Self-assembly of copper(ii) complexes with ladder, bi-rack, rack–ladder–rack and layer structures by the directional-bonding approach using a T-shaped ligand

2005 ◽  
pp. 2899 ◽  
Author(s):  
Ming-Sheng Wang ◽  
Guo-Cong Guo ◽  
Ming-Lai Fu ◽  
Ling Xu ◽  
Li-Zhen Cai ◽  
...  
Author(s):  
Ahyoung Kim ◽  
Lehan Yao ◽  
Falon Kalutantirige ◽  
Shan Zhou ◽  
Qian Chen

Biological building blocks (i.e., proteins) are encoded with the information of target structure into the chemical and morphological patches, guiding their assembly into the levels of functional structures that are crucial for living organisms. Learning from nature, researchers have been attracted to the artificial analogues, “patchy particles,” which have controlled geometries of patches that serve as directional bonding sites. However, unlike the abundant studies of micron-scale patchy particles, which demonstrated complex assembly structures and unique behaviors attributed to the patches, research on patchy nanoparticles (NPs) has remained challenging. In the present chapter, we discuss the recent understandings on patchy NP design and synthesis strategies, and physical principles of their assembly behaviors, which are the main factors to program patchy NP self-assembly into target structures that cannot be achieved by conventional non-patched NPs. We further summarize the self-assembly of patchy NPs under external fields, in simulation, and in kinetically controlled assembly pathways, to show the structural richness patchy NPs bring. The patchy NP assembly is novel by their structures as well as the multicomponent features, and thus exhibits unique optical, chemical, and mechanical properties, potentially aiding applications in catalysts, photonic crystals, and metamaterials as well as fundamental nanoscience.


2000 ◽  
Vol 86 (1-2) ◽  
pp. 96-102 ◽  
Author(s):  
Andrew J Black ◽  
Paul F Nealey ◽  
Joseph H Thywissen ◽  
Mandar Deshpande ◽  
Nada El-Zein ◽  
...  

2020 ◽  
Vol 76 (7) ◽  
pp. 695-705
Author(s):  
Aristyo Soecipto ◽  
Lawrence W.-Y. Wong ◽  
Herman H.-Y. Sung ◽  
Ian D. Williams

The spiroborate anion, namely, 2,3,7,8-tetracarboxamido-1,4,6,9-tetraoxa-5λ4-boraspiro[4.4]nonane, [B(TarNH2)2]−, derived from the diol L-tartramide TarNH2, [CH(O)(CONH2)]2, shows a novel self-assembly into two-dimensional (2D) layer structures in its salts with alkylammonium cations, [NR 4]+ (R = Et, Pr and Bu), and sparteinium, [HSpa]+, in which the cations and anions are segregated. The structures of four such salts are reported, namely, the tetrapropylazanium salt, C12H28N+·C8H12BN4O8 −, the tetraethylazanium salt hydrate, C8H20N+·C8H12BN4O8 −·6.375H2O, the tetrabutylazanium salt as the ethanol monosolvate hemihydrate, C16H36N+·C8H12BN4O8 −·C2H5OH·0.5H2O, and the sparteinium (7-aza-15-azoniatetracyclo[7.7.1.02,7.010,15]heptadecane) salt as the ethanol monosolvate, C15H27N2 +·C8H12BN4O8 −·C2H5OH. The 2D anion layers have preserved intermolecular hydrogen bonding between the amide groups and a typical metric repeat of around 10 × 15 Å. The constraint of matching the interfacial area organizes the cations into quite different solvated arrangements, i.e. the [NEt4] salt is highly hydrated with around 6.5H2O per cation, the [NPr4] salt apparently has a good metric match to the anion layer and is unsolvated, whilst the [NBu4] salt is intermediate and has EtOH and H2O in its cation layer, which is similar to the arrangement for the chiral [HSpa]+ cation. This family of salts shows highly organized chiral space and offers potential for the resolution of both chiral cations and neutral chiral solvent molecules.


