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Search for "UV–vis spectra" in Full Text gives 245 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

Stimuli-responsive HBPS-g-PDMAEMA and its application as nanocarrier in loading hydrophobic molecules

  • Yongsheng Chen,
  • Li Wang,
  • Haojie Yu,
  • Zain-Ul-Abdin,
  • Ruoli Sun,
  • Guanghui Jing,
  • Rongbai Tong and
  • Zheng Deng

Beilstein J. Org. Chem. 2016, 12, 939–949, doi:10.3762/bjoc.12.92

Graphical Abstract
  • 400M spectrometer. The molecular weight of polymer was determined by gel permeation chromatography (GPC) (Waters-Wyatt) equipped with RI, UV, viscosity and LS detectors using tetrahydrofuran (THF) as eluent. The UVvis spectra were recorded on a UV3802 (UNICO) ultraviolet spectrophotometer. The size
  • ) PDI of HBPS-g-PDMAEMA as function of the temperature in aqueous solutions with pH 7.4 and 8.5. (A) The UVvis spectra of HBPS-g-PDMAEMA/pyrene solution with different polymer concentrations; (B) the absorption at 337 nm of HBPS-g-PDMAEMA/pyrene solution with different polymer concentrations. (C)The
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Published 10 May 2016

Separation and identification of indene–C70 bisadduct isomers

  • Bolong Zhang,
  • Jegadesan Subbiah,
  • David J. Jones and
  • Wallace W. H. Wong

Beilstein J. Org. Chem. 2016, 12, 903–911, doi:10.3762/bjoc.12.88

Graphical Abstract
  • ] and C70 bis-malonate isomers [17], was expected to provide further information on adduct configurations. The UVvis spectra of fractions 1, 2 and 3 showed very similar spectral features when compared with the spectrum of the 5 o’clock isomer of C70 bis-malonate, suggesting that they are all 5 o’clock
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Published 06 May 2016

Indenopyrans – synthesis and photoluminescence properties

  • Andreea Petronela Diac,
  • Ana-Maria Ţepeş,
  • Albert Soran,
  • Ion Grosu,
  • Anamaria Terec,
  • Jean Roncali and
  • Elena Bogdan

Beilstein J. Org. Chem. 2016, 12, 825–834, doi:10.3762/bjoc.12.81

Graphical Abstract
  • lattice, along with an emission-band broadening, as compared to the solution fluorescence spectra. Keywords: indenopyran-3-ones; organic fluorophores; pyrones; solid-state emission spectra; solution emission spectra; UVvis spectra; Introduction Indenopyrans are functionalized oxygen-containing
  • , Supporting Information File 1) exhibit characteristic signals for the aliphatic protons: one singlet at 4.19 ppm for derivative 5c and one signal at 3.97 ppm for compound 4c, respectively. Next, the photoluminescence properties of the isolated indenopyrones 4c, 5c and 6a were investigated. The UVvis spectra
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Published 27 Apr 2016

Syntheses of dibenzo[d,d']benzo[2,1-b:3,4-b']difuran derivatives and their application to organic field-effect transistors

  • Minh Anh Truong and
  • Koji Nakano

Beilstein J. Org. Chem. 2016, 12, 805–812, doi:10.3762/bjoc.12.79

Graphical Abstract
  • quantum yield (Φ = 61% in CHCl3 solution). To investigate the structure–property relationship of DBBDFs and DNBDFs, the optical properties of syn-DBBDF 5 and syn-DNBDF 6 were compared with those of anti-DBBDF 3 and anti-DNBDF 4. The UVvis spectra of anti-DBBDF 3 and anti-DNBDF 4 were reported to show
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Published 26 Apr 2016

Interactions between 4-thiothymidine and water-soluble cyclodextrins: Evidence for supramolecular structures in aqueous solutions

  • Vito Rizzi,
  • Sergio Matera,
  • Paola Semeraro,
  • Paola Fini and
  • Pinalysa Cosma

Beilstein J. Org. Chem. 2016, 12, 549–563, doi:10.3762/bjoc.12.54

Graphical Abstract
  • almost catalytic effect of glucose. It is noteworthy that the same experiments performed adding glucose at ratios S4TdR/glucose of 1:1, 1:5, and 1:10 did not show any influence on the UVvis spectra of S4TdR aqueous solutions (data not shown). In conclusion the synergic use of UV–vis measurements and CV
  • S4TdR was necessary in order to detect significant signals in measurements. UV–vis measurements were carried out using a S4TdR concentration of 1 × 10−5 M. Before use, these solutions were maintained under agitation for 10 min at room temperature. Analysis UV–vis measurements UVvis spectra were
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Published 21 Mar 2016

