Microporous porphyrin assemblies: Interaction of NO2 gas with sublimed layers of meso-mono-4-pyridyl-tri-phenylporphyrinatocobalt(II)

2003 ◽  
Vol 07 (12) ◽  
pp. 775-779 ◽  
Author(s):  
Tigran S. Kurtikyan ◽  
Arthur N. Mardyukov ◽  
Robert K. Kazaryan ◽  
John A. Goodwin
Keyword(s):  
Self Assembly ◽  
Supramolecular Structure ◽  
The Self ◽  
Pyridyl Group ◽  
Transfer Activity ◽  
Coordination Site ◽  
Nitro Complexes ◽  
Sublimed Layers ◽  
Uv Visible ◽  
Adjacent Molecule

The interaction of NO 2 (15 NO 2) gas with sublimed layers of meso-mono-4-pyridyl-triphenylporphyrinatocobalt(II) (CoMPyTPP) has been investigated by means of IR and UV-visible spectroscopies. These studies have led to the characterisation of two nitro-complexes: (1) the five-coordinated nitro complex similar to that observed earlier for the closely-related meso-tetraphenylporphyrinatocobalt(II) (CoTPP), and (2) the six-coordinated complex, in which the fifth coordination site is occupied by the pyridyl group of an adjacent molecule. Upon storage of the films, the concentration of six-coordinate complexes increases at the expense of the five-coordinate. These experimental observations indicate the self-assembly of CoMPyTPP in layers with formation of coordinatively linked oligomers. Due to the specificity of the supramolecular structure, the layers conserve their microporosity upon storage and reveal the oxo-transfer activity relative to appropriate oxygen acceptors.

Interaction of diatomic ligands with Fe(II) meso-mono-4-pyridyl-tri-phenyl-porphyrinate. Spectral evidence of self-assembly in sublimed layers

2003 ◽  
Vol 07 (09) ◽  
pp. 623-629 ◽  
Author(s):  
Tigran S. Kurtikyan ◽  
J. Steven Ogden ◽  
Robert K. Kazaryan ◽  
Valery N. Madakyan
Keyword(s):  
Low Temperature ◽  
Self Assembly ◽  
Thin Layers ◽  
The Self ◽  
Ambient Conditions ◽  
Visible Spectroscopy ◽  
Pyridyl Group ◽  
Sublimed Layers ◽  
Uv Visible ◽  
Adjacent Molecule

The interaction of CO , NO and O2 gases with thin layers of meso-mono-4-pyridyl-tri-phenylporphyrinatoiron(II) ( FeMPyTPP ) obtained by sublimation onto low-temperature (T = 77 K ) substrates has been investigated by means of IR and UV-visible spectroscopy. In contrast to the closely-related meso-tetraphenylporphyrinatoiron(II) ( FeTPP ), the formation of two types of axial complexes has been observed. In one of these the 5th coordination site is occupied by the pyridyl group of an adjacent molecule indicating the self-assembly of Fe ( MPyTPP ) in layers with formation of coordinatively linked oligomers. The degree of oligomerisation depends on the nature of the interacting gas. Due to the specificity of the supramolecular structure, the layers are fairly stable in ambient conditions and conserve their microporosity to bind reversibly with the aforementioned ligands.

Crystal structure of the supramolecular linear polymer formed by the self-assembly of mono-6-deoxy-6-adamantylamide-β-cyclodextrin

2004 ◽  
Vol 60 (2) ◽  
pp. 204-210 ◽  
Author(s):  
Victor Hugo Soto Tellini ◽  
Aida Jover ◽  
Luciano Galantini ◽  
Francisco Meijide ◽  
José Vázquez Tato
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Self Assembly ◽  
The Self ◽  
Linear Polymer ◽  
Water Molecules ◽  
Orthorhombic Space Group ◽  
Cyclodextrin Cavity ◽  
Adjacent Molecule ◽  
Secondary Side

