Towards New Oligomesogenic Phosphonic Acids as Stabilizers of Nanoparticles Colloids in Nematic Liquid Crystals

Abstract

Several synthetic strategies for the construction of linear and branched oligomesogenic phosphonic acids are examined, which differ in the method of building the key bimesogen unit. An efficient synthetic approach to the most promising compounds employs regioselective Kumada cross-coupling between [11-(4′-pentylbiphenyl-4-yl)undecyl]magnesium bromide and 4-(11-bromoundecyl)-4′-iodobiphenyl as the key step. Preliminary studies on the ability of the new ligands to stabilize nanoparticles colloids in nematic liquid crystals are undertaken for the example of quantum dots.

Key words

acylation - cross-coupling - phosphonic acids - total synthesis - ligands

• References and Notes

• 1 Stamatoiu O, Mirzaei J, Feng X, Hegmann T. Top. Curr. Chem. 2012; 331
• 2 Lewandowski W, Wójcik M, Górecka E. ChemPhysChem 2014; 1283
• 3 Blanc C, Coursault D, Lacaze E. Liq. Cryst. Rev. 2013; 83
• 4 Mirzaei J, Reznikov M, Hegmann T. J. Mater. Chem. 2012; 22350
• 5 Draper MI, Saez MS, Cowling JP, Heinrich GB, Donnio B, Guillon D, Goodby JW. Adv. Funct. Mater. 2011; 1260
• 6 Saliba S, Mingotaud C, Kahn ML, Marty J.-D. Nanoscale 2013; 5: 6641
• 7 Marx VM, Girgis H, Heiney PA, Hegmann T. J. Mater. Chem. 2008; 2983
• 8 Khatua S, Manna P, Chang W.-S, Tcherniak A, Friedlander E, Zubarev ER, Link S. J. Phys. Chem. C 2010; 7251
• 9 Prodanov MF, Kolosov MA, Krivoshey AI, Fedoryako AP, Yarmolenko SN, Semynozhenko VP, Goodby JW, Vashchenko VV. Liq. Cryst. 2012; 1512
• 10 Prodanov MF, Pogorelova NV, Kryshtal AP, Klymchenko AS, Mely Y, Semynozhenko VP, Krivoshey AI, Reznikov YA, Yarmolenko SN, Goodby JW, Vashchenko VV. Langmuir 2013; 9301
• 11 Buluy O, Burseva D, Hakobyan MR, Goodby JW, Kolosov MA, Reznikov Yu, Hakobyan RS, Slyusarenko K, Prodanov MF, Vashchenko V. Mol. Cryst. Liq. Cryst. 2012; 149
• 12 Milette J, Cowling SJ, Toader V, Lavigne C, Saez IM, Lennox RB, Goodby JW, Reven L. Soft Matter 2012; 173
• 13 Leea J, Hong S.-K, Jung H. Mol. Cryst. Liq. Cryst. 2015; 134
• 14 Rodarte AL, Nuno ZS, Cao BH, Pandolfi RJ, Quint MT, Ghosh S, Hein JE, Hirst LS. ChemPhysChem 2014; 1413
• 15 Milette J, Toader V, Soulé ER, Lennox RB, Rey AD, Reven LA. Langmuir 2013; 1258
• 16 Cseh L, Mehl GH. J. Am. Chem. Soc. 2006; 13376
• 17 Vardanyan KK, Sita DM, Walton RD, Gurfinkiel IS, Saidel WM. Liq. Cryst. 2012; 1083
• 18 Soule ER, Milette J, Reven L, Rey AD. Soft Matter 2012; 2860
• 19 Mirzaei J, Urbanski M, Kitzerow H.-S, Hegmann T. ChemPhysChem 2014; 1381
