TABLE OF CONTENTS

Tributyltin(IV)chloride, TBTCl, causes dose- and time-dependent histopathological changes on different target organs of new toxicity test organism: Liza saliens. The exemplars treated in 10^-7 M and 10^-9 M TBTCl solution showed thymus atrophy, spleen reduction and some alterations have been observed in various organs, including eye, gills, muscles (see figure), liver, intestine,idney, heart and pancreas. As far as the reproductive system is concerned, the Liza saliens juveniles were sensitive to perturbation of reproductive cells and this could play a significant role in population decline.

Vinyl-type polymerization of norbornene as well as random copolymerization of norbornene with styrene was studied by using a series of copper complexes/MAO. The precatalysts used here are copper complexes with -ketoamine ligands based on pyrazolone derivatives and the molecular structure of complex 4 was determined using X-ray analysis. All of these catalyst systems are moderately active for the vinyl-type polymerization of norbornene and random copolymerization of norbornene with styrene.

A series of cycloalkylidene-bridged mixed cyclopentadienyl-indenyl tetracarbonyldiruthenium complexes have been synthesized by reactions of the corresponding ligands RC₅H₄CR₂C₉H₇ with Ru₃(CO)₁₂ in refluxing xylene.

Because natural silicates are potential sources of oligosiloxanes of the type QxMy, a collection of natural silicates of similar structure was used to obtain mainly Q₂M₆ oligosiloxanes by trimethylsilylation. The tailings from silver and gold flotation beneficiation provide an important silicate source. The main silicate phase reactive to TMS was found to be anorthite. Other minerals containing silicates with a structure similar to anorthite (labradorite and augite) were also used as a Q₂M₆ source.

Efforts to use Me4NCl/NaOH mixtures in place of Me4NOH gave very poor conversions to octaanion, OA, a low cost octahedral nanobuilding block.inetic studies show very low concentrations of Me4NCl in Me4NOH greatly inhibit OA formation perhaps through formation of a stable pentacoordinate surface species.

A novel complex [Pr(bib)₂(NO₃)₃] (1){a1073ga.eps} with two-dimensional herringbone-like structure was obtained by reaction of 1-bromo-3,5-bis(imidazol-1-ylmethyl)benzene (bib) with Pr(NO₃)·6H₂O and characterized by X-ray crystallography. Its variable-temperature magnetic measurements show that the _MT value decreases continuously over the whole temperature range.

Bis(N,N-dialkyldithiocarbamato)arsenic(III)/antimony(III) diphenyldithiophosph ate/diphenyldithiophosphinate complexes of the type [R₂NCS₂]₂MS(S)PX₂ [where M = As and Sb; NR₂ = N(CH₃)₂, N(C₂H₅)₂ and N(CH₂)₄; X = OC₆H₅ and C₆H₅] have been synthesized and characterized by physico-chemical, spectral [UV, IR and NMR (¹H, ¹³C and ³¹P)] and thermal (TG, DTA and DSC) analysis. The TG analysis shows single-step decomposition of the complex to Sb₂S₃. These complexes have been screened for antibacterial and antifungal activity using the disc diffusion method. All the complexes have shown good activity as antibacterial and antifungal agents, which increased with increasing concentration. Where, R = Me and Et and M = As; R = Me, Et and R₂ = (CH₂)₄ and M = Sb and X = OPh and Ph.

A series of methylbismuth(III) O,O-a1068ga1.eps alkylenedithiophosphates have been synthesized and characterized. Transformation of two representative compounds to pure Bi₂S₃ have been carried out successfully at refluxing xylene temperature(142 °C) as revealed by XRD and SEM studies.

A novel 1,2-dicarba-closo-dodecaborane-lactose conjugate (4a) with an N-glycosidic linkage was synthesized. This conjugate was found to be much more stable against hydrolytic deboronation (closo to nido tranformation of the carborane cage) under neutral conditions than a related carborane-lactose conjugate (1a) with an O-glycosidic linkage. This result demonstrates that the hydrolytic stability of carborane-carbohydrate conjugates in neutral aqueous solutions may depend dramatically on the chemical nature of the spacer that links the carbohydrate moiety with the boron cage, the rate of hydrolysis varying by orders of magnitude. We relate a significant decrease in the deboronation rate to the formation of more strongly bound supramolecular aggregates, in which the boron cage is less accessible to nucleophilic attack by solvent molecules, in the solution of the carborane-N-lactoside conjugate 4a.