ExBox: A Polycyclic Aromatic Hydrocarbon Scavenger

ExBox: A Polycyclic Aromatic Hydrocarbon Scavenger Jonathan C. Barnes,, Michal Juríček,, Nathan L. Strutt, Marco Frasconi, Srinivasan Sampath, Marc A. Giesener, Psaras L. McGrier, Carson J. Bruns, Charlotte L. Stern, Amy A. Sarjeant, and J. Fraser Stoddart,* Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, United States These authors contributed equally to this work. Supplementary Information

Table of Contents Section A. Materials / General Methods / Instrumentation S4 Section B. Synthetic Protocols S5 1) 4,4 -(1,4-Phenylene)bispyridine Extended Bipyridine = ExBIPY S5 2) Bisbromomethyl(bis-p-benzyl-4,4 -(1,4-phenylene)bispyridine)bis(hexafluorophosphate) = DB 2PF 6 S6 3) Cyclobis(4,4 -(1,4-phenylene)bispyridine-p-phenylene)tetrakis(hexafluorophosphate) Extended Viologen Box = ExBox 4PF 6 S7 4) Cyclobis(4,4 -(1,4-phenylene)bispyridine-p-phenylene)tetrachloride Extended Viologen Box = ExBox 4Cl S8 5) [4]Helicene S8 Section C. Crystallographic Characterization S10 1) ExBox 4PF 6 S10 a) Methods b) Crystal Parameters 2) ExBox Azulene 4PF 6 (Azulene) S11 a) Methods b) Crystal Parameters 3) ExBox Anthracene 4PF 6 (Anthracene) S12 a) Methods b) Crystal Parameters 4) ExBox Phenanthrene 4PF 6 (Phenanthrene) S13 a) Methods b) Crystal Parameters 5) ExBox Pyrene 4PF 6 (Pyrene) S14 a) Methods b) Crystal Parameters 6) ExBox Tetracene 4PF 6 S15 a) Methods b) Crystal Parameters S2

7) ExBox Tetraphene 4PF 6 S17 a) Methods b) Crystal Parameters 8) ExBox Chrysene 4PF 6 S18 a) Methods b) Crystal Parameters 9) ExBox [4]Helicene 4PF 6 S19 a) Methods b) Crystal Parameters 10) ExBox Triphenylene 4PF 6 S20 a) Methods b) Crystal Parameters 11) ExBox Perylene 4PF 6 S22 a) Methods b) Crystal Parameters 12) ExBox Coronene 4PF 6 S23 a) Methods b) Crystal Parameters Section D. Spectroscopic and Spectrometric Characterizations S24 1) ExBox 4PF 6 and Its Complexes S24 a) UV/Vis Absorption Spectra b) 1 H NMR / 13 C NMR Spectroscopic Analysis 2) DB 2PF 6 S37 3) Isothermal Titration Calorimetry S38 a) ExBox 4+ Phenanthrene b) ExBox 4+ Pyrene c) ExBox 4+ Tetraphene d) ExBox 4+ [4]Helicene Section F. References S43 S3

Section A. Materials / General Methods / Instrumentation All reagents were purchased from commercial suppliers (Aldrich or Fisher) and used without further purification. The crude oil samples were purchased from ONTA Inc., (Geology) Coal and Petroleum/Crude Oil Samples based out of Ontario, CA (www.onta.com) and were diluted with CD 2 Cl 2 before extraction, as described in the main text. Analytical high-performance liquid chromatography (HPLC) was performed on reverse phase-hplc (RP-HPLC) instruments, using a C 18 column and a binary solvent system (MeCN and H 2 O with 0.1% CF 3 CO 2 H). Thin-layer chromatography (TLC) was performed on silica gel 60 F254 TLC plates (Merck). Column chromatography was carried out on silica gel 60F (Merck 9385; 0.040 0.063 mm). UV/Vis Absorbance spectra were recorded using a UV-3600 Shimadzu spectrophotometer. Nuclear magnetic resonance (NMR) spectra were recorded on a BrukerAvance 600 and Varian P-Inova 500 spectrometers, with working frequencies of 600 and 500 MHz, respectively. Chemical shifts are reported in ppm relative to the signals corresponding to the residual non-deuterated solvents (CD 3 CN: δ H = 1.94 ppm and δ C = 1.32 ppm; CDCl 3 : δ H = 7.26 ppm; CD 2 Cl 2 : δ H = 5.32 ppm; CD 3 COCD 3 : δ H = 2.05 ppm and δ C = 29.84 ppm; D 2 O: δ H = 4.79 ppm). High-resolution mass spectra (HRMS) were measured on an Agilent 6210 Time of Flight (TOF) LC-MS, using an ESI source, coupled with Agilent 1100 HPLC stack, using direct infusion (0.6 ml min 1 ). Isothermal titration calorimetry (ITC) experiments were performed on a MicroCal system, VP-ITC model. Cyclic voltammetry (CV) experiments were carried out at room temperature in argon-purged solutions of DMF with a Gamry Multipurpose instrument (Reference 600) interfaced to a PC. All CV experiments were performed using a glassy carbon working electrode (0.071 cm 2 ). The electrode surface was polished routinely with 0.05 μm alumina water slurry on a felt surface immediately before use. The counter electrode was a Pt coil and the reference electrode was a Ag/AgCl electrode. The concentration of the sample and supporting electrolyte, tetrabutylammonium hexafluorophosphate (TBAPF 6 ), were 1.0 mm and 0.1 M, respectively. The CV cell was dried in an oven immediately before use, and Ar was continually flushed through the cell as it was cooled down to room temperature to avoid condensation of water. SEM imaging was performed on a FEI Quanta 600F sfeg ESEM scanning electron microscope (SEM) at an accelerating electron voltage of 30 kv under high vacuum. S4