• 20 Prodanov MF, Buluy AG, Popova KV, Gamzaeva SA, Reznikov Yu, Vashenko VV In Nanoscale Systems and Nanomaterials: Research in Ukraine . Naumovets AG. NAS of Ukraine Academperiodika; Ukraine: 2014: 719 ; ISBN 978-966-360-260-8
• 21 Matvienko OO, Prodanov MF, Gorobets NYu, Vashchenko VV, Vovk OM, Babayevskaya NV, Savin YN. Colloid Polym. Sci. 2014; 707
• 22 Prodanov, M.; Buluy, O.; Popova, E.; Kurochkin, O.; Gamzaeva, S.; Reznikov, Y.; Vashchenko, V. Proceedings of the 25th International Liquid Crystal Conference, Trinity College Dublin, Ireland, June 24–July 4 2014, Abstract N-O2.002.
• 23 Popova EV, Gamzaeva SA, Krivoshey АI, Kryshtal AP, Fedoryako AP, Prodanov MF, Kolosov MA, Vashchenko VV. Liq. Cryst. 2015; 334
• 24 Frein S, Boudon J, Vonlanthen M, Scharf T, Barbera J, Suss-Fink G, Burgi T, Deschenaux R. Helv. Chim. Acta 2008; 2321
• 25 Wojcik M, Lewandowski W, Matraszek J, Mieczkowski J, Borysiuk J, Pociecha D, Gorecka E. Angew. Chem. Int. Ed. 2009; 5167
• 26 Mischler S, Guerra S, Deschenaux R. Chem. Commun. 2012; 2183
• 27 Buathong S, Ung D, Daou TJ, Ulhaq-Bouillet C, Pourroy G, Guillon D, Ivanova L, Bernhardt I, Bégin-Colin S, Donnio B. J. Phys. Chem. C 2009; 12201
• 28 Demortière A, Buathong S, Pichon BP, Panissod P, Guillon D, Bégin-Colin S, Donnio B. Small 2010; 1341
• 29 Barnes PJ, Douglass AG, Heeks SK, Luckhurst GR. Liq. Cryst. 1993; 603
• 30 Schubert H, Sagitdinov I, Svetkin JV. Z. Chem. 1975; 222
• 31 Mallon JJ, Kantor SW. Mol. Cryst. Liq. Cryst. 1988; 157: 25
• 32 Lukáč I, Csaba K, Weiss RG. Photochem. Photobiol. Sci. 2009; 1389
• 33 Jana R, Pathak TP, Sigman MS. Chem. Rev. 2011; 1417
• 34 In Organic Chemistry . McMurry J. Cengage Learning; Boston: 2012. 8th ed., 575
• 35 To a suspension of AlCl₃ (7.86 g, 59 mmol) in CH₂Cl₂ (250 mL), a solution of iodobiphenyl 17 (15.0 g, 53 mmol) was added at 0 °C. To this mixture, a solution of 11-bromoundecanoyl chloride (16.7 g, 59 mmol) was added dropwise during 20 min at 0 °C. After stirring at 0°C for 2 h and at r.t. for 7 h, a solution of triethylsilane (13.7 g, 0.12 mol) in CH₂Cl₂ (20 mL) was added dropwise at r.t. during 45 min. The reaction mixture was stirred overnight and then evaporated to dryness; the residue was dissolved in hexane (400 mL) and subjected to flash chromatography through a short pad of silica (hexane). The solution was evaporated to dryness and the residue was recrystallized from i-PrOH (300 mL). The washed precipitate was transferred to a modified Soxhlet extractor and washed with hot CCl₄ (500 mL) for 12 h. The solvent was evaporated and the residue was recrystallized from i-PrOH. The colorless solid product was dried in vacuo at 80–100 °C to