Supramolecular self-assembly of water-soluble nanoparticles based on amphiphilic p-tert-butylthiacalix[4]arenes with silver nitrate and fluorescein

Colloids and Surfaces A: Physicochem. Eng. Aspects 454 (2014) 74–83

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Supramolecular self-assembly of water-soluble nanoparticles based on amphiphilic p-tert-butylthiacalix[4]arenes with silver nitrate and fluorescein Elena A. Andreyko, Pavel L. Padnya, Ivan I. Stoikov ∗ Kazan Federal University, A.M. Butlerov Chemical Institute, Kremlevskaya 18, 420008 Kazan, Russian Federation

h i g h l i g h t s

g r a p h i c a l

a b s t r a c t

• New

p-tert-butylthiacalix[4]arenes were synthesized and characterized. • The effective interaction of the calix[4]arenes with fluorescein was shown. • The formation of supramolecular assemblies with fluorecein was observed. • Formed supramolecular particles effectively interact with BSA.

a r t i c l e

i n f o

Article history: Received 8 January 2014 Received in revised form 3 April 2014 Accepted 6 April 2014 Available online 18 April 2014 Keywords: Dynamic light scattering Thiacalix[4]arenes Synthesis Synthetic receptors Molecular recognition Supramolecular chemistry Nanoparticles

a b s t r a c t New p-tert-butylthiacalix[4]arenes containing amide, ester, phthalimide and quaternary ammonium fragments in cone conformation were synthesized and characterized. The effective interaction of the p-tert-butylthiacalix[4]arenes with silver nitrate and fluorescein was shown by electron spectroscopy. As was shown by dynamic light scattering (DLS) all the macrocycles are able to form nanoscaled particles with silver nitrate. In the case of fluorescein, the formation of supramolecular assemblies was observed only for p-tert-butylthiacalix[4]arenes able of self-associating. It was shown that the interaction of nanoparticles based on the macrocycles and silver nitrate or fluorescein with bovine serum albumin (BSA) led to the formation of the particles of about 7 nm in size. © 2014 Elsevier B.V. All rights reserved.

1. Introduction Synthesis of the nanoscale structures for molecular recognition of different substrates is one of the perspective tendencies of the investigations in the supramolecular chemistry and nanotechnology [1–4]. Nanoscale particles can be used to the formation

∗ Corresponding author. Tel.: +7 843 2337241; fax: +7 843 2752253. E-mail address: [email protected] (I.I. Stoikov). http://dx.doi.org/10.1016/j.colsurfa.2014.04.021 0927-7757/© 2014 Elsevier B.V. All rights reserved.

of sensors, catalysts, biomimetic systems, selective extractants and drug delivery systems [5–11]. Nanosized structures can be by covalent synthesis or supramolecular self-assembly. The spontaneous association of a number of chemical compounds (ligands) due to non-covalent intermolecular interactions is most convenient way to create nanosized particles [1,2,12–31]. The formation of supermolecules and supramolecular assemblies by self-assembly makes it possible to control shape, “dentate” of colloidal particles and their ability to interact with substrates. Depending on the nature of functional groups of ligand, nanosize particles soluble in organic and

E.A. Andreyko et al. / Colloids and Surfaces A: Physicochem. Eng. Aspects 454 (2014) 74–83

aqueous phases and able to recognize different substrates, e.g., low molecular compound or biomacromolecules, can be obtained. The p-tert-butylthiacalix[4]arenes as synthetic macrocyclic platform can be used as building blocks for the synthesis of various ligands [32–43]. The synthesis of water-soluble supramolecular particles for recognition of biomacromolecules based on amphiphilic p-tert-butylthiacalix[4]arenes functionalized with amide, quaternary ammonium groups at the lower rim can be achieved. For this goal, ligands with different potential coordination centers, i.e. proton donors (–NH-fragments) and acceptors (carbonyl groups) able to supramolecular self-assembling with the formation of nanoparticles due to intermolecular forces between a receptor and a substrate can be specified. The introduction of ammonium groups in the structure of macrocycles is necessary for creation of amphiphilic receptors based on ptert-butylthiacalix[4]arene. The ability of water-soluble nanosized particles to self-association and recognition of different substrates, including biopolymers, can vary depending on the nature and structure of the macrocycles with quaternary ammonium fragments with different groups at the nitrogen atom. The introduction of quaternary ammonium fragments with phthalimide groups at the nitrogen atom in has good prospects for the development of intercalators which can also involve p-tert-butylthiacalix[4]arene moiety for further recognition of proteins and hydrophobic interactions with DNA molecules [44]. However, in order to increase the efficiency of interaction of amphiphilic p-tert-butylthiacalix[4]arenes with biopolymers, the synthesis of nanoscale particles based on the macrocycles is necessary. It is well known that nanoscale aggregates have sufficiently large surface area for simultaneous multiple non-covalent interactions with biomacromolecules that lead to increasing efficiency of the interaction. Previously it was shown that the formation of nanosized particles based p-tert-butylthiacalix[4]arenes occurs in several ways: (1) by self-association of the macrocycles or (2) by aggregation of macrocycles with different substrates [45–49]. According to the results [48,49] we suggested the surface of water-soluble aggregates formed by self-assembly of amphiphilic p-tert-butylthiacalix[4]arenes should contain different functional groups for the further interaction with biopolymers. To examine this hypothesis, the macrocycles containing amide and quaternary ammonium fragments with alkyl, aryl, ester, phthalimide groups at the nitrogen atom as amphiphilic p-tert-butylthiacalix[4]arenes were taken for the synthesis and investigation. Silver nitrate and fluorescein were specified as substrates. As was shown earlier, the introduction of the silver nitrate into the system containing molecules of p-tert-butylthiacalix[4]arene resulted in the formation of nanoparticles in the organic phase [45–49]. The addition of the silver nitrate to the amphiphilic macrocycles can significantly influence the formation of water-soluble nanoscale aggregates, either. Fluorescein was selected as a fluorescent probe. In contrast to silver nitrate that acts as a linker in the formation of nanosized particles with macrocycles, the formation of nanoscale aggregates based on macrocycles and fluorescein by the same way is less probable because of the structure of the fluorescent probe. However, the possibility for involvement of the fluorescein into supramolecular particles formed by self-association of p-tert-butylthiacalix[4]arenes or aggregation with silver nitrate remains. Thus, two approaches were studied for the synthesis of nanosized particles in the aqueous phase based on amphiphilic p-tert-butylthiacalix[4]arenes with silver nitrate and fluorescein, i.e. (I) self-assembly of associates by the introduction of the substrates into the system containing p-tert-butylthiacalix[4]arenes. This seems most suitable for the formation of particles based on macrocycles and silver nitrate (Fig. 1(A)); (II) self-association of p-tert-butylthiacalix[4]arenes with the formation of nanoparticles able to further interaction with fluorescent probe (Fig. 1(B)). To

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study the ability of nanoparticles based on macrocycles and silver nitrate, and those aggregating with fluorescent molecules, to interact with protein, bovine serum albumin (BSA) was applied. In this work, the synthesis of p-tert-butylthiacalix[4]arenes containing amide and quaternary ammonium fragments with alkyl, aryl, ester and phthalimide groups at the nitrogen atom, and the design of self-assembled supramolecular nanoparticles based on these macrocycles with silver nitrate and fluorescein are described for recognition of biopolymers.

