Supporting Information. Direct palladium-catalysed C H arylation of BODIPY dyes at the 3- and 3,5-positions

Supporting Information Direct palladium-catalysed C H arylation of BODIPY dyes at the 3- and 3,5-positions Bram Verbelen, Volker Leen, Lina Wang, Noël Boens, Wim Dehaen* Department of Chemistry, KU Leuven, Celestijnenlaan 0f bus 024, 01 Leuven, Belgium. Fax: +32 16 3279; Tel: +32 16 327439; E-mail: wim.dehaen@chem.kuleuven.be Contents Experimental procedures and characterisation data... S2 Optimisation of reaction protocol... S2 General C H arylation procedure... S3 NMR-spectra of new compounds... S9 Spectroscopic data... S24 S1

Experimental procedures and characterisation data Chemicals where purchased from Acros Organics and Sigma Aldrich, and used as received. All reactions were carried out in flame dried glassware, but no special precautions were taken for the exclusion of moisture. Solvents were not dried prior to use, except o-xylene which was dried over molecular sieves. All reactions were carried out under a nitrogen atmosphere. 1 H and 13 C NMR spectra were recorded at room temperature on a Bruker Avance 0 instrument operating at a frequency of 0 MHz for 1 H and 75 MHz for 13 C. In the case of ambiguous assignments, spectra were run on a Bruker 0 or Bruker 0. 1 H NMR spectra in CDCl 3 were referenced to tetramethylsilane (0.00 ppm) as an internal standard. 13 C NMR spectra in CDCl 3 were referenced to the CDCl 3 (77.16 ppm) signal. Mass spectra were recorded on a Hewlett-Packard 5989A mass spectrometer (EI mode and CI mode). Highresolution mass data were obtained with a Kratos MSTC instrument. Melting points were taken on a Reichert Thermovar and are uncorrected. The electronic absorption spectra and absorbances were measured at C on a Perkin- Elmer Lambda UV vis spectrophotometer. Corrected steady-state excitation and emission spectra were recorded on a Spex Fluorolog instrument with temperature-controlled cell holder. Freshly prepared samples in 1 cm quartz cells were used to perform all UV vis absorption and fluorescence measurements. 8-Arylated BODIPY dyes were prepared according to published literature procedures, through a water based dipyrromethane synthesis followed by oxidation and condensation. 1 Optimisation of reaction protocol Table S1 Optimisation of the reaction protocol for the direct C H arylation of 8-(2,6-dichlorophenyl)-BODIPY Entry Reaction condition a,b Yield / % c Catalyst Ligand Additive Base Solvent PhX Temp Time 1 2a 3a 1 Pd(OAc) 2 PPh 3 / K 2 CO 3 toluene PhBr-d5 C 24 h 75 3 0 2 Pd(OAc) 2 PPh 3 / K 2 CO 3 toluene PhBr-d5 C 4 d 73 4 1 3 Pd(OAc) 2 PPh 3 PivOH K 2 CO 3 toluene PhBr-d5 C 24 h 59 15 3 4 Pd(OAc) 2 PPh 3 PivOH K 2 CO 3 toluene PhBr-d5 C 4 d 54 17 4 5 Pd(OAc) 2 P(tBu) 3 HBF 4 PivOH K 2 CO 3 toluene PhBr-d5 C 24 h 94 0 0 6 d Pd(OAc) 2 PCy 3 HBF 4 PivOH K 2 CO 3 toluene PhBr-d5 C 24 h 33 45 19 7 Pd(OAc) 2 DavePhos PivOH K 2 CO 3 toluene PhBr-d5 C 24 h 68 0 0 8 Pd 2 (dba) 3 PCy 3 HBF 4 PivOH K 2 CO 3 toluene PhBr-d5 C 24 h 22 37 21 9 Pd(TFA) 2 PCy 3 HBF 4 PivOH K 2 CO 3 toluene PhBr-d5 C 24 h 92 5 0 Pd(OAc) 2 PCy 3 HBF 4 PivOH Cs 2 CO 3 toluene PhBr-d5 C 24 h 32 19 14 11 Pd(OAc) 2 PCy 3 HBF 4 PivOH Na 2 CO 3 toluene PhBr-d5 C 24.5 h 92 5 1 12 Pd(OAc) 2 PCy 3 HBF 4 PivOH KOAc toluene PhBr-d5 C 24 h 77 17 4 1 V. Leen, M. Van der Auweraer, N. Boens and W. Dehaen, Org. Lett., 11, 13, 14. S2

