Ligand exchange in zirconocene dichloride–diethylzinc bimetallic systems

The reaction between zirconocene dichloride and excess diethylzinc in d-6-benzene solution was studied. It was found that the exchange reaction between Cp2ZrCl2 and Et2Zn is accompanied by the formation of such complexes as bis-(cyclopentadienyl)ethylzirconium chloride (EtZrCp2Cl), a zirconium-organozinc complex, and bis-(cyclopentadienyl)diethylzirconium (Et2ZrCp2). It was also found that as a result of ligand exchange in zirconocene dichloride–diethylzinc bimetallic systems, the zirconium-organozinc complex is formed in minor amounts. An assessment of the thermodynamic stability of the obtained products is given based on the results of DFT analysis. The description of the NMR spectral data of the obtained organozirconium complexes is carried out.

Ligand exchange in zirconocene dichloride–diethylzinc bimetallic systems

The reaction between zirconocene dichloride and excess diethylzinc in d-6-benzene solution was studied. It was found that the exchange reaction between Cp2ZrCl2 and Et2Zn is accompanied by the formation of such complexes as bis-(cyclopentadienyl)ethylzirconium chloride (EtZrCp2Cl), a zirconium-organozinc complex, and bis-(cyclopentadienyl)diethylzirconium (Et2ZrCp2). It was also found that as a result of ligand exchange in zirconocene dichloride–diethylzinc bimetallic systems, the zirconium-organozinc complex is formed in minor amounts. An assessment of the thermodynamic stability of the obtained products is given based on the results of DFT analysis. The description of the NMR spectral data of the obtained organozirconium complexes is carried out.

Anti-leukemogenic Efficacy of Aloe vera Gel on Benzene-induced Leukemia in Wistar Rats

Backgroud: The toxicity of benzene leading to leukemia induction has been well documented in animal model. Aloe vera is a succulent perennial evergreen flowering plant used traditionally in the treatment of jaundice and was found to have potent cytotoxic effect against HL60 human acute myeloid leukemia. The present study investigated the in vivo chemoprotective effects of Aloe vera gel on benzene-induced leukemia in rats. Methodology: Leukemia was induced in male Wistar rats of 80-90g weight by intravenously administered 0.2ml benzene solution alternate days for four weeks. Following induction, leukemic rats and normal baseline control rats were randomly assigned into four experimental groups of 6 animals each as follows: Group CTRL (control), normal baseline control rats; Group AVG (Aloe vera gel), normal baseline rats treated with Aloe vera gel (150 mg/kg) for 7 days, Group LKR (leukemic rats), untreated leukemic rats serving as leukemia control and Group LKR + AVG, leukemic rats treated with Aloe vera gel (150 mg/kg) for 7 days. Results: Leukemic rats showed altered hematology and morphological deformations such as anisocytosis, poikilocytosis and blast cells occurrence in peripheral blood. Also hypercellularity, severe dysplasia and significantly elevated micronucleated polychromatic erythrocyte were observed in marrow of leukemic rats. Moreover, benzene caused a significant elevation in plasma level of advanced oxidation protein products (AOPPs) with concomitant reduction in total sulfhydryl and arylesterase activity. However, treatment with Aloe vera gel restored blood hematology to near normal and mitigated the deformities in blood cell morphology induced by benzene. Aloe vera supplementation also effected a disappearance of dysplasia and diminution in the frequency of micronucleus in the bone marrow of treated leukemic rats. It also enhanced plasma antioxidant capability by restoring sulfhydryl content and arylesterase activity of the blood and abrogated the increase in plasma content of AOPPs. Conclusion: Overall, Aloe vera gel offered chemoprotective effect on Benzene-induced leukemia in rats.