Mono-6-deoxy-6-adamantylamide-β-cyclodextrin–dimethylformamide–15H2O, C53H85NO35·C3H7NO·15H2O, crystallizes in the orthorhombic space group P212121. The adamantyl group is inserted into the cyclodextrin cavity of the adjacent molecule, entering by the side of the secondary hydroxy rim, thus forming a supramolecular linear polymer by self-assembly. Adjacent macrocycles are linked into columns by hydrogen bonds involving the nearest glucose residues, and the structure is further stabilized by their involvement in hydrogen bonding with water molecules which reside in channels surrounding the polymer columns, thus acting as bridges between the cyclodextrin units. The centroid of the adamantyl group lies below the plane formed by the seven glycosidic O atoms of the host cyclodextrin, excluding water molecules from the secondary side of β-cyclodextrin (β-CD). Between the adamantyl group and the primary hydroxy rim of the cyclodextrin cavity lies a dimethylformamide molecule, which shields the hydrophobic adamantyl group from the primary hydroxy rim of its carrying β-CD and excludes water molecules from the primary side of the β-CD cavity.

Fluorescent Rosette Nanotubes from the C-analogue of the Guanine–Cytosine (G∧C) Motif

2015 ◽  
Vol 1796 ◽  
pp. 1-6 ◽  
Author(s):  
Belete Legesse ◽  
Jae-Young Cho ◽  
Rachel L. Beingessner ◽  
Takeshi Yamazaki ◽  
Hicham Fenniri
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
The Self ◽  
Visible Spectroscopy ◽  
Fluorescent Properties ◽  
Force Microscopy ◽  
Rosette Nanotubes ◽  
Atomic Force ◽  
Transmission Electron ◽  
Uv Visible

ABSTRACTRosette nanotubes (RNTs) are tubular architectures generated through the hierarchical self-assembly of the guanine-cytosine (G∧C) motif 1 or 2 (Figure 1). Motif 2 differs from 1 by the substitution at the N-atom in the G-ring with a C-atom as shown in red. In this paper, we prepare a new tricyclic G∧C base 3 from a functionalized derivative of 2 and demonstrate its self-assembly into fluorescent helical RNTs in N,N-dimethylformamide (DMF). The self-assembly and fluorescent properties of RNTs 3 were established using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM) and UV-visible spectroscopy.

Interaction of NO2 gas with sublimed microporous layers of iron(II)-meso-mono-4-pyridyl-tri-aryl-porphyrins: Two different reaction pathways

2008 ◽  
Vol 12 (01) ◽  
pp. 65-72
Author(s):  
Astghik A. Hovhannisyan ◽  
Tigran S. Kurtikyan ◽  
Robert K. Kazaryan ◽  
John A. Goodwin
Keyword(s):  
Fourier Transform ◽  
Reaction Pathways ◽  
Pyridyl Nitrogen ◽  
Pyridyl Group ◽  
Nitro Complexes ◽  
Ft Ir ◽  
Sublimed Layers ◽  
Neighboring Molecule ◽  
Porphyrin Dianions ◽  
Ft Ir Spectroscopy

Sublimed layers of Fe II MPyTPP and Fe II MPyTTP ( MPyTPP and MPyTTP are meso-mono-4-pyridyl-triphenyl- and meso-mono-4-pyridyl-tri-p-tolyl-porphyrin dianions, respectively) consist of coordination oligomers that are formed by binding of pyridyl nitrogen atoms with the iron centers of the adjacent molecules in the film. Fourier transform infrared (FT-IR) spectroscopy including experiments with the 15 NO 2 isotopomer demonstrates that the reaction of low pressure NO 2 gas with these layers leads to the formation of two types of complexes: six-coordinate nitro-complexes, in which the fifth site is occupied by the pyridyl group of the neighboring molecule in the layer and five-coordinate nitrito-complexes that terminate the oligomers. Further addition of NO 2 increments leads to the preferential oxidation of these nitrito ligands to bidentate nitrato ligands. These layers conserve their porosity upon standing and allow study of the oxo-transfer reactivity from coordinated nitro-groups to appropriate oxygen acceptors.