13 Pd(OAc) 2 PCy 3 HBF 4 / CsOPiv toluene PhBr-d5 C 24 h 69 23 6 14 Pd(OAc) 2 PCy 3 HBF 4 PivOH K 2 CO 3 o-xylene PhBr-d5 C 24 h 28 45 22 15 Pd(OAc) 2 PCy 3 HBF 4 PivOH K 2 CO 3 o-xylene PhBr-d5 144 C 24 h 22 41 26 16 Pd(OAc) 2 PCy 3 HBF 4 PivOH K 2 CO 3 1,4-dioxane PhBr-d5 1 C 24 h 56 9 17 Pd(OAc) 2 PCy 3 HBF 4 PivOH K 2 CO 3 DMF PhBr-d5 C 3.5 h 0 0 18 Pd(OAc) 2 PCy 3 HBF 4 PivOH K 2 CO 3 DMF PhBr-d5 C 24 h 0 0 0 19 Pd(OAc) 2 PCy 3 HBF 4 PivOH K 2 CO 3 toluene PhCl e C 4 d 94 2 0 Pd(OAc) 2 PCy 3 HBF 4 PivOH K 2 CO 3 toluene PhI e C 4 d 4 0 a Experimental condition: 5 mol% catalyst, mol% ligand, mol% additive, 3 eq base, 1.1 eq arylhalide, solvent (0.1 M solution). b R is 2,6-dichlorophenyl. c All yields were determined via NMR-spectroscopy using pentadeuterated phenylhalides to avoid overlapping peaks. d Highest yielding condition. e No deuterated phenylhalide was used. General C H arylation procedure BODIPY 1 (one equivalent) was weighed together with K 2 CO 3 (3 equivalents), Pd(OAc) 2 (5 mol%), PCy 3 HBF 4 ( mol%), pivalic acid ( mol%, IUPAC name 2,2-dimethylpropanoic acid)) and, if a solid, the bromoarene (1.1 equivalents). This was placed in a Schlenk flask with a magnetic stirring bar and dissolved in toluene (or o-xylene) to form a 0.1 M solution. Next, the reaction vessel was thrice evacuated and backfilled with nitrogen. If the bromoarene (1.1 equivalents) was a liquid it was added next, using a syringe. This reaction mixture was heated to C for the indicated time. Upon completion, the reaction mixture was cooled to room temperature. Subsequently, the solution was poured in diethyl ether ( ml), washed three times with water ( ml), dried over MgSO 4, filtered, and evaporated to dryness. The crude product was purified chromatographically. 3-Phenyl-8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 2a The compound was prepared following the general procedure using mmol 8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene in o-xylene for 24 h. Bromobenzene was the bromoarene used. The crude product was purified via column chromatography (silica; petroleum ether/ch 2 Cl 2 ; 2:1 v/v) providing the desired product 2a in 44% (73 mg) and the diarylated product 3a in 17% (34 mg) yield. 2a: Red crystals with a green lustre; Mp 278 C; 1 H-NMR (CDCl 3, 0 MHz): δ 6-7.95 (m, 2H), 7.85 (s, 1H), 7.56-7.39 (m, 6H), 6.75 (d, 1H, J = 3.96 Hz), 6.68 (d, 1H, J = 3.96 Hz), 6.62 (d, 1H, J = 3.00 Hz), 9 (s, 1H) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ 161.8, 143.4, 13, 13, 131.8, 131.3, 131.1,.5, 129.8, 129.7, 129.6, 129.5, 128.5, 12, 128.1, 121.8, 118.6 ppm; MS (EI): 412; HRMS: Calculated for C 21 H 13 BCl 2 F 2 N 2 : 415169, found 415171. 3a: Purple crystals with a copper lustre; Mp C; 1 H-NMR (CDCl 3, 0 MHz): δ 7.96-7.86 (m, 4H), 7.54-7.37 (m, 9H), 6.66 (d, 2H, J = 4.14 Hz), 6.61 (d, 2H, J = 4.14 Hz) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ 159.9, 135.8, 132.5, 132.2, 13, 129.9, 129.7, 129.7, 129.6, S3

