A sodium barium borosilicate glass matrix with a higher solubility of sulfate has been developed recently at Bhabha Atomic Research Centre for vitrification of sulfate bearing high-level nuclear waste. We report here the studies carried out to understand the influence of sulfate ion on the three-dimensional borosilicate network. Experiments were carried out with sodium barium borosilicate base glass samples loaded with varying amounts of SO 4 2À (0-5 mol%). Phase separation studies on the samples revealed that as much as 3 mol% of SO 4 2À can be loaded within the base glass without any phase separation, however, beyond this limit BaSO 4 (barite) crystallizes within the matrix. Thermal analyses of the samples indicated a shift in glass transition temperature from 5341 (0 mol% SO 4 2À ) to 4951C (3 mol% SO 4 2À ) and it remained more or less unaltered afterwards even with high SO 4 2À loading. A similar observation of structure stabilization was obtained from 29 Si MAS-NMR studies also, which showed that with 2 mol% of SO 4 2À loading, the Q 2 :Q 3 ratio changed from 59:41 (for samples with 0 mol% SO 4 2À loading) to 62:38 and it remained almost the same afterwards even with higher SO 4 2À loading. 11 B MAS NMR patterns of the glass samples, however, remained unchanged with SO 4 2À loading ([BO 4 ]:[BO 3 ] 5 38:62). Based on 29 Si and 11 B MAS NMR studies, the authors propose two different ways of interaction of SO 4 2À ions with the borosilicate network: (i) the network modifying action of SO 4 2À ions with -Si-O-Si-linkages, at low SO 4 2À ion concentration (o2 mol%) and (ii) the preferential interaction of SO 4 2À with the Ba 21 ions at high SO 4 2À concentration (42 mol%).

High cesium (Cs)‐bearing sodium borosilicate glasses incorporated with varying concentrations of TiO2 up to 10 mol% at the expense of B2O3 were prepared by the conventional melt quenching method. Physicochemical properties of the glasses studied include Cs volatilization losses, leaching, and glass transition temperatures. Structural aspects of the glasses were investigated using Fourier transform infrared, 11B MAS NMR, and UV‐visible optical absorption techniques. From the detailed investigations on these glasses, optimum concentration of TiO2 for minimum volatilization losses of Cs has been established. Structural studies revealed the role of TiO2 in the Cs volatilization as well as leaching characteristics of the glass. Based on our studies, it can be inferred that the glass sample with 5 mol% TiO2 content gives the optimum formulation with regard to the leaching and Cs volatilization losses. Results of the study are useful in the development of high Cs‐bearing glasses for their use as a gamma source for radiation technology application.

Treatment of [PdCl2(PhCN)2] with diaryl telluride in 1 : 2 molar ratio gave mononuclear palladium complexes, trans-[PdCl2(TeR2)2] () (R = Mes () (Mes = 2,4,6-trimethylphenyl), Ph (), o-tol () (o-tol = ortho-tolyl)). Reaction of [PdCl2(TeMes2)2] with one equivalent of [PdCl2(PhCN)2] or Na2PdCl4 with TeRR' afforded chloro-bridged binuclear complexes, [Pd2(μ-Cl)2Cl2(TeRR')2] () (R/R' = Mes/Mes (); Mes/Ph (); Ph/Ph ()). A toluene-methanol solution of trans-[PdCl2(TeMes2)2] on refluxing for 30 minutes yielded a binuclear cyclopalladated complex, [Pd2(μ-Cl)2{CH2C6H2(4,6-Me2)TeMes)}2] (). When the refluxing was prolonged, a mononuclear complex cis-[PdCl2{MesTeCH2C6H2(4,6-Me2)TeMes}] () was isolated. Treatment of palladium acetate with TeMes2 afforded an acetato-bridged analogue of , [Pd2(μ-OAc)2{CH2C6H2(4,6-Me2)TeMes}2] () together with a very minor component, a tetranuclear complex, [Pd(μ-OAc)(μ-TeMes)]4 (). This reaction with unsymmetrical tellurides, MesTeR, also gave cyclopalladated complexes [Pd2(μ-OAc)2{CH2C6H2(4,6-Me2)TeR}2] (R = o-tol () and Ph ()) in which 2-methyl of the mesityl group of the telluride was exclusively metallated. The complex trans-[PdCl2(TeMes2)2] on refluxing in xylene gave palladium telluride, Pd7Te3. These complexes were characterized by elemental analyses, IR and NMR ((1)H, (13)C and (125)Te) spectroscopy. The molecular structures of trans-[PdCl2(TeMes2)2] (), [Pd2(μ-Cl)2Cl2(TeMes2)2]·2acetone (·2acetone), cis-[PdCl2{MesTeCH2C6H2(4,6-Me2)TeMes}] (), [Pd2(μ-OAc)2{CH2C6H2(4,6-Me2)TeMes)}2]·toluene (·toluene), [Pd2(μ-OAc)2{CH2C6H2(4,6-Me2)Tetol-o}2] () and [Pd(μ-OAc)(μ-TeMes)]4 () were established by single crystal X-ray diffraction analyses. The mononuclear complex was isolated in two polymorphic forms each with the trans configuration.

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