give 19a and 19b as a mixture of compounds. Yield: 16.3 g (59%). According to GCMS, HPLC and NMR spectroscopy (Figure 2) the obtained mixture contained about 35% of chloro derivative 19b. Mp 61–64 °C. IR (KBr): 2918, 2848, 1678, 1461, 1387, 1131, 1069, 1000, 857, 810, 792, 723, 686, 646, 472 cm^–1. ¹H NMR (200 MHz, CDCl₃): δ = 1.29 (m, 14 H, 3-CH₂, 4-CH₂, 5-CH₂, 6-CH₂, 7-CH₂, 8-CH₂, 9-CH₂), 1.56–1.73 (m, 2 H, 10-CH₂), 1.73–1.94 (m, 2 H, 2-CH₂), 2.64 (t, J = 8.3 Hz, 2 H, 11-CH₂), 3.41 (t, J = 6.9 Hz, 1.36 H, 1-CH₂Br), 3.53 (t, J = 6.7 Hz, 0.64 H, 1-CH₂Cl), 7.25 (d, J = 7.8 Hz, 2 H, ArH), 7.32 (d, J = 8.4 Hz, 2 H, ArH), 7.47 (d, J = 8.1 Hz, 2 H, ArH), 7.75 (d, J = 8.2 Hz, 2 H, ArH). MS (EI, 70 eV): m/z (%) = 468 (22) [M⁺, 19b], 512 (22) [M⁺, 19a], 293 (100), 207 (30), 165 (62).
• 36 To magnesium turnings (0.08 g, 3.3 mmol), activated with iodine, anhydrous THF (100 mL) was added under Ar. To this mixture, a few drops of 4-(11-bromoundecyl)-4′-pentylbiphenyl solution in THF was added. The mixture was heated to 80 °C and a solution of 4-(11-bromoundecyl)-4′-pentylbiphenyl (15; 1.35 g, 2.9 mmol) was added dropwise during 1.5 h. The obtained Grignard reagent was pumped through a Teflon capillary tube into a dropping funnel under argon pressure. The Grignard reagent was then added dropwise at r.t. to a stirred degassed suspension of PdCl₂(dppf) catalyst (4 mol%) and 4-(11-haloundecil)-4′-iodobiphenyl (19a,b; 1.14 g, 2.2 mmol) for several minutes under Ar. The mixture was stirred for 1 h and then poured into 17% solution of ammonium chloride in water. The resulting mixture was extracted with toluene; the organic extracts were collected, washed with water, dried over Na₂SO₄, filtered, and evaporated to dryness. The crude product was recrystallized from a mixture of MeCN–CH₂Cl₂ (50%, 30 mL). Yield: 1.34 g (79%). According to HPLC analysis in combination with NMR spectroscopy (see the Supporting Information) the obtained mixture contained 33% 20b. Mp 72–74 °C. IR (KBr): 3033, 2918, 2847, 1909, 1499, 1468, 1401, 1135, 1003, 809, 793, 763, 718, 648, 591, 516, 483 cm^–1. ¹H NMR (CDCl₃, 200 MHz): δ = 0.91 (br t, 3 H, CH₃), 1.18–1.50 [m, 32 H, (CH₂)₁₆], 1.65 [m, 8 H, (CH₂)₄], 1.86 (m, 2 H, CH₂), 2.64 [t, J = 7.7 Hz, 8 H, (CH₂)₄], 3.40 (t, J = 7.4 Hz, 1.41 H, CH₂), 3.53 (t, J = 6.6 Hz, 0.59 H, CH₂), 7.24 (d, J = 8.4 Hz, 8 H, ArH), 7.50 (d, J = 8.4 Hz, 8 H, ArH). MS (MALDI TOF): m/z = 718.5 [M]⁺ (C₅₁H₇₁Cl), 757.5 [M + K]⁺ (C₅₁H₇₁ClK), 764.5 [M + 2H]⁺ (C₅₁H₇₃Br), 808.5 [M+2Na]⁺ (C₅₁H₇₁BrNa₂), 840.5 [M + 2K]⁺ (C₅₁H₇₁ BrK₂).
• 37 Prodanov MF, Vashchenko OV, Vashchenko VV. Tetrahedron Lett. 2014; 275