New synthetic strategies for xanthene-dye-appended cyclodextrins

  • Milo Malanga,
  • Andras Darcsi,
  • Mihaly Balint,
  • Gabor Benkovics,
  • Tamas Sohajda and
  • Szabolcs Beni

Beilstein J. Org. Chem. 2016, 12, 537–548, doi:10.3762/bjoc.12.53

Graphical Abstract
  • inexpensive dyes, we prepared rhodamine- and fluorescein-appended cyclodextrins. The compounds were characterized by NMR and IR spectroscopy and MS spectrometry, their UVvis spectra were recorded at various pH, and their purity was determined by capillary electrophoresis. Two potential models for the
  • that the fluorophore in Rho-β-CD is (if isolated according to the procedure reported in the Experimental section) in a nonfluorescent cyclic form. The same conclusion can be also reached through the analysis of the UVvis spectra (Supporting Information File 1, Figure S16). The UVvis spectra of Rho-β
  • of Flu-β-CD In Supporting Information File 1, Figure S18, the UVvis spectra of fluorescein disodium salt and of Flu-β-CD are shown. Under acidic conditions (at pH 3), the UV–vis spectrum and the fluorescence of the free dye changes remarkably. In particular, the UV band at around 490 nm is almost
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Published 17 Mar 2016

Hydroquinone–pyrrole dyads with varied linkers

  • Hao Huang,
  • Christoffer Karlsson,
  • Maria Strømme,
  • Martin Sjödin and
  • Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 89–96, doi:10.3762/bjoc.12.10

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  • , Box 576, SE-751 23 Uppsala, Sweden 10.3762/bjoc.12.10 Abstract A series of pyrroles functionalized in the 3-position with p-dimethoxybenzene via various linkers (CH2, CH2CH2, CH=CH, C≡C) has been synthesized. Their electronic properties have been deduced from 1H NMR, 13C NMR, and UVvis spectra to
  • -3c. This illustrates the well-known caveat for chemical shift predictions [26]. To assess the electronic properties as indicated in UVvis spectra, reference spectra of pyrrole, DMB, 1,4-dimethoxy-2-vinylbenzene (DMB-VI), and 1,4-dimethoxy-2-ethynylbenzene (DMB-EN) were recorded. The UVvis spectra
  • therefore a measure of the charge delocalization in the molecule. This effect can be viewed as an increased delocalized system that results in a lowering of the HOMO–LUMO gap, which can be traced by the red shifts of the highest wavelength absorption in UVvis spectra (Table 1). The extent of conjugation
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Published 18 Jan 2016

Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism

  • David Porter,
  • Belinda M.-L. Poon and
  • Peter J. Rutledge

Beilstein J. Org. Chem. 2015, 11, 2549–2556, doi:10.3762/bjoc.11.275

Graphical Abstract
  • chromatographs were equipped with split/splitless capillary inlets and flame ionization detectors (FID). UVvis spectra were recorded on a Varian Carey 4000 UV–vis spectrophotometer. Synthesis of iron complexes 4, 5 and 6 and N-Boc-hydroxylamine (8) Tris(2-pyridylmethyl)amine (TPA, 1) [48] and N,N′-bis(2
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Published 11 Dec 2015

Urethane tetrathiafulvalene derivatives: synthesis, self-assembly and electrochemical properties

  • Xiang Sun,
  • Guoqiao Lai,
  • Zhifang Li,
  • Yuwen Ma,
  • Xiao Yuan,
  • Yongjia Shen and
  • Chengyun Wang

Beilstein J. Org. Chem. 2015, 11, 2343–2349, doi:10.3762/bjoc.11.255

Graphical Abstract
  • •+) were formed, which was possibly supported by the increase of the absorption bands around 600–900 nm (Figure 5a) [2][4]. Moreover, the UVvis spectra of self-assembled nanoribbons doped with iodine were collected. It was concluded that the assembled solid structures were maintained. Figure 5b shows the
  • glass substrates (drop-coated from diluted T1 or T2 solution). The UVvis spectra of T1 (a) and T2 (b) at different concentrations in ethyl acetate. IR spectra of (a) T1, (b) T2, (c) TCNQ, (d) T2/TCNQ, and (e) T1/TCNQ. (a) UVvis spectra of T1 solutions TCNQ and T1/TCNQ in ethyl acetate (1 × 10−3 M). (b
  • ) UVvis spectra of T1 before and after iodine doping for 30 min. Cyclic voltammograms of T1 and T2 in DCM. Conditions: 0.1 M tetrabutylammonium hexafluorophosphate, 100 mV s−1, Ag/AgCl as the reference electrode, Pt wire as the counter electrode, and glassy carbon as the working electrode; measured
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Published 27 Nov 2015