2. Materials and methods 2.1. General The 1 H NMR spectra of compounds (3–5% solution in CDCl3 , (CD3 )2 SO) were recorded with 400 MHz Bruker Avance 400 spectrometer using CDCl3 and (CD3 )2 SO as internal standard. The IR spectra (suspension in vaseline oil) were recorded with Tensor 27 (Bruker) IR spectrometer. The IR spectra from 4000 to 400 cm−1 were considered in this analysis. The spectra were measured with 1 cm−1 resolution and 64 scans co-addition. The time required for obtaining each specter under the conditions stated was approximately 16 s. Elemental analysis was performed with Perkin-Elmer 2400 Series II instruments. Mass spectra (MALDI-TOF) were recorded with Ultraflex III in the 4-nitroaniline matrix. Melting points were determined using Boetius Block apparatus. The purity of the compounds was monitored by melting, boiling points, 1 H NMR and thin layer chromatography (TLC) on 200 ␮m UV 254 silica gel plate using UV-light (254 nm). In this work, the following reagents and solvents were used: methanol (chemical pure), N,N-dimethylpropane-1,3diamine (chemical pure), N,N-diethylethane-1,2-diamine (chemical pure), iodomethane (chemically pure), benzyl bromide (chemical pure), ethyl bromoacetate (chemical pure), N-(3-bromopropyl)phthalimide (chemical pure), toluene (chemical pure), acetonitrile (chemically pure), silver nitrate (chemically pure). 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis-[(N(3 ,3 -dimethylaminopropyl)carbamoylmethoxy]-2,8,14,20tetrathiacalix[4]arene (cone-2) was synthesized according to the literature procedure [50]. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis-[(N-(3 ,3 ,3 trimethylammoniumpropyl)carbamoylmethoxy]-2,8,14,20thiacalix[4]arene tetraiodide (cone-3) was synthesized according to the literature procedure [50]. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis-[(N-(3 ,3 dimethyl-3 -benzylammoniumpropyl)carbamoylmethoxy]2,8,14,20-thiacalix[4]arene tetrabromide (cone-6) was synthesized according to the literature procedure [50]. General procedure for the synthesis of the compounds 4, 5, and 7. In a round bottom flask equipped with magnetic stirrer and a reflux condenser, compound 2 (0.10 g) in 2 ml of methanol was dissolved. Equimolar amount of the alkylating reagent (iodoethane, ethyl bromoacetate, N-(3-bromopropyl)phthalimide) for each amino group was added. The reaction mixture was refluxed for 72 h. The solvent was removed under reduced pressure. The precipitate was dried under reduced pressure over phosphorus pentoxide. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetra-[(N-(3 ,3 dimethyl-3 -(ethylammoniumpropyl)carbamoylmethoxy]2,8,14,20-thiacalix[4]arene tetraiodide (cone-4). Yellow powder, yield: 0.14 g (98%). Mp: 165 ◦ C. 1 H NMR (400 MHz, 298 K, CDCl3 ) ı 1.11 (s, 36H, (CH3 )3 C), 1.47 (t, 3 JHH = 7.1 Hz, 12H, N+ CH2 CH3 ) 2.22

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Fig. 1. Possible paths of the formation of supramolecular structures based on (A) p-tert-butylthiacalix[4]arenes 8 and 9 and (B) p-tert-butylthiacalix[4]arenes 11 and 12.

(m, 8H, NCH2 CH2 CH2 NH), 3.36 (s, 24H, (CH3 )2 N+ ), 3.52 (m, 8H, NCH2 CH2 CH2 NH), 3.66 (q, 3 JHH = 7.1 Hz, 8H, N+ CH2 CH3 ), 3.81 (m, 8H, NCH2 CH2 CH2 NH), 4.99 (s, 8H, OCH2 CO), 7.35 (s, 8H, ArH), 8.53 (t, 3 JHH = 5.8 Hz, 4H, CONH). 13 C NMR (125 MHz, CDCl3 ) ı 168.97, 157.20, 147.68, 134.89, 128.08, 74.39, 62.12, 60.46, 51.05, 36.27, 34.31, 31.10, 23.02, 9.03. IR, /cm−1 :1664 (C O), 2956, 3316 (N H). MALDI-TOF: calcd for [M−I− ]+ m/z = 1785.6, found m/z = 1785.9. El. Anal. Calcd for C76 H124 I4 N8 O8 S4 : C, 47.70; H, 6.53; N, 5.86; S, 6.70. Found: C, 47.15; H, 6.25; N, 5.41; S, 6.64. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetra-[(N-(3 ,3 dimethyl-3 -(ethoxycarbonylmethyl)ammoniumpropyl) carbamoylmethoxy]-2,8,14,20-thiacalix[4]arene tetrabromide (cone-5). White powder, yield: 0.13 g (94%). Mp: 112 ◦ C. 1 H NMR (400 MHz, 298 K, CDCl3 ) ı 1.11 (s, 36H, (CH3 )3 C), 1.34 (t, 3J NCH2 CH2 CH2 NH), HH = 7.1 Hz, 12H, OCH2 CH3 ), 2.29 (m, 8H, 3.52 (m, 8H, NCH2 CH2 CH2 NH), 3.63 (s, 24H, (CH3 )2 N+ ), 4.18 (m, 8H, NCH2 CH2 CH2 NH), 4.28 (q, 3 JHH = 7.1 Hz, 8H, OCH2 CH3 ), 4.81 (s, 8H, N+ CH2 CO), 4.99 (s, 8H, OCH2 CO), 7.36 (s, 8H, ArH), 8.75 (t, 3 JHH = 5.7 Hz, 4H, CONH). 13 C NMR (125 MHz, CDCl3 ) ı 169.13, 164.80, 157.25, 147.63, 134.86, 128.18, 74.40, 63.61, 62.75, 61.54, 51.65, 36.20, 34.29, 31.08, 22.98, 14.04. IR, /cm−1 :1665, 1742 (C O), 2959, 3332 (N H). MALDI-TOF: calcd for [M−Br− ]+ m/z = 1878.5, found m/z = 1878.0. El. Anal. Calcd for

C84 H132 Br4 N8 O16 S4 : C, 51.53; H, 6.80; N, 5.72; S, 6.55. Found: C, 51.49; H, 6.67; N, 5.51; S, 6.44. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetra[(N-(2 ,2 -methyl-2 -{3 -propylphthalimide}ammoniumpropyl)carbamoylmethoxy]-2,8,14,20thiacalix[4]arene tetrabromide (cone-7). White powder, yield: 0.14 g (98%). Mp: 152 ◦ C. 1 H NMR (400 MHz, 298 K, CDCl3 ) ı 1.10 (s, 36H, (CH3 )3 C), 2.21 (m, 8H, CH2 ), 2.30 (m, 8H, CH2 ), 3.42 (s, 12H, (CH3 )2 N+ ), 3.48 (m, 8H, CH2 ), 3.68 (m, 8H, CH2 ), 3.83 (m, 8H, CH2 ), 3.88 (m, 8H, CH2 ), 4.81 (s, 8H, OCH2 CO), 7.33 (s, 8H, ArH), 7.57 (m, 8H, Pht), 7.71 (m, 8H, Pht), 8.63 (t, 3 JHH = 5.3 Hz, 4H, CONH). 13 C NMR (125 MHz, CDCl3 ) ı 163.74, 163.14, 152.08, 142.15, 129.61, 128.72, 126.60, 123.03, 118.01, 69.10, 57.46, 56.72, 46.08, 31.13, 29.91, 29.01, 25.85, 17.76, 17.30. IR, /cm−1 : 1666, 1705, 1770 (C O), 2958, 3334 (N H). MALDI-TOF: calcd for [M−Br− ]+ m/z = 2282.7, found m/z = 2283.2. El. Anal. Calcd for C112 H144 Br4 N12 O16 S4 : C, 56.94; H, 6.14; N, 7.12; S, 5.43, Br, 13.53. Found: C, 56.72; H, 6.26; N, 7.01; S, 5.45, Br, 13.39. General procedure for the synthesis of the compounds 8–12. In a round bottom flask equipped with magnetic stirrer, compounds 3–7 (0.10 g) in 5 ml of acetonitrile were dissolved. Equimolar amount of the silver nitrate for each quaternary ammonium group was added. The reaction mixture was refluxed for 24 h. Silver