B. Synthetic Protocols 1) 4,4 -(1,4-Phenylene)bispyridine Extended Bipyridine = ExBIPY Scheme S1. Synthesis of 4,4 -(1,4-phenylene)bispyridine Extended Bipyridine = ExBIPY. ExBIPY: The bispyridyl compound was prepared (Scheme S1) using a modified literature procedure. S1 Pyridylboronic pinacol ester (3.64 g, 17.8 mmol), 1,4-dibromobenzene (1.40 g, 5.92 mmol), and Cs 2 CO 3 (11.6 g, 35.5 mmol) were added to a 1:1 mixture of dry PhMe/DMF (300 ml), which had been degassed with Ar for 15 min. Next, Pd(PPh 3 ) 4 (0.68 g, 0.59 mmol) was added to the reaction mixture and the solution heated to 130 ºC under Ar for 48 h. Then, the reaction mixture was cooled to room temperature and the palladium catalyst filtered off using Celite. The organic phase was concentrated under vacuum and then dissolved in CH 2 Cl 2 followed by extraction with H 2 O three times. The organic layer was made acidic (ph 2 3) by adding dropwise concentrated HCl, which caused the desired product to precipitate from solution. The precipitate was collected by filtration and then dissolved in H 2 O. Finally, aq. NaOH (10 M) was added dropwise to the water layer until the ph was ~8 9, which resulted in precipitation of pure product ExBIPY (973 mg, 71%) as a white solid. A previously reported synthesis S1 recorded the yield of the product to be 63%; we were able to increase slightly the yield of the product obtained in the reaction to 71%, most likely as a result of using acid base extraction techniques instead of carrying out column chromatography. 1 H NMR (500 MHz, CDCl 3, ppm): δ H 8.72 (AA' of AA'XX', J = 4.6, 1.6 Hz, 4H), 7.80 (s, 4H), 7.59 (XX' of AA'XX', J = 4.6, 1.6 Hz, 4H). These 1 H NMR peaks are consistent with those already reported in the literature. S1 S5

2) Bisbromomethyl(bis-p-benzyl-4,4 -(1,4-phenylene)bispyridine)bis(hexafluorophosphate) = DB 2PF 6 Scheme S2. Synthesis of DB 2PF 6. DB 2PF 6 : α,α'-dibromo-p-xylene (4.58 g, 17.2 mmol) was added to CH 2 Cl 2 (30 ml) in a 250 ml round-bottomed three-neck flask and the resulting mixture was refluxed while stirring until all of the solid material dissolved. Next, the temperature of the oil bath was raised to 90 ºC, allowing the reaction mixture to reflux while a suspension of ExBIPY (400 mg, 1.72 mmol) in MeCN (60 ml), was added in five aliquots slowly over 1 h. After only 30 min, however, a yellow precipitate, indicative of DB 2Br formation, began to appear. After heating under reflux for 48 h, the reaction mixture was cooled to room temperature and the yellow precipitate was collected by filtration and washed with CH 2 Cl 2. The yellow solid was dissolved in cold ( 25 C) MeOH (~500 750 ml) followed by the addition of NH 4 PF 6 (~100 200 mg) and cold ( 25 C) H 2 O (~2 L), resulting in the precipitation of pure DB 2PF 6 (1.41 g, 92%) that was collected by filtration as a white solid (Scheme S2). (HRMS-ESI) For DB 2PF 6, Calcd for C 32 H 28 Br 2 F 12 N 2 P 2 : m/z = 743.0256 [M PF 6 ] +, 597.0536 [M 2PF 6 ] 2+ ; found: 743.0262 [M PF 6 ] +, 597.0538 [M 2PF 6 ] 2+. 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.66 (AA' of AA'XX', J = 6.9 Hz, 4H), 8.19 (XX' of AA'XX', J = 6.9 Hz, 4H), 7.97 (s, 4H), 7.40 (AA' of AA'BB', J = 8.2 Hz, 4H), 7.31 (BB' of AA'BB', J = 8.2 Hz, 4H), 5.58 (s, 4H), 4.46 (s, 4H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C 155.0, 144.3, 139.9, 136.7, 132.9, 129.8, 129.1, 129.1, 125.6, 63.1, 32.3. S6

3) Cyclobis(4,4 -(1,4-phenylene)bispyridine-p-phenylene)tetrakis(hexafluorphosphate) Extended Viologen Box = ExBox 4PF 6 Scheme S3. Synthesis of ExBox 4PF 6. Pyrene-templated synthesis of ExBox 4PF 6, as well as the non-templated synthesis, are shown. ExBox 4PF 6 : Two synthetic routes were employed (Scheme S3) to prepare the tetracationic cyclophane. The first route consisted of adding DB 2PF 6 (312 mg, 0.350 mmol) and ExBIPY (81.3 mg, 0.350 mmol) to dry MeCN (200 ml) and stirring at room temperature. After 17 d, the reaction was stopped by adding concentrated HCl (2 3 ml), which caused the crude product to precipitate from solution. The precipitate was collected by filtration, dissolved in H 2 O, and precipitated again by adding NH 4 PF 6 (~100 200 mg). The solid material was collected by filtration and then subjected to column chromatography using silica gel and 1% NH 4 PF 6 in MeCN (w/v) as the eluent. The final product was purified further through recrystallization in MeCN on slow vapor diffusion of ipro 2, yielding pure ExBox 4PF 6 (83 mg, 19%) as a white solid. The second synthetic route consisted of adding DB 2PF 6 (312 mg, 0.350 mmol), ExBIPY (81.3 mg, 0.350 mmol), and the template Pyrene (212 mg, 1.05 mmol) to dry MeCN (200 ml) and stirring at room temperature. After 17 d, the reaction was stopped by adding concentrated HCl (2 3 ml), causing the crude product to precipitate from solution. The yellowish orange S7