Effective ascorbate-free and photolatent click reactions in water using a photoreducible copper(II)-ethylenediamine precatalyst

  • Redouane Beniazza,
  • Natalia Bayo,
  • Florian Molton,
  • Carole Duboc,
  • Stéphane Massip,
  • Nathan McClenaghan,
  • Dominique Lastécouères and
  • Jean-Marc Vincent

Beilstein J. Org. Chem. 2015, 11, 1950–1959, doi:10.3762/bjoc.11.211

Graphical Abstract
  • Cambridge Crystallographic Data Centre as deposition CCDC 1414149 for 4, and CCDC 1410011 for 1. Evolution of the UVvis spectra of deaerated (freeze-pump-thaw degassed, sealed quartz cuvettes) THF (left) or water (right) solutions (3 mL) of complex 1 (2 mM) under irradiation at 365 nm using a TLC lamp
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Published 21 Oct 2015

Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

  • Dileep Kumar Singh and
  • Mahendra Nath

Beilstein J. Org. Chem. 2015, 11, 1434–1440, doi:10.3762/bjoc.11.155

Graphical Abstract
  • , 12b and 13b), and zinc porphyrins (Zn-TPP, 6c, 6f, 7a and 13a) are shown in Figure 1a–c. Besides the Soret and Q-bands, an additional absorption band was also observed at ~340 nm in the UVvis spectra of these porphyrin–xanthone conjugates due to the presence of xanthone moiety (Figure 1a–c) which
  • applications. (a) Electronic absorption spectra of Cu-TPP, 6a, 7e, 12a and 13c. (b) Electronic absorption spectra of TPP, 6b, 7b, 12b and 13b. (c) Electronic absorption spectra of Zn-TPP, 6c, 6f, 7a and 13a in CHCl3 (1.5 × 10−6 mol L−1) at 298 K and inset shows the expanded UVvis spectra with Q-bands. (d
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Published 17 Aug 2015

Synthesis of photoresponsive cholesterol-based azobenzene organogels: dependence on different spacer lengths

  • Yuchun Ren,
  • Bin Wang and
  • Xiuqing Zhang

Beilstein J. Org. Chem. 2015, 11, 1089–1095, doi:10.3762/bjoc.11.122

Graphical Abstract
  • , respectively. It should be emphasized that such reversible spectral transformation could be repeated several times. The trans-to-cis isomerization of the azobenzenze unit had been demonstrated. Compounds M2, M5, M6, and M12 have the same recoverable photoresponsive properties as M0. Their UVvis spectra were
  • organogelators and soft matter. Changes in the absorption over time in the UVvis spectra of dilute THF solution of M0: (a) upon UV-light irradiation (λ = 365 nm) and (b) upon visible-light irradiation (λ = 450 nm) of the solution obtained after irradiation of 365 nm. DSC thermogram of the compounds M0-n
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Published 29 Jun 2015

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ

  • Raúl García,
  • M. Ángeles Herranz,
  • Edmund Leary,
  • M. Teresa González,
  • Gabino Rubio Bollinger,
  • Marius Bürkle,
  • Linda A. Zotti,
  • Yoshihiro Asai,
  • Fabian Pauly,
  • Juan Carlos Cuevas,
  • Nicolás Agraït and
  • Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

Graphical Abstract
  • experimental procedures for the synthesis and characterization of 5, break junction experiments and theoretical methods. Acknowledgements We thank Dr. Jose Manuel Santos Barahona for help with preparing the CT complex with TCNQ, and recording and interpreting the UVvis spectra. Financial support by the
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Published 24 Jun 2015

Carboxylated dithiafulvenes and tetrathiafulvalene vinylogues: synthesis, electronic properties, and complexation with zinc ions

  • Yunfei Wang and
  • Yuming Zhao

Beilstein J. Org. Chem. 2015, 11, 957–965, doi:10.3762/bjoc.11.107

Graphical Abstract
  • vis spectra of TTFVs 5 and 6 (solid lines) and DTF 4 and 7 (dashed lines). Compounds 4 and 5 were measured in CH2Cl2, while compounds 6 and 7 were in THF. Cyclic voltammograms of compounds 4–9. Experimental conditions: supporting electrolyte: Bu4NBF4 (0.1 M), working electrode: glassy carbon, counter
  • containing Et3N/EtOH (6 mL, 1:2). The jar was sealed and left standing for 2 days. The precipitate formed in the vial was collected by centrifugation and rinsed with EtOH to afford Zn-DTF 9 (15.1 mg) as a yellow solid. FTIR (neat): 3360, 2990, 2916, 1585, 1559, 1538, 1494, 1392, 1187, 803, 768, 472 cm−1. UV
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Published 03 Jun 2015