E.A. Andreyko et al. / Colloids and Surfaces A: Physicochem. Eng. Aspects 454 (2014) 74–83

halides were filtered. The solvent was removed under reduced pressure. The precipitate was dried under reduced pressure over phosphorus pentoxide. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis-[(N-(3 ,3 ,3 trimethylammoniumpropyl)carbamoylmethoxy]-2,8,14,20thiacalix[4]arene tetranitrate (cone-8). White powder, yield: 0.09 g (92%). Mp: 164 ◦ C. 1 H NMR (400 MHz, 298 K, DMSO-d6 ) ı 1.08 (s, 36H, (CH3 )3 C), 1.91 (m, 8H, NCH2 CH2 CH2 NH), 3.05 (s, 36H, (CH3 )3 N+ ), 3.25 (m, 8H, NCH2 CH2 CH2 NH), 3.34 (m, 8H, NCH2 CH2 CH2 NH), 4.82 (s, 8H, OCH2 CO), 7.40 (s, 8H, ArH), 8.51 (t, 3J 13 C NMR (125 MHz, DMSO-d ) ı 173.59, HH = 5.4 Hz, 4H, CONH). 6 163.19, 152.00, 139.67, 133.29, 79.53, 68.63, 57.51, 40.68, 39.16, 35.95, 28.08. IR, /cm−1 : 1666 (C O), 2962, 3334 (N H). MALDITOF: calcd for [M−NO3 − ]+ m/z = 1534.7, found m/z = 1535.1. El. Anal. Calcd for C72 H116 N12 O20 S4 : C, 54.12; H, 7.32; N, 10.52; S, 8.03. Found: C, 53.93; H, 7.40; N, 10.55; S, 7.99. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetra-[(N-(3 ,3 dimethyl-3 -ethylammoniumpropyl)carbamoylmethoxy]2,8,14,20-thiacalix[4]arene tetranitrate (cone-9). White powder, yield: 0.09 g (93%). Mp: 144 ◦ C. 1 H NMR (400 MHz, 298 K, DMSOd6 ) ı 1.08 (s, 36H, (CH3 )3 C), 1.22 (t, 3 JHH = 7.1 Hz, 12H, N+ CH2 CH3 ) 1.88 (m, 8H, NCH2 CH2 CH2 NH), 2.98 (s, 24H, (CH3 )2 N+ ), 3.24 (m, 8H, NCH2 CH2 CH2 NH), 3.26 (q, 3 JHH = 7.1 Hz, 8H N+ CH2 CH3 ), 3.34 (m, 8H, NCH2 CH2 CH2 NH), 4.82 (s, 8H, OCH2 CO), 7.40 (s, 8H, ArH), 8.50 (t, 4H, 3 JHH = 5.8 Hz, CONH). 13 C NMR (125 MHz, DMSO-d6 ) ı 168.25, 157.89, 146.64, 134.44, 128.01, 74.13, 60.29, 58.71, 49.30, 35.12, 33.80, 30.69, 22.38, 7.99. IR, /cm−1 : 1668 (C O), 2961, 3330 (N H). MALDI-TOF: calcd for [M−NO3 − ]+ m/z = 1590.8, found m/z = 1591.7. El. Anal. Calcd for C76 H124 N12 O20 S4 : C, 55.18; H, 7.56; N, 10.16; S, 7.75. Found: C, 55.23; H, 7.64; N, 10.05; S, 7.34. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetrakis-[(N-(3 ,3 dimethyl-3 -benzylammoniumpropyl)carbamoylmethoxy]2,8,14,20-thiacalix[4]arene tetranitrate (cone-10). White powder, yield: 0.09 g (91%). Mp: 133 ◦ C. 1 H NMR (400 MHz, 298 K, DMSOd6 ) ı 1.07 (s, 36H, (CH3 )3 C), 2.00 (m, 8H, NCH2 CH2 CH2 NH), 2.94 (s, 24H, (CH3 )2 N+ ), 3.19–3.27 (m, 8H, NCH2 CH2 CH2 NH and 8H, NCH2 CH2 CH2 NH), 4.50 (s, 8H, N+ CH2 Ph), 4.81 (s, 8H, OCH2 CO), 7.38 (s, 8H, ArH), 7.46–7.50 (m, 20H, Ar H), 8.51 (br. t, 4H, CONH). 13 C NMR (125 MHz, DMSO-d ) ı 168.29, 158.01, 146.74, 134.42, 6 132.84, 130.25, 128.86, 127.99, 127.86, 74.19, 66.35, 61.29, 49.24, 35.45, 33.91, 30.67, 22.53. IR, /cm−1 : 1639 (C O), 2960, 3300 (N H). MALDI-TOF: calcd for [M−NO3 − ]+ m/z = 1838.9, found m/z = 1839.4. El. Anal. Calcd for C96 H132 N12 O20 S4 : C, 60.61; H, 6.99; N, 8.84; S, 6.74. Found: C, 60.55; H, 6.84; N, 8.73; S, 6.70. 3 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetra-[(N-(3 , dimethyl-3 -(ethoxycarbonylmethyl)ammoniumpropyl) carbamoylmethoxy]-2,8,14,20-thiacalix[4]arene tetranitrate (cone-11). White powder, yield: 0.08 g (88%). Mp: 96 ◦ C. 1 H NMR (400 MHz, 298 K, DMSO-d6 ) ı 1.08 (s, 36H, (CH3 )3 C), 1.24 (t, 3J NCH2 CH2 CH2 NH), HH = 7.1 Hz, 12H, OCH2 CH3 ), 1.92 (m, 8H, 3.19 (s, 24H, (CH3 )2 N+ ), 3.24 (m, 8H, NCH2 CH2 CH2 NH), 3.49 (m, 8H, NCH2 CH2 CH2 NH), 4.20 (q, 3 JHH = 7.1 Hz, 8H, OCH2 CH3 ), 4.41 (s, 8H, N+ CH2 CO), 4.80 (s, 8H, OCH2 CO), 7.40 (s, 8H, ArH), 8.50 (t, 3 JHH = 5.7 Hz, 4H, CONH). 13 C NMR (125 MHz, DMSO-d6 ) ı 168.26, 164.64, 157.85, 146.79, 134.44, 128.00, 74.03, 62.43, 62.00, 60.66, 51.13, 35.29, 33.90, 30.67, 22.48, 13.76. IR, /cm−1 : 1667, 1745 (C O), 2962, 3347 (N H). MALDI-TOF: calcd for [M−Br− ]+ m/z = 1822.8, found m/z = 1823.9. El. Anal. Calcd for C84 H132 N12 O20 S4 : C, 53.49; H, 7.05; N, 8.91; S, 6.80. Found: C, 53.30; H, 7.13; N, 8.82; S, 6.79. 5,11,17,23-Tetra-tert-butyl-25,26,27,28-tetra[(N-(2 ,2 -methyl-2 -{3 -propylphthalimide}ammoniumpropyl)carbamoylmethoxy]-2,8,14,20thiacalix[4]arene tetranitrate (cone-12). White powder, yield: 0.09 g (96%). Mp: 137 ◦ C. 1 H NMR (400 MHz, 298 K, DMSO-d6 )