precipitate was collected by filtration and then dissolved in H 2 O, followed by extracting five times with CH 2 Cl 2 (200 ml per extraction). This solvent extraction step caused the color of the solution to change from yellowish orange to white, indicating that most, if not all, of the template had been removed. The extracted material was precipitated from solution by adding NH 4 PF 6 (~100 200 mg) before being subjected to column chromatography using silica gel and CH 2 Cl 2 /MeCN (1:1) and 1% NH 4 PF 6 in MeCN (w/v) as the eluents, followed by recrystallization as in the case of non-templated reaction, to yield the pure product (184 mg, 42%) as a white solid. (HRMS-ESI) For ExBox 4PF 6, Calcd for C 48 H 40 F 24 N 4 P 4 : m/z = 1107.2173 [M PF 6 ] +, 481.1263 [M 2PF 6 ] 2+ ; found: 1107.2184 [M PF 6 ] +, 481.1278 [M 2PF 6 ] 2+. 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.78 (AA' of AA'XX', J = 7.0 Hz, 8H), 8.18 (XX' of AA'XX', J = 6.9 Hz, 8H), 7.93 (s, 8H), 7.61 (s, 8H), 5.68 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C 155.5, 145.1, 137.4, 137.1, 131.1, 130.2, 126.7, 64.8. 1 H NMR (500 MHz, CD 3 COCD 3, ppm): δ H 9.28 (AA' of AA'XX', J = 7.1 Hz, 8H), 8.51 (XX' of AA'XX', J = 7.1 Hz, 8H), 8.15 (s, 8H), 7.86 (s, 8H), 6.08 (s, 8H). 13 C NMR (125 MHz, CD 3 COCD 3, ppm): δ C 155.2, 145.5, 137.4, 137.3, 131.3, 130.2, 126.6, 64.7. 4) Cyclobis(4,4 -(1,4-phenylene)bispyridine-p-phenylene)tetrachloride Extended Viologen Box = ExBox 4Cl ExBox 4Cl: For the purposes of PAHs extraction from crude oil, ExBox 4PF 6 (50 mg, 0.040 mmol) was converted to the water-soluble chloride salt by dissolving it in MeCN (50 ml) and adding tetrabutylammonium chloride (~50 mg) to precipitate ExBox 4Cl from solution. The precipitate was collected by filtration, washed with MeCN (100 200 ml), and dried in vacuum to afford pure ExBox 4Cl (32 mg, 98%) as a white solid. 1 H NMR (500 MHz, D 2 O, ppm): δ H 8.91 (AA' of AA'XX', J = 6.4 Hz, 8H), 8.15 (XX' of AA'XX', J = 6.3 Hz, 8H), 7.84 (s, 8H), 7.63 (s, 8H), 5.76 (s, 8H). 13 C NMR (125 MHz, D 2 O, ppm): δ C 155.1, 143.7, 136.5, 136.0, 129.9, 128.8, 125.7, 63.8. 5) [4]Helicene [4]Helicene. [4]Helicene was prepared (Scheme S4) in four steps starting from benzo- phenone as previously described (Step 1, S2 Step 2, S2 Step 3, S3 Step 4, S3 and the preparation of [Ru(HB(pz) 3 )(PPh 3 )(MeCN) 2 ]PF 6 S3,S4 ) by using the following modifications to the original procedures: (1) The reaction conditions (PhMe, reflux, 24 h) were applied instead of the S8

Scheme S4. Modified synthesis of [4]Helicene. reported reaction conditions (C 6 H 6, 145 C, 64 h S2 ) in Step 1. Product 12 was obtained in 64% yield as opposed to the originally reported yield of 79%. (2) The reaction conditions (TMSA (3 equiv), Pd(PPh 3 ) 4 (5%), CuI (10%), ipr 2 NH, 75 C, 52 h) were applied instead of the reported reaction conditions (TMSA (4.5 equiv), PdCl 2 (PPh 3 ) 2 (6%), CuI (11%), Et 3 N, 95 C, 65 h S2 ) in Step 2. Product 13 was obtained in the same yield (94%) as the reported one. (3) Product 14 was obtained as a pale yellow solid in 99% yield as opposed to the literature (colorless oil, 94% yield S3 ) following the described reaction conditions in Step 3. (4) The reaction conditions ([Ru(HB(pz) 3 )(PPh 3 )(MeCN) 2 ]PF 6 (3.4%), 48 h) were applied instead of the reported reaction conditions ([Ru(HB(pz) 3 )(PPh 3 )(MeCN) 2 ]PF 6 (10%), 24 h S3 ) in Step 4. [4]Helicene was obtained in 40% yield as opposed to the originally reported yield of 81%. The NMR data for compounds 12 14 are in agreement with those reported previously. S2,S3,S4 S9

Section C. Crystallographic Characterization All crystallographic data are available free of charge from the Cambridge Crystallographic Data Centre (CCDC) via www.ccdc.cam.ac.uk/data_request/cif. 1) ExBox 4PF 6 a) Methods. ExBox 4PF 6 (3.0 mg, 2.4 µmol) was dissolved in MeCN (0.8 ml) and the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the solution of ExBox 4PF 6 in MeCN (3.0 mm) over the course of one week yielded colorless single crystals of ExBox 4PF 6 (Figure S1). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a CuK α microsource with Quazar optics. Figure S1. Different crystallographic views of ExBox 4PF 6. Counterions and solvent molecules are omitted for the sake of clarity. b) Crystal Parameters. [C 48 H 40 N 4 (PF 6 ) 4 ] (MeCN) 3. Colorless block (0.13 0.12 0.11 mm). Monoclinic, C2/c, a = 21.920(6), b = 16.300(5), c = 36.904(11) Å, α = 90.000, β = 98.513(2), γ = S10

90.000º, V = 13040.3(7) Å 3, Z = 8, T = 100(2) K, ρ calc = 1.402 g cm 3, μ = 2.059 mm 1. Of a total of 52258 reflections which were collected, 10885 were unique (R int = 0.0477). Final R 1 (F 2 > 2σF 2 ) = 0.0825 and wr 2 = 0.2283. The structure was solved by direct methods and expanded using Fourier techniques. S5 Disordered PF 6 molecules were refined with similarity restraints on P F and F F distances to keep geometries reasonable, as well as with rigid bond and similarity restraints to keep displacement parameters reasonable. CCDC Number: 893549. 2) ExBox Azulene 4PF 6 (Azulene) a) Methods. Solid Azulene (0.34 mg, 2.7 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 0.8 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Azulene and ExBox 4PF 6 in MeCN over the period of 3 d yielded gold single crystals of ExBox Azulene 4PF 6 (Azulene) (Figure S2). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a CuK α microsource with MX optics. b) Crystal Parameters. [C 48 H 40 N 4 C 10 H 8 (PF 6 ) 4 ] (C 10 H 8 ) (MeCN) 3. Gold block (0.33 0.24 0.14 mm). Triclinic, P 1, a = 10.090(3), b = 11.382(3), c = 18.082(5) Å, α = 71.694(10), β = 79.448(10), γ = 65.810(10)º, V = 1794.77(9) Å 3, Z = 1, T = 100(2) K, ρ calc = 1.510 g cm 3, μ = 1.971 mm 1. Of a total of 43173 reflections which were collected, 6433 were unique (R int = 0.0233). Final R 1 (F 2 > 2σF 2 ) = 0.0543 and wr 2 = 0.1456. The structure was solved by direct methods and expanded using Fourier techniques. S5 The two Azulene molecules were disordered over symmetry positions and refined with PART 1 commands. The 1,2 C C distances were refined with similarity restraints (SADI) as well as the 1,3 distances for the seven-membered ring carbons only. Each Azulene was subjected to a flat restraint and displacement parameters for the carbon atoms were subjected to rigid bond (DELU) and similarity (SIMU) restraints. The disordered PF 6 anions were refined with SADI restraints to regularize the environment around each P atom, and with rigid bond and similarity restraints on all atoms. The N C, N Me, and C C bond distances on the MeCN molecules were refined with similarity restraints (SADI). All atoms of the disordered MeCN molecule were refined with global anisotropic displacement parameters. CCDC Number: 893550. S11

