A series of dissymmetric dinuclear complexes were synthesized, as dual site catalysts in ethylene polymerization, by coupling the allylated a-diimine complexes of the metals Ti, Zr, V, Ni and Pd with the ansa-zirconocene complex [C5H4-SiH(Me)-C5H4]ZrCl2 possessing a hydride silane moiety. The different stages of syntheses included the formation of bis(cyclopentadienide)methyl silane which was u...

The molecular structure of the title compound, [ZnBr(2)(C(10)H(8)N(2)S(2))], contains a seven-membered chelate ring in which the zinc atom is coordinated by two bromide ions and by the two pyridyl N atoms of a single 2,2'-dipyridyldisulfide (dpds) ligand within a slightly distorted tetra-hedron. As is usual for this type of complex, the disulfide group does not participate in zinc coordination....

We consider a new construction, the weak Delaunay triangulation of a finite point set in a metric space, which contains as a subcomplex the traditional (strong) Delaunay triangulation. The two simplicial complexes turn out to be equal for point sets in Euclidean space, as well as in the (hemi)sphere, hyperbolic space, and certain other geometries. There are weighted and approximate versions of ...

Calnexin is a membrane-bound lectin and a molecular chaperone that binds newly synthesized glycoproteins in the endoplasmic reticulum (ER). To analyze the oligomeric properties of calnexin and calnexin-substrate complexes, sucrose velocity gradient centrifugation and chemical cross-linking were used. After CHAPS solubilization of Chinese Hamster Ovary cells, the unoccupied calnexin behaved as a...

The asymmetric unit of the title complex, [Zn(SCN)2(C6H6N2O)2], consists of one Zn(2+) cation located on a twofold rotation axis, as well as of one thio-cyanate anion and one neutral isonicotinamide ligand, both occupying general positions. The Zn(2+) cation is tetra-hedrally coordinated into a discrete complex by the N atoms of two symmetry-related thio-cyanate anions and by the pyridine N ato...

In the title compound, C(3)H(12)N(2) (2+)·2BF(4) (-)·2C(12)H(24)O(6), the central C atom of the propane-1,3-diammonium cation lies on a crystallographic twofold rotation axis. The terminal NH(3) (+) groups insert into the crown rings through strong N-H⋯O hydrogen-bonding inter-actions, resulting in the formation of a 1:2 supra-molecular [(C(3)H(12)N(2))·(C(12)H(24)O(6))(2)](2+) complex. The ani...

Alginate-metal complexes were prepared with divalent (Ca, Ba, Zn) and trivalent metals (Fe, Al) via congealing method in form of beads. Alginate mixed metals (Ca & Fe) complexes were also prepared by simultaneous and consecutive congealing. The studied beads were blank beads and racemic ketoprofen (KTP) loaded beads. Metal content was determined by atomic absorption spectroscopy and was 1.8% to...

We present a simple model which allows us to investigate the equilibrium aspects of molecular recognition between rigid biomolecules on a generic level. Using a two-stage approach, which consists of a design and a testing step, the role of cooperativity and of varying bond strength in molecular recognition is investigated. Cooperativity is found to enhance selectivity. In complexes which requir...

The interaction between benzo-15-crown-5 (B15C5), dibenzo-18-crown-6 (DB18C6), dibenzyl-daza-18crown-6 (DBzDA18C6), N-phenyl-aza-15-crown-5 (NPhA15C5) and dibenzopyridine-18-crown-6 (DBPy18C6) with π-acceptor 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in chloroform solution was studied spectrophotometrically. The interaction of B15C5-DDQ and DB18C6-DDQ caused the formation...