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ı 1.07 (s, 36H, (CH3 )3 C), 1.88 (m, 8H, CH2 ), 2.05 (m, 8H, CH2 ), 2.99 (s, 12H, (CH3 )2 N+ ), 3.26 (m, 8H, CH2 ), 3.35 (m, 8H, CH2 ), 3.37 (m, 8H, CH2 ), 3.67 (m, 8H, CH2 ), 4.80 (s, 8H, OCH2 CO), 7.39 (s, 8H, ArH), 7.82–7.85 (m, 16H, Pht), 8.48 (t, 3 JHH = 5.3 Hz, 4H, CONH). 13 C NMR (125 MHz, DMSO-d6 ) ı 168.23, 168.00, 157.97, 146.78, 134.42, 131.65, 128.03, 123.03, 74.24, 61.30, 61.04, 50.07, 35.43, 35.38, 34.60, 33.91, 30.69, 22.44, 21.64. IR, /cm−1 : 1665, 1705, 1770 (C O), 2958, 3331 (N H). MALDI-TOF: calcd for [M−NO3 − ]+ m/z = 2228.7, found m/z = 2228.9. El. Anal. Calcd for C112 H144 N16 O28 S4 : C, 58.72; H, 6.34; N, 9.78; S, 5.60. Found: C, 58.61; H, 6.25; N, 9.56; S, 5.63. 2.2. Determination of the association constant and stoichiometry of the complex by UV titration UV–vis spectra were recorded by using a “Shimadzu UV-3600” spectrometer; the cell thickness was 1 cm. A 1 × 10−3 M aqueous solution of silver nitrate, 1 × 10−5 M aqueous solution of fluorescein and BSA (0.5 × 10−3 , 1 × 10−3 , 1.5 × 10−3 , 2.0 × 10−3 , 2.5 × 10−3 , 3.0 × 10−3 , 3.5 × 10−3 , 4.0 × 10−3 , 4.5 × 10−3 , and 5.0 × 10−3 mL) was added to 1 mL of aqueous solution of the receptor 8–12 (3 × 10−6 M) or nanoparticles based on the macrocycles 8–12 (3 × 10−6 M) and substrates. The volume was brought to 3 mL with water, while the concentration of p-tert-butylthiacalix[4]arenes 8–12 (10−6 M) remained constant. The UV spectra of the obtained solutions were then recorded. The stability constant and stoichiometry of complexes were calculated as described elsewhere [49]. Three independent experiments were carried out for each series. Student’s t test was used in statistical data processing. 2.3. Determination of the hydrodynamic size of the particles by DLS The particle size was determined by Zetasizer Nano ZS instrument at 20 ◦ C. The instrument contains a 4 mW He Ne laser operating at a wavelength of 633 nm and incorporates noninvasive backscatter optics (NIBS). The measurements were performed at detection angle of 173◦ , and the measurement position within the quartz cuvette was automatically determined by the software. The results were processed with the DTS (Dispersion Technology Software 4.20) software package. A 1 mL aqueous solution of silver nitrate, fluorescein and BSA (3 × 10−6 M) was added to 1 mL of the aqueous solution of the receptor 8–12 (3 × 10−6 M) or nanoparticles based on the macrocycles 8–12 (3 × 10−6 M) and substrates. The volume was brought to 3 mL with water. The mixture was mechanically shaken for 3 h and then magnetically stirred in a thermostatted water bath at 20 ◦ C for 1 h. Three independent experiments were carried out for each combination of a ligand and substrates. Student’s t test was used in statistical data processing. 3. Results and discussion 3.1. Synthesis of p-tert-butylthiacalix[4]arenes tetrasubstituted at the lower rim with amine, amide, quaternary ammonium groups To synthesize water-soluble p-tert-butylthiacalix[4]arenes containing quaternary ammonium fragments, the macrocycle 2 tetrasubstituted at the lower rim with tertiary amino groups in cone conformation was selected as initial reagent. p-tertButylthiacalix[4]arene 2 was synthesized according to the literature procedure (Scheme 1) [50]. The quaternary ammonium salts based on thiacalix[4]arene were obtained by the interaction of the compound 2 with various alkylating agents in acetonitrile under reflux. The salts 3–7 were obtained with 90–98% yields (Scheme 2).

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S

O

H2N

S S S O O O O O O

O O

N

S S S O O O O

S

methanol/toluene

O O

O O

O

HN

O

HN

1

O HN

HN

2

N

N

N

N

Scheme 1. Reagents and conditions: (i) (CH3 )2 N(CH2 )3 NH2 , CH3 OH/PhCH3 , reflux.

RX, CH3CN

S O OO

S

O O

O

HN

HN

S S O

S

O HN

O

HN

HN

S S S O O O O

HN

O O

O HN

HN

X

X N

N

N

N 2

X

N

X

N

N

R R R 3, R = CH3, X = I; 4, R = CH2CH3, X = I; 5, R = CH2COOEt, X = Br; 6, R = CH2Ph, X = Br; 7, R = CH2CH2CH2Pht, X = Br R

N

Scheme 2. Reagents and conditions: (i) RX, CH3 CN, reflux.

The structure of the synthesized compounds 3–7 was determined by physical methods, i.e. 1 H and 13 C NMR, IR spectroscopy, and mass spectrometry. To increase the solubility of the macrocycles 3–7 in water, iodide and bromide counter ions were replaced by nitrate anion. The interaction of quaternary ammonium salts 3–7 with AgNO3 in acetonitrile at room temperature resulted in the macrocycles 8–12 with 88–96% yields (Scheme 3). The structure and composition of the synthesized compounds 4, 5, and 7–12 were determined by 1 H and 13 C NMR, IR spectroscopy,

S

HN X

O O

O

NH

N

X

S

HN

S S S O O O O O

HN X N

N R R R 3, R = CH3, X = I; 4, R = CH2CH3, X = I; 5, R = CH2COOEt, X = Br; 6, R = CH2Ph, X = Br; 7, R = CH2CH2CH2Pht, X = Br R

The UV spectroscopy is a universal tool for studying complexation properties of the p-tert-butylthiacalix[4]arene (Scheme 4) derivatives toward the substrates (silver nitrate and

HN X

N

3.2. The study of the interaction of p-tert-butylthiacalix[4]arenes tetrasubstituted at the lower rim with silver nitrate and fluorescein by UV spectroscopy and DLS

AgNO3, CH3CN

S S S O O O O O

HN

mass spectrometry (MALDI-TOF) and elemental analysis. The purity of the compounds was checked by TLC.

O O

O HN

HN

NO3 N

NO3

NO3 N

N R1 N NO3 R1 R1 8, R1 = CH3; 9, R1 = CH2CH3; 10, R1 = CH2Ph; 11, R1 = CH2COOEt; 12, R1 = CH2CH2CH2Pht R1

Scheme 3. Reagents and conditions: (i) AgNO3 , CH3 CN, reflux.

E.A. Andreyko et al. / Colloids and Surfaces A: Physicochem. Eng. Aspects 454 (2014) 74–83

S

HN NO3

S S S O O O O O O

O HN

O HN

HN

NO3

N N

NO3 N

R1 R1 R1 8, R1 = CH3; 9, R1 = CH2CH3; 10, R1 = CH2Ph; 11, R1 = CH2COOEt; 12, R1 = CH2CH2CH2Pht R1

N NO3

Scheme 4. The structures of compounds 8–12.