Figure S2. Different crystallographic views of ExBox Azulene 4PF 6 (Azulene). Counterions and solvent molecules are omitted for the sake of clarity. 3) ExBox Anthracene 4PF 6 (Anthracene) a) Methods. Solid Anthracene (0.52 mg, 2.9 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 0.9 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Anthracene and ExBox 4PF 6 in MeCN over the period of 2 d yielded red single crystals of ExBox Anthracene 4PF 6 (Anthracene) (Figure S3). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a CuK α microsource with MX optics. b) Crystal Parameters. [C 48 H 40 N 4 C 14 H 10 (PF 6 ) 4 ] (C 14 H 10 ) (MeCN) 2. Red block (0.11 0.05 0.05 mm). Monoclinic, P2/c, a = 11.174(3), b = 18.965(5), c = 33.876(8) Å, α = 90.000, β = 90.818(10), γ = 90.000º, V = 7177.8(3) Å 3, Z = 4, T = 100(2) K, ρ calc = 1.565 g cm 3, μ = 1.992 mm 1. Of a total of 64930 reflections which were collected, 12907 were unique (R int = 0.0427). S12

Figure S3. Different crystallographic views of ExBox Anthracene 4PF 6 (Anthracene). Counterions and solvent molecules are omitted for the sake of clarity. Final R 1 (F 2 > 2σF 2 ) = 0.0383 and wr 2 = 0.0954. The structure was solved by direct methods and expanded using Fourier techniques. S5 CCDC Number: 893551. 4) ExBox Phenanthrene 4PF 6 (Phenanthrene) a) Methods. Solid Phenanthrene (0.52 mg, 2.9 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 0.9 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Phenanthrene and ExBox 4PF 6 in MeCN over the period of 2 d yielded yellow single crystals of ExBox Phenanthrene 4PF 6 (Phenanthrene) (Figure S4). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a CuK α microsource with Quazar optics. S13

Figure S4. Different crystallographic views of ExBox Phenanthrene 4PF 6 (Phenanthrene). Counterions and solvent molecules are omitted for the sake of clarity. b) Crystal Parameters. [C 48 H 40 N 4 C 14 H 10 (PF 6 ) 4 ] (C 14 H 10 ) (MeCN) 2. Yellow block (0.37 0.12 0.09 mm). Monoclinic, C2/c, a = 11.247(7), b = 19.121(13), c = 33.700(2) Å, α = 90.000, β = 90.897(14), γ = 90.000º, V = 7246(8) Å 3, Z = 4, T = 100(2) K, ρ calc = 1.550 g cm 3, μ = 1.973 mm 1. Of a total of 16633 reflections which were collected, 5949 were unique (R int = 0.0227). Final R 1 (F 2 > 2σF 2 ) = 0.0503 and wr 2 = 0.1328. The structure was solved by direct methods and expanded using Fourier techniques. S5 A group anisotropic displacement parameter was refined for the disordered Phenanthrene. Distances were also restrained for the disordered Phenanthrene. CCDC Number: 893552. 5) ExBox Pyrene 4PF 6 (Pyrene) a) Methods. Solid Pyrene (0.67 mg, 3.3 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 1 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 S14

ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Pyrene and ExBox 4PF 6 in MeCN over the period of 3 d yielded orange single crystals of ExBox Pyrene 4PF 6 (Pyrene) (Figure S5). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a CuK α microsource with Quazar optics. Figure S5. Different crystallographic views of ExBox Pyrene 4PF 6 (Pyrene). Counterions and solvent molecules are omitted for the sake of clarity. b) Crystal Parameters. [C 48 H 40 N 4 C 16 H 10 (PF 6 ) 4 ] (C 16 H 10 ) (MeCN) 2. Orange block (0.30 0.14 0.14 mm). Triclinic, P 1, a = 9.926(3), b = 10.725(4), c = 18.056(6) Å, α = 97.803(10), β = 91.899(10), γ = 103.705(10)º, V = 1845.73(11) Å 3, Z = 1, T = 100(2) K, ρ calc = 1.565 g cm 3, μ = 1.956 mm 1. Of a total of 28734 reflections which were collected, 6520 were unique (R int = 0.0331). Final R 1 (F 2 > 2σF 2 ) = 0.025 and wr 2 = 0.0895. The structure was solved by direct methods and expanded using Fourier techniques. S5 CCDC Number: 893553. 6) ExBox Tetracene 4PF 6 a) Methods. A mixture of Tetracene (0.30 mg, 1.3 µmol), ExBox 4PF 6 (1.5 mg, 1.2 µmol), MeCN (0.8 ml), and PhMe (0.8 ml) was heated at 100 ºC for 30 min before an additional S15