2011 ◽  
Vol 412 ◽  
pp. 384-387 ◽  
Author(s):  
Zhao Long Huang ◽  
Gui Yang Liu ◽  
Ying He ◽  
Zhong Zhou Yi ◽  
Jun Ming Guo

To study the interaction between hydroxyapatite (HAP) and collagen in bone, we researched the phenomenon of collagen biomineralization and self-assembly in viro by uv-vis spectra and circular dichroism (CD) spectra. The materials prepared by self-assembly collagen and collagen-HAP showed layer structures. And the product prepared by collagen-HAP had better and more compact appearance. The decrease of speed of collagen self-assembly was caused by calcium ion or strontium ion added. The trough of CD spectra moved down in calcium-containing solution and moved up when forming precipitation of calcium phosphate from the solution. It indicated that the effect of collagen self-assembly was caused by calcium ions, strontium ions etc. in the solution. The IR spectrum proved that a coordinate bond formed between calcium ion and amide groups on collagen.


2018 ◽  
Vol 9 (41) ◽  
pp. 5116-5122 ◽  
Author(s):  
Xiaoliang Yu ◽  
Xiaoyan Yuan ◽  
Zhengyi Xia ◽  
Lixia Ren

A magnetic norbornenyl-based amphiphilic polymer was successfully prepared and the polymer self-assembled into multi-layer structures in aqueous solution.


2012 ◽  
Vol 554-556 ◽  
pp. 39-42
Author(s):  
Chun Hua Liu ◽  
Yun Zhi Xie ◽  
Yong Dong Li ◽  
Xun Li ◽  
Yi Bao Li ◽  
...  

The compound of perylene-3,4,9,10-tetracarboxylic acid (PTCA) has been synthesized and characterized. By varying the concentration, it can be used to modulate the supramolecular self-assembly morphologies. Atom force microscopy (AFM) images show that the nano-layer structure will be obtained in relatively high concentration. This structure mainly depends on the intermolecular hydrogen-bonding and π–π stacking interactions.


2021 ◽  
Vol 118 (12) ◽  
pp. e2019996118
Author(s):  
Prabesh Gyawali ◽  
Rony Saha ◽  
Gregory P. Smith ◽  
Miroslaw Salamonczyk ◽  
Prakash Kharel ◽  
...  

Although its mesomorphic properties have been studied for many years, only recently has the molecule of life begun to reveal the true range of its rich liquid crystalline behavior. End-to-end interactions between concentrated, ultrashort DNA duplexes—driving the self-assembly of aggregates that organize into liquid crystal phases—and the incorporation of flexible single-stranded “gaps” in otherwise fully paired duplexes—producing clear evidence of an elementary lamellar (smectic-A) phase in DNA solutions—are two exciting developments that have opened avenues for discovery. Here, we report on a wider investigation of the nature and temperature dependence of smectic ordering in concentrated solutions of various “gapped” DNA (GDNA) constructs. We examine symmetric GDNA constructs consisting of two 48-base pair duplex segments bridged by a single-stranded sequence of 2 to 20 thymine bases. Two distinct smectic layer structures are observed for DNA concentration in the range ∼230to∼280 mg/mL. One exhibits an interlayer periodicity comparable with two-duplex lengths (“bilayer” structure), and the other has a period similar to a single-duplex length (“monolayer” structure). The bilayer structure is observed for gap length ≳10 bases and melts into the cholesteric phase at a temperature between 30 °C and 35 °C. The monolayer structure predominates for gap length ≲10 bases and persists to >40 °C. We discuss models for the two layer structures and mechanisms for their stability. We also report results for asymmetric gapped constructs and for constructs with terminal overhangs, which further support the model layer structures.


CrystEngComm ◽  
2011 ◽  
Vol 13 (3) ◽  
pp. 734-737 ◽  
Author(s):  
Hailong Sun ◽  
Haibo Mei ◽  
Guanghui An ◽  
Jianlin Han ◽  
Yi Pan

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.


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