Solvent mediated self-assembly of organic nanostructures

2011 ◽  
Vol 35 (4) ◽  
pp. 784 ◽  
Author(s):  
Andrew K. Maerz ◽  
Drew A. Fowler ◽  
Andrew V. Mossine ◽  
Miten Mistry ◽  
Harshita Kumari ◽  
...  
Keyword(s):  
Self Assembly ◽  
Organic Nanostructures

scholarly journals Initiating Ullmann-like coupling of Br2Py by a semimetal surface

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jinping Hu ◽  
Jinbang Hu ◽  
Hongbing Wang ◽  
Kongchao Shen ◽  
Huan Zhang ◽  
...  
Keyword(s):  
Self Assembly ◽  
Reaction Mechanisms ◽  
Density Functional ◽  
Coupling Reaction ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Metallic Substrates ◽  
Organic Nanostructures ◽  
Tunnelling Microscopy ◽  
Ag Substrate

AbstractIntensive efforts have been devoted to surface Ullmann-like coupling in recent years, due to its appealing success towards on-surface synthesis of tailor-made nanostructures. While attentions were mostly drawn on metallic substrates, however, Ullmann dehalogenation and coupling reaction on semimetal surfaces has been seldom addressed. Herein, we demonstrate the self-assembly of 2, 7-dibromopyrene (Br2Py) and the well controllable dehalogenation reaction of Br2Py on the Bi(111)–Ag substrate with a combination of scanning tunnelling microscopy (STM) and density functional theory calculations (DFT). By elaborately investigating the reaction path and formed organic nanostructures, it is revealed that the pristinely inert bismuth layer supported on the silver substrate can initiate Ullmann-like coupling in a desired manner by getting alloyed with Ag atoms underneath, while side products have not been discovered. By clarifying the pristine nature of Bi–Ag(111) and Ullmann-like reaction mechanisms, our report proposes an ideal template for thoroughly exploring dehalogenative coupling reaction mechanisms with atomic insights and on-surface synthesis of carbon-based architectures.

MODELLING ION, WATER AND ION–WATER CLUSTER ENTERING PEPTIDE NANOTUBES

2015 ◽  
Vol 57 (1) ◽  
pp. 62-78
Author(s):  
N. THAMWATTANA
Keyword(s):  
Self Assembly ◽  
Water Cluster ◽  
Cyclic Peptides ◽  
Simple Structure ◽  
Cyclic Peptide ◽  
Initial Energy ◽  
Jones Potential ◽  
Peptide Nanotubes ◽  
Organic Nanostructures ◽  
Peptide Nanotube

Recently, organic nanostructures have attracted much attention, and amongst them peptide nanotubes are of interest in many fields of application including medicine and nanobiotechnology. Peptide nanotubes are formed by self-assembly of cyclic peptides with alternating L- and D-amino acids. Due to their biodegradability, flexible design and easy synthesis, many applications have been proposed such as artificial transmembrane ion channels, templates for nanoparticles, mimicking pore structures, nanoscale testing tubes, biosensors and carriers for targeted drug delivery. The mechanisms of an ion, a water molecule and an ion–water cluster entering into a peptide nanotube of structure cyclo[(-D-Ala-L-Ala-)$_{4}$] are explored here. In particular, the Lennard-Jones potential and a continuum approach are employed to determine three entering mechanisms: (i) through the tube open end, (ii) through a region between each cyclic peptide ring and (iii) around the edge of the tube open end. The results show that while entering the nanotube by method (i) is possible, an ion or a molecule requires initial energy to overcome an energetic barrier to be able to enter the nanotube through positions (ii) and (iii). Due to its simple structure, the D-, L-Ala cyclopeptide nanotube is chosen in this model; however, it can be easily extended to include more complicated nanotubes.

Self-Assembly and Photopolymerization of Sub-2 nm One-Dimensional Organic Nanostructures on Graphene

2012 ◽  
Vol 134 (40) ◽  
pp. 16759-16764 ◽  
Author(s):  
Aparna Deshpande ◽  
Chun-Hong Sham ◽  
Justice M. P. Alaboson ◽  
Jonathan M. Mullin ◽  
George C. Schatz ◽  
...  
Keyword(s):  
Self Assembly ◽  
One Dimensional ◽  
Organic Nanostructures

Controllable growth of organic nanostructures from 0D to 1D with different optical properties

RSC Advances ◽  
2015 ◽  
Vol 5 (122) ◽  
pp. 100457-100463 ◽  
Author(s):  
Yusen Luo ◽  
Zheng Xue ◽  
Yongjun Li ◽  
Huibiao Liu ◽  
Wensheng Yang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Optical Properties ◽  
Self Assembly ◽  
Organic Nanostructures ◽  
Controllable Growth ◽  
The Difference

Controllable nano/microstructures from 0D to 1D were fabricated by adjusting the growth rate. The difference in symmetry between two molecules results in distinct self-assembly behaviours and different optical properties.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

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.

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