portion of MeCN (0.8 ml) was added. The resulting solution was then allowed to slowly cool to room temperature and was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~1.5 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Tetracene and ExBox 4PF 6 in MeCN/PhMe over the period of 3 d yielded red single crystals of ExBox Tetracene 4PF 6 (Figure S6). Data were collected at 100 K on a Bruker Kappa APEX2 CCD Diffractometer equipped with a CuK α microsource with Quazar optics. Note the chemical formula in the Crystal Parameters section below reflects that only half of the total number of ExBox 4PF 6 cyclophanes in the crystal are occupied with Tetracene molecules. Figure S6. Different crystallographic views of ExBox Tetracene 4PF 6. Only half of the total number of ExBox 4PF 6 cyclophanes in the crystal are occupied with Tetracene molecules. Counterions and solvent molecules are omitted for the sake of clarity. b) Crystal Parameters. [C 48 H 40 N 4 (C 18 H 12 ) 0.5 (PF 6 ) 4 ] (C 7 H 8 ) 2 (MeCN) 2. Red block (0.47 0.16 0.07 mm). Triclinic, P 1, a = 10.140(3), b = 11.252(3), c = 17.944(5) Å, α = 72.280(17), β = 86.535(17), γ = 65.818(15)º, V = 1774.21(9) Å 3, Z = 1, T = 105.4(2) K, ρ calc = 1.529 g cm 3, μ = S16

1.989 mm 1. Of a total of 9607 reflections which were collected, 5636 were unique (R int = 0.0180). Final R 1 (F 2 > 2σF 2 ) = 0.0647 and wr 2 = 0.1766. The structure was solved by direct methods and expanded using Fourier techniques. S5 Rigid bond restraints were imposed on the displacement parameters as well as restraints on similar amplitudes separated by less than 1.7 Å on the disordered PhMe and PF 6 molecules. Distance restraints were refined for the disordered PF 6 molecules and an idealized six-membered ring was constrained for the disordered PhMe molecule. CCDC Number: 893554. 7) ExBox Tetraphene 4PF 6 a) Methods. Solid Tetraphene (0.60 mg, 2.6 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 0.8 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O Figure S7. Different crystallographic views of ExBox Tetraphene 4PF 6. Only half of the total number of ExBox 4PF 6 cyclophanes in the crystal are occupied with Tetraphene molecules. Counterions and solvent molecules are omitted for the sake of clarity. S17

(~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Tetraphene and ExBox 4PF 6 in MeCN over the period of 2 d yielded orange single crystals of ExBox Tetraphene 4PF 6 (Figure S7). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a CuK α microsource with Quazar optics. Note the chemical formula in the Crystal Parameters section below reflects that only half of the total number of ExBox 4PF 6 cyclophanes in the crystal are occupied with Tetraphene molecules. b) Crystal Parameters. [C 48 H 40 N 4 (C 18 H 12 ) 0.5 (PF 6 ) 4 ] (MeCN) 3. Orange block (0.76 0.22 0.12 mm). Triclinic, P 1, a = 10.143(4), b = 11.110(4), c = 17.953(7) Å, α = 74.054(2), β = 84.440(2), γ = 64.486(2)º, V = 1754.90(12) Å 3, Z = 1, T = 100(2) K, ρ calc = 1.410 g cm 3, μ = 1.959 mm 1. Of a total of 19182 reflections which were collected, 5682 were unique (R int = 0.0407). Final R 1 (F 2 > 2σF 2 ) = 0.1085 and wr 2 = 0.3481. The structure was solved by direct methods and expanded using Fourier techniques. S5 Rigid bond restraints (esd 0.01) were imposed on the displacement parameters as well as restraints on similar amplitudes (esd 0.05) separated by less than 1.7 Å on the disordered fluorine atoms. A group anisotropic displacement parameter was refined for the disordered Tetraphene molecule. CCDC Number: 893555. 8) ExBox Chrysene 4PF 6 a) Methods. Solid Chrysene (0.60 mg, 2.6 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 0.8 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Chrysene and ExBox 4PF 6 in MeCN over the period of 3 d yielded orange single crystals of ExBox Chrysene 4PF 6 (Figure S8). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a MoK α sealed tube with graphite. b) Crystal Parameters. [C 48 H 40 N 4 (C 18 H 12 ) (PF 6 ) 4 ] (MeCN) 6. Orange block (0.58 0.33 0.17 mm). Monoclinic, P21/n, a = 11.017(5), b = 14.579(7), c = 24.259(7) Å, α = 90.000, β = 98.998(2), γ = 90.000º, V = 3848.5(3) Å 3, Z = 2, T = 100(2) K, ρ calc = 1.491 g cm 3, μ = 0.209 mm 1. Of a total of 83941 reflections which were collected, 11236 were unique (R int = 0.1244). Final R 1 (F 2 > 2σF 2 ) = 0.0825 and wr 2 = 0.1886. The structure was solved by direct methods and expanded using Fourier techniques. S5 CCDC Number: 893556. S18

Figure S8. Different crystallographic views of ExBox Chrysene 4PF 6. Counterions and solvent molecules are omitted for the sake of clarity. 9) ExBox [4]Helicene 4PF 6 a) Methods. Solid [4]Helicene (0.60 mg, 2.6 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 0.8 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of [4]Helicene and ExBox 4PF 6 in MeCN over the period of 3 d yielded yellow single crystals of ExBox [4]Helicene 4PF 6 (Figure S9). Data were collected at 100 K on a Bruker Kappa APEX2 CCD Diffractometer equipped with a CuK α microsource with Quazar optics. b) Crystal Parameters. [C 48 H 40 N 4 (C 18 H 12 ) (PF 6 ) 4 ] (MeCN) 2. Yellow block (0.11 0.08 0.02 mm). Triclinic, P 1, a = 10.561(6), b = 11.101(6), c = 18.025(11) Å, α = 72.955, β = 82.376(2), γ = 63.569º, V = 1809.2(18) Å 3, Z = 1, T = 220(2) K, ρ calc = 1.417 g cm 3, μ = 1.918 mm 1. Of a total of 9232 reflections which were collected, 5453 were unique (R int = 0.0343). S19

Figure S9. Different crystallographic views of ExBox Helicene 4PF 6. Counterions and solvent molecules are omitted for the sake of clarity. Final R 1 (F 2 > 2σF 2 ) = 0.1247 and wr 2 = 0.3582. The structure was solved by direct methods and expanded using Fourier techniques. S5 Rigid bond restraints (esd 0.01) were imposed on the displacement parameters as well as restraints on similar amplitudes (esd 0.05) separated by less than 1.7 Å on the disordered fluorine and [4]Helicene atoms. Distance restraints were imposed on the [4]Helicene molecule. CCDC Number: 893557. 10) ExBox Triphenylene 4PF 6 a) Methods. Solid Triphenylene (0.60 mg, 2.6 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 0.8 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Triphenylene and ExBox 4PF 6 in MeCN over the period of 3 d yielded yellow single crystals of S20

