Gas Chromatographic Retention Indices of 2-chlorobenzylidenemalononitrile and its Analogues

Riot control agent, 2-chlorobenzylidenemalononitrile (CS) and its analogues have both skin irritating and lacrymating properties. Herein, we report retention indices (RI) of CS and its thirteen analogues relative to the homologues n-alkanes series. These values are determined on nonpolar BP-1 and polar BP-10 capillary column under programmed temperature and isothermal chromatographic condition. The analogues differ in substitution at ortho or para position of phenyl ring and retention indices are found to vary according to the nature of the substituent.Defence Science Journal, 2012, 62(5), pp.319-323, DOI:http://dx.doi.org/10.14429/dsj.62.116

Polymer-clay Nano Composites

Nano has now become a theme in almost all the established discipline. The confluence ofinnovative methodologies, sophisticated characterisation techniques, and potential technologicalutility has resulted in intense research activity in the field of polymer nano composites. Polymercomposites made out of nano materials display unique properties in terms of improved tensilestrength, flexibility, and flexural endurance. The paper discusses the development of polymerclaynano composites, both from the conceptual point of view as well as practical methods forthe synthesis of nano composites. These are monomer intercalation, monomer modification,common solvent, and melt-intercalation methods. Various models have been discussed thatdescribe improvements in mechanical and barriers properties due to the incorporation of nanomaterials. Ongoing R&D work in the two DRDO laboratories on the development of nanocomposites has been briefly mentioned. The emerging use of polymer-nano composites has alsobeen described

Structure-biological Activity Relationship of Analogues of 2-Chlorobenzylidenemalononitrile -A Riot-control Agent

The riot-control agent 2-chlorobenzylidenemalononitrile (CS) and its ortho-and parasubstituted benzylidenemalononitrile (BMN) analogues were synthesised and characterised by spectroscopic techniques (IR, NMR, and mass spectrometry) and microanalysis, and their structure-biological activity relationship studies were carried out to know the factors responsible for sensory irritation. Hydrophobicity of substituted BMNs were determined by high-performance liquid chromatography (HPLC), which is an important determinant of the irritancy. The vapour pressure of a compound is a physico-chemical property important for the assessment of its fate in the environment. The vapour pressures of BMNs were determined by static method by an isoteniscope. A systematic investigation of sensory irritation was carried out by evaluating decrease in respiratory rate (RDs,) in mice. The R.Dsi as biological parameter was correlated with physical parameters such as hydrophobicity, vapour pressure, size of molecules, and chemical reactivity of its BMNs with dimethylaminoethyl mercaptans (DEAEMs) as a simulant of protein-SH group. A biosignifkant correlation (0.75-0.80) was obtained.by correlating all the above parameters using multiple linear regression equation

Fluorinated Epoxy Resins-based Sorbent Coating Materials for Quartz Piezoelectric Crystal Detector

Fluorinated epoxy resins were synthesised and evaluated as sorbent coating materials for the detection of organophosphorus compounds using quartz piezoelectric crystal detector. These resins were prepared by reacting excess of epichlorohydrin with each of or in combination of fluorinated diols, ie, a, a, a', a' tetrakis (trifluoromethyl) 1,3 benzene dimethanol (TTFMBD), 4,4'bis-2-hydroxy hexafluoro isopropyl) biphenyl (BHHFIBP), 4,4'dihydroxyocta fluorodiphenyl (DHOFDP) and 2,2,3,3,4,4 hexafluoro 1,5 pentanediol (HFPD) in the presence of sodium hydroxide at reflux temperature. These polymers were extracted in organic solvents and dried. Each of these fluoroepoxy resins were coated over quartz piezoelectric crystal by solution-casting method and tested using dimethylmethyl phosphonate (DMMP) as model compound. Change in the  frequency (AF) of quartz piezoelectric crystal oscillator was recorded. Sensitive and potential fluorinated epoxy resins, ie, diglycidylethers (DGE) of HFPD-TTFMBD (in the molar ratio 6:4) and DGE (HFPD-BHHFIBP in the molar ratio 4:6) were characterised by viscosity, number average molecular weight (Mn), epoxy equivalent, infrared spectroscopy, and thermal stability