CO-Solute control of the self-assembly of a biopolymeric supramolecular structure

1989 ◽  
Vol 154 (5) ◽  
pp. 477-483 ◽  
Author(s):  
P.L. san Biagio ◽  
J. Newman ◽  
F. Madonia ◽  
M.U. Palma
Keyword(s):  
Self Assembly ◽  
Supramolecular Structure ◽  
The Self

scholarly journals Synthesis, Characterization and Anticancer Activity of Porphyrin-Containing Organometallic Cubes

2010 ◽  
Vol 63 (11) ◽  
pp. 1529 ◽  
Author(s):  
Nicolas P. E. Barry ◽  
Olivier Zava ◽  
Paul J. Dyson ◽  
Bruno Therrien
Keyword(s):  
Mass Spectrometry ◽  
Cell Viability ◽  
Anticancer Activity ◽  
Cancer Cells ◽  
Drug Concentration ◽  
Self Assembly ◽  
The Self ◽  
Visible Spectroscopy ◽  
Silver Triflate ◽  
Uv Visible

Self‐assembly of 5,10,15,20‐tetra(4‐pyridyl)porphyrin (tpp‐H2) and 5,10,15,20‐tetra(4‐pyridyl)porphyrin‐M(ii) (M = Ni (tpp‐Ni); Zn (tpp‐Zn)) tetradentate panels with the dinuclear p‐cymene ruthenium clips [Ru2(p-cymene)2(C2O4)Cl2] and [Ru2(p-cymene)2(C6H2O4)Cl2] (C2O4 = oxalato; C6H2O4 = 2,5‐dioxydo‐1,4‐benzoquinonato) affords the cationic organometallic cubes: [Ru8(p-cymene)8(tpp‐H2)2(C2O4)4]8+ (1); [Ru8(p-cymene)8(tpp‐Ni)2(C2O4)4]8+ (2); [Ru8(p-cymene)8(tpp‐Zn)2(C2O4)4]8+ (3); [Ru8(p-cymene)8(tpp‐H2)2(C6H2O4)4]8+ (4); [Ru8(p-cymene)8(tpp‐Ni)2(C6H2O4)4]8+ (5); and [Ru8(p-cymene)8(tpp‐Zn)2(C6H2O4)4]8+ (6). In addition, the new dinuclear arene ruthenium 2,5‐dioxydo‐1,4‐benzoquinonato clips [Ru2(indane)2(C6H2O4)Cl2] (7) and [Ru2(nonylbenzene)2(C6H2O4)Cl2] (8) react in methanol with tpp‐H2 in the presence of silver triflate to afford the corresponding cationic cubes [Ru8(indane)8(tpp‐H2)2(C6H2O4)4]8+ (9) and [Ru8(nonylbenzene)8(tpp‐H2)2(C6H2O4)4]8+ (10) respectively. All cationic metalla‐cubes were isolated as triflate salts and characterized by NMR, infrared, electro‐spray mass spectrometry and UV‐visible spectroscopy. Moreover, the formation of unsymmetrical metalla‐cubes built using a mixture of the different porphyrin panels during the self‐assembly of the 2,5‐dioxydo‐1,4‐benzoquinonato metalla‐cubes, [Ru8(p-cymene)8(tpp‐H2)(tpp‐Ni)(C6H2O4)4]8+ (11), [Ru8(p-cymene)8(tpp‐H2)(tpp‐Zn)(C6H2O4)4]8+ (12), and [Ru8(p-cymene)8(tpp‐Ni)(tpp‐Zn)(C6H2O4)4]8+ (13), was studied by electro‐spray mass spectrometry. The cytotoxicities of all metalla‐cubes as well as the mixtures containing the unsymmetrical metalla‐cubes were established on human ovarian A2780 and A2780cisR cancer cell lines. All symmetrical compounds are equally cytotoxic (IC50 = 7–15 μM) (IC50 being the drug concentration necessary for 50% inhibition of cell viability) against both A2780 and cisplatin‐resistant A2780cisR cancer cells, with stronger cytotoxicities (IC50 = 2–5 μM) observed for the mixtures containing the unsymmetrical 2,5‐dioxydo‐1,4‐benzoquinonato metalla‐cubes.

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

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.

