scholarly journals An amphiphilic pseudo[1]catenane: neutral guest-induced clouding point change

2018 ◽  
Vol 14 ◽  
pp. 1937-1943 ◽  
Author(s):  
Tomoki Ogoshi ◽  
Tomohiro Akutsu ◽  
Tada-aki Yamagishi
Keyword(s):  
Alkyl Chain ◽  
Aqueous Media ◽  
Chemical Stimulus ◽  
Bicyclic Compound ◽  
Chain Ring ◽  
Point Change ◽  
Hydrophobic Chain ◽  
Inclusion Structure ◽  
Clouding Point

The hydrophobic/hydrophilic ratio in a molecule largely affects its assembled properties in aqueous media. In this study, we synthesized a new bicyclic compound which could dynamically change its hydrophobic/hydrophilic ratio by chemical stimulus. The bicyclic compound consisted of amphiphilic pillar[5]arene and hydrophobic alkyl chain rings, and formed a self-inclusion structure in aqueous media, which was assigned as a pseudo[1]catenane structure. The hydrophobic chain ring was hidden inside the pillar[5]arene cavity in the pseudo[1]catenane structure, thus the bicyclic compound was soluble in water at 20 °C with a clouding point at 24 °C. The pseudo[1]catenane was converted to the de-threaded structure upon addition of the neutral guest 1,4-dicyanobutane, which displaced the alkyl chain ring from the inside to the outside of the cavity. The hydrophobic alkyl chain ring was now exposed to the aqueous media, causing aggregation of the hydrophobic alkyl chain rings, which induced insolubilization of the bicyclic compound in aqueous media at 20 °C and a decrease in its clouding point.

Conjugated Polymer Nanoparticles in Aqueous Media by Assembly with Phospholipids via Dense Alkyl Chain Packing

2017 ◽  
Vol 50 (17) ◽  
pp. 6935-6944 ◽  
Author(s):  
Yeol Kyo Choi ◽  
Dabin Lee ◽  
Sang Yup Lee ◽  
Tae Joo Shin ◽  
Juhyun Park ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Alkyl Chain ◽  
Aqueous Media ◽  
Polymer Nanoparticles ◽  
Chain Packing ◽  
Conjugated Polymer Nanoparticles

scholarly journals Interactions of short chain phenylalkanoic acids within ionic surfactant micelles in aqueous media

2012 ◽  
Vol 77 (2) ◽  
pp. 201-210 ◽  
Author(s):  
Kashif Naeem ◽  
Syed Shah ◽  
Bushra Naseem ◽  
Syed Shah
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Alkyl Chain ◽  
Aqueous Media ◽  
Sodium Dodecyl ◽  
Standard Free Energy ◽  
Bulk Water ◽  
Uv Spectra ◽  
Ionic Surfactant ◽  
Standard Free Energy Change ◽  
Surfactant Micelles

% SDS KR nema Solubilization and interactions of phenylalkanoic acids induced by cationic surfactant, cetyltrimethylammonium bromide (CTAB) and an anionic surfactant, sodium dodecyl sulfate (SDS) was investigated spectrophotometrically at 25.0?C. The UV spectra of the additives (acids) were measured with and without surfactant above and below critical micelle concentration (cmc) of the surfactant. The presence of alkyl chain in phenylalkanoic acids is responsible for hydrophobic interaction resulting in shift of the spectra towards longer wavelength (red shift). The value of partition coefficient (Kx) between the bulk water and surfactant micelles and in turn standard free energy change of solubilization (?Gp?) were also estimated by measuring the differential absorbance (?A) of the additives in micellar solutions.

scholarly journals An expedient synthesis of 5-n-alkylresorcinols and novel 5-n-alkylresorcinol haptens

2009 ◽  
Vol 5 ◽  
Author(s):  
Kirsti Parikka ◽  
Kristiina Wähälä
Keyword(s):  
Wittig Reaction ◽  
Alkyl Chain ◽  
Open Systems ◽  
Aqueous Media ◽  
Whole Grain ◽  
Detection Techniques ◽  
Immunochemical Detection ◽  
Grain Products ◽  
Derivatives Of ◽  
Long Alkyl Chain