Synthesis and characterization of the cyanobenzene-ethylenedithio-TTF donor

  • Sandrina Oliveira,
  • Dulce Belo,
  • Isabel C. Santos,
  • Sandra Rabaça and
  • Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 951–956, doi:10.3762/bjoc.11.106

Graphical Abstract
  • investigated by UV–vis absorption spectroscopy in dichloromethane solution. The UVvis spectra in DCM (Figure S6 in Supporting Information File 1) showed π–π* transitions typical of TTF donors [21], with an intense absorption band centred at approximately at 231 nm and other weaker bands at 269, 305 and 329 nm
  • as solvents respectively and TMS the internal reference. UVvis spectra were recorded on an UV-1800 Shimadzu spectrophotometer. Cyclic voltammetry data were obtained using a BAS C3 Cell Stand. The voltammograms were obtained at room temperature with a scan rate of 100 mV/s, platinum wire working and
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Published 03 Jun 2015

Tuning of tetrathiafulvalene properties: versatile synthesis of N-arylated monopyrrolotetrathiafulvalenes via Ullmann-type coupling reactions

  • Vladimir A. Azov,
  • Diana Janott,
  • Dirk Schlüter and
  • Matthias Zeller

Beilstein J. Org. Chem. 2015, 11, 860–868, doi:10.3762/bjoc.11.96

Graphical Abstract
  • reaction with bromophenol 8d to form the adduct 4f also confirmed the possibility of the reaction with hydroxy-substituted aryl derivatives, paving the way for application of this method with non-protected calix[4]arene derivatives [27]. Compounds 4a–c,e,f (Figure 3) display UVvis spectra typical for TTF
  • = 0.86 V, E1/2ox3 = 1.77 V. Molecular structures of tetrathiafulvalenes 1, bis-pyrrolotetrathiafulvalenes 2 and monopyrrolotetrathiafulvalenes 3. Copper(I) ligands 9a and 9b. UVvis spectra of compounds 4a,c–f (CH2Cl2, c = 4 × 10−5 M). Cyclic voltammograms of compounds 4a,c [22] and 4d–f (plotted vs SCE
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Published 21 May 2015

Impact of multivalent charge presentation on peptide–nanoparticle aggregation

  • Daniel Schöne,
  • Boris Schade,
  • Christoph Böttcher and
  • Beate Koksch

Beilstein J. Org. Chem. 2015, 11, 792–803, doi:10.3762/bjoc.11.89

Graphical Abstract
  • ) Dynamic light scattering of 0.05 µM Au/MUA nanoparticles at pH 9. (B) Cryo TEM image of 0.05 µM Au/MUA nanoparticles at pH 9. (C) UVvis spectra of 0.05 µM Au/MUA nanoparticles at pH 9 and in the presence of 30 µM VW05. (D) Time and concentration dependent shift in the absorption maximum of 0.05 µM Au/MUA
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Published 15 May 2015

TTFs nonsymmetrically fused with alkylthiophenic moieties

  • Rafaela A. L. Silva,
  • Bruno J. C. Vieira,
  • Marta M. Andrade,
  • Isabel C. Santos,
  • Sandra Rabaça,
  • Dulce Belo and
  • Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 628–637, doi:10.3762/bjoc.11.71

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  • internal reference. UVvis spectra were recorded on a UV-1800 Shimadzu spectrophotometer. Mass spectra were obtained in QIT/MS Bruker HCT by collision-induced dissociation (CID). 5-(tert-Butyl)thieno[2,3-d][1,3]dithiol-2-one (I): 0.536 g of aluminum chloride in 12 mL dichloromethane was cooled to −78 °C in
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Published 05 May 2015

Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo

  • Alireza Shakoori,
  • John B. Bremner,
  • Mohammed K. Abdel-Hamid,
  • Anthony C. Willis,
  • Rachada Haritakun and
  • Paul A. Keller

Beilstein J. Org. Chem. 2015, 11, 481–492, doi:10.3762/bjoc.11.54

Graphical Abstract
  • intermediate, structure 27, together with comparison data for analogous structures from 9 and 7. In vitro antiplasmodial, anticancer, and antitubercular activity of compounds 12–14, 17, 18, 32–35, 8, 9, and 31.a Supporting Information Supporting Information File 98: Experimental procedures, UVvis spectra
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Published 15 Apr 2015

Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s

  • Natalia A. Danilkina,
  • Petr S. Vlasov,
  • Semen M. Vodianik,
  • Andrey A. Kruchinin,
  • Yuri G. Vlasov and
  • Irina A. Balova

Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43

Graphical Abstract
  • at the optimal excitation wavelength of 425 nm which corresponds to the absorption bands at ≈425 nm in UVvis spectra of both samples (Figure 6). An additional ethynyl moiety in the repeating unit of olygomer 10b led to the increase in quantum yield from 1% for 10a to 2% for 10b, while qualitative
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Published 20 Mar 2015

A facile synthesis of functionalized 7,8-diaza[5]helicenes through an oxidative ring-closure of 1,1’-binaphthalene-2,2’-diamines (BINAMs)

  • Youhei Takeda,
  • Masato Okazaki,
  • Yoshiaki Maruoka and
  • Satoshi Minakata

Beilstein J. Org. Chem. 2015, 11, 9–15, doi:10.3762/bjoc.11.2

Graphical Abstract
  • Supporting Information File 2: Experimental procedures, characterization data, copies of NMR charts, UVvis spectra, cyclic voltammograms, and TGA profiles. Acknowledgements This research was partly supported by the research Grant from The Murata Science Foundation, the Sasakawa Scientific Research Grant
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Published 05 Jan 2015

Synthesis and characterization of a new photoinduced switchable β-cyclodextrin dimer

  • Florian Hamon,
  • Claire Blaszkiewicz,
  • Marie Buchotte,
  • Estelle Banaszak-Léonard,
  • Hervé Bricout,
  • Sébastien Tilloy,
  • Eric Monflier,
  • Christine Cézard,
  • Laurent Bouteiller,
  • Christophe Len and
  • Florence Djedaini-Pilard

Beilstein J. Org. Chem. 2014, 10, 2874–2885, doi:10.3762/bjoc.10.304

Graphical Abstract
  • trans to its cis form resulting in a marked change in the UVvis spectra. As the irradiation continued, the absorption band at around 320 nm gradually decreased while the bands at 420 nm and 250 nm slightly increased. This change is clearly due to the simple, but partial, isomerization of the azo groups
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Published 04 Dec 2014

A novel 4-aminoantipyrine-Pd(II) complex catalyzes Suzuki–Miyaura cross-coupling reactions of aryl halides

  • Claudia A. Contreras-Celedón,
  • Darío Mendoza-Rayo,
  • José A. Rincón-Medina and
  • Luis Chacón-García

Beilstein J. Org. Chem. 2014, 10, 2821–2826, doi:10.3762/bjoc.10.299

Graphical Abstract
  • (Scheme 1). The 4-AAP–Pd(II) complex is thermally stable, not sensitive to oxygen or moisture, and highly soluble in common solvents such as CHCl3, CH2Cl2 and AcOEt. The newly synthesized 4-AAP–Pd(II) complex was characterized by UV–vis, FTIR, 1H, 13C NMR spectroscopy and MS (Table 1). The UVvis spectra
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Published 01 Dec 2014

Linear-g-hyperbranched and cyclodextrin-based amphiphilic block copolymer as a multifunctional nanocarrier

  • Yamei Zhao,
  • Wei Tian,
  • Guang Yang and
  • Xiaodong Fan

Beilstein J. Org. Chem. 2014, 10, 2696–2703, doi:10.3762/bjoc.10.284

Graphical Abstract
  •  3 presents the UVvis spectra of the LND solution in the presence of MP1, MP2 and MP3 in buffer solution. Obviously, the peak intensity of the LND solutions gradually decreased at 272 nm when the samples changed from MP1 to MP2, and finally to MP3 at the same concentration. In general, the
  • . Experimental Experimental details can be found in the Supporting Information. Particle size distributions of MP1, MP2, and MP3 at 25 °C as determined by DLS. TEM images of P1 (A), P2 (B) and P3 (C) micelles. UVvis spectra of LND solutions in the presence of MP1, MP2 and MP3 in buffer solutions. Particle size
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Published 18 Nov 2014

Encapsulation of biocides by cyclodextrins: toward synergistic effects against pathogens

  • Véronique Nardello-Rataj and
  • Loïc Leclercq

Beilstein J. Org. Chem. 2014, 10, 2603–2622, doi:10.3762/bjoc.10.273

Graphical Abstract
  • potentiometric titration whereas the stability constant of the Ag0–CD complex was determined from the UVvis spectra. The constants were estimated at 360 and 3.07 × 106 M−1 for Ag0 and Ag+, respectively. Antibacterial activities against E. coli and S. aureus were determined for the fabrics grafted with CD and
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Published 07 Nov 2014
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