Interrelationship of the cellular distribution and secretion of regular structure (RS) protein in Bacillus licheniformis nm 105

1992 ◽  
Vol 50 (1) ◽  
pp. 712-713
Author(s):  
Xiaorong Zhu ◽  
Richard McVeigh ◽  
Bijan K. Ghosh
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Licheniformis ◽  
Self Assembly ◽  
Gel Electrophoresis ◽  
Culture Supernatant ◽  
Regular Structure ◽  
The Self ◽  
Cellular Distribution ◽  
Structural Protein ◽  
Laboratory Cultures

A mutant of Bacillus licheniformis 749/C, NM 105 exhibits some notable properties, e.g., arrest of alkaline phosphatase secretion and overexpression and hypersecretion of RS protein. Although RS is known to be widely distributed in many microbes, it is rarely found, with a few exceptions, in laboratory cultures of microorganisms. RS protein is a structural protein and has the unusual properties to form aggregate. This characteristic may have been responsible for the self assembly of RS into regular tetragonal structures. Another uncommon characteristic of RS is that enhanced synthesis and secretion which occurs when the cells cease to grow. Assembled RS protein with a tetragonal structure is not seen inside cells at any stage of cell growth including cells in the stationary phase of growth. Gel electrophoresis of the culture supernatant shows a very large amount of RS protein in the stationary culture of the B. licheniformis. It seems, Therefore, that the RS protein is cotranslationally secreted and self assembled on the envelope surface.

Nanoscale Self-Assembly Using Ion and Electron Beam Techniques: A Rapid Review

MRS Advances ◽  
2020 ◽  
Vol 5 (64) ◽  
pp. 3507-3520
Author(s):  
Chunhui Dai ◽  
Kriti Agarwal ◽  
Jeong-Hyun Cho
Keyword(s):  
Electron Beam ◽  
Self Assembly ◽  
Ion Beam ◽  
Three Dimensional ◽  
The Self ◽  
Stress Generation ◽  
Rapid Review ◽  
High Yield ◽  
3D Nanostructures ◽  
Self Assembled

AbstractNanoscale self-assembly, as a technique to transform two-dimensional (2D) planar patterns into three-dimensional (3D) nanoscale architectures, has achieved tremendous success in the past decade. However, an assembly process at nanoscale is easily affected by small unavoidable variations in sample conditions and reaction environment, resulting in a low yield. Recently, in-situ monitored self-assembly based on ion and electron irradiation has stood out as a promising candidate to overcome this limitation. The usage of ion and electron beam allows stress generation and real-time observation simultaneously, which significantly enhances the controllability of self-assembly. This enables the realization of various complex 3D nanostructures with a high yield. The additional dimension of the self-assembled 3D nanostructures opens the possibility to explore novel properties that cannot be demonstrated in 2D planar patterns. Here, we present a rapid review on the recent achievements and challenges in nanoscale self-assembly using electron and ion beam techniques, followed by a discussion of the novel optical properties achieved in the self-assembled 3D nanostructures.

Bottom-up Evolution from Disks to High-Genus Polymersomes

2018 ◽  
Author(s):  
Claudia Contini ◽  
Russell Pearson ◽  
Linge Wang ◽  
Lea Messager ◽  
Jens Gaitzsch ◽  
...  
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Amphiphilic Copolymers ◽  
Chain Entanglement ◽  
Bottom Up ◽  
New Approach ◽  
High Genus ◽  
Transmission Electron ◽  
Minimal Radius ◽  
Stop Flow

<div><div><div><p>We report the design of polymersomes using a bottom-up approach where the self-assembly of amphiphilic copolymers poly(2-(methacryloyloxy) ethyl phosphorylcholine)–poly(2-(diisopropylamino) ethyl methacrylate) (PMPC-PDPA) into membranes is tuned using pH and temperature. We study this process in detail using transmission electron microscopy (TEM), nuclear magnetic resonance (NMR) spectroscopy, dynamic light scattering (DLS), and stop-flow ab- sorbance disclosing the molecular and supramolecular anatomy of each structure observed. We report a clear evolution from disk micelles to vesicle to high-genus vesicles where each passage is controlled by pH switch or temperature. We show that the process can be rationalised adapting membrane physics theories disclosing important scaling principles that allow the estimation of the vesiculation minimal radius as well as chain entanglement and coupling. This allows us to propose a new approach to generate nanoscale vesicles with genus from 0 to 70 which have been very elusive and difficult to control so far.</p></div></div></div>

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