Thermodynamic theory of two-dimensional to three-dimensional growth transition in quantum dots self-assembly

2010 ◽  
Vol 12 (18) ◽  
pp. 4768 ◽  
Author(s):  
Xinlei Li ◽  
Yuanyuan Cao ◽  
Guowei Yang
Keyword(s):  
Quantum Dots ◽  
Self Assembly ◽  
Three Dimensional ◽  
Thermodynamic Theory ◽  
Two Dimensional ◽  
Dimensional Growth

Square-grid coordination networks of (5,10,15,20-tetra-4-pyridylporphyrinato)zinc(II) in its clathrate with two guest molecules of 1,2-dichlorobenzene: supramolecular isomerism of the porphyrin self-assembly

2009 ◽  
Vol 65 (3) ◽  
pp. m139-m142 ◽  
Author(s):  
Rajesh Koner ◽  
Israel Goldberg
Keyword(s):  
Self Assembly ◽  
Metal Ion ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Coordination Networks ◽  
Guest Molecules ◽  
Square Grid ◽  
Supramolecular Isomerism ◽  
Self Assembled ◽  
Solvent Molecules

The title compound, (5,10,15,20-tetra-4-pyridylporphyrinato)zinc(II) 1,2-dichlorobenzene disolvate, [Zn(C40H24N8)]·2C6H4Cl2, contains a clathrate-type structure. It is composed of two-dimensional square-grid coordination networks of the self-assembled porphyrin moiety, which are stacked one on top of the other in a parallel manner. The interporphyrin cavities of the overlapping networks combine into channel voids accommodated by the dichlorobenzene solvent. Molecules of the porphyrin complex are located on crystallographic inversion centres. The observed two-dimensional assembly mode of the porphyrin units represents a supramolecular isomer of the unique three-dimensional coordination frameworks of the same porphyrin building block observed earlier. The significance of this study lies in the discovery of an additional supramolecular isomer of the rarely observed structures of metalloporphyrins self-assembled directly into extended coordination polymers without the use of external ligand or metal ion auxiliaries.

From Two-Dimensional Colloidal Self-Assembly to Three-Dimensional Nanolithography

Nano Letters ◽  
2011 ◽  
Vol 11 (6) ◽  
pp. 2533-2537 ◽  
Author(s):  
C.-H. Chang ◽  
L. Tian ◽  
W. R. Hesse ◽  
H. Gao ◽  
H. J. Choi ◽  
...  
Keyword(s):  
Self Assembly ◽  
Three Dimensional ◽  
Two Dimensional

Sensitivity To Disorder Of Graphene-Like Lattices Of Quantum Dots And Antidots In Two-Dimensional Electron Gas

2016 ◽  
Vol 11 (1) ◽  
pp. 80-87
Author(s):  
Olga Tkachenko ◽  
Vitaliy Tkachenko
Keyword(s):  
Quantum Dots ◽  
Electron Gas ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Two Dimensional Electron Gas ◽  
Semiconductor Structures ◽  
Dimensional Electron Gas ◽  
Artificial Graphene ◽  
Electronic Channels

We compare three-dimensional electrostatics of semiconductor structures with graphene-like lattices of quantum dots and antidots formed in the plane of the two dimensional electron gas. With lattice constant fixed, the shape of the potential may be tuned so that both lattices have minband spectrum where the second Dirac feature is pronounced and not overlaid by the other states. We show that the lattice of quantum dots is more sensitive to fabrication imperfections, because sources of the disorder are located directly above the electronic channels. Thus the lattices of antidots should be preferred semiconductor artificial graphene candidates.

Crystallization Time Dependence of Nanohybrid Shish-Kebab Structure in HDPE/PA66 Nanofibers Composites via Solution Crystallization

2011 ◽  
Vol 110-116 ◽  
pp. 3786-3790
Author(s):  
Wen Juan Han ◽  
Guo Qiang Zheng ◽  
Yan Yan Liang ◽  
Chun Tai Liu ◽  
Chang Yu Shen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Time Dependence ◽  
Isothermal Crystallization ◽  
Three Dimensional ◽  
Crystallization Time ◽  
Two Dimensional ◽  
Solution Crystallization ◽  
Dimensional Growth ◽  
Scanning Electron

In this study, PA66 nanofibers were successfully solution electrospun. The crystalline morphological features of HDPE solution induced by nanofibers were investigated by scanning electron microscopy (SEM). Nanohybrid shish-kebab (NHSK) can be formed in HDPE solution via isothermal crystallization, in which PA66 nanofibers serve as shish and HDPE lamellae act as kebabs surrounding the nanofibers periodically. Additionally, crystallization time has significant effect on the structure of HDPE kebab in NHSK, i.e., as crystallization time increases, the size of the kebab increases and the crystals decorated on PA66 nanofibers exhibit a three-dimensional growth (i.e., aggregate of crystallites) rather than a two-dimensional one (i.e., disc-like lamellae normal to the axis of nanofiber).

