Bidhan C. Roy

Studies on water soluble conducting polymer: Aniline initiated polymerization of m-aminobenzene sulfonic acid

Abstract The synthesis of poly( m -aminobenzene sulfonic acid) homopolymer (PABS), by aniline initiated polymerization of m -aminobenzene sulfonic acid using ammonium persulfate oxidation has been attempted. The water soluble polymer PABS thus synthesized was characterized by IR, UV, TG-DSC, 1 H -NMR, SEM and ESR spectroscopic techniques. A co-ordinated IR and thermal analysis (TG, DSC) indicate that thermal desulfonation occurs preferentially in PABS–Na compared to PABS, commencing at 310°C and 370°C, respectively. The steric hindrance due to the large ortho substitution causes lowering of conductivity of PABS and its Na-salt which was found to be 5.4×10 −5 S/cm and 2.4×10 −6 S/cm, respectively. The ESR spectra show that the polymer to be strongly paramagnetic with a g value of 2.0013.

Synthesis and characterization of poly(2,5-dimethoxyaniline) and poly(aniline-Co-2,5-dimethoxyaniline): The processable conducting polymers

Poly(2,5-dimethoxyaniline) (PDMOA) and its copolymers with aniline (PADMOA), which exhibit remarkably improved solubility in common organic solvents, were obtained by chemical polymerization, and characterized by a host of physical techniques. The lowering of the quinoid absorption in the IR spectra and the upshifting of the N1s envelope in the XPS spectra indicate residual doping in the XPS polymers and thermal characteristic of the polymers provide evidence for hydrogen bonding, which appear to enhance the thermal stability of the homopolymer. These polymers are highly planar and conjugated, with well-developed polaronic features, shown by the XRD, ESR and UV-spectral data. The conductivity, however, is not high and apparently may be due to localization of polaronic charges at the hydrogen-bonding sites and the increased proportion of the insulating methoxy component in the polymer matrix.

Structurally designed novel furogamma lactams as inhibitors for bacterial propagations

Some novel furogamma lactams have been synthesised by one step condensation of arylaminomalonates with substituted furyl acryloyl chlorides. The annulation of substituted monocyclic gammalactams followed by cyclization produced novel tricyclic furogamma lactams. Some of these furogammalactams are found to exhibit Gram-positive and Gram-negative antibacterial activity at very high concentrations.

Synthesis and characterization of conducting poly (1-aminonaphthalene), poly (2-aminonaphthalene) and poly (aniline-co-1-aminonaphthalene)

Poly (1&2)-aminonaphthalene and poly (aniline-co-1-aminonaphthalene) have been synthesized in high yields by chemical oxidative polymerization method. The polymers are soluble in polar solvents such as DMSO, NMP etc. In PNA-2 as head-to-tail coupling cannot occur, the electrical conductivity is lower than PNA-1. The copolymer exhibits distinct morphology, higher viscosity, characteristic exciton peak, appreciable thermal stability and electrical conductivity compared to PNA-1.

A Simple and New Synthetic Method for the Preparation of 2-Pheynl-6-substituted Quinolines

Abstract 2-Phenylquinoline derivatives have been synthesized through the thermolysis of suitable enaminoimine hydrochiorides.

Conjugation of poor inhibitors with surface binding groups: a strategy to improve inhibition.

Conjugation of surface binding groups with inhibitors for carbonic anhydrase leads to the conversion of weak inhibitors to strong inhibitors.

14-n-Butyl­dibenz­[a,h]­acridine

The crystal structure of the monoclinic form of the title compound, C25H21N, is influenced by the presence of the alkyl chain, whose trans conformation leads to distortion of the aromatic moiety from planarity, the dihedral angle between the two outer rings being ca 20°. The C—C—C ring angles and C—C ring distances nearest to the n-butyl substituent are perturbed from typical values to minimize the steric effect.

Diethyl 5-Oxo-1-phenyl-3-(2-thienyl)pyrrolidine-2,2-dicarboxylate, C20H21NO5S

The possibility of the 180° rotation of the thiophene ring is observed. The phenyl ring is almost perpendicular to the pyrrolidine ring. The structure is stabilized by van der Waals interactions.

Highly site-selective alkylation reaction of bent aza-heterocycles by alkyllithium and alkyl halides

Cavity-shaped azaarenes have been converted to site-selective alkyl derivatives by alkyllithium and alkyl halides.

Selective recognition of carbonic anhydrase using transition metal complexes

A metal complex was designed to bind to the protein carbonic anhydrase strongly and selectively in aqueous medium.