The preparation of heterodinuclear complexes, especially those comprising early-late transition metals coordinated by a simple or symmetrical ancillary ligand, represents a fundamental challenge and an opportunity to prepare catalysts benefitting from synergic properties. Here, two new mixed titanium(iv)-zinc(ii) complexes, [LTi(OiPr)2ZnEt] and [LTi(OiPr)2ZnPh], both coordinated by a diphenolat...

Stoichiometric reactions of YCl3(THF)3 with potassium 2-((arylimino)methyl)quinolin-8-olates or 2-(1(arylimino)ethyl)quinolin-8-olates in THF solution gave the mononuclear LYCl2(DMSO)2 complexes 1−5 in the presence of DMSO and a representative dinuclear complex 6 in the absence of DMSO. All yttrium complexes were fully characterized by NMR measurements and elemental analysis, and the crystal st...

A review of the present state of organozinc coordination chemistry. with special emphasis on compounds of the type RZnX is given. Their preparation as well as some factors determining their structure and stability are discussed. Certain organozinc coordination compounds have been found to be effective catalysts for cyclo-oligomerization and polymerization reactions. in particular of oxygen-cont...

in suspension polymerization, particle size distribution of polymer is the outcome of dynamic equilibrium between the break up and coalescence phenomena. the rates of break up and coalescence and consequently polymerization stability depend on several parameters, the most important of which are type and concentration of stabilizer. in this study, the effects of type and concentration of stabili...

This research aimed to investigate the copolymerization of ethylene and various 1-olefins. The comonomer lengths were varied from 1-hexene (1-C₆) up to 1-octadecene (1-C₁₈) in order to study the effect of comonomer chain length on the activity and properties of the polymer in the metallocene/MAO catalyst system. The results indicated that two distinct cases can be described for the effect of 1-...

For complex rocks in which the structure of minerals, rather than their chemical composition, changes with progressive evolution of the system, it makes sense to try and monitor such an evolving system through the progressive change in the crystal structures of the constituent phases. In effect, the paragenetic sequences of minerals in such complex environments should be related to the crystal ...

Proper chromosome segregation in eukaryotes depends upon the mitotic and meiotic spindles, which assemble at the time of cell division and then disassemble upon its completion. These spindles are composed in large part of microtubules, which either generate force by controlled polymerization and depolymerization or transduce force generated by molecular microtubule motors. In this review, we di...

Phagocytosis in macrophages is thought to involve insertion of cytoplasmic vesicles at sites of membrane expansion before particle ingestion (“focal” exocytosis). Capacitance (Cm) measurements of cell surface area were biphasic, with an initial rise indicative of exocytosis followed by a fall upon phagocytosis. Unlike other types of regulated exocytosis, the Cm rise was insensitive to intracell...

Factor requirements for yeast and rat liver ribosomes were determined in several different reactions using either yeast or liver factors. In polymerization assays yeast ribosomes required a factor in addition to elongation factor 1 (EF-1) and elongation factor 2 (EF-2). The third factor (EF3) requirement was observed with EFs from either yeast or liver for both poly(U)-directed polyphenylalanin...