129.2, 12, 128.3, 12 ppm; MS (EI): 488; HRMS: Calculated for C 27 H 17 BCl 2 F 2 N 2 : 488299, found 488194. 3-p-Anisyl-8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 2b The compound was prepared following the general procedure using mmol 8-(2,6-dichloropheny)l-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene in toluene for 43 h. 4-Bromoanisole was the bromoarene used. The crude product was purified via column chromatography (silica; petroleum ether/diethyl ether; 2:1 v/v) providing the desired product 2b in 42% (74 mg) and the diarylated product 3b in % (21 mg) yield. 2b: Dark red crystals with a copper lustre; Mp C; 1 H-NMR (CDCl 3, 0 MHz): δ 4 (d, 2H, J = 5 Hz), 7. (s, 1H), 7.52-7.37 (m, 3H), 7.02 (d, 2H, J = 5 Hz), 6.76-6.69 (m, 2H), 6.56 (s, 1H), 6 (s, 1H), 3.89 (s, 3H) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ 162.1, 161.8, 141.9, 137.5, 135.7, 13, 131.8, 131.7, 131.7, 131.4, 13, 128.3, 12, 124.2, 121.9, 11, 114.2, 55.5 ppm; MS (EI): 442; HRMS: Calculated for C 22 H 15 BCl 2 F 2 N 2 O: 446226, found 446248. 3b: Purple crystals with a green lustre; Mp 63 C; 1 H-NMR (CDCl 3, 0 MHz): δ 7.93 (d, 4H, J = 5 Hz), 7.52-7.38 (m, 3H), 6.97 (d, 4H, J = 5 Hz), 6. (s, 4H), 3.86 (s, 6H) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ.9, 159.1, 135.8, 132.2, 131.3, 131.3, 13,.9, 128.5, 128.2, 125.0,.9, 113.8, 55.3 ppm; MS (EI): 548; HRMS: Calculated for C 29 H 21 BCl 2 F 2 N 2 O 2 : 548.412, found 548.536. 3-Thien-3-yl-8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 2d The compound was prepared following the general procedure using 0.1 mmol 8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene in toluene for 27 h. 3-Bromothiophene was the bromoarene used. The crude product was purified via column chromatography (silica; petroleum ether/ch 2 Cl 2 ; 2:1 v/v) providing the desired product 2d in 55% (23 mg) and the diarylated product 3d in % (5 mg) yield. 2d: Dark purple crystals with a green lustre; Mp 214 C; 1 H-NMR (CDCl 3, 0 MHz): δ 4 (d, 1H, J = 1.53 Hz), 7.84 (s, 1H), 7.72 (d, 1H, J = 4.71 Hz), 7.53-7.35 (m, 4H), 0 (d, 1H, J = 4.32 Hz), 6.72 (d, 1H, J = 4.32 Hz), 6.58 (d, 1H, J = 3.39 Hz), 9 (s, 1H) ppm; 13 C- NMR (CDCl 3, 75 MHz): δ 155.7, 14, 13, 13, 13, 132.1, 131.9, 131.3, 13, S4

