Synthesis and photoswitchable amphiphilicity and self-assembly properties of photochromic spiropyran derivatives

2020 ◽  
Vol 8 (39) ◽  
pp. 13676-13685
Author(s):  
Yiwei Zhang ◽  
Maggie Ng ◽  
Eugene Yau-Hin Hong ◽  
Alan Kwun-Wa Chan ◽  
Nathan Man-Wai Wu ◽  
...  

H-Aggregate formation of photochromic spiropyran derivatives via photoswitchable amphiphilicity.

2015 ◽  
Vol 19 (07) ◽  
pp. 845-851 ◽  
Author(s):  
Margaret A. Gradova ◽  
Vladimir V. Artemov ◽  
Anton V. Lobanov

Porphyrin-surfactant interactions in aqueous solutions are known to result in the selfassembly of various supramolecular structures, including pigment-surfactant complexes, J- and H-aggregates, and solubilized dye species. Detailed studies on the mechanisms of the intermolecular interactions governing the above self-assembly processes allow to predict the aggregation state and hence, the photophysical properties of the dye-surfactant assemblies in order to perform a direct synthesis of the desired porphyrin-based nanostructures at the appropriate experimental conditions. This paper describes a novel example of the surfactant-induced J-aggregate formation from the diprotonated hydrophobic tetraphenylporphyrin species in submicellar aqueous anionic surfactant solutions. The above assemblies are characterized by a rod-like morphology and possess supramolecular chirality according to the CD measurements.


2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Martina Pannuzzo ◽  
Antonio Raudino ◽  
Danilo Milardi ◽  
Carmelo La Rosa ◽  
Mikko Karttunen

RSC Advances ◽  
2015 ◽  
Vol 5 (116) ◽  
pp. 95613-95617 ◽  
Author(s):  
N. Kumari ◽  
P. K. Verma ◽  
P. N. Pathak ◽  
A. Gupta ◽  
A. Ballal ◽  
...  

Nanoaggregate formation by self assembly was noticed during the cloud formation of Triton X-114 in the presence of dibenzoylmethane (DBM), thenoyltrifluoroacetone (HTTA) and 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP) and tributyl phosphate (TBP).


Author(s):  
Gary Yu ◽  
Martin Walker ◽  
Mark Richard Wilson

Cyanine dyes are known to form large-scale aggregates of various morphologies via spontaneous self-assembly in aqueous solution, akin to chromonic liquid crystals. Atomistic molecular dynamics simulations have been performed on...


2006 ◽  
Vol 937 ◽  
Author(s):  
Margarita Garcia ◽  
E.W. Meijer ◽  
Albertus Schenning

ABSTRACTA variety of α, α'-subtituted quaterthiophenes containing ester, amide and polymerizable side chains have been synthesized and fully characterized. The self-assembly properties of these oligothiophenes were studied as function of the side chain. Introduction of amide functionalities highly promotes the self-assembly via π-stacking and hydrogen bond interactions, while the lack of amides prevent aggregate formation. Initial experiments show that by introducing a sorbyl moiety as a polymerizable group it is possible to achieve covalent fixation of the oligothiophene units in the self-assembled state.


1992 ◽  
Vol 71 (3) ◽  
pp. 1401-1406 ◽  
Author(s):  
Kazuhiro Saito ◽  
Keiichi Ikegami ◽  
Shin‐ichi Kuroda ◽  
Yuka Tabe ◽  
Michio Sugi

Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


Author(s):  
M. Kessel ◽  
R. MacColl

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.


Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.


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