Reaction of d(0) Zr(NMe2)2[MeC(N(i)Pr)2]2 (1) with O2 at -30 °C gives three Zr containing products: a peroxo trimer {(μ-η(2):η(2)-O2)Zr[MeC(N(i)Pr)2]2}3 (2), an oxo dimer {(μ-O)Zr[MeC(N(i)Pr)2]2}2 (3), and an oxo polymer {(μ-O)Zr[MeC(N(i)Pr)2]2}n (4). is a rarely observed peroxo complex from the reaction of a d(0) complex with O2.

Addition of 1-hexene to methylalumoxane-activated catalyst systems based on rac-Me(2)Si(ind)(2)ZrMe(2) causes, concurrent with polyhexene formation and diminution of the otherwise prevalent cation [rac-Me(2)Si(ind)(2)Zr(mu-Me)(2)AlMe(2)](+), formation of a hitherto unobserved species [rac-Me(2)Si(ind)(2)Zr(mu-R)(mu-Me)AlMe(2)](+), where R is a Zr-bound polyhexyl chain. As hexene is increasingly...

A method for direct determination of cadmium, chromium, copper and lead in sediments and soil samples by electrothermal atomic absorption spectrometry using Zr, Ir, etylenediamine acetic acid (EDTA), Zr + EDTA, Ir + EDTA, Zr + Ir and Zr + Ir + EDTA as chemical modifiers in 0.5% (v/v) Triton X-100 plus 0.2% (v/v) nitric acid mixture used as diluent was developed. The effects of mass and mass rat...

A new series of titanium(IV) and zirconium(IV) amides have been prepared from the reaction between M(NMe(2))(4) (M = Ti, Zr) and chiral ligands, (R)-2,2'-bis(p-toluenesulfonylamino)-1,1'-binaphthyl (1H(2)), (R)-2,2'-bis(diphenylphosphinoylamino)-1,1'-binaphthyl (2H(2)), (R)-2,2'-bis(mesitoylamino)-1,1'-binaphthyl (3H(2)), (R)-5,5',6,6',7,7',8,8'-octahydro-2,2'-bis(pyrrol-2-ylmethyleneamino)-1,1...

The reactions of a zirconium salt with 1,2,4,5-benzenetetracarboxylate (btec), bathophenanthroline (Bphen) and thiocyanate ions were synthesized and studied by changing the mole ratio, the order of reactant and their pH. It is found that the coordination mode of btec acid depends on the control of reaction conditions. Monodentate, bidentate and bridging modes were investigated by FT-IR spectros...

Chiral group 4 NHC-metal complexes were prepared in good yields by amine elimination from M(NR2)4 (M = Ti, Zr, Hf; R = Me, Et) and chiral pincer NHC-ligands, L4(L4a and L4b), L5 and L6, which are derived from (S,S)-diphenyl-1,2-ethanediamine. Treatment of M(NR2)4 with 1 equiv. of L4 in THF gives, after recrystallization from a benzene solution, the chiral titanium amides (L4)Ti(NMe2)(Br)(THF) (...

Introduction: It is well known that shergottites have a large variation of rare earth elements (REEs) abundance patterns and isotopic compositions. Jones [1] and Borg and Draper [2] suggest that light REEs (LREEs)-enriched shergottites resulted from mixing of a LREEs-enriched component with their parental magma. The LREEsenriched component is thought to be either Martian crust [1] or a KREEP-li...

The somatostatin analogue octreotide (SMS 201-995) inhibits secretion and growth of certain tumor cells, and current efforts are directed toward the elucidation of its mode of antiproliferative action. In this study, the effect of octreotide on the growth of ZR-75-1 human breast cancer cells has been characterized in immunodeficient nude mice and in cell culture. These results have been related...

UNLABELLED Transforming growth factor-β (TGF-β) promotes cancer invasion and metastasis and is therefore a potential drug target for cancer treatment. Fresolimumab, which neutralizes all mammalian active isoforms of TGF-β, was radiolabeled with (89)Zr for PET to analyze TGF-β expression, antibody tumor uptake, and organ distribution. METHODS (89)Zr was conjugated to fresolimumab using the che...

Vascular heme oxygenase (HO) metabolizes heme to form carbon monoxide (CO). Increased heme-derived CO inhibits nitric oxide synthase and can contribute to hypertension via endothelial dysfunction in Dahl salt-sensitive rats. Obese Zucker rats (ZR) are models of metabolic syndrome. This study tests the hypothesis that endogenous CO formation is increased and contributes to hypertension and endot...