Synthesis and morphological study of aminoglycosides-modified gold and silver nanoparticles

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A one-dimensional superstructure from the self-assembly of Ag nanoparticles induced by Cu2+ ion coordination

The self-assembly of spherical silver nanoparticles with variable size and controlled organization using triglycine as an organic template is described. Triglycine and silver nitrate were used as the starting materials for the preparation of the spherical nanoparticles, and in the presence of copper cations, the particles further self-assembled into one dimensional nanostructures

Kanamycin A 6 '-pyrenylamide: a selective probe for heparin detection

We have synthesized a novel derivative of kanamycin A bearing a pyrenyl fluorophore which can be used for the specific recognition of heparin in EtOH:H 2O (1:3) through formation of a 2:1 complex

Supramolecular self-assembled nanowires by the aggregation of a protoporphyrin derivative in low-polarity solvents

The self-assembly of a simple tetraalkyl-substituted protoporphyrin derivative into fibril wire-like nanostructures from CHCl3/cyclohexane solvent mixes is explored. The protoporphyrin IX derivative is synthesised in two efficient steps by amidation of the two propylenic acid groups followed by a cross metathesis of the vinyl groups using Grubbs' second-generation catalyst. The self-assembly of the functionalised protoporphyrin is sensitive to solvent and under favourable conditions forms 'nanowires' of micrometre length. The nanowires were characterised by absorption and fluorescence spectroscopy, transmission electron microscopy and atomic force microscopy

Solvent induced ordered-supramolecular assembly of highly branched protoporphyrin IX derivative

Protoporphyrin IX species bearing highly branched alkyl chains were self-assembled into well-defined nanostructures such as rod-like in CHCl3-cylcohexane (1: 9, v/v) and a honeycomb-like morphology in a polar solvent dimethyl sulfoxide (DMSO). The rod-like morphologies observed in the atomic force microscopy (AFM) and transmission electron microscopy (TEM) suggest that the lamellar phase self-organises into multilamellar vesicles. The X-ray diffraction (XRD) results indicate molecular arrangements resulting from longitudinal and transverse stacking of the porphyrin head groups in the lamellar structure. The typical nanostructures were derived from a high level of cooperativity between the porphyrin cores via pi-sigma interactions and supported by hydrogen bonding and van der Waals interactions. The nanostructures were characterised by means of UV-vis, fluorescence, AFM, TEM and XRD analysis. Our methodology confirms the potential of protoporphyrin IX derivatives in supramolecular chemistry

Supramolecular self-assembly of protoporphyrin IX amphiphile into worm-like and particular aggregates

A protoporphyrin IX amphiphile bearing hydrophobic-hydrophilic functional regions was synthesised by coupling protoporphyrin IX with methoxytriethylene glycol using (3-(dimethylamino)propyl)ethyl carbodiimide hydrochloride/1-hydroxybenzotriazole followed by a double-cross metathesis with 1-undecene using second- generation Grubb's catalyst. The self-assembling behaviour of the amphiphile in varying concentration of CHCl3/MeOH was investigated, with well-defined nanostructures described as worm-like fibrils and particular aggregates being formed in 1:1 and 1:9 v/v of MeOH/CHCl3, respectively

Revisit: Eaton's reagent catalyzed synthesis of mono and bis-chalcone derivatives

Eaton's reagent efficiently catalyzed the Claisen-Schmidt condensation reaction of aryl aldehydes with aromatic and cyclic ketones under solvent free microwave irradiation conditions to afford mono and bis-chalcone derivatives. The present approach offers several advantages such as shorter reaction times, cleaner reactions, good yields, inexpensive reagent and mild reaction condition

One pot multi-component synthesis of N-substituted decahydroacridine-1,8-diones catalyzed by MoO3/SiO2 as an efficient and reusable heterogeneous catalyst

A simple, efficient and ecofriendly one pot synthesis protocol has been developed for the synthesis of N-substituted decahydroacridine-1,8-diones by using an efficient and recyclable solid acidic silica supported MoO3/SiO2 catalyst from a condensation of aldehyde, amine and cyclic 1,3-diketone in THF. The reaction using MoO3/SiO2 catalyst was carried out under mild condition with very high yields up to 92%. The present approach of this methodology offers several advantages such as shorter reaction times, good yields, low cost, environmentally benign, milder reaction conditions, easy recovery of catalyst and reusability

pH dependent molecular self-assembly of octaphosphonate porphyrin of nanosale dimensions: sperical and tubular aggregates

Self-assembled nanostructures of zwitterionic octaphosphanatoporphyrin 1, of either nanoparticles or nanorods, depending on small changes in the pH, is demonstrated based on the J-aggregates. Porphyrin 1 self- assembled into nanosphere aggregates with a diameter of about 70-80 nm in the pH range 5-7, and nanorod aggregates were observed at pH 8.5. Hydrogen bonding, pi-pi stacking and hydrophilic interactions play important roles in the formation of this nanostructure morphology. Nanostructures were characterized by UV/Vis absorbance, fluorescence, atomic force microscopy (AFM) and transmission electron microscopy (TEM). This interesting pH dependent self-assembly phenomenon could provide a basis for development of novel biomaterials