The size-dependent metal to nonmetal transition in metal nanoparticles has been investigated using photoelectron and tunneling spectroscopic techniques. Metal nanoparticles capped by thiols are shown to organize into ordered 2D and 3D structures. Single-walled nanotubes and aligned carbon nanotube bundles have been synthesized by controlling the size of metal nanoparticles produced in situ duri...

The review describes articles that provide data on the synthesis and study of properties catalysts for oxidation alkanes, olefins, alcohols. These are polynuclear complexes iron, copper, osmium, nickel, manganese, cobalt, vanadium. Such example are: [Fe2(HPTB)(m-OH)(NO3)2](NO3)2·CH3OH·2H2O, where HPTB-¼N,N,N0,N0-tetrakis(2-benzimidazolylmethyl)-2-hydroxo-1,3-diaminopropane; complex [(PhSiO1,5)6...

Can cyclen (1,4,7,10-tetraazacyclododecane) bind alkali metal azides? This question is addressed by studying the geometric and electronic structures of the alkali metal azide-cyclen [M(cyclen)N3] complexes using density functional theory (DFT). The effects of adding a second cyclen ring to form the sandwich alkali metal azide-cyclen [M(cyclen)2N3] complexes are also investigated. N3(-) is found...

Nitric oxide (NO) was found to inhibit the copper-dependent induction of the yeast CUP1 gene. This effect is attributable to an inhibition of the copper-responsive CUP1 transcriptional activator Ace1. A mechanism is proposed whereby the metal binding thiols of Ace1 are chemically modified via NO- and O(2)-dependent chemistry, thereby diminishing the ability of Ace1 to bind and respond to copper...

Metal-based drugs are largely undeveloped in pharmacology. One limiting factor is the systemic toxicity of metal-based compounds. A solid-phase, sequestratable delivery agent for local delivery of metals could reduce systemic toxicity, facilitating new drug development in this nascent area. Amorphous peroxotitanates (APT) are ion-exchange materials with high affinity for several heavy metal ion...

Arsenic (atomic number, 33; relative atomic mass, 74.92) has chemical and physical properties intermediate between a metal and a nonmetal, and is often referred to as a metalloid or semi-metal. It belongs to Group VA of the Periodic Table, and can exist in four oxidation states: –3, 0, +3, and +5. Arsenite, AsIII, and arsenate, AsV, are the predominant oxidation states under, respectively, redu...

A recently developed extension of the CNDO-method is used to study the electronic structure of a number of binuclear transition metal carbonyls and carboxylates with fourfold or quasi-fourfold symmetry. The results are compared to those available from nonempirical calculations. Special attention is paid to the nature of the metal-metal bond. Connections with qualitative MO-considerations allow ...

First-principles electronic structure and positron state calculations for transition metal carbides and nitrides are performed. Perfect NaC1-structures as well as structures with metal or carbonJnitrogen vacancies are considered. The positron affinities and lifetimes are determined. The trends are discussed and the results are compared with recent positron lifetime measurements for group IV and...