.6,.5, 128.9, 12, 127.1, 125.9, 121.8, 118.3 ppm; MS (EI): 418; HRMS: Calculated for C 19 H 11 BCl 2 F 2 N 2 S: 4811, found 4869. 3d: Blue solid; Mp 5 C; 1 H-NMR (CDCl 3, 0 MHz): δ 8.37 (s, 2H), 9 (d, 2H, J = 4.71 Hz), 7.52-7.33 (m, 5H), 6.75 (d, 2H, J = 3.78 Hz), 6.59 (d, 2H, J = 3.78 Hz) ppm; 13 C- NMR (CDCl 3, 75 MHz): δ 15, 13, 135.9, 132.7, 131.1, 129.3, 129.2, 129.0, 129.0, 128.6, 128.3, 12, 121.1 ppm; MS (EI): 0; HRMS: Calculated for C 23 H 13 BCl 2 F 2 N 2 S 2 : 499.99583, found 499.99666. 3-Mesityl-8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 2e The compound was prepared following the general procedure using 0.1 mmol 8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene in toluene for 43 h. 2-Bromo-1,3,5-trimethylbenzene was the bromoarene used. The crude product was purified via column chromatography (silica; petroleum ether/ch 2 Cl 2 ; 1:1 v/v) providing the desired product 2e in 35% (16 mg) yield. Orange solid with a green lustre; Mp 152 C; 1 H-NMR (CDCl 3, 0 MHz): δ 7.72 (s, 1H), 7.55-7.39 (m, 3H), 6.96 (s, 2H), 6.79 (d, 1H, J = 4.14 Hz), 6.62 (d, 1H, J = 4.14 Hz), 4 (d, 1H, J = 3.75 Hz), 6.37 (d, 1H, J = 4.14 Hz), 2.34 (s, 3H), 2.17 (s, 6H) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ 162.3, 14, 139.2, 139.1, 137.4, 135.7, 135.5, 131.8, 131.3, 131.1, 13, 129.1, 129.0, 12, 127.8, 121.7, 11, 21.4,.1 ppm; MS (EI): 454 (M), 434 (M-HF); HRMS: Calculated for C 24 H 19 BCl 2 F 2 N 2 : 459864, found 459852. 3-(1-Naphthyl)-8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 2f The compound was prepared following the general procedure using mmol 8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene in o-xylene for 24 h. 1-Bromonaphthalene was the bromoarene used. The crude product was purified via column chromatography (silica; petroleum ether/ch 2 Cl 2 ; 2:1 v/v) providing the diarylated product 3f in 16% (37 mg) yield and impure 2f. Analytically pure 2f was obtained through HPLC purification (silica; toluene/ch 2 Cl 2 ; 2:1 v/v), providing the desired product 2f in % (37 mg) yield. 2f: Red crystals with a green lustre; Mp 282 C; 1 H-NMR (CDCl 3, 0 MHz): δ 3-7.95 (m, 2H), 7.94-7.84 (m, 2H), 7.77 (s, 1H), 2 (t, 1H, J = 7.73 Hz), 7.55-7.43 (m, 5H), 3 (d, 1H, J = 4.14 Hz), 6.65 (m, 2H), 6 (d, 1H, J = 3.03 Hz) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ.1, 14, 139.3, 136.1, 13, 134.2, 13, 131.9, 131.8, 131.3,.3,.0, S5