fluorescein). Changes in the absorbance spectrum of the p-tertbutylthiacalix[4]arenes after addition of the silver nitrate and fluorescein indicated the formation of their complexes with the substrates. The interaction between silver nitrate and fluorescein with p-tert-butylthiacalix[4]arenes 8–12 in water monitored by UV spectroscopy showed significant changes in the absorbance spectrum of the macrocycles after the addition of “guest” molecules. Increased absorption at 190–250 nm (hyperchromic effect) was established for the complexes of the p-tert-butylthiacalix[4]arenes 8–12 with some substrates, except systems based on the macrocycles 8–10 and fluorescein. To quantify molecular recognition of the silver nitrate and fluorescein by p-tert-butylthiacalix[4]arenes 8–12, the stability constants and the stoichiometry of the macrocycle–substrate complex formed in the aqueous phase were established. It was shown that the interaction of p-tert-butylthiacalix[4]arenes 8–12 in cone conformation with the substrates led to formation of the 1:1 complexes (Table 1). For the systems comprising of the macrocycles 8–12 and silver nitrate, the efficiency of interaction increased in the range of macrocycles 8–10 containing ammonium fragments with methyl, ethyl and benzyl groups at the nitrogen atom (Table 1). However, the logarithms of the association constant with silver nitrate decreased from the p-tert-butylthiacalix[4]arene 11 containing ester fragments at the ammonium nitrogen atom to macrocycle 12 with phthalimide groups. The UV study of the interaction of the macrocycles 8–12 with fluorescein showed that p-tert-butylthiacalix[4]arenes 8–10 did not interact with the substrate. Effective interaction with fluorescein was observed only for p-tert-butylthiacalix[4]arenes 11 and 12. The logarithms of the association constant with fluorescein increased from p-tertbutylthiacalix[4]arene 11 containing ester fragments to macrocycle 12 with phthalimide groups (Table 1). As was shown earlier, p-tert-butylthiacalix[4]arenes are able to form supramolecular aggregates with silver nitrate in organic phase [45–49]. The logarithms of the association constant varied from 4 to Table 1 Logarithms of the association constant (log Kass ) of the complexes of p-tertbutylthiacalix[4]arenes 8–12 with silver nitrate and fluorescein. Macrocycle

AgNO3

8 9 10 11 12

4.66 4.72 5.58 5.16 4.48

± ± ± ± ±

Fluorescein 0.07 0.11 0.11 0.16 0.10

– – – 5.76 ± 0.65 7.39 ± 0.21

79

6 [45–49], the stoichiometry of the complexes was the same (1:1) as in the case of p-tert-butylthiacalix[4]arenes 8–12 with silver nitrate and fluorescein. It is interesting to note that only macrocycles 11–12 with sufficiently bulk substituents against those in the p-tert-butylthiacalix[4]arenes 8–10 can interact with fluorescein. It can be explained by the ability of the macrocycles 11 and 12 to form self-associates which interact with fluorescein. The DLS is one of the methods successfully applied for the study of the formation of supermolecules and supramolecular assemblies in solution. Self-association and aggregation of the compounds 8–12 in cone conformation were studied in water. The study of self-association of the macrocycles 8–12 in water at 1 × 10−6 M concentration showed that only p-tertbutylthiacalix[4]arenes 10–12 formed nanosized particles of about 61, 4 and 15 nm in size (Table 2). The formation of large particles (61 nm) was observed only for the macrocycle 10 with benzyl fragments and without other potential additional coordination sites. p-tert-Butylthiacalix[4]arene 11 forms about 4 nm particles. The presence of quaternary ammonium fragments with smaller ester groups in the structure of the macrocycle 11 in comparison with phthalimide or benzyl groups resulted in the formation of the particles with smaller hydrodynamic diameter (Table 2). It should be noted that in the case of compounds 8 and 9 taken in the same concentration, no self-associates were observed in water. According to the UV spectroscopy results obtained with this concentration, the formation of supramolecular associates in water requires the presence of quaternary ammonium fragments with bulk alkyl or aryl substituents at the nitrogen atom in a receptor structure. The DLS study of interaction of the macrocycles 8–12 in cone conformation with silver nitrate and fluorescein in water showed that the p-tert-butylthiacalix[4]arenes 8–12 are able to form nanoscale particles with silver nitrate. In the case of fluorescein, only macrocycles 11 and 12 interact with fluorescent probe (Table 2). As was shown earlier, the formation of supramolecular particles based on thiacalix[4]arenes with silver nitrate occurs due to the coordination of the bridging sulfur atom and the oxygen atoms of the carbonyl groups of a macrocycle with silver cations [45–49]. Similar coordination can be assumed for the interaction of the macrocycles 8–12 with silver nitrate in water. It is interesting that the macrocycles 10–12 form by self-assembling with silver nitrate supramolecular particles that significantly differ in size. For the macrocycle 10, the formation of nanosized particles with silver cations decreased the aggregate size to the hydrodynamic diameter of 27 nm. However in case of conpound 11, particle sizes with silver ions increased from 3.8 to 8.2 nm. In contrast to ptert-butylthiacalix[4]arene 11, macrocycle 10 containing lipophilic substituents (benzyl groups) at the ammonium nitrogen atom. Lipophilic substituents of compound 10 make additional contribution to the formation of self-associate in water due to the hydrophobic interactions. As a result, the size of self-associates based on macrocycle 10 is bigger than in the case of compound 11. A new type of particles is formed during the addition of silver nitrate to the system, consisting of self-associates of the macrocycle 10, due to the coordination of silver cations by sulfur atoms and amide groups of the macrocycle. The formation of a new type of particle with polar substrates leads to decreasing of the size of aggregates. In the case of p-tert-butylthiacalix[4]arene 11, containing instead of the benzyl fragments polar proton acceptor and electron donor ester substituents, during the self-association the small particles are formed. The small size of self-associates based on the macrocycle 11 is determined by the best ability of the polar groups (ester fragments at the ammonium nitrogen atom) to the shielding of the hydrophobic core of self-associates from contact with water. It leads to limit the growth of self-associates. As a result of addition of silver nitrate to the p-tert-butylthiacalix[4]arene 11 the aggregation of macrocycles occurs due to the coordination of substrate by sulfur atoms

80

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Table 2 Size (size distribution by number) of aggregates (average hydrodynamic diameters, d1 , d2 , (nm)), peak area intensity, S1 , S2 , (%), for peaks 1 and 2, obtained with the p-tert-butylthiacalix[4]arene derivatives and silver nitrate and fluorescein in H2 O at 20 ◦ C, and polydispersity index (PDI). System

d1 (nm)/S1 (%)

d2 (nm)/S2 (%)

PDI

10 11 12

61.3 ± 16.8/100 3.8 ± 0.7/100 14.6 ± 2.5/100

–

0.26 ± 0.07 0.46 ± 0.11 0.38 ± 0.07

8 + AgNO3 9 + AgNO3 10 + AgNO3 11 + AgNO3 11 + fluorescein 12 + AgNO3 12 + fluorescein

0.7 88.3 27.4 8.2 6.8 20.6 17.1

± ± ± ± ± ± ±

0.05/60 12.9/100 9.7/100 2.2/100 0.9/100 10.4/100 10.5/100

80.7 ± 52.8/40

0.51 0.18 0.37 0.41 0.43 0.36 0.41

± ± ± ± ± ± ±

0.30 0.05 0.07 0.11 0.09 0.06 0.05

[8 + AgNO3 ]agr + fluorescein [9 + AgNO3 ]agr + fluorescein [11 + AgNO3 ]agr + fluorescein [12 + AgNO3 ]agr + fluorescein