The first synthesis of bioactive long alkyl chain 5-n-alkylresorcinols, present in whole grain products, by a novel modification of the Wittig reaction is described. All the main long chain 5-n-alkylresorcinols present in rye and wheat, including C23 and C25 analogues and haptens, which have not been previously prepared, were synthesised. Microwave-promoted reactions of a semi-stabilized ylid and alkanals in water gave good yields in both pressurized and open systems. An alternative microwave-promoted synthesis starting from non-stabilized alkyltriphenylphosphonium salts and 3,5-dimethoxybenzaldehyde worked as well. Aqueous media were suitable for the reactions even if the starting materials were not soluble in water. The 5-n-alkylresorcinols are potential biomarkers of whole grain intake, and the new hapten derivatives of 5-n-alkylresorcinols will open the way for the immunochemical detection techniques of alkylresorcinols.

scholarly journals Selective recognition of ATP by multivalent nano-assemblies of bisimidazolium amphiphiles through “turn-on” fluorescence response

2020 ◽  
Vol 16 ◽  
pp. 2728-2738
Author(s):  
Rakesh Biswas ◽  
Surya Ghosh ◽  
Shubhra Kanti Bhaumik ◽  
Supratim Banerjee
Keyword(s):  
Self Assembly ◽  
Alkyl Chain ◽  
Ph Value ◽  
Aqueous Media ◽  
Green Emission ◽  
Selective Recognition ◽  
Atp Binding ◽  
Surface Charges ◽  
Turn On ◽  
Efficient Detection

Bisimidazolium receptors, tagged with chromophoric pyrene at one end and linked to an n-alkyl chain at the other, underwent self-assembly in aqueous media depending on the length of the alkyl segment. The amphiphilic derivatives having n-decyl or longer chains, formed nano-assemblies with cyanic–green emission resulting from the stacked pyrene chromophores in the aggregates. The presence of positive surface charges on the multivalent aggregates led to ATP binding which was accompanied by a significant increase in the excimeric emission intensity. This provided a convenient way of monitoring ATP binding in a “turn-on” mode and an efficient detection of ATP was achieved in aqueous buffer and also in buffer containing 150 mM NaCl at physiological pH value. Furthermore, the multivalent aggregates demonstrated a significant selectivity in ATP detection over ADP, AMP and pyrophosphate.

Template mediated crystal engineering

1994 ◽  
Vol 52 ◽  
pp. 480-481
Author(s):  
Brigid R. Heywood ◽  
S. Champ
Keyword(s):  
Crystal Engineering ◽  
Electrostatic Interactions ◽  
Alkyl Chain ◽  
Crystallographic Axis ◽  
Two Dimensional ◽  
Engineering Process ◽  
Solution Interface ◽  
Extensive Program ◽  
Geometric Homology ◽  
Long Alkyl Chain

Recent work on the crystallisation of inorganic crystals under compressed monomolecular surfactant films has shown that two dimensional templates can be used to promote the oriented nucleation of solids. When a suitable long alkyl chain surfactant is cast on the crystallisation media a monodispersied population of crystals forms exclusively at the monolayer/solution interface. Each crystal is aligned with a specific crystallographic axis perpendicular to the plane of the monolayer suggesting that nucleation is facilitated by recognition events between the nascent inorganic solid and the organic template.For example, monolayers of the long alkyl chain surfactant, stearic acid will promote the oriented nucleation of the calcium carbonate polymorph, calcite, on the (100) face, whereas compressed monolayers of n-eicosyl sulphate will induce calcite nucleation on the (001) face, (Figure 1 & 2). An extensive program of research has confirmed the general principle that molecular recognition events at the interface (including electrostatic interactions, geometric homology, stereochemical complementarity) can be used to promote the crystal engineering process.

Highly efficient and selective photocatalytic CO2 to CO conversion in aqueous solution

2020 ◽  
Vol 56 (27) ◽  
pp. 3851-3854 ◽  
Author(s):  
Xiaomin Chai ◽  
Hai-Hua Huang ◽  
Huiping Liu ◽  
Zhuofeng Ke ◽  
Wen-Wen Yong ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photocatalytic Performance ◽  
Aqueous Media ◽  
Highly Efficient ◽  
Co Conversion

A Co-based complex displayed the highest photocatalytic performance for CO2 to CO conversion in aqueous media.

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