first step towards nano-optics at surface.

Transcription

1 Fluorescent molecular self-assembly on graphene, a first step towards nano-optics at surface. Sylvain LE LIEPVRE 1, Ping DU 2, David KREHER 2, Fabrice MATHEVET 2, André-Jean ATTIAS 2, Céline FIORINI-DEBUISSCHERT 1, Ludovic DOUILLARD 1, Fabrice CHARRA 1 1 Service de Physique de l Etat Condensé, SPEC CEA CNRS Université Paris-Saclay, CEA Saclay F Gif-sur-Yvette CEDEX, France 2 Sorbonne Universités, UPMC Université Paris 6, CNRS UMR 8232, Institut Parisien de Chimie Moléculaire, Université Pierre et Marie Curie, 4 Place Jussieu, F-755 Paris, France SUPPORTING INFORMATION Janus tecton PTCDI-JT synthesis. General methods. Unless otherwise indicated, all starting materials were obtained from commercial suppliers and were used without further purification. Analytical thin-layer chromatography (TLC) was performed on silica coated on aluminum plates with a particle size of 2-25 mm and a pore size of 6 Å. Merck 6 (7-23 mesh) silica was used for flash chromatography. The 1H NMR spectra were recorded on a 2 MHz spectrometer in the indicated solvents. Chemical shifts are expressed in parts per million (δ) using residual solvent protons as internal standard (chloroform: δ 7.26 ppm, dichloromethane: δ 5.3 ppm). The 13C NMR spectra were recorded on a 2 MHz spectrometer in the indicated solvents. Chemical shifts are expressed in parts per million (chloroform: δ ppm, dichloromethane: δ

2 ppm). Multiplicities are abbreviated as follows: singlet (s), doublet (d), triplet (t), quartet (q), quintet (quint), multiplet (m), and broad (br). Matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectra were obtained using a Bruker Autoflex3; trans-2-[3-(4-tertbutylphenyl)-2-methyl-2-propenylidene]malononitrile (DCTB) was selected as the matrix. ESI- HRMS were recorded using a Waters UPLC Acquity system equipped with a Waters LCT Premier XE mass spectrometer and a ZQ Mass detector model 2. Compounds 1 and 2 are commercially available from TCI and ACROS, respectively. Synthesis of compounds 5 and 7 were reported elsewhere (Ping 214). The synthesis of PTCDI-JT is outlined in Scheme 1S. Starting from the commercial compound 2, a Williamson reaction was conducted to give compound 3. Then a Horner-Wadsworth- Emmons reaction between 1 and 3 leads to 4, which again underwent a second Horner- Wadsworth-Emmons reaction with 5 to afford 6. Finally, a nucleophilic substitution reaction with 7 converted 6 to the target derivative PTCDI-JT, in 62% yield. 2

3 Scheme 1S. Synthesis of PTCDI-JT. 3: To a mixture of Br(CH 2 ) 1 Br (44.8 ml, 2 mmol) and K 2 CO 3 (5.52 g, 39.9 mmol) in DMF (12 ml) was added dropwise a solution of 2 (2.44 g, 2. mmol) in DMF (4 ml). The resulting mixture was stirred at room temperature overnight, then DMF was removed under reduced pressure. The residue was purified by flash column chromatography on silica gel (DCM/petroleum ether 1:1) to give 3 as white solid (6.11 g, 9%). 1 H NMR (2 MHz, CDCl 3 ): δ (m, 12H), (m, 4H), 3.4 (t, J = 6.9 Hz, 2H), 4.3 (t, J = 6.5 Hz, 2H), 6.98 (d, J = 8.8 Hz, 2H), 7.82 (d, J = 8.8 Hz, 2H), 9.87 (s, 1H). 13 C NMR (5 MHz, CDCl 3 ): δ 25.9, 28.1, 28.7, 29., 29.3, 29.4, 32.8, 34., 68.4, 114.7, 129.8, 132., 164.2,

