Rich Structural Chemistry Research Articles

Copper(I) halide supramolecular networks linked by N-heterocyclic donor bridging ligands

Abstract

ChemInform Abstract: Rings, Cages and Chains — The Rich Structural Chemistry of the Polycations of the Chalcogens

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Quaternary chalcogenides containing a rare earth and an alkali- or alkaline-earth metal

This paper reviews the recent synthesis and characterization of quaternary solid-state compounds that contain three metal elements from different major blocks of the Periodic Table, namely an s-block alkali- or alkaline-earth metal, an f-block lanthanide or scandium, and a p-block main-group metal or a d-block transition metal. The rich structural chemistry of such compounds is discussed.

Polyoxoalkoxy molybdenum and vanadium clusters

While the chemistry of polyoxoanions has been extensively studied, the related polyoxoalkoxide clusters remain relatively unexplored. Recent investigations into the coordination chemistry of polyoxoanions with alkoxide ligands demonstrate the existence of a rich structural chemistry which is now emerging. The introduction of alkoxide ligands into polyoxoanion cores significantly expands the structural diversity of the cluster types and allows the isolation not only of fully-oxidized cores with all metal centers possessing d0 electronic configurations but of fully-reduced and mixed valence systems.

New developments in actinide alkoxide chemistry

Much new information on the synthesis, physicochemical properties, solid state structures, and reaction chemistry of actinide alkoxide complexes has begun to emerge in the last decade. We have developed several new starting materials that facilitate easy entry into thorium and uranium alkoