Sidhanath V. Bhosale

The synthesis of novel core-substituted naphthalene diimides via Suzuki cross-coupling and their properties

This paper reports the efficient core-substitution of halogenated naphthalene diimides utilizing the Suzuki cross-coupling reaction to install various aryl substituents at the 2,6 positions. The UV-visible spectra of these compounds show a clear absorbance red shift and an enhanced fluorescence output, making them potential candidates for solar-cell dyes and electroactive elements for supramolecular materials.

One-Pot Synthesis of 2,4,5-Trisubstituted Imidazoles Using MoO3/SiO2, an Efficient and Recyclable Catalyst

Abstract A simple one-pot synthesis has been developed for the synthesis of 2,4,5-trisubstituted imidazoles using an efficient and recyclable MoO3/SiO2 solid acid catalyst by condensation of benzil or benzoin, benzaldehyde, and ammonium acetate in acetonitrile as a solvent. Using this solid catalyst, the reactions could be carried out under mild reaction conditions with very good yield of imidazoles, up to 95%. This catalyst could be recycled very easily, which makes this methodology environmentally benign.

Supramolecular self-assembly of protoporphyrin IX amphiphiles 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 Grubbs 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.

Self-Assembly of Protoporphyrin IX-TEG Derivatives into Tunable Nanoscaled Spherical Structures

The results of a solvo-controlled self-assembly process involving a novel non-ionic protoporphyrin IX functionalized with triethylene glycol (Proto-NTEG) chains is discussed. In relatively non-polar aprotic solvents (cyclohexane/CHCl3), the protoporphyrin forms stable, uniformly-sized multilamellar micro-vesicles of approximately 65u2009nm diameter, while in more polar protic solvent mixes (CHCl3/MeOH), the same protoporphyrin forms micellar aggregates with dimensions of approximately 6u2009nm. The solvo-control operates based on the differing properties of glycol units in cyclohexane and methanol leading to inverse self-assembled structures.

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.

Comparative binding study of neurotransmitters in hydrophobic and hydrophilic yoctowells in water

A discrimination study of the neurotransmitters 3,4-dihydroxy-L-phenylalanine (DOPA), adrenaline, noradrenaline, tyramine and serotonin in aqueous solution utilising hydrophobic and hydrophilic yoctowells bearing oligoethylene walls is reported. The catecholamines were bound selectively to the hydrophobic yoctowells. Serotonin showed a preference for hydrophilic yoctowells.

Construction of trimeric porphyrin-fullerene-porphyrin stacks within surface-derived pores of nano-scale dimensions

A new efficient strategy of a zinc porphyrin based yoctowell cavity as a receptor for the formation of stable inclusion complexes of fullerenes via pi-electronic donor-acceptor and hydrophobic interactions, and finally anionic porphyrin used as a cover to the wells.

Light‐Induced Electron Transfer over Distances of 5, 10, and 15 Å within Water‐Filled Yoctowells

A small series of variable-depth yoctowell cavities with functional walls on aminated silica particles and gold electrodes has been established. The dimensions of the gaps formed were 2.2 nm in diameter with varying functional depths of 5, 10, and 15 Å, depending on the length of bolaphiles applied and the position of the positive rim; these gaps were prepared through a Michael addition of the incorporated ene-amide groups. Using this construct and electrostatic interactions between the positive rim and anionic quinones as a means of immobilization, a porphyrin-quinone dyad system has been prepared. The distance between the donor and acceptor was changed systematically in aqueous solution, whilst maintaining a similar environment in each case. Upon photoexcitation of the porphyrin, efficient electron transfer occurs between the porphyrin and quinone units in a distance-dependent manner on the nanosecond timescale.

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. The formation of supramolecular nanoaggregates was evaluated by means of UV/vis, TEM, SEM, and energy dispersive X-ray spectroscopy.