4 4: To a solution of compound 1 (1.6 g, 28. mmol) and compound 3 (8.69 g, 25.5 mmol) in dry THF (2 ml) immersed in an ice bath was added t-buok (3.72 g, 33.2 mmol). The reaction mixture was stirred at room temperature for 2 h, then 1mL H 2 O was added to quench the reaction, THF was removed under reduced pressure, extracted by dichloromethane (1 ml 3), washed by water, brine, dried over MgSO 4, filtered and concentrated. The crude was purified by flash chromatography (CH 2 Cl 2 /EtOAc 1:1) to afford 4 as pale green solid (3.53 g, 25%). 1 H NMR (2 MHz, CD 2 Cl 2 ): δ 1.24 (t, J = 7.1 Hz, 6H), (m, 12H), (m, 4H), 3.11 (d, J = 21.8 Hz, 2H), 3.41 (t, J = 6.8 Hz, 2H), (m, 6H), 6.88 (d, J = 8.6 Hz, 2H), 7.1 (d, J = 8.6 Hz, 2H), (m, 2H), 7.44 (d, J = 8.2 Hz, 4H). 13 C NMR (5 MHz, CD 2 Cl 2 ): δ 16.1, 16.2, 26., 28.1, 28.7, 29.2, 29.3, 29.4, 32., 32.9, 34.2, 34.7, 61.9, 62., 68.1, 114.6, 125.8, 126.2, 127.6, 128., 128.1, 129.8, 13., 13.1, 13.9, 131., 136.2, 136.3, HR-MS (ESI): m/z [M+H] + calcd for C 29 H 43 O 4 BrP, : The phosphonate 4 (395 mg,.698 mmol) and aldehyde 5 (537 mg,.349 mmol) were added to a three-necked flask, degassed and filled with nitrogen, and dry toluene (12 ml) was added to dissolve the starting material, then t-buok (118 mg, 1.5 mmol) was added slowly to the above solution. After stirring at room temperature for 5 hours, H 2 O (1 ml) was added to quench the reaction, toluene was evaporated under reduced pressure. The residue was extracted by dichloromethane (1 ml 4), combined dichloromethane phase was washed by water, brine, dried with MgSO 4, filtered and concentrated. The crude was purified by flash chromatography (CH 2 Cl 2 /hexane 2:3) to give compound 6 as yellow green waxy solid (458 mg, 67%). 1 H NMR (2 MHz, CD 2 Cl 2 ): δ (m, 12H), (m, 68H), (m, 12H), 3.43 (d, J = 6.9 Hz, 2H), 3.6 (s, 4H), (m, 12H), 4.35 (d, J = 13 Hz, 2H), 5.81 (s, 4

5 1H), (m, 3H), (m, 4H), (m, 4H), (m, 16H), (m, 6H), (m, 7H), (m, 3H), (m, 7H). 13 C NMR (5 MHz, CD 2 Cl 2 ): δ 14., 22.8, 26.2, 28.3, 28.8, 29.5, 29.6, 29.7, 32., 33., 34.3, 68.1, 112.4, 114., 114.5, 119.2, 123.5, 124.5, 125.5, 125.9, 126.6, 127.7, 128.1, 128.4, 129.1, 129.7, 13., 135., 135.5, 136., 136.8, 137.4, 138., 138.2, 138.6, 139.9, 158.9, MS (MALDI): m/z [M+H] +. HR-MS (ESI): m/z [M+H] + calcd for C 13 H 164 O 5 BrS 2, PTCDI-JT: A mixture of 6 (238 mg,.122 mmol), 7 (8.6 mg,.134 mmol) and K 2 CO 3 (37.1 mg,.268 mmol) in DMF (3.2 ml) was heated at 1 C for 3 h, then DMF was removed under reduced pressure, the residue was extracted by dichloromethane (1 ml), washed by water, brine, dried with MgSO 4, filtered and concentrated. The crude was purified by flash column chromatography on silica gel (CH 2 Cl 2 /hexane 3:2) to give PTCDI-JT as red waxy solid (188 mg, 62%). 1 H NMR (2 MHz, CD 2 Cl 2 ): δ (m, 18H), (m, 88H), (m, 12H), (m, 4H), 3.59 (s, 4H), (m, 14H), (m, 2H), (m, 1H), 5.8 (s, 1H), (m, 2H), (m, 9H), (m, 1H), (m, 17H), 7.18 (s, 3H), 7.22 (s, 2H), (m, 5H), 7.3 (s, 1H), (m, 3H), (m, 7H), (m, 8H). 13 C NMR (5 MHz, CD 2 Cl 2 ): δ 13.9, 22.8, 26.1, 27.1, 29.4, 29.7, 3., 31.2, 32., 68.1, 12.8, 112.4, 114., 114.5, 114.9, 119.1, 122.1, 122.7, 122.9, 124.4, 125.5, 125.9, 126.5, 127.7, 128.3, 129.1, 129.6, 13.6, 134., 134.3, 135.1, 135.5, 135.9, 136.8, 138., 138.2, 138.6, 138.7, 139.9, 159.6, 162.8, 175.1, MS (MALDI): m/z [M+H] +. HR-MS (ESI): m/z [M+H] + calcd for C 169 H 23 O 9 N 2 S 2, Molecular self-assembly on graphene 5

