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Organotin(IV) derivatives of 3-phenyl and 3-p-chloro-phenyl-2-mercaptoquinazol-4-ones of the type , (R=Ph, n-Bu, Me; R′=C6H5, p-Cl-C6H4; n = 1,2) have been synthesized by the reaction of the sodium salt of the ligand with corresponding organotin(IV) chlorides in non-aqueous media. These compounds have been -characterized by elemental and spectral analyses. IR and NMR studies of these compounds show the monodentate behaviour of the ligand in the case of triorganotin(IV) derivatives and bidentate behaviour in the case of diorganotin(IV) derivatives.

In a convenient one-pot sequence, treatment of benzil-dibenzylimine with sodium in dry tetrahydrofuran followed by addition of phosphorodichloridate and phosphorothiodichloridate yields 3-oxo-P-1,5,3-diazaphosphepines and 3-thioxo-P-1,5,3-diazaphosphepines, respectively.

Sodium borovanadate glasses have been investigated using infrared spectroscopy (IR) and magic angle spinning nuclear magnetic resonance (MAS NMR) studies. It is found that modification of borovanadate glass structure leads to the formation of tetrahedral boron and the ratio of tetrahedral $(B_4)$ to trigonal boron $(B_3)$ exhibits a maximum value of unity in these systems. A structural model has been proposed for these glasses keeping in view this observation. The model, which envisages formation of two isomorphous diborovanadate species whose structures are similar to that of diborate units, is able to account for the variation of $B_4/B_3$ ratio over the entire composition range. Variation of the glass transition temperature of these glasses has been investigated using the structural model in conjunction with cluster-tissue model of glass transition. It is emphasized throughout that electronegativities of structural units are of vital importance in understanding local oxide ion reactions which results in structural modification.

A simple method for the preparation of monophasic β-SiAlON using nitridation of Si and AIN with an oxygen partial pressure of 10 -4 atm is described. The effect of the AIN/Si ratio in the initial mixture on the formation of β-SiAlON is discussed. The likely mechanism of the formation of β-SiAlON is outlined.

Selected aryl aldehydes were treated with 17-oxo-5-androsten-3β-yl acetate (I) to give the corresponding 16-arylidene 17-oxo-5-androsten-3β-yl acetates(IIa-e). Condensation of these chalcones with urea revealed the formation of the corresponding substituted pyrimidin-2′-ones (IIIa-e) respectively.

A simple, novel, and fast method of preparation of metal nitride powders (GaN, TiN, and VN) using microwave-assisted carbothermal reduction and nitridation has been demonstrated. The procedure uses the respective oxides and amorphous carbon powder as the starting materials. Ammonia gas is found to be more effective in nitridation than high-purity N2 gas. Complete nitridation is achieved by the use of a slight excess of amorphous carbon. Metals themselves are not found to be effectively nitrided. The products were characterized using XRD, TEM, and SAED and found to possess good crystallinity and phase purity. The method can be of general applicability for the preparation of metal nitrides.

An investigation of the essential oil of Ageratum conyzoides afforded, in addition to known precocenes I and II, four new compounds, an isodihydroeuparin derivative, a chromene, chromone, and a chromanone. Their structures were established by spectroscopic methods as 2-(2′-methylethyl)-5,6-dimethoxybenzofuran, 2-(1′-oxo-2′-methylpropyl)-2-methyl-6,7-dimethoxy-chromene, 3-(2′-methylpropyl)-2-methyl-6,8-dimethoxy-chrom-4-one and 2-(2′-methylprop-2′-enyl)-2-methyl-6,7-dimethoxy-chroman-4-one respectively. The topical application of the oil to the nymphs of Schistocerca gregaria showed high nymphal mortality (91%).

Structures of NASICON glasses of the general formula AB(2)(PO4)(3), Where A = Li, Na or K and B = Fe, Ga, Ti, V or Nb, have been investigated using vibrational (IR and Raman) spectroscopies. Phosphate species appear to establish an equilibrium via a disproportionation reaction involving a dynamical bond-switching mechanism where both charge and bonds are conserved. B ions in the system acquire different coordinations to oxygens. Alkali ions cause absorptions due to cage vibrations. All the observed spectroscopic features are consistent with speciation involving disproportionation reactions.

A bioassay guided fractionation of the essential oil of Ageratum conyzoides results in the isolation of an unsaturated branched chain fatty acid. Spectroscopic analysis has been used to identify the compound as (Z)-6-methyl-12-heptadecenoic acid. The compound shows insecticidal and growth regulatory activity against the desert locust Schistocerca gregaria. Besides mortality, the compound also causes disturbances at the nymphal-adult moult resulting in deformity. The characteristic features of the deformity is the short fore-wings due to incomplete expansion.

Ultrasonic velocities at 10 MHz have been measured in two series of lithium, sodium, and potassium phosphomolybdate glasses with two fixed P2O5 concentrations. Elastic moduli, Poisson's ratio, and Debye temperature have been calculated. The composition dependence of most of the properties of lithium glasses exhibits a trend opposite to that of potassium glasses. Properties of sodium glasses lie between the other two alkali systems. Alkali oxide modification is suggested to be accompanied by ring reformation in lithium and sodium glasses. Ring size effects have been shown to account for all of the composition dependence.

The physical and thermal properties (density, molar volume, microhardness, heat capacity, glass transition temp.) and IR spectra of K2O-WO3-P2O5 glasses are studied over a wide composition range.