0.8 64.3 10.0 13.0

± ± ± ±

0.4/30 8.8/100 0.8/100 9.9/100

67.2 ± 9.3/70

0.28 0.31 0.32 0.31

± ± ± ±

0.04 0.05 0.05 0.14

5.5 6.6 7.7 6.1 6.7 7.5

± ± ± ± ± ±

0.5/100 0.6/100 0.7/100 0.9/100 0.3/100 0.4/100

0.33 0.14 0.11 0.16 0.16 0.12

± ± ± ± ± ±

0.05 0.02 0.03 0.02 0.01 0.02

BSA 8 + BSA [8 + AgNO3 ]agr + BSA 12 + BSA [12 + AgNO3 ]agr + BSA [12 + fluorescein]agr + BSA

and carbonyl groups (amide and ester fragments). Additional coordination of silver nitrate with ester groups of macrocycle 11, in comparison with the compound 10, leads to increase the particle size. In the case of the p-tert-butylthiacalix[4]arene 12, the hydrodynamic diameters of particles observed after the addition of silver nitrate slightly differed from the size of self-associates formed by the macrocycles 12. Only the p-tert-butylthiacalix[4]arene 8 and silver nitrate form two types of particles with the size of 0.8 and 80.7 nm, from which the first one dominates.As was noted above, only macrocycles 11 and 12 that form self-associates are able to form nanoscale aggregates with fluorescein (Table 2). The particle size slightly increases after the addition of fluorescein against the size of the self-associates formed by the host molecules (Table 2). However, it was shown by the UV spectroscopy, that the introduction of fluorescein into the system containing macrocycles 11 and 12, the significant absorbance changes took place. This indicates interaction of the p-tert-butylthiacalix[4]arenes 11 and 12 with the substrate. The UV spectroscopy and DLS data confirm the ability of the self-associates based on p-tert-butylthiacalix[4]arenes 11 and 12 to recognize the substrates (Tables 1 and 2). It should be noted that in the case of the compound 10 which also forms selfassociates, no aggregates with fluorescein were observed by the UV spectroscopy and DLS. The absence of interaction between the ptert-butylthiacalix[4]arene 10 and fluorescein can be explained by the absence of additional binding sites in the structure of the substituents at the ammonium nitrogen atom of the macrocycle 10.It was shown by the UV spectroscopy and DLS that the macrocycles 8–12 effectively interact with the silver nitrate to form nanoscale particles, but only the p-tert-butylthiacalix[4]arenes 11 and 12 can form supramolecular assemblies with fluorescein. We suggest that the self-associates of the p-tert-butylthiacalix[4]arene 11 and 12 interact with fluorescein. 3.3. The interaction of nanoparticles based on the macrocycles 8–12 and silver nitrate with fluorescein As was shown by DLS, the macrocycles 8–12 can form nanoscale aggregates with silver nitrate (Table 2). However, self-assembling of nanosized particles based on amphiphilic ptert-butylthiacalix[4]arenes 8–12 and silver nitrate in water should provide the access to different functional groups on the aggregate

surface to establish further interaction with other substrates like fluorescein. Also it has been shown that only compounds 11 and 12 that form self-associates at 1 10−6 M concentration are able to form nanoscale aggregates with fluorescein. The ability of nanoscale particles based on p-tertbutylthiacalix[4]arenes 8–12 and silver nitrate to interact with fluorescein was studied by UV spectroscopy. The 1:1 stoichiometry was found in all the cases (Table 3). All supramolecular assemblies except that of the macrocycle 10 and silver nitrate can effectively interact with the fluorescent tracer. The logarithms of the association constant are between 4.75 and 7.77. The presence of quaternary ammonium fragments with bulk benzyl fragments and no other coordination sites at the nitrogen atom in the structure of p-tert-butylthiacalix[4]arene 10 did not lead to the interaction of fluorescein with nanoparticles based on the macrocycle 10 and silver nitrate. Macrocycles 8 and 9 do not contain additional coordination sites in the structure of quaternary ammonium fragments, however, the particles based on p-tert-butylthiacalix[4]arenes 8, 9 and silver nitrate interact with fluorescein. Small methyl and ethyl substituents at the quaternary ammonium fragments in the structure of the p-tert-butylthiacalix[4]arenes 8 and 9 allow the amide groups of macrocycles 8 and 9 to interact with fluorescein. It is interesting to note that in the case of the macrocycles 11 and 12 the efficiency of interaction of fluorescein with nanoparticles based on them and silver nitrate decreases like the self-associates based on the p-tert-butylthiacalix[4]arenes 11 and 12 (Table 3). In comparison with the self-associates of the macrocycles 11 and 12, the logarithms of the association constants of the nanoparticles based on them and silver nitrate with fluorescein decreases due to lower amount of the binding sites in the structure of hosting macrocycles because of their coordination with silver nitrate.

Table 3 Logarithms of the association constant (log Kass ) of the complexes of nanoparticles based on the p-tert-butylthiacalix[4]arenes 8–12 and silver nitrate with fluorescein. System

Fluorescein

8 + AgNO3 9 + AgNO3 10 + AgNO3 11 + AgNO3 12 + AgNO3

6.34 ± 0.58 7.77 ± 0.31 – 4.75 ± 1.02 6.03 ± 0.72

E.A. Andreyko et al. / Colloids and Surfaces A: Physicochem. Eng. Aspects 454 (2014) 74–83

81

Fig. 2. Possible types of supramolecular structures formed by tetrasubstituted p-tert-butylthiacalix[4]arenes with silver nitrate and fluorescein.

It was shown by DLS that the introduction of fluorescein into the supramolecular assemble based on the macrocycles 8, 9, 11, 12 and silver nitrate resulted in the changes in size of supramolecular particles (Fig. 2 and Table 2). In all the cases, except the system of p-tert-butylthiacalix[4]arene 11 and silver nitrate, the particle size decreased after the addition of fluorescein. For the particles based on silver nitrate and macrocycles 11, 12 containing ester and phthalimide fragments with complementary coordination centers, the particle size was equal to 10 and 13 nm after the addition of the fluorescent tracer. In the case of supramolecular assemblies based on silver nitrate and p-tert-butylthiacalix[4]arenes 8 and 9 containing alkyl substituents without additional coordination sites, the particle sizes after addition of fluorescein was equal to 67 and 64 nm. For the system [macrocycle 8 + AgNO3 ]agr + fluorescein the formation of two types of particles with sizes of about 0.8 and 67 nm was observed similarly to the nanoparticles based on the macrocycle 8 and AgNO3 . However, in contrast to the system [macrocycle 8 + AgNO3 ]agr nanoscale aggregates with a hydrodynamic diameter of about 67 nm dominated for the system ([macrocycle 8 + AgNO3 ]agr + fluorescein). Thus, it was shown by UV spectroscopy and DLS that only supramolecular assemblies formed by self-association of the

macrocycles or aggregation of p-tert-butylthiacalix[4]arenes with silver nitrate can interact with fluorescein. Macrocycles unable to form nanoscale particles and supramolecular aggregates without additional coordination sites on surface did not interact with fluorescein. 3.4. The interaction of the macrocycles 8 and 12, nanoscale particles based on macrocycles 8, 12 and silver nitrate or fluorescein with BSA It was shown by DLS and UV spectroscopy that the nanoparticles based on the macrocycles 8–9, 11–12 and silver nitrate are able to further interact with a third component, e.g., fluorescein in this study. BSA was selected as a substrate instead of fluorescein to study the interaction with nanoparticles based macrocycles and silver nitrate or fluorescein. The macrocycles 8 and 12 containing various functional groups and different in ability to form self-associates were selected for this study. It was shown by UV-spectroscopy that the macrocycles 8 and 12 effectively interact with BSA. The logarithms of the association constant were 6.96 and 6.70, respectively, and the stoichiometry equal to 1:1 (Table 4). In the range of the nanoparticles formed by

Fig. 3. Possible types of supramolecular structures formed by nanoparticles based on the p-tert-butylthiacalix[4]arenes and silver nitrate or fluorescein with BSA.

