Jayanta K. Ray

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.

Novel and rapid palladium-assisted 6pi electrocyclic reaction affording 9,10-dihydrophenanthrene and its analogues.

A novel methodology for the synthesis of 9,10-dihydrophenanthrene and its analogues has been developed via a palladium-assisted 6pi electrocyclic reaction followed by formaldehyde elimination.

Synthesis of a New Family of Receptors having Dibenz[c,h]acridine as Spacers and their Binding Affinity with Urea

Abstract New molecular receptors with a dibenz[ c , h ]acridine as spacer and having functionality complementary to urea have been developed.

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.

Molecular recognition: studies on the synthesis of some bis thiophene carboxamide derivatives as ditopic receptors for long chain dicarboxylic acids

Abstract New molecular receptors 6, 7 and 8 with diphenyl ether/diphenyl sulphide as spacer having functional groups complementary to long chain dicarboxylic acids have been developed. Binding studies with different dicarboxylic acids showed high association constants with the receptor 6.

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.

On the Regio and Stereo Selective Formylations of Acyclic Alpha Methylene Ketones towards Vilsmeier Haack Reagent

Abstract The regio and stereo selectivities of Vilsmeier Haack reaction of ketomethylene compounds have been predicted. The possible mechanistic pathway has also been proposed.

Synthetic studies towards furosesquiterpenes: Construction of linearly-fused AB trans- and AB cis-furo[3,2-b]-and furo[2,3-b] decalins

Abstract Linearly fused furo[2,3-b]- and furo[3,2-b] decalin systems with cis trans ring junctions are present in several furosesquiterpenes obtained from marine sponges. A short and efficient synthesis of this ring system is described starting from Hagemans ester (1). The method has been extended for the synthesis of compound 8 and 14 via the diketones 5,6 and 12 respectively.

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.

Chemoselective method for the synthesis of 4-allyl-4-hydroxycyclohexa-2,5-dienone derivatives from 1,4-quinones by an indium-mediated allylation protocol

Allyl indium halide on reaction with 1,4-quinones produced 4-allyl-4-hydroxycyclohexa-2,5-dienone derivatives. Unsymmetrical quinones show high chemoselectivity in addition of allyl indium halide reagent to the carbonyl group.