Substituent effects of two isophthalate derivatives on the construction of cadmium coordination polymers incorporating a dipyridyl ligand

2018 ◽  
Vol 74 (8) ◽  
pp. 894-900 ◽  
Author(s):  
Lin Wang ◽  
Qian-Kun Zhou ◽  
Yun Xu ◽  
Ni-Ya Li
Keyword(s):  
Coordination Polymers ◽  
Self Assembly ◽  
Three Dimensional ◽  
Substituent Effects ◽  
Dicarboxylic Acids ◽  
Two Dimensional ◽  
Reaction Conditions ◽  
Thermal Stabilities ◽  
Coordination Network ◽  
Potential Applications

In recent years, the design and construction of crystalline coordination complexes by the assembly of metal ions with multitopic ligands have attracted considerable attention because of the unique architectures and potential applications of these compounds. Two new coordination polymers, namely poly[[μ-trans-1-(2-aminopyridin-3-yl)-2-(pyridin-4-yl)ethene-κ2 N:N′](μ3-5-methylisophthalato-κ4 O 1,O 1′:O 3:O 3′)cadmium(II)], [Cd(C9H6O4)(C12H11N3)] n or [Cd(5-Me-ip)(2-NH2-3,4-bpe)] n , (I), and poly[[μ-trans-1-(2-aminopyridin-3-yl)-2-(pyridin-4-yl)ethene-κ2 N:N′](μ2-5-hydroxyisophthalato-κ4 O 1,O 1′:O 3:O 5)cadmium(II)], [Cd(C8H4O5)(C12H11N3)] n or [Cd(5-HO-ip)(2-NH2-3,4-bpe)] n , (II), have been prepared hydrothermally by the self-assembly of Cd(NO3)2·4H2O and trans-1-(2-aminopyridin-3-yl)-2-(pyridin-4-yl)ethene (2-NH2-3,4-bpe) with two similar dicarboxylic acids, i.e. 5-methylisophthalic acid (5-Me-H2ip) and 5-hydroxyisophthalic acid (5-HO-H2ip). The coordination network of (I) is a two-dimensional sql net parallel to (101). Adjacent sql nets are further linked to form a three-dimensional supramolecular framework via hydrogen-bonding interactions. Compound (II) is a two-dimensional (3,5)-connected coordination network parallel to (010) with the point symbol (63)(55647). As the other reactants and reaction conditions are the same, the structural differences between (I) and (II) are undoubtedly determined by the different substituent groups in the 5-position of isophthalic acid. Both (I) and (II) exhibit good thermal stabilities and photoluminescence properties.

Structures of the ZrZn22 family: suprapolyhedral nanoclusters, methods of self-assembly and superstructural ordering

2009 ◽  
Vol 65 (3) ◽  
pp. 300-307 ◽  
Author(s):  
G. D. Ilyushin ◽  
V. A. Blatov
Keyword(s):  
Crystal Structures ◽  
Self Assembly ◽  
Topological Analysis ◽  
Three Dimensional ◽  
Topological Type ◽  
Point Symmetry ◽  
Two Dimensional ◽  
The Matrix ◽  
Nanocluster Precursor ◽  
Dimensional Crystal

A combinatorial topological analysis is carried out by means of the program package TOPOS4.0 [Blatov (2006), IUCr Comput. Commun. Newsl. 7, 4–38] and the matrix self-assembly is modeled for crystal structures of the ZrZn22 family (space group Fd\bar 3m, Pearson code cF184), including the compounds with superstructural ordering. A number of strict rules are proposed to model the crystal structures of intermetallics as a network of cluster precursors. According to these rules the self-assembly of the ZrZn22-like structures was considered within the hierarchical scheme: primary polyhedral cluster → zero-dimensional nanocluster precursor → one-dimensional primary chain → two-dimensional microlayer → three-dimensional microframework (three-dimensional supraprecursor). The suprapolyhedral cluster precursor AB 2 X 37 of diameter ∼ 12 Å and volume ∼ 350 Å3 consists of three polyhedra (one AX 16 of the \bar 43m point symmetry and two regular icosahedra BX 12 of the \bar 3m point symmetry); the packing of the clusters determines the translations in the resulting crystal structure. A novel topological type of the two-dimensional crystal-forming 4,4-coordinated binodal net AB 2, with the Schläfli symbols 3636 and 3366 for nodes A and B, is discovered. It is shown that the ZrZn22 superstructures are formed by substituting some atoms in the cluster precursors. Computer analysis of the CRYSTMET and ICSD databases shows that the cluster AB 2 X 37 occurs in 111 intermetallics belonging to 28 structure types.

scholarly journals A versatile strategy towards non-covalent functionalization of graphene by surface-confined supramolecular self-assembly of Janus tectons

2015 ◽  
Vol 6 ◽  
pp. 632-639 ◽  
Author(s):  
Ping Du ◽  
David Bléger ◽  
Fabrice Charra ◽  
Vincent Bouchiat ◽  
David Kreher ◽  
...  
Keyword(s):  
Self Assembly ◽  
Three Dimensional ◽  
Building Blocks ◽  
The Other ◽  
Two Dimensional ◽  
Covalent Functionalization ◽  
Flat Surfaces ◽  
Carbon Based

Two-dimensional (2D), supramolecular self-assembly at surfaces is now well-mastered with several existing examples. However, one remaining challenge to enable future applications in nanoscience is to provide potential functionalities to the physisorbed adlayer. This work reviews a recently developed strategy that addresses this key issue by taking advantage of a new concept, Janus tecton materials. This is a versatile, molecular platform based on the design of three-dimensional (3D) building blocks consisting of two faces linked by a cyclophane-type pillar. One face is designed to steer 2D self-assembly onto C(sp2)-carbon-based flat surfaces, the other allowing for the desired functionality above the substrate with a well-controlled lateral order. In this way, it is possible to simultaneously obtain a regular, non-covalent paving as well as supramolecular functionalization of graphene, thus opening interesting perspectives for nanoscience applications.

From two-dimensional to three-dimensional quantum dots

2002 ◽  
Vol 13 (2-4) ◽  
pp. 638-641 ◽  
Author(s):  
S. Lindemann ◽  
T. Ihn ◽  
T. Heinzel ◽  
K. Ensslin ◽  
K. Maranowski ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Three Dimensional ◽  
Two Dimensional
Sign in / Sign up

Export Citation Format

Share Document