Syntheses, Magnetic, Spectral and Biological Studies on the Coordination Compounds of N-(2-Hydroxyphenyl)-C-(3′- Carboxy-2′-Hydroxyphenyl) Thiazolidin-4-One

A dry benzene solution of the Schiff base, N-(2-hydroxyphenyl)-3′-carboxy-2′- hydroxybenzylideneimine upon reacting with mercaptoacetic acid undergoes cyclization and forms N- (2-hydroxyphenyl)-C-(3′-carboxy-2′-hydroxyphenyl)thiazolidin-4-one, LH3 (I). A MeOH solution of I reacts with Ni(II) and UO2(VI) ions and forms the monomeric coordination compounds, [Ni(LH)(MeOH)3] and [UO2(LH)(MeOH)]. The coordination compounds have been characterized on the basis of elemental analyses, molar conductance, molecular weight, spectral (IR, reflectance) studies and magnetic susceptibility measurements. I behaves as a dibasic tridentate OOS donor ligand in these compounds. The compounds are non-electrolytes (M = 4.3-6.4 mho cm2 mol-1) in DMF. Octahedral structure for Ni(II) and UO2(VI) compounds are suggested. LH3 (I) and its complexes while testing with E.Coli. (Gram Negative) and S. Aureus (Gram positive) bacteria show antibacterial activities.

STUDYING THE REACTION ROUTE OF α, β-DIBROMO KETONE AT PRESENCES OF SOME AMINES

Bromo-chalcone with containing thiene ring by the reaction of selective de­hyd­ro­bromination of α, β-dibromo ketone at presences of different amines in benzene solution and α-ethoxy-β-bromo-ketone in etha­no­lic solution in good yields were prepared. α, β-Dibromo ketone with the reaction of thiosemicarbazide le­ad to the formation of new pyrazole derivative.

Synthesis, Spectroscopic Studies and Antispermatogenic Activity of Tri- and Pentavalent Organoantimony Derivatives of Schiff Bases

Diphenyl antimony(III) and triphenylantimony(V) derivatives of Schiff bases having general formulae Ph2Sb[OC(R)CHC(R′)NC6H5] and Ph3Sb[OC(R)CHC(R′)NC6H5]2 (where R=R′=CH3,C6H5; R = CH3, R′=C6H5), respectively have been prepared. Trivalent organoantimony derivatives have been synthesized by the reaction of RC(O)CHC(R′)-NH(C6H5) with Ph3Sb in 1: 1 molar ratio whereas, pentavalent organoantimony derivatives have been synthesized by the reaction of Ph3SbBr2 with Na[OC(R)CHC(R′)N(C6H5)] in 1:2 molar ratio, respectively in benzene solution. The structures of these complexes have been assigned on the basis of chemical analysis, molecular weight measurements and spectral (IR 1H & 13C NMR) studies. Schiff base (R = CH3, R′ = C6H5 ) and its corresponding organoantimony(III) and antimony(V) compounds were used for evaluation of reproductive physiological activity in male rats and for studying antifertility activity. Compounds were administrated orally for 30 days to male albino rats and after termination of treatment, animal tissue and serum were taken for histopathological, biochemical and hematological parameters

6,6′-[(3,3′-Di-tert-butyl-5,5′-dimethoxy-1,1′-biphenyl-2,2′-diyl)bis(oxy)]bis(dibenzo[d,f][1,3,2]dioxaphosphepine) benzene monosolvate

The crystal structure of the benzene monosolvate of the well known organic diphosphite ligand BIPHEPHOS, C46H44O8P2·C6H6, is reported for the first time. Single crystals of BIPHEPHOS were obtained from a benzene solution after layering with n-heptane at room temperature. One specific property of this type of diphosphite structure is the twisting of the biphenyl units. In the crystal, C—H...π contacts and π–π stacking interactions [centroid-to-centroid distance = 3.8941 (15) Å] are observed.

Synthesis, Characterization, Spectral Studies and Antimicrobial Study on Mixed Ligand Complexes of Chloro-arsenic(III) Derived from β-Ketiminates & Piperidine Dithiocarbamate Ligand Moity

A series of Chloro-arsenic(III) complexes with N, O donor β-ketiminate ligand (L1) and S, S donor piperidine dithiocarbamate ligand (L2) have been synthesized by the reactions of AsCl3 with both ligands in equimolar ratio by stirring at room temperature in benzene solution. All these synthesized compounds have been characterized by Elemental Analysis, IR, (1H and 13C) NMR Spectral and ESI-Mass Studies. Both Ligands and their corresponding Chloro-arsenic (III) complexes have been screened for antimicrobial activity against the various bacterial (E. Coli, B. Subtalis and P. Aeruginosa) and fungal (T. Resei, P. Funiculosum and Fusarium) strains and results obtained .