129.8, 128.6, 12, 126.7, 126.2, 126.1, 125.0, 123.4, 11 ppm; MS (EI): 462; HRMS: Calculated for C 25 H 15 BCl 2 F 2 N 2 : 466734, found 466839. 3f: Purple solid with a copper lustre; Mp: decomposition at 3 C; 1 H-NMR (CDCl 3, 0 MHz): δ 7.91-7.77 (m, 8H), 0-7.54 (m, 2H), 7.52-7.37 (m, 7H), 6.79 (d, 2H, J = 1 Hz), 6.59 (d, 2H, J = 3.39 Hz) ppm; 13 C-NMR: product is too insoluble to obtain a fully resolved spectrum; MS (EI): 588; HRMS: Calculated for C 35 H 21 BCl 2 F 2 N 2 : 588.11429, found 588.11553. 3,8-Diphenyl-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 2i The compound was prepared following the general procedure using 0.2 mmol 8-phenyl-4,4- difluoro-4-bora-3a,4a-diaza-s-indacene in o-xylene for 28 h. Bromobenzene was the bromoarene used. The crude product was purified via column chromatography (silica; petroleum ether/ch 2 Cl 2 ; 2:1 v/v) providing the desired product 2i in 31% (21 mg) and the diarylated product 3i in 32% (27 mg) yield. 2i: Red solid with a green lustre; Mp 58 C; 1 H-NMR (CDCl 3, 0 MHz): δ 0-7.92 (m, 2H), 7.85 (s, 1H), 3-7.45 (m, 8H), 6.99 (d, 1H, J = 4.17 Hz), 6 (d, 1H, J = 0 Hz), 6.69 (d, 1H, J = 4.35 Hz), 6.52 (d, 1H, J = 6 Hz) ppm; 13 C-NMR (CDCl 3, MHz): δ.6, 145.8, 142.5, 137.3, 134.3, 132.9, 132.3,.7,.6,.1, 129.8, 129.6, 128.5, 128.5, 125.9, 121.1, 118.2 ppm; MS (EI): 344; HRMS: Calculated for C 21 H 15 BF 2 N 2 : 344.12964, found 344.11. 3i: Dark purple solid; Mp 191 C; 1 H-NMR (CDCl 3, 0 MHz): δ 7.91-7.83 (m, 4H), 3-7. (m, 5H), 7.47-7.37 (m, 6H), 6. (d, 2H, J = 4.35 Hz), 6.63 (d, 2H, J = 4.17 Hz) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ 159.0, 144.2, 136.5, 13, 132.7, 131.0,.7,.2, 129.6, 12, 128.3, 121.0 ppm (one carbon overlap); MS (EI): 4; HRMS: Calculated for C 27 H 19 BF 2 N 2 : 4.94, found 4.16196. 3-Phenyl-8-(p-nitrophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 2j The compound was prepared following the general procedure using 0.2 mmol 8-(pnitrophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene in o-xylene for 46 h. Bromobenzene was the bromoarene used. The crude product was purified via column chromatography (silica; petroleum ether/ch 2 Cl 2 ; 1:1 v/v) providing the desired product 2j in 28% (22 mg) and the diarylated product 3j in 18% (17 mg) yield. S6

2j: Purple crystals with a green lustre; Mp 193 C; 1 H-NMR (CDCl 3, 0 MHz): δ 1 (d, 2H, J = 5 Hz), 0-7.93 (m, 2H), 7.89 (s, 1H), 7.77 (d, 2H, 8.67 Hz), 7.55-7.47 (m, 3H), 9 (d, 1H, J = 4.53 Hz), 6.79-6. (m, 2H), 6.55 (d, 1H, J = 1 Hz) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ 149.1, 143.5, 14, 136.9, 133.7, 13, 131.8, 131.5,.6, 129.7, 129.6, 129.6, 129.2, 128.6, 123.8, 122.1, 118.9 ppm; MS (EI): 389; HRMS: Calculated for C 21 H 14 BF 2 N 3 O 2 : 389.11471, found 389.11459. 3j: Dark purple solid; Mp 99 C; 1 H-NMR (CDCl 3, 0 MHz): δ 2 (d, 2H, J = 8.67 Hz), 7.92-7.83 (m, 4H), 7.79 (d, 2H, J = 6 Hz), 7.49-7.39 (m, 6H), 6.79 (d, 2H, J = 4.14 Hz), 6.67 (d, 2H, J = 3.96 Hz) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ.3, 14, 13, 132.3, 13, 13,.1, 129.7, 129.6, 129.6, 128.5, 123.7, 121.8 ppm; MS (EI): 465; HRMS: Calculated for C 27 H 18 BF 2 N 3 O 2 : 465.141, found 465.14769. 3-Phenyl-5-thien-3-yl-8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-sindacene 4 The compound was prepared following the general procedure using 0.2 mmol 3-phenyl-8- (2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 2a in o-xylene for 48 h. 3-Bromothiophene was the bromoarene used. The crude product was purified via column chromatography (silica; petroleum ether/ch 2 Cl 2 ; 3:1 v/v) providing the desired product in 62% (61 mg) yield. Dark purple solid; Mp 197 C; 1 H-NMR (CDCl 3, 0 MHz): δ 8.32 (s, 1H), 7.97 (d, 2H, J = 3 Hz), 5 (d, 1H, J = 4.71 Hz), 7.54-7.39 (m, 6H), 7.38-7.31 (m, 1H), 6.75 (d, 1H, J = 3.93 Hz), 6.68-6.58 (m, 3H) ppm; 13 C-NMR (CDCl 3, 75 MHz): δ 159.0, 15, 136.2, 135.9, 13, 13, 132.2, 131.1, 129.7, 129.7, 129.4, 129.0, 12, 128.3, 12, 121.4, 12 ppm; MS (EI): 494; HRMS: Calculated for C 25 H 15 BCl 2 F 2 N 2 S: 493941, found 4922. 1,4-Di(3-phenyl-5-yl-8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-sindacene)benzene 5 S7

The compound was prepared following the general C H arylation procedure using 0.36 mmol 3-phenyl-8-(2,6-dichlorophenyl)-4,4-difluoro-4-bora-3a,4a-diaza-s-indacene 2a in toluene for 53 h. 1,4-Dibromobenzene (0.15 mmol, 2 equivalents) was used as bromoarene. The crude product was purified via column chromatography (silica; petroleum ether/ diethyl ether; 1:1 v/v) providing the desired product 5 in 23% (31 mg) yield. Dark crystals; Mp: decomposition at 2 C; 1 H-NMR (CDCl 3, 0 MHz): δ 2 (s, 4H), 7.93 (d, 4H, J = 5.85 Hz), 7.55-7.38 (m, 12 H), 6.71 (s, 2H), 6.67 (s, 4H), 6.63 (s, 2H) ppm; 13 C-NMR (CDCl 3, MHz): δ.2, 158.9, 137.1, 136.5, 136.3, 135.9, 133.4, 132.5, 132.1, 13, 129.9, 129.7, 129.2, 129.2, 12, 128.3, 121.9, 121.7 ppm (two carbons overlap); MS (ESI): 923 (M + + Na + ), 1823 (M + + M + + Na + ). S8

NMR-spectra of new compounds 2a, 1 H, 0 MHz, CDCl 3 5 1.0000 6.54 0.9983 1.0419 0.9684 0.9987 065 7.99 7.8451 7. 7.4861 7.4485 7.4271 7.39 6.75 6.7398 6.68 6.6758 6.6287 6.6187 894 2a, 13 C, 75 MHz, CDCl 3 161.7851 143.3516 135.5732 131.97 131.83 13748 131.1257 13639 129.76 129.75 129.6493 129.5947 128.5292 128.36 121 121.17 118.6416 1 0 S9

3a, 1 H, 0 MHz, CDCl 3 000 9.0331 1.45 056 7.9249 7.9167 7.8985 7.56 7.4962 7.45 7.4328 7.4171 6.6695 6.6557 6.6143 6.05 3a, 13 C, 75 MHz, CDCl 3 159.9341 135.8386 132.5258 132.1585 131.1657 129.8711 129.7147 129.62 129.93 129.1656 128.3474 121.5653 S

