 } 0.3 (3): C 77.3 H 72 Ag 5.3 F 9.9 N 24 O 9.9 S 3.3, M = 2361.15, monoclinic, space group P2 1 /c (No. 14), a = 13.612(3) Å, b = 38.593(8) Å, c = 17.636(4) Å, β = 97.50(3), V = 9186(3) Å 3, Z = 4, T = 173 K, D c = 1.720 g cm -3. The structure, refined on F 2, converged for 16093 unique reflections (R int = 0.0581) and 13284 observed reflections with I > 2σ(I) to give R 1 = 0.1143 and wr 2 = 0.2852 and a goodness-of-fit = 1.193. There are two kinds of closed silver carbide clusters in 3. Four silver atoms (Ag1, Ag2, Ag3 and Ag4) share their positions in both two cluster aggregates and the remaining three silver atoms are disordered with a refined site-occupancy ratio of 0.70:0.30 between Ag5 and a pair of silver atoms Ag5A and Ag5B. Two triflate groups (S1 and S2) are disordered at two positions with a refined site-occupancy ratio of 0.59:0.41 and 0.52:0.48, respectively. Triflate anions S4 and S5 are arranged at two anti-parallel orientations. Thus only half parts of these two triflates are shown in the crystal asymmetrical unit. These two triflates (S4 and S5) S3
plus another one S3 each has a partial occupancy ratio of 0.40, 0.46 and 0.45, respectively. Several disordered atoms including C75, S1, C75, C76, O4, O5, O6, C76, C77 and O3W were refined isotropically. In the check cif report, there is a short interatomic contact of 2.48 Å between O5 and O6. This can be rationalized by the fact that the triflate anion S2 is disordered at two positions as shown below. References (1) (a) Liu, S.-Q.; Wang, D.-X.; Zheng, Q.-Y.; Wang, M.-X. Chem. Commun. 2007, 3856. (b) Zhang, E.- X.; Wang, D.-X.; Zheng, Q.-Y.; Wang, M.-X. Org. Lett. 2008, 10, 2565. (2) Zhao, L.; Mak, T. C. W. J. Am. Chem. Soc. 2004, 126, 6852. (3) (a) Barbour, L. J. J. Supramol. Chem. 2001, 1, 189. (b) Atwood, J. L.; Barbour, L. J. Cryst. Growth Des. 2003, 3, 3. S4
Supporting Figures Figure S1. Theoretical (blue) and experimental (red) electrospray ionization (ESI) mass spectra of the charged species [(CF 3 SO 3 )Ag 3 ( t BuC C)(Py6)] + in complex 1, {[Ag 5 (C C)(Py6) 2 ](CF 3 SO 3 )} 2+ in complex 3 and [(CF 3 SO 3 ) 3 Ag 6 (C C C C)(Py6) 2 ] + and [(CF 3 SO 3 ) 2 Ag 6 (C C C C)(Py6) 2 ] 2+ in complex 2. S5
Figure S2. Coordination environments of the central Ag 5-6 aggregate in {[Ag 5 (C C)(Py6) 2 ](CF 3 SO 3 ) 3 } 0.7 {[Ag 6 (C C)(Py6) 2 ](CF 3 SO 3 ) 4 } 0.3 (3). Ag-C distances for silver-aromatic π interactions (Å): Ag2-C9 2.803; Ag2-C10 2.863; Ag2-C36 2.820; Ag2-C37 2.771; Ag4-C33 2.933; Ag4-C25 2.898; Ag5A-C12 2.758; Ag5A-C13 2.801; Ag5A-C21 2.778; Ag5A-C22 2.721; Ag1-C61 2.978; Ag1-C69 2.904; Ag3-C48 2.966; Ag3-C49 2.850; Ag3-C57 2.818; Ag3-C58 2.935; Ag5B-C45 2.783; Ag5B-C46 2.679; Ag5B-C72 2.770; Ag5B-C73 2.745. S6
Figure S3. 1 H NMR spectrum (600MHz, methanol-d 4 ) of complex 1. S7
Figure S4. Partial 1 H NMR spectra (600MHz, methanol-d 4 ) of the pyridyl and bridging N-Me protons of the Py6 ligand in complex 2 at different temperatures. S8