Polyethylene Maleate Copolyesters as Coating Materials for Piezoelectric Quartz Crystal-based Chemical Sensors

Polyethylene maleate (PEM) was synthesised by direct polycondensation of maleic anhydride and ethylene glycol in toluene under reflux usingp-toluene sulphonic acid as a catalyst. Structure of PEM was further modified by varying nature of diols and acid components, chain length of glycols, incorporation of aromatic and fluorine groups in the chain. Formation of PEM was monitored by gas chromatography. The parameters like degree of polymerisation, number average molecular weight (Mn), and weight average molecular weight (Mw) were calculated from the extent of reaction and stoichiometric ratio of the reactants. The number average molecular weight was also determined using Knauer vapour pressure osmometer. Cohesive energy, volume, and solubility parameters of PEM-based copolyesters were calculated by group contribution method. These PEM-based copolyesters’ have been evaluated as sorbent-coating materials for the detection of organ0 phosphorus(OP)compo using dimethylmethylphosphonate (DMMP) as model compound and piezoelectric crystal detector. PEMbisphenol A is found to be the most sensitive and potential coating material for the detection of OP compounds using piezoelectric crystal detector. Potential PEM-based copolyesters have been characterised by viscosity, infrared spectroscopy, NMR spectroscopy, Mn and thermal stability

Laboratory Evaluation of Dibenz (b,t)-1,4-0xazepine for the Protection of Nylon Tapes against Rodents Attack

The efficacy of dibenz (b,f)-1 ,4-oxazepine (CR), a potent sensory irritant and deltarnethrin a wellknown insecticide, in providing protection to the multi-element nylon tapes, used as aircraft arresters at airports have been evaluated. The results obtained indicate that 5 per cent CR-admixed UV resistant nylon tapes got adequate protection against attacks from wild type laboratory bred Rattus rattus for up to 160 days. CR treatment was found to be water wash resistant against 7, 30 and 60 days protectionoffered by 3, 4 and 5 per cent deltarnethrin, respectively

<em>N</em>,<em>N</em>-Dichloro poly(styrene-co-divinylbenzene) sulfonamide beads as an efficient, selective and reusable reagent for oxidation of thiols to disulfides

1082-1088A novel method for oxidative coupling of thiols to their corresponding disulfides using N,N-dichloro poly(styrene-co-divinylbenzene) sulfonamide (PS-DVS) beads is described. PS-DVS beads act as novel and selective oxidative agents which efficiently reduce the reaction time, increase the product yield without producing over oxidized products and suitable under air atmosphere

Synthesis, characterization and mass spectrometric fragmentation of <i>gem-</i>dicyanooxiranes derived from benzylidene malononitrile

243-247Benzylidene Malononitriles react with calcium hypochlorite in carbon tetrachloride at room temperature to afford substituted phenyl-1,1'-dicyanooxiranes, a class of important synthetic intermediates. The structure of these phenyl gem-dicyanooxiranes have been confirmed by spectral methods. The electron impact mass spectrometric fragmentation of these gem-dicyan ooxiranes show some interesting features which have been substantiated by using tandem mass spectrometry

Detoxification of <i style="">O,S</i>-diethyl methyl phosphonothiolate (OSDEMP), a simulant of VX, by <i>N,N-</i>dichlorourethane as an effective decontaminating agent

1504-1509N,N-Dichlorourethane has been synthesized and characterized by FT-IR, NMR. Efficiency of this compound as decontaminant has been evaluated by the reaction of O,S-diethyl methyl phosphonothiolate (OSDEMP), a simulant of VX at RT. The decontamination reaction has been monitored by gas chromato­graphy (GC) and the products have been identified by GC-MS