Samaresh Ghosh

Synthesis of photoresponsive polyamidoamine (PAMAM) dendritic architecture

Abstract Polyamidoamine (PAMAM) dendrimer 1 with an azobenzene central linker has been synthesized and found to undergo reversible trans / cis isomerization upon exposure to UV-light.

Towards fluorescence sensing polyamidoamine (PAMAM) dendritic architectures

A novel polyamidoamine (PAMAM) dendrimer (G2.5) 1 with a naphthalene core unit has been prepared and was found to display acid sensitive fluorescence signal amplification making it of potential use as a pH sensor material.

Fluorophore-labeled Polyamidoamine (PAMAM) Dendritic Architectures: Synthesis and Fluorescence Sensing Properties

Novel polyamidoamine (PAMAM) dendrimers (G=0.5–2.5) with a naphthalene core unit have been prepared. They were found to display acid as well as metal ion sensitive fluorescence signal amplification, making them of potential use as chemosensing materials. PAMAM dendritic wedges as well as naphthalene-centered PAMAM dendrimers were characterized by FT-IR, 1H and 13C NMR spectroscopic methods and elemental analysis.

An approach to novel polyamidoamine (PAMAM) side chain dendritic polyesterurethane (SCDPEU) block copolymer architectures

Abstract A novel polyamidoamine (PAMAM) side chain dendritic polyesterurethane (SCDPEU) block architecture derived from ester terminated polyamidoamine dendritic diol (G2.3), sebacoyl chloride and 2,4-toluidene diisocyanate (TDI) is reported. This material was characterized by means of IR and NMR spectroscopies, as well as by intrinsic viscosity and differential scanning calorimetry measurements. SCDPEU synthesis was conducted in bulk by using the catalytic amount of dibutyl tin dilaurate (DBTDL).

Novel Ibuprofen‐based Polyurethane: A New Approach for Drug Delivery

Facile synthesis of novel ibuprofen bearing polyurethane 1 has been achieved for the first time and found to display the release pattern of ibuprofen based on the easy cleavage of ester linkages. Thorough characterizations (FT‐IR, UV‐Vis, NMR, and elemental analysis) were performed to ascertain the structure of polyurethane 1.

Photochromism and photoreactivity of 2,6-dichloro-4-methyl-3-pyridinecarboxaldehyde in the solid state

Photochromism of the title compound and its photoreactivity on prolonged UV irradiation leading to products including the benzocyclobutenol 2, presumably formed by electrocyclization of an (E)-o-xylylenol intermediate in the solid state, is described.

Cyclopentanoid allysilanes in synthesis: Generation via intramolecular ene reaction of activated 1,6-dienes and application to the synthesis of functionalized diquinanes

A new general route to cis-1,2-disubstituted cyclopentanoid allylsilanes useful in di-and triquinane synthesis is described based on intramolecular ene reaction of activated 1,6-dienes featuring a homoallylsilane unit as the ene donor.

Epoxy-based polymer bearing activated azo dye (methyl orange) units: novel colorimetric indicator for amines

Novel epoxy-based polymer 2-bearing activated azo dye, 4-(4-sulphophenylazo)-N,N-dimethylaniline (methyl orange), moieties were synthesised by post-azo-coupling reaction of poly(hydroxy ether amine) 1 and investigated sensory responses towards amines. The reversible protonation–deprotonation chemistry of activated azobenzene moiety makes it of potential use as a colorimetric indicator for amines.

Epoxy-based oligomer containing dithia-aza-based naphthylazobenzene pendant: a chemosensor for Hg2+ and Cu2+ ions

A simple epoxy-based oligomer 1 containing naphthylazobenzene-appended dithia-aza moieties was prepared. In UV–vis measurements, the proposed oligomer showed the ion-sensing ability to Hg2+ and Cu2+ ions. The discrimination between two differently responding Hg2+ and Cu2+ ions was also realised from ‘ON–OFF’ type fluorescence responses of 1.

Antibacterial Effects of Silver Doped Polyethyleneglycol Based Polyamidoamine Side Chain Dendritic Polyurethane

Antibacterial activity was imparted with polyamidoamine (PAMAM) side chain dendritic polyurethane (SCDPU‐PEG) by doping of silver particles. Antibacterial activities of both the polyurethane (SCDPU‐PEG) and its silver doped structures were investigated against Escherichia coli bacteria. The silver doped polymeric structures were found to exhibit antibacterial activity while the polymer without silver loading showed no antibacterial activity. Formation of silver doped side chain dendritic polymers was investigated from the UV‐vis plasmon absorption band of silver particles.