2b, 1 H, 0 MHz, CDCl 3 512 1.0000 3.1274 161 8 1.0021 1.0461 3.0711 516 221 7.7981 7.31 7.4955 7.4729 7.4359 7.4146 7.45 7.3832 7.0386 7.0091 6.7379 6.7235 6.78 6.6934 6.5666 6.5547 5 3.8921 0.0 2b, 13 C, 75 MHz, CDCl 3 162.51 161.7851 141.87 137.78 134 131.9839 131.7912 131.7294 13675 131.4166 131.1621 128.3329 12383 124.2418 121.9363 117.9688 114.1614 55.5483 0 S11

3b, 1 H, 0 MHz, CDCl 3 124 3.1768 312 3.9195 000 7.9431 7.9136 7.5131 7.75 7.4842 7.4378 7.4158 7. 7.3851 6.99 6.9514 6.11 3.8614 0.0 3b, 13 C, 75 MHz, CDCl 3 16882 159.0518 135.36 132.2326 131.53 137 131.1926 135 12579 128.1488 124.98.93 113.8319 5951 0 S12

2d, 1 H, 0 MHz, CDCl 3 0.9522 1.0000 0.9994 4. 0.95 0.9875 0.9779 1.0065 446 395 7.83 7.7246 7.89 7.12 7.4943 7.4723 7.4372 7.4158 7.58 7.3895 051 6.77 6.7254 6.7 6.5823 6.57 863 2d, 13 C, 75 MHz, CDCl 3 155.7194 142.38 13314 13422 133 132.1512 131.9148 131.39 13166.6348.5293 128.9256 128.3547 127.1183 125.9364 121.7763 118.2743 0 S13

3d, 1 H, 0 MHz, CDCl 3 1.7592 826 113 000 1.9378 8.3667 9 813 7.45 7.4667 7.42 7.3719 6.7518 6.7392 6.5999 6.5873 3d, 13 C, 75 MHz, CDCl 3 153.19 95 135.8968 132.65 131.0784 129.28 129.1729 129.0383 128.9947 128.6165 128.3147 125.5691 121.0817 S14

2e, 1 H, 0 MHz, CDCl 3 1.0377 144 1.92 0.9434 0.9521 0.9785 0.9574 2.9562 000 7.7214 7.5432 7.56 7.5 7.4898 7.4534 7.4321 7.42 7.07 6.9594 6.7956 6.7818 6.6268 6.6 441 316 6.3776 6.3638 2.3398 2.1723 2e, 13 C, 75 MHz, CDCl 3 162.2942 143.5516 139.2315 139.1442 137.3732 137 135.4786 131.7621 13821 131.03.7657 129.12 128.9947 128.36 127.7983 121.78 17 21.4415.1433 S15

2f, 1 H, 0 MHz, CDCl 3 511 2.1174 1.0000 1.1356 5.3321 0.9494 1.88 0.99 7.9958 7.9776 7.9669 7.9336 7.54 7.89 7.8552 7.7679 412 154 7.5897 7.5338 7.4968 7.4874 7.4679 7.4453 7.4146 327 189 6.6676 6.6538 6.6394 643 542 0.0 2f, 13 C, 75 MHz, CDCl 3.0977 143.9662 139.3369 13495 135.5586 134.2167 133.5767 131.9294 131.7694 131.3439.3329 129.92 129.93 128.6492 56 126.71 126.91 12564 125.0382 123.39 118.77 S16

3f, 1 H, 0 MHz, CDCl 3 8.1766 2.1529 7.52 000 318 7.8489 7.8213 7.5872 7.5621 7. 7.4748 7.4321 6.77 6. 6.5967 6.5854 S17

2i, 1 H, 0 MHz, CDCl 3 3 1.0000 8.1964 0.9814 0.9581 0.9649 0.9673 7.9757 7.9669 7.90 7.84 004 7.53 7.5771 7.5558 7.5363 7.43 7.4861 6.9922 6.9783 679 559 6.6972 6.6827 6.5252 6.5 0.0 2i, 13 C, MHz, CDCl 3.5941 145.79 14826 137.3422 134.2872 132.18 132.34.67.5613.1311 129.8395 129.5916 128.52 12833 125.9314 121.1483 118.2245 S18