ExBox Triphenylene 4PF 6 (Figure S10). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a MoK α sealed tube with graphite. Figure S10. Different crystallographic views of ExBox Triphenylene 4PF 6. Counterions and solvent molecules are omitted for the sake of clarity. b) Crystal Parameters. [C 48 H 40 N 4 (C 18 H 12 ) (PF 6 ) 4 ] (MeCN) 3. Yellow block (0.35 0.21 0.04 mm). Triclinic, P 1, a = 10.019(12), b = 10.770(13), c = 18.071(2) Å, α = 73.537(6), β = 74.926(6), γ = 70.374(4)º, V = 1731.9(4) Å 3, Z = 1, T = 100(2) K, ρ calc = 1.538 g cm 3, μ = 0.224 mm 1. Of a total of 20831 reflections which were collected, 7170 were unique (R int = 0.1272). Final R 1 (F 2 > 2σF 2 ) = 0.0991 and wr 2 = 0.2832. The structure was solved by direct methods and expanded using Fourier techniques. S5 Rigid bond restraints (esd 0.01) were imposed on the displacement parameters as well as restraints on similar amplitudes separated by less than 1.7 Å on the disordered fluorine (esd 0.02), Triphenylene, and MeCN (esd 0.01) molecules. Similar distance restraints were also restrained for the disordered PF 6, Triphenylene, and MeCN molecules. CCDC Number: 893558. S21

11) ExBox Perylene 4PF 6 a) Methods. Solid Perylene (0.74 mg, 2.9 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 0.9 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Perylene and ExBox 4PF 6 in MeCN over the period of 2 d yielded red single crystals of ExBox Perylene 4PF 6 (Figure S11). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a CuK α microsource with Quazar optics. Figure S11. Different crystallographic views of ExBox Perylene 4PF 6. Counterions and solvent molecules are omitted for the sake of clarity. b) Crystal Parameters. [C 48 H 40 N 4 (C 20 H 12 ) (PF 6 ) 4 ] (MeCN) 7. Red block (0.59 0.44 0.33 mm). Monoclinic, P21/c, a = 20.957(5), b = 17.985(5), c = 22.883(6) Å, α = 90.000, β = 107.919(10), γ = 90.000º, V = 8206.5(4) Å 3, Z = 4, T = 100(2) K, ρ calc = 1.451 g cm 3, μ = 1.793 mm 1. Of a total of 53076 reflections which were collected, 13781 were unique (R int = 0.0224). S22

Final R 1 (F 2 > 2σF 2 ) = 0.0645 and wr 2 = 0.1675. The structure was solved by direct methods and expanded using Fourier techniques. S5 Rigid bond restraints (esd 0.01) were imposed on the displacement parameters as well as restraints on similar amplitudes (esd 0.05) separated by less than 1.7 Å on the disordered fluorine and carbon atoms. CCDC Number: 893559. 12) ExBox Coronene 4PF 6 a) Methods. Solid Coronene (0.88 mg, 2.9 µmol) was added to a solution of ExBox 4PF 6 in MeCN (3.0 mm, 0.9 ml) and, after it dissolved, the mixture was passed through a 0.45 μm filter equally into three 1 ml tubes. The tubes were placed together in one 20 ml vial containing ipr 2 O (~3 ml) and the vial was capped. Slow vapor diffusion of ipr 2 O into the 1.1:1 solution of Coronene and ExBox 4PF 6 in MeCN over the period of 2 d yielded orange single crystals of ExBox Coronene 4PF 6 (Fig. S12). Data were collected at 100 K on a Bruker Kappa APEX CCD Diffractometer equipped with a MoK α microsource with Quazar optics. Figure S12. Different crystallographic views of ExBox Coronene 4PF 6. Counterions and solvent molecules are omitted for the sake of clarity. S23

b) Crystal Parameters. [C 48 H 40 N 4 (C 24 H 12 ) (PF 6 ) 4 ] (MeCN) 7. Orange block (0.46 0.30 0.09 mm). Triclinic, P 1, a = 10.573(6), b = 14.317(7), c = 14.733(8) Å, α = 102.508(3), β = 93.376(3), γ = 109.336(3)º, V = 2033.67(19) Å 3, Z = 1, T = 100(2) K, ρ calc = 1.503 g cm 3, μ = 0.203 mm 1. Of a total of 23957 reflections which were collected, 11913 were unique (R int = 0.0662). Final R 1 (F 2 > 2σF 2 ) = 0.0459 and wr 2 = 0.0832. The structure was solved by direct methods and expanded using Fourier techniques. S5 Rigid bond restraints (esd 0.01) were imposed on the displacement parameters as well as restraints on similar amplitudes (esd 0.05) separated by less than 1.7 Å on the disordered fluorine atoms and MeCN molecules. CCDC Number: 893560. Section D. Spectroscopic and Spectrometric Characterizations 1) ExBox 4PF 6 and Its Complexes a) UV/Vis Absorption Spectra Optical absorption spectra (all at 0.5 mm, 298 K; Figure S13) were obtained for (i) the PAH guests (in MeCN or CHCl 3 /MeCN (1:1) depending on solubility), (ii) ExBox 4+ (in MeCN), and (iii) the corresponding 1:1 complexes (in MeCN), with the exception of Tetracene because of issues with solubility (heating to 100 ºC is required to solubilize Tetracene in PhMe). Heating the 1:1 mixture of host and guest would, however, inevitably lead to a much lower binding affinity. The data reflects the emergence of a new charge-transfer band ranging from 350 to 600 nm for all of the 1:1 complexes studied, except for Azulene, which showed no noticeable shifting of the bands when the host and guest were combined. b) 1 H NMR / 13 C NMR Spectroscopic Analysis 1 H NMR (298 K, 500 MHz) titrations were performed by adding small volumes of a concentrated guest solution/suspension in CDCl 3 to a solution of ExBox 4+ in CD 3 CN. Tetramethylsilane (TMS) was used as a reference. Significant upfield shifts of the 1 H resonances for γ protons were observed and used to determine the association constants (K a ). The K a values were calculated using Dynafit, S6 a program which employs nonlinear least-squares regression on ligand receptor binding data. In the case of 10 and 11, the low solubility of Perylene and Coronene prohibited the calculation of reliable K a values. The estimated K a value for 10 is reported, however, the error is substantial (76%). S24

