Discrete multiporphyrin pseudorotaxane assemblies from di- and tetravalent porphyrin building blocks

Two pairs of divalent and tetravalent porphyrin building blocks carrying the complementary supramolecular crown ether/secondary ammonium ion binding motif have been synthesized and their derived pseudorotaxanes have been studied by a combination of NMR spectroscopy in solution and ESI mass spectrometry in the gas phase. By simple mixing of the components the formation of discrete dimeric and trimeric (metallo)porphyrin complexes predominates, in accordance to binding stoichiometry, while the amount of alternative structures can be neglected. Our results illustrate the power of multivalency to program the multicomponent self-assembly of specific entities into discrete functional nanostructures.

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Symmetrical Tris(4,6-diamino-5-methylene-2-pyrimidones): New Building Blocks for Self-Assembly of Hollow Spherical Supramolecules Locked by Hydrogen Bonds

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19961464 ◽

1996 ◽

Vol 61 (10) ◽

pp. 1464-1472 ◽

Cited By ~ 3

Author(s):

Daniel Alexander ◽

Petr Holý ◽

Pavel Fiedler ◽

Zdeněk Havlas ◽

Jiří Závada

Keyword(s):

Molecular Modeling ◽

Hydrogen Bonds ◽

Gas Phase ◽

Self Assembly ◽

Building Blocks ◽

The Self ◽

Circumstantial Evidence ◽

Self Assembling ◽

Molecular Modeling Study ◽

Modeling Study

Concise synthesis of the tris(pyrimidones) 1a,b is described. Molecular modeling study demonstrated that both the prepared models 1a,b are capable of self-assembling under formation of spherical dimers locked by 18 hydrogen bonds. Extreme insolubility in all common solvents precluded investigation of the self-assembly in solution. Circumstantial evidence in favor of the self-assembly has been provided in the solid and gas phase.

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99 Semesters of Chemistry - A Personal Retrospective on the Molecular State Approach by Preparative Chemists

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19970001 ◽

1997 ◽

Vol 62 (1) ◽

pp. 1-41 ◽

Cited By ~ 3

Author(s):

Hans Bock

Keyword(s):

Gas Phase ◽

Time Domain ◽

Self Assembly ◽

Electron Distribution ◽

Building Blocks ◽

Molecular State ◽

Reaction Pathways ◽

Dynamic Relaxation ◽

The Time Domain ◽

Microscopic Reaction

Molecular states are the real building blocks of the chemist, because the structure of a molecule can change considerably as its energy and thus its electron distribution varies within the time-domain of dynamic relaxation. The ever increasing use of measuring methods from the armory of physics to characterize molecules by their molecular state fingerprints and, above all, of computers to rationalize both their properties and their microscopic reaction pathways, provides a wealth of information for the development of chemistry. To deal with the complexity of molecular states, a qualitative model based on the topology and symmetry of their structures as well as of their energies resulting from the electron distribution over the respective effective nuclear potentials is presented and is illustrated by examples of our own efforts to elucidate molecular state properties including time-dependent dynamics, microscopic reaction pathways both in the gas phase and in solution, and the self-assembly of molecules on crystallization. In conclusion, a personal retrospective is summarized and some prospects for the future are outlined.

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Self-Assembly of Organic Nanomaterials and Biomaterials: The Bottom-Up Approach for Functional Nanostructures Formation and Advanced Applications

Materials ◽

10.3390/ma13051048 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1048 ◽

Cited By ~ 15

Author(s):

Domenico Lombardo ◽

Pietro Calandra ◽

Luigi Pasqua ◽

Salvatore Magazù

Keyword(s):

Self Assembly ◽

Spatial Configuration ◽

Molecular Level ◽

Building Blocks ◽

Key Factors ◽

Science And Engineering ◽

Functional Nanostructures ◽

Cooperative Interactions ◽

Nanostructured Systems ◽

Organic Nanomaterials

In this paper, we survey recent advances in the self-assembly processes of novel functional platforms for nanomaterials and biomaterials applications. We provide an organized overview, by analyzing the main factors that influence the formation of organic nanostructured systems, while putting into evidence the main challenges, limitations and emerging approaches in the various fields of nanotechology and biotechnology. We outline how the building blocks properties, the mutual and cooperative interactions, as well as the initial spatial configuration (and environment conditions) play a fundamental role in the construction of efficient nanostructured materials with desired functional properties. The insertion of functional endgroups (such as polymers, peptides or DNA) within the nanostructured units has enormously increased the complexity of morphologies and functions that can be designed in the fabrication of bio-inspired materials capable of mimicking biological activity. However, unwanted or uncontrollable effects originating from unexpected thermodynamic perturbations or complex cooperative interactions interfere at the molecular level with the designed assembly process. Correction and harmonization of unwanted processes is one of the major challenges of the next decades and requires a deeper knowledge and understanding of the key factors that drive the formation of nanomaterials. Self-assembly of nanomaterials still remains a central topic of current research located at the interface between material science and engineering, biotechnology and nanomedicine, and it will continue to stimulate the renewed interest of biologist, physicists and materials engineers by combining the principles of molecular self-assembly with the concept of supramolecular chemistry.