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Table 4 Logarithms of the association constant (log Kass ) of the complexes of the p-tert-butylthiacalix[4]arenes 8, 12 and nanoparticles based on p-tertbutylthiacalix[4]arenes 8, 12 and silver nitrate or fluorescein with BSA. System

BSA

8 (8 + AgNO3 ) 12 (12 + AgNO3 ) (12+ fluorescein)

6.96 7.12 6.70 6.63 6.49

– scholarships of the President of the Russian Federation (CP1753.2012.4) is gratefully acknowledged. Appendix A. Supplementary data

± ± ± ± ±

0.15 0.11 0.09 0.11 0.13

Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.colsurfa.2014. 04.021. References

the macrocycles 8 to 12 the logarithms of the association constant were near 6 except that of the p-tert-butylthiacalix[4]arene 8 and silver nitrate and the efficiency of interaction increased (Table 4). Nanoparticles based on the macrocycles 8, 12 and silver nitrate or fluorescein contain positively charged quaternary ammonium substituent on the surface, while BSA (pI = 4.8) at pH 5.6 has a negative surface charge. Thus, the interaction of the nanoparticles with the protein occurs due to the electrostatic forces. Hydrogen bonds and hydrophobic interactions as electrostatic interactions also significantly impact on the interaction of nanoparticles with BSA. It was shown by DLS particles with the size of about 5.5 nm were observed in aqueous BSA solution (Table 2). However, after the addition of the p-tert-butylthiacalix[4]arenes 8, 12 or nanoparticles based on macrocycles 8, 12 and silver nitrate or fluorescein to BSA the particle size increased by 1–2 nm (Table 2). These slight changes in hydrodynamic diameter caused by the interaction of BSA with the p-tert-butylthiacalix[4]arenes 8, 12 or nanoparticles based on the macrocycles can be explained by sufficiently smaller size (about 0.4 nm) of the macrocycles. In the case of supramolecular aggregates, the hydrodynamic diameter of nanoparticles based on p-tert-butylthiacalix[4]arenes 8, 12 with silver nitrate or fluorescein is close to the size of BSA, or is much less than that (0.7 nm for the system [macrocycle 8 + AgNO3 ]agr ) (Fig. 3.) Thus, the ability of nanoparticles based on the p-tertbutylthiacalix[4]arenes 8, 12 and silver nitrate or fluorescein to effectively interact with BSA to form supramolecular structures of about 6–7 nm was shown by UV-spectroscopy and DLS. 4. Conclusions New amphiphilic p-tert-butylthiacalix[4]arenes containing quaternary ammonium fragments with alkyl, aryl, ester and phthalimide groups at the nitrogen atom in cone conformation were synthesized. It was shown by UV-spectroscopy that the macrocycles 8–12 can effectively interact with silver nitrate and fluorescein. It was shown by DLS that p-tert-butylthiacalix[4]arenes form nanosized particles with silver nitrate, but only macrocycles 11–12 able to self-association interact with fluorescein. The nanoparticles based on silver nitrate and macrocycles 8–12 can effectively interact with fluorescein and BSA. High efficiency of interaction of nanoparticles based on p-tert-butylthiacalix[4]arene 8 and silver nitrate with BSA was observed in comparison with other systems. It was found that supramolecular particles formed by the p-tert-butylthiacalix[4]arenes 8 and 12 with fluorescein effectively interact with BSA. According to these results, the nanoparticles based on p-tert-butylthiacalix[4]arenes 8–12 and fluorescein can be used as fluorescent markers for the construction of sensors and drug delivery systems. Acknowledgements The financial support of RFBR (12-03-31137 mol a and 1203-00252-a) and the Program of the President of the Russian Federation for the State support of young Russian scientists

[1] J.M. Lehn, Toward self-organization and complex matter, Science 295 (2002) 2400–2403. [2] J.M. Lehn, Supramolecular Chemistry: Concepts and Perspectives, Wiley-VCH, New York, 1995. [3] J.W. Steed, J.L. Atwood, Supramolecular Chemistry, 2nd ed., John Wiley Hoboken, NJ, 2009. [4] J.L. Atwood, J.W. Steed, Organic Nanostructures, Wiley-VCH, Weinheim, 2008. [5] M.M. Conn, J. Rebek Jr., Self-assembling capsules, J. Chem. Rev. 97 (1997) 1647–1668. [6] B. Linton, A.D. Hamilton, Formation of artificial receptors by metal templated self-assembly, Chem. Rev. 97 (1997) 1669–1680. [7] U. Ocak, M. Ocak, R.A. Bartsch, Calixarenes with dansyl groups as potential chemosensors, Inorg. Chim. Acta 381 (2012) 44–57. [8] A. Acharya, B. Ramanujam, J.P. Chinta, C.P. Rao, 1,3-Diamido-calix[4]arene conjugates of amino acids: recognition of COOH side chain present in amino acids, peptides, and proteins by experimental and computational studies, J. Org. Chem. 76 (2011) 127–137. [9] J. De Mendoza, Self-assembling cavities: present and future, Chem. Eur. J. 4 (1998) 1373–1377. [10] J. Rebek Jr., Reversible encapsulation and its consequences in solution, Acc. Chem. Res. 32 (1999) 278–286. [11] J.L. Atwood, J.E.D. Davies, D.D. MacNicol, F. Vogtle, J.M. Lehn, G.W. Gokel, Comprehensive Supramolecular Chemistry, Pergamon, London, 1996. [12] I.I. Stoikov, E.A. Yushkova, I.S. Antipin, A.I. Konovalov, Synthesis of silver and lithium sub-micro- and nanoparticles coated with derivatives of p-tert-butyl thiacalix[4]arenes, J. Nanopart. Res. 13 (2011) 6603–6611. [13] H.-J. Schneider, L. Tianjun, M. Sirish, V. Malinovsky, Dispersive interactions in supramolecular porphyrin complexes, Tetrahedron 58 (2002) 779–786. [14] H.-J. Schneider, Binding mechanisms in supramolecular complexes, Angew. Chem. Int. Ed. 48 (2009) 3924–3977. [15] I. Piantanida, B.S. Palm, P. Cudic, M. Zinic, H.-J. Schneider, Phenanthridinium cyclobisintercalands. Fluorescence sensing of AMP and selective binding to single-stranded nucleic acids, Tetrahedron Lett. 42 (2001) 6779–6783. [16] I. Piantanida, B.S. Palm, P. Cudic, M. Zinic, H.-J. Schneider, Interactions of acyclic and cyclic bis-phenanthridinium derivatives with ss- and ds-polynucleotides, Tetrahedron 60 (2004) 6225–6231. [17] D.K. Chand, H.-J. Schneider, J.A. Aguilar, F. Escarti, E. Garcıa-Espan, S.V. Luis, Copper complexes of polyaza[n]cyclophanes and their interaction with DNA and RNA, Inorg. Chim. Acta 316 (2001) 71–78. [18] H.-J. Schneider, Ligand binding to nucleic acids and proteins: does selectivity increase with strength? Eur. J. Med. Chem. 43 (2008) 2307–2315. [19] N. Lomadze, H.-J. Schneider, A chitosan-based chemomechanical polymer triggered by stacking effects with aromatic effectors including aminoacid derivatives, Tetrahedron 61 (2005) 8694–8698. [20] S. Negi, H.-J. Schneider, Metal coordination and stacking effects in supramolecular catalysis. Effects of structural variations of copper complexes for the hydrolysis of phosphate esters, Tetrahedron Lett. 43 (2002) 411–414. [21] E. Da Silva, F. Nouar, M. Nierlich, B. Rather, M.J. Zaworotko, C. Barbey, A. Navaza, A.W. Coleman, A comparative structural study of four parasulphonatocalix[4]arene organic di- and triammonium cation complexes, Cryst. Eng. 6 (2003) 123–135. [22] E. Da Silva, A.W. Coleman, Synthesis and complexation properties towards amino acids of mono-substituted p-sulphonato-calix-[n]-arenes, Tetrahedron 59 (2003) 7357–7364. [23] P. Shahgaldian, E. Da Silva, A.W. Coleman, B. Rather, M.J. Zaworotko, Paraacyl-calix-arene based solid lipid nanoparticles (SLNs): a detailed study of preparation and stability parameters, Int. J. Pharm. 253 (2003) 23–38. [24] M. Lamouchi, E. Jeanneau, R. Chiriac, D. Ceroni, F. Meganem, A. Brioude, A.W. Coleman, C. Desroches, Monosubstituted lower rim thiacalix[4]arene derivatives, Tetrahedron Lett. 53 (2012) 2088–2090. [25] E. Da Silva, P. Shahgaldian, A.W. Coleman, Haemolytic properties of some watersoluble para-sulphonato-calix[n]arenes, Int. J. Pharm. 273 (2004) 57–62. [26] P. Shahgaldian, A.W. Coleman, V.I. Kalchenko, Synthesis and properties of novel amphiphilic calix-[4]-arene derivatives, Tetrahedron Lett. 42 (2001) 577–579. [27] O. Kundrat, V. Eigner, P. Curinov, J. Kroupa, P. Lhotak, Anion binding by meta ureido-substituted thiacalix[4]arenes, Tetrahedron 67 (2011) 8367–8372. [28] J. Kroupa, I. Stibor, M. Pojarova, M. Tkadlecova, P. Lhotak, Anion receptors based on ureido-substituted thiacalix[4]arenes and calix[4]arenes, Tetrahedron 64 (2008) 10075–10079. [29] K. Flidrova, M. Tkadlecova, K. Lang, P. Lhotak, Anion recognition by calix[4]arene-based p-nitrophenyl amides, Tetrahedron Lett. 53 (2012) 678–680.