6 Scanning tunneling microscopy The self-assembly properties of PTCDI-C13, PTCDI-JT pedestal and PTCDI-JT on sp2- hybdridized graphene are characterized by scanning tunneling microscopy STM at the liquid/solid interface at room temperature. The roughness imposed on the CVD graphene monolayer by the underlying polyethylene terephthalate PET substrate makes STM observations noisy. We use graphene transferred on mica as a substrate for the characterization of PTCDI-JT. The image sequence displayed in figure 4S corresponds to observations recorded at the liquid / graphene interface for three different solutions: (a) a solution of PTCDI-C13, b) PTCDI- JT pedestal, the naked precursor clipping unit which constitutes the base of the Janus tecton, and (c) an equimolar solution of PTCDI-JT and PTCDI-JT pedestal. a) b) c) Figure 1S. Structural characterization of the self-assembled a) PTCDI-C13 (18 nm x 18 nm, 1 pa, -8 mv), b) PTCDI-JT pedestal (75 nm x 75 nm, 3 pa, -135 mv) and c) 1:1 ratio of PTCDI-JT and PTCDI-JT pedestal (38 nm x 38 nm, 5 pa, -156 mv) monolayers on graphene on PET. The images were acquired at the interface between the substrate and a ~1-5 M solution in phenyloctane at room temperature. Number of interacting dye groups 6

7 We computed the length of the spacer group and the dye group with a chemical simulation software (Accelrys Discovery Dassault System BioVia): d = 4.4 nm. We assume that the flexibility of the spacer allows the presence of the dye group everywhere inside a half-sphere centered on top of the disulfur pillar and of radius d. We use the experimental assembly geometrical parameters to compute the number of dye groups that can possibly overlap (Figure 2S). Crystallographic parameters of the considered surface lattice are (a = 3.8 nm, b = 2.1 nm, alpha = 64 ). Vertical axis (nm) Number of overlapping entities Horizontal axis (nm) Horizontal axis 2 (nm) Number of overlapping entities Horizontal axis 1 (nm) Figure 2S. Number of overlapping entities in the substrate surface perpendicular plane and parallel plane. We compute the occurrence probability of aggregate composed of every possible number of overlapping dye entities (Figure 3S). The most probable aggregate counts 6 different entities. The formation of this aggregate is more probable at 1.6 nm above and 2.8 nm and 4.2 nm away from the disulfur pillar. (Figure 4S). 7

8 .25 Probability of occurence Number of overlapping entities Figure 3S. Occurrence probability of dye aggregate sizes Occurrence number Height (nm) Horizontal distance (nm) Figure 4S. Spatial distribution above and away from the disulfur pillar of the 6 sized dye aggregate. 8