Figure S13a f. UV/Vis Absorption spectra of PAH guests (black), ExBox 4+ (green), and the corresponding 1:1 complexes (red) all at 0.5 mm in MeCN at 298 K. Note: The individual guest spectra (black) were obtained in a 1:1 mixture of CHCl 3 and MeCN. S25

Figure S13i j. UV/Vis Absorption spectra of PAH guests (black), ExBox 4+ (green), and the corresponding 1:1 complexes (red) all at 0.5 mm in MeCN at 298 K. Note: The individual guest spectra (black) were obtained in a 1:1 mixture of CHCl 3 and MeCN. Figure S14. 1 H and 13 C NMR spectra of ExBox 4PF 6. S26

Figure S15. 1 H 1 H COSY and NOESY NMR spectra of ExBox 4PF 6. S27

ExBox 4+ Azulene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.77 (AA' of AA'XX', J = 6.9 Hz, 8H), 8.30 (d, J = 9.3 Hz, 2H), 8.14 (XX' of AA'XX', J = 6.9 Hz, 8H), 7.86 (s, 8H), 7.74 (t, J = 3.8 Hz, 1H), 7.62 (s, 8H), 7.52 (t, J = 9.9 Hz, 1H), 7.29 (d, J = 3.7 Hz, 2H), 7.11 (dd, J = 9.8, 9.7 Hz, 2H), 5.68 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C 155.5, 145.1, 140.9, 138.3, 137.7, 137.4, 137.3, 137.1, 131.1, 130.1, 126.6, 123.7, 118.8, 64.8. Figure S16. 1 H NMR Spectra of Azulene, ExBox 4+, and the 1:1 complex of the two. ExBox 4+ Anthracene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.74 (AA' of AA'XX', J = 6.9 Hz, 8H), 7.89 (XX' of AA'XX', J = 6.9 Hz, 8H), 7.83 (s, 2H), 7.78 (s, 8H), 7.38 (s, 8H), 7.35 (AA' of AA'XX', J = 6.5, 3.3 Hz, 4H), 6.18 (XX' of AA'XX', J = 6.6, 3.2 Hz, 4H), 5.69 (s, 8H). S28

13 C NMR (125 MHz, CD 3 CN, ppm): δ C 154.8, 144.8, 137.7, 136.4, 131.9, 131.4, 129.3, 128.3, 126.7, 126.4, 125.8, 64.8. Figure S17. 1 H NMR Spectra of Anthracene, ExBox 4+, and the 1:1 complex of the two. ExBox 4+ Phenanthrene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.75 (AA' of AA'XX', J = 6.9 Hz, 8H), 7.90 (d, J = 8.3 Hz, 2H), 7.83 (XX' of AA'XX', J = 6.9 Hz, 8H), 7.81 (s, 8H), 7.26 (s, 8H), 7.25 (s, 2H), 6.75 (d, J = 7.8 Hz, 2H), 6.61 (ddd, J = 8.3, 6.9, 1.3 Hz, 2H), 5.83 (dd, J = 7.5, 7.4 Hz, 2H), 5.70 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C 154.7, 144.7, 137.7, 136.1, 132.0, 131.3, 130.4, 129.1, 128.5, 127.2, 126.8, 126.7, 126.3, 123.0, 64.7. S29

Figure S18. 1 H NMR Spectra of Phenanthrene, ExBox 4+, and the 1:1 complex of the two, along with the 1 H 1 H NOESY spectrum for the 1:1 complex. S30

ExBox 4+ Pyrene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.76 (AA' of AA'XX', J = 6.9 Hz, 8H), 7.91 (s, 8H), 7.65 (XX' of AA'XX', J = 6.8 Hz, 8H), 7.46 (s, 4H), 6.78 (d, J = 7.6 Hz, 4H), 6.75 (s, 8H), 5.93 (t, J = 7.6 Hz, 2H), 5.73 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C 154.1, 144.6, 138.0, 135.2, 131.4, 130.9, 128.1, 127.57, 126.1, 126.0, 124.8, 124.3, 64.7. Figure S19. 1 H NMR Spectra of Pyrene, ExBox 4+, and the 1:1 complex of the two. ExBox 4+ Tetraphene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.72 (AA' of AA'XX', J = 6.9 Hz, 8H), 8.41 (s, 1H), 7.99 (d, J = 8.1 Hz, 1H), 7.84 (s, 8H), 7.72 (XX' of AA'XX', J = 6.9 Hz, 8H), 7.53 (d, J = 8.4 Hz, 1H), 7.47 (dd, J = 7.8, 1.4 Hz, 1H), 7.32 (ddd, J = 8.1, 6.6, 1.1 Hz, 1H), 7.22 7.18 (m, 9H), 7.17 (d, J = 7.9 Hz, 1H), 7.10 (d, J = 9.0 Hz, 1H), 7.07 (ddd, J = 8.1, 6.7, 1.2 S31

Hz, 1H), 6.84 (d, J = 9.1 Hz, 1H), 6.81 (d, J = 9.0 Hz, 1H), 6.31 (dd, J = 7.6, 7.5 Hz, 1H), 5.71 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C (1C overlapped) 154.7, 144.8, 137.7, 136.1, 132.19, 132.15, 131.9, 131.5, 130.7, 129.07, 129.06, 128.9, 128.8, 128.1, 127.8, 127.5, 127.5, 127.02, 127.00, 126.99, 126.6, 126.1, 123.5, 122.4, 64.8. Figure S20. 1 H NMR Spectra of Tetraphene, ExBox 4+, and the 1:1 complex of the two, along with the 1 H 1 H NOESY spectrum for the 1:1 complex. S32