3i, 1 H, 0 MHz, CDCl 3 000 5.3312 6.1188 1.9591 1.9889 7.9114 7.8931 009 7.5795 7.5521 7.5339 7.4425 7.4273 6.37 915 6.6419 6.6297 3i, 13 C, 75 MHz, CDCl 3 158.91 144.62 13689 132 132.7221 131.0163.68.2243 129.5846 128.3661 128.52 121.0249 S19

2j, 1 H, 0 MHz, CDCl 3 1.94 5 1.0467 147 3.0355 0.9289 000 1.0157 2 8.3975 7.9851 7.9726 7.96 7.9531 7.8885 7.7868 7.7579 7.5219 7.87 7.4999 9 779 6.7637 6.75 6.7361 6.5597 6.54 0.0 2j, 13 C, 75 MHz, CDCl 3 149.1191 143.5371 14 136.9368 133.7294 132.3767 131.83 131.43.6311 129.02 129.6493 129.5947 129.2384 128.6129 123.7618 122.1145 118.9216 0 S

3j, 1 H, 0 MHz, CDCl 3 1.89 178 1.9695 6.12 1.8756 000 364 075 7.8941 7.8815 7.8696 7.8627 7.62 7.7774 7.4642 7.4491 7.4378 7.43 6.7995 6.7857 6.6796 6.6658 3j, 13 C, 75 MHz, CDCl 3.26 14352 135.9986 132.3476 131.5584 132.0566 129.6711 129.6166 129.5656 128 123.72 121.8417 0 S21

4, 1 H, 0 MHz, CDCl 3 0.9296 1.9932 0.9746 6.2591 1.0747 0.9761 3.0000 8.32 7.9826 7.9625 587 4 7.5144 7.4899 7.4667 7.45 7.4284 7.3976 7.3556 7.3462 6.7649 6.7518 6.6532 6.6212 4, 13 C, 75 MHz, CDCl 3 159.04 66 136.1914 135.8641 132.7621 133 132.1839 131.1257 129.7475 129.02 129.56 128.9874 56 128.3329 55 121.4126 175 165 155 145 135 125 115 5 95 85 75 65 55 45 35 25 15 5 S22

5, 1 H, 0 MHz, CDCl 3 000 249 12.243 154 3.8436 3 221 7.9418 7.9223 7.5257 7.18 7.4547 7.43 6.7147 6.62 6.66 0.0 5, 13 C, MHz, CDCl 3.15 153 137.81 13737 136.2768 135.8612 133.4183 13995 132.1422 131.1797 129.9473 129.6848 129.2473 129.1525 12233 128.34 121.8896 121.73 S23

Spectroscopic data Figure S1 (a) Normalized, visible absorption spectra of a selection of meso-(2,6-dichlorophenyl) substituted BODIPY dyes (1, 2d, 2f, 3d, 4) in THF. (b) Corresponding normalized fluorescence emission spectra. Note that merging figures (a) and (b) produces the congested Figure 1. S24

Table S2 Spectroscopic and fluorescence quantum yield data of bis-bodipy 5 as a function of solvent. The solvents are listed from top to bottom according to increasing refractive index n. Product 5 Solvent λ abs (max) a / nm λ em (max) b / nm ν c Φ d / cm -1 MeOH 621 7 1959 MeCN 612 7 2196 e Ethyl acetate 625 8 1876 0.58 ± 0.01 THF 636 717 1776 0.524 ± 0.003 Toluene 638 718 1746 0.634 ± 0.004 a Absorption maximum. b Fluorescence emission maximum. c Stokes shift (=1/λ abs (max) 1/λ em (max)). d Fluorescence quantum yield ± one standard uncertainty. Φ determined vs. cresyl violet in methanol (Φ r = 0.55) as reference. e Not possible to obtain reliable Φ values due to very limited solubility in the solvents indicated. e S25