E.A. Andreyko et al. / Colloids and Surfaces A: Physicochem. Eng. Aspects 454 (2014) 74–83 [30] M. Yilmaz, S. Erdemir, Calixarene-based receptors for molecular recognition, Turk. J. Chem. 37 (2013) 558–585. [31] O. Hudecek, P. Curinova, J. Budka, P. Lhotak, Regioselective upper rim substitution of calix[4]arenes, Tetrahedron 67 (2011) 5213–5218. [32] C.D. Gutsche, Calixarenes revisited, in: Monographs in Supramolecular Chemistry, RSC, London, 1998. [33] N. Iki, S. Miyano, Can thiacalixarene surpass calixarene? J. Incl. Phenom. Macrocycl. Chem. 41 (2001) 99–105. [34] P. Lhotak, Chemistry of thiacalixarenes, Eur. J. Org. Chem. 71 (2004) 1675–1692. [35] N. Morohashi, F. Narumi, N. Iki, T. Hattori, S. Miyano, Thiacalixarenes, Chem. Rev. 106 (2006) 5291–5316. [36] H. Kumagai, M. Hasegawa, S. Miyanari, Y. Sugawa, Y. Sato, T. Hori, S. Ueda, H. Kamiyama, S. Miyano, Facile synthesis of p-tert-butylthiacalix[4]arene by the reaction of p-tert-butylphenol with elemental sulfur in the presence of a base, Tetrahedron Lett. 38 (1997) 3971–3972. [37] I.I. Stoikov, V.A. Smolentsev, I.S. Antipin, W.D. Habicher, M. Gruner, A.I. Konovalov, Array of fluorescent chemosensors for the molecular recognition of halide anions on the basis of the stereoisomers of thiacalix[4]arene tetranaphthylamides, Mend. Commun. 16 (2006) 294–297. [38] I.I. Stoikov, A.Yu. Zhukov, M.N. Agafonova, R.R. Sitdikov, I.S. Antipin, A.I. Konovalov, p-tert-Butyl thiacalix[4]arenes functionalized at the lower rim by o-, m-, p-amido and o-, m-, p-(amidomethyl)pyridine fragments as receptors for ␣-hydroxy- and dicarboxylic acids, Tetrahedron 66 (2010) 359–367. [39] I.I. Stoikov, A.A. Yantemirova, R.V. Nosov, I.Kh. Rizvanov, A.R. Julmetov, V.V. Klochkov, I.S. Antipin, A.I. Konovalov, I. Zharov, p-tert-Butyl thiacalix[4]arenes functionalized at the lower rim by amide, hydroxyl and ester groups as anion receptors, Org. Biomol. Chem. 9 (2011) 3225–3234. [40] I.I. Stoikov, A.A. Yantemirova, R.V. Nosov, A.R. Julmetov, V.V. Klochkov, I.S. Antipin, A.I. Konovalov, Chemo- and stereocontrolled alkylation of 1,2disubstituted at the lower rim 1,2-alternate p-tert-butylthiacalix[4]arene, Mend. Commun. 21 (2011) 41–43. [41] I.I. Stoikov, E.A. Yushkova, I. Zharov, I.S. Antipin, A.I. Konovalov, Supramolecular self-assemblies of stereoisomers of p-tert-butylthiacalix[4]arenes functionalized with hydrazide groups at the lower rim with some metal cations, Tetrahedron 65 (2009) 7109–7114.

83

[42] M. Yamada, Y. Ootashiro, Y. Kondo, F. Hamada, A 3D supramolecular network assembly based on thiacalix[4]arene by halogen–halogen, CH–Br, CH–p, and S–p interactions, Tetrahedron Lett. 54 (2013) 1510–1514. [43] E.V. Ukhatskaya, S.V. Kurkov, S.E. Matthews, A.E. Fagui, C. Amiel, F. Dalmas, Th. Loftsson, Evaluation of a cationic calix[4]arene: solubilization and selfaggregation ability, Int. J. Pharm. 402 (2010) 10–19. [44] M.K. Rauf, R. Mushtaq, A. Badshah, R. Kingsford-Adaboh, J.J.E.K. Harrison, H. Ishida, Synthesis and crystal structure studies of three N-phenylphthalimide derivatives, J. Chem. Crystallogr. 43 (2013) 144–150. [45] I.I. Stoikov, E.A. Yushkova, A.Yu. Zhukov, I. Zharov, I.S. Antipin, A.I. Konovalov, The synthesis of p-tert-butylthiacalix[4]arenes functionalized with secondary amide groups at the lower rim and their extraction properties and self-assembly into nanoscale aggregates, Tetrahedron 64 (2008) 7112–7121. [46] I.I. Stoikov, E.A. Yushkova, A.Yu. Zhukov, I. Zharov, I.S. Antipin, A.I. Konovalov, Solvent extraction and self-assembly of nanosized aggregates of p-tertbutylthiacalix[4]arenes tetrasubstituted at the lower rim by tertiary amide groups and monocharged metal cations in the organic phase, Tetrahedron 64 (2008) 7489–7497. [47] E.A. Yushkova, I.I. Stoikov, p-tert-Butylthiacalix[4]arenes functionalized with amide and hydrazide groups at the lower rim in cone, partial cone, and 1,3alternate conformations are “smart” building blocks for constructing nanosized structures with metal cations of s-, p-, and d-elements in the organic phase, Langmuir 25 (2009) 4919–4928. [48] E.A. Yushkova, I.I. Stoikov, J.B. Puplampu, I.S. Antipin, A.I. Konovalov, Cascade and commutative self-assembles of nanoscale three-component systems controlled by the conformation of thiacalix[4]arene, Langmuir 27 (2011) 14053–14064. [49] E.A. Yushkova, I.I. Stoikov, A.Yu. Zhukov, J.B. Puplampu, I.Kh. Rizvanov, I.S. Antipin, A.I. Konovalov, Heteroditopic p-tert-butylthiacalix[4]arenes for creating supramolecular self-assembles by cascade or commutative mechanisms, RSC Adv. 2 (2012) 3906–3919. [50] E.A. Andreyko, P.L. Padnya, R.R. Daminova, I.I. Stoikov, Supramolecular “containers”: self-assembly and functionalization of thiacalix[4]arenes for recognition of amino- and dicarboxylic acids, RSC Adv. 4 (2014) 3556–3565.