ExBox 4+ Chrysene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.71 (AA' of AA'XX', J = 6.7 Hz, 8H), 8.31 (d, J = 8.5 Hz, 2H), 8.01 (d, J = 9.0 Hz, 2H), 7.90 (s, 8H), 7.62 (XX' of AA'XX', J = 6.3 Hz, 8H), 7.52 (ddd, J = 8.3, 6.9, 1.3 Hz, 2H), 7.19 (ddd, J = 7.9, 6.9, 1.0 Hz, 2H), 7.10 (s, 8H), 6.72 (d, J = 9.0 Hz, 2H), 5.86 (d, J = 7.8 Hz, 2H), 5.72 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C 154.4, 144.7, 137.8, 135.8, 131.8, 131.5, 130.8, 128.8, 128.2, 128.1, 128.1, 127.7, 127.6, 127.5, 126.0, 123.9, 121.9, 64.8. Figure S21. 1 H NMR Spectra of Chrysene, ExBox 4+, and the 1:1 complex of the two, along with the 1 H 1 H NOESY spectrum for the 1:1 complex. S33

ExBox 4+ [4]Helicene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.71 (AA' of AA'XX', J = 6.9 Hz, 8H), 8.09 (d, J = 8.5 Hz, 2H), 7.96 (s, 8H), 7.54 (XX' of AA'XX', J = 6.9 Hz, 8H), 7.02 (d, J = 8.5 Hz, 2H), 6.97 (ddd, J = 8.5, 6.9, 1.5 Hz, 2H), 6.93 (s, 8H), 6.47 (d, J = 8.5 Hz, 2H), 6.37 (d, J = 7.9 Hz, 2H), 6.25 (dd, J = 7.4, 7.4 Hz, 2H), 5.72 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C (3C overlapped) 154.0, 144.5, 138.1, 135.5, 133.0, 131.7, 129.9, 128.6, 128.3, 127.80, 127.2, 126.5, 126.5, 126.0, 64.8. Figure S22. 1 H NMR Spectra of [4]Helicene, ExBox 4+, and the 1:1 complex of the two, along with the 1 H 1 H NOESY spectrum for the 1:1 complex. S34

ExBox 4+ Triphenylene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.75 (AA' of AA'XX', J = 6.8 Hz, 8H), 7.93 (s, 8H), 7.63 (XX' of AA'XX', J = 6.8 Hz, 8H), 7.43 (AA' of AA'XX', J = 6.2, 3.4 Hz, 6H), 6.90 (s, 8H), 6.50 (XX' of AA'XX', J = 6.3, 3.2 Hz, 6H), 5.72 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C 154.2, 144.5, 138.1, 135.7, 131.5, 129.4, 128.6, 127.8, 126.1, 123.3, 64.7. Figure S23. 1 H NMR Spectra of Triphenylene, ExBox 4+, and the 1:1 complex of the two. ExBox 4+ Perylene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.68 (AA' of AA'XX', J = 6.8 Hz, 8H), 8.03 (s, 8H), 7.51 (d, J = 7.9 Hz, 4H), 7.49 (XX' of AA'XX', J = 6.9 Hz, 8H), 6.90 (s, 8H), 6.43 (dd, J = 7.7, 7.6 Hz, 4H), 6.05 5.89 (m, 4H), 5.71 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, S35

ppm): δ C 153.5, 144.4, 138.4, 135.4, 133.7, 131.9, 131.1, 128.6, 128.3, 127.8, 127.2, 125.9, 120.5, 64.9. Figure S24. 1 H NMR Spectra of Perylene, ExBox 4+, and the 1:1 complex of the two. ExBox 4+ Coronene: 1 H NMR (500 MHz, CD 3 CN, ppm): δ H 8.74 (AA' of AA'XX', J = 6.9 Hz, 8H), 8.32 (s, 8H), 7.75 (s, 12H), 6.88 (XX' of AA'XX', J = 6.6 Hz, 8H), 5.81 (s, 8H), 5.40 (s, 8H). 13 C NMR (125 MHz, CD 3 CN, ppm): δ C 152.3, 144.3, 138.8, 133.7, 132.3, 128.2, 126.7, 126.47, 125.3, 122.1, 65.0. S36

Figure S25. 1 H NMR Spectra of Coronene, ExBox 4+, and the 1:1 complex of the two. 2) DB 2PF 6 Figure S26. 1 H NMR Spectrum of DB 2PF 6. S37

Figure S27. 13 C NMR Spectrum of DB 2PF 6. 3) Isothermal Titration Calorimetry (ITC) All ITC measurements were performed in dry, degassed MeCN at 298 K. A solution of ExBox 4+ (in MeCN) was used as the host solution in a 1.8 ml cell. Solutions of aromatic guests (in MeCN) were added by successively injecting 10 μl of titrant over 20 s (25 ) with a 300 s interval between each injection. Experiments were repeated three times. Thermodynamic information was calculated using a one-site binding model utilizing data from which the heat of dilution of the guest was subtracted, with the average of three runs reported. S38

a) ExBox 4+ Phenanthrene Figure S28. ITC of ExBox 4+ Phenanthrene. S39

b) ExBox 4+ Pyrene Figure S29. ITC of ExBox 4+ Pyrene. S40

c) ExBox 4+ Tetraphene Figure S30. ITC of ExBox 4+ Tetraphene. S41

d) ExBox 4+ [4]Helicene Figure S31. ITC of ExBox 4+ [4]Helicene. S42

Section D. References (S1) Su, Y.-S.; Chen, C. F. Org. Lett. 2010, 12, 1888 1891. (S2) Donovan, P. M.; Scott, L. T. J. Am. Chem. Soc. 2004, 126, 3108 3112. (S3) Shen, H.-C.; Tang, J.-M.; Chang, H. K.; Yang, C.-W.; Liu, R. S. J. Org. Chem. 2005, 70, 10113 10116. (S4) Chan, W.-C.; Lau, C.-P.; Chen, Y.-Z.; Fang, Y.-Q.; Ng, S.-M. Organometallics 1997, 16, 34 44. (S5) Sheldrick, G. M. SHELXTL Version 6.14; Bruker Analytical X-Ray Instruments, Inc.: Madison, WI, 2003. (S6) Kuzmic, P. Anal. Biochem. 1996, 237, 260 273. S43