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Electrochemical Synthesis of Multi-Material Nanowires as Building Blocks for Functional Nanostructures

MRS Proceedings ◽

10.1557/proc-636-d4.6.1 ◽

2000 ◽

Vol 636 ◽

Cited By ~ 11

Author(s):

David J. Pena ◽

Baharak Razavi ◽

Peter A. Smith ◽

Jeremiah K. Mbindyo ◽

Michael J. Natan ◽

...

Keyword(s):

Electrical Properties ◽

Self Assembly ◽

Ohmic Contacts ◽

Electronic Devices ◽

Building Blocks ◽

Anisotropic Particles ◽

Functional Nanostructures ◽

Electrochemically Deposited ◽

Multilayered Nanowires ◽

Surface Chemistries

AbstractNanostructures are electrochemically deposited into alumina or polycarbonate templates resulting in monodisperse, anisotropic particles with a range of tunable sizes. These particles have been synthesized with diameters of 20–250 nm and with lengths of 1–10 μm. Currently, structures have been made with stripes of Au, Ag, CdSe, Co, Cu, Ni, Pd, and Pt. These materials offer a variety of different properties. In particular, many of the metals in this group are excellent conductors, meaning these particles can actually be used as nanowires. Co and Ni are ferromagnetic and may be used for separation or assembly. CdSe is a semiconductor, possibly allowing for the synthesis of electronic devices such as transistors. Furthermore, many of these materials have different surface chemistries, making the orthogonal functionalization and assembly of these nanowires more accessible. This research focuses on increasing the number of materials available, especially semiconductors, incorporating these potentially useful materials into multilayered nanowires and evaluating their electrical properties, either individually or in small bundles. In addition, the surface chemistry of the various materials in the nanowires is being compared to aid in orthogonal self-assembly of functional nanostructures such as memory devices. The work presented will demonstrate the effects of rod composition on electrical properties. In particular, the effects of changing the work function of the materials on either side of a semiconductor to form Schottky junctions or ohmic contacts will be shown.

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Imaging superatomic molecular orbitals in a C60 molecule through four 800-nm photons

International Journal of Modern Physics B ◽

10.1142/s0217979215501155 ◽

2015 ◽

Vol 29 (17) ◽

pp. 1550115 ◽

Cited By ~ 6

Author(s):

G. P. Zhang ◽

H. P. Zhu ◽

Y. H. Bai ◽

J. Bonacum ◽

X. S. Wu ◽

...

Keyword(s):

Angular Distribution ◽

Gas Phase ◽

Building Blocks ◽

Molecular Orbitals ◽

Thermal Ionization ◽

Natural Explanation ◽

Functional Nanostructures ◽

Photoelectron Angular Distribution ◽

Velocity Image ◽

Image Difference

Superatomic molecular orbitals (SAMOs) in C 60 are ideal building blocks for functional nanostructures. However, imaging them spatially in the gas phase has been unsuccessful. It is found experimentally that if C 60 is excited by an 800-nm laser, the photoelectron casts an anisotropic velocity image, but the image becomes isotropic if excited at a 400-nm wavelength. This diffuse image difference has been attributed to electron thermal ionization, but more recent experiments (800 nm) reveal a clear nondiffuse image superimposed on the diffuse image, whose origin remains a mystery. Here we show that the nondiffuse anisotropic image is the precursor of the f SAMOs. We predict that four 800-nm photons can directly access the 1f SAMO, and with one more photon, can image the orbital, with the photoelectron angular distribution having two maxima at 0° and 180° and two humps separated by 56.5°. Since two 400-nm photons only resonantly excite the spherical 1s SAMO and four 800-nm photons excite the anisotropic 1f SAMO, our finding gives a natural explanation of the nondiffuse image difference, complementing the thermal scenario.

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Factors Affecting Molecular Self-Assembly and Its Mechanism

Scientific Research Journal ◽

10.24191/srj.v9i1.5385 ◽

2012 ◽

Vol 9 (1) ◽

pp. 43 ◽

Cited By ~ 1

Author(s):

Hueyling Tan

Keyword(s):

Self Assembly ◽

Building Blocks ◽

Molecular Engineering ◽

Molecular Structures ◽

Polymer Science ◽

New Approach ◽

Factors Affecting ◽

Dna Structures ◽

Self Assembling ◽

Wide Range

Molecular self-assembly is ubiquitous in nature and has emerged as a new approach to produce new materials in chemistry, engineering, nanotechnology, polymer science and materials. Molecular self-assembly has been attracting increasing interest from the scientific community in recent years due to its importance in understanding biology and a variety of diseases at the molecular level. In the last few years, considerable advances have been made in the use ofpeptides as building blocks to produce biological materials for wide range of applications, including fabricating novel supra-molecular structures and scaffolding for tissue repair. The study ofbiological self-assembly systems represents a significant advancement in molecular engineering and is a rapidly growing scientific and engineering field that crosses the boundaries ofexisting disciplines. Many self-assembling systems are rangefrom bi- andtri-block copolymers to DNA structures as well as simple and complex proteins andpeptides. The ultimate goal is to harness molecular self-assembly such that design andcontrol ofbottom-up processes is achieved thereby enabling exploitation of structures developed at the meso- and macro-scopic scale for the purposes oflife and non-life science applications. Such aspirations can be achievedthrough understanding thefundamental principles behind the selforganisation and self-synthesis processes exhibited by biological systems.

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A Bottom-Up Approach to Solution-Processed, Atomically Precise Graphitic Cylinders on Surfaces

10.26434/chemrxiv.7158959 ◽

2018 ◽

Author(s):

Erik Leonhardt ◽

Jeff M. Van Raden ◽

David Miller ◽

Lev N. Zakharov ◽

Benjamin Aleman ◽

...

Keyword(s):

Self Assembly ◽

Carbon Nanostructures ◽

Carbon Nanomaterials ◽

Circle Packing ◽

Pyrolytic Graphite ◽

Building Blocks ◽

Bottom Up ◽

Casting Technique ◽

New Class ◽

Solution Casting Technique

Extended carbon nanostructures, such as carbon nanotubes (CNTs), exhibit remarkable properties but are difficult to synthesize uniformly. Herein, we present a new class of carbon nanomaterials constructed via the bottom-up self-assembly of cylindrical, atomically-precise small molecules. Guided by supramolecular design principles and circle packing theory, we have designed and synthesized a fluorinated nanohoop that, in the solid-state, self-assembles into nanotube-like arrays with channel diameters of precisely 1.63 nm. A mild solution-casting technique is then used to construct vertical “forests” of these arrays on a highly-ordered pyrolytic graphite (HOPG) surface through epitaxial growth. Furthermore, we show that a basic property of nanohoops, fluorescence, is readily transferred to the bulk phase, implying that the properties of these materials can be directly altered via precise functionalization of their nanohoop building blocks. The strategy presented is expected to have broader applications in the development of new graphitic nanomaterials with π-rich cavities reminiscent of CNTs.

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Reversible microscale assembly of nanoparticles driven by the phase transition of a thermotropic liquid crystal

10.26434/chemrxiv.5691169 ◽

2017 ◽

Author(s):

Niamh Mac Fhionnlaoich ◽

Stephen Schrettl ◽

Nicholas B. Tito ◽

Ye Yang ◽

Malavika Nair ◽

...

Keyword(s):

Phase Transition ◽

Liquid Crystal ◽

Self Assembly ◽

Nematic Phase ◽

Hierarchical Control ◽

Building Blocks ◽

Model System ◽

Microscopic Level ◽

Reversible Process ◽

Thermotropic Liquid Crystal

The arrangement of nanoscale building blocks into patterns with microscale periodicity is challenging to achieve via self-assembly processes. Here, we report on the phase transition-driven collective assembly of gold nanoparticles in a thermotropic liquid crystal. A temperature-induced transition from the isotropic to the nematic phase leads to the assembly of individual nanometre-sized particles into arrays of micrometre-sized aggregates, whose size and characteristic spacing can be tuned by varying the cooling rate. This fully reversible process offers hierarchical control over structural order on the molecular, nanoscopic, and microscopic level and is an interesting model system for the programmable patterning of nanocomposites with access to micrometre-sized periodicities.

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Synthesis and Self-assembly of Amphiphilic Precision Glycomacromolecules

Polymer Chemistry ◽

10.1039/d1py00422k ◽

2021 ◽

Author(s):

Alexander Banger ◽

Julian Sindram ◽

Marius Otten ◽

Jessica Kania ◽

Alexander Strzelczyk ◽

...

Keyword(s):

Self Assembly ◽

Solid Phase ◽

Building Blocks ◽

Polymer Synthesis

We present the synthesis of so called amphiphilic glycomacromolecules (APGs) by using solid-phase polymer synthesis. Based on tailor made building blocks, monosdisperse APGs with varying compositions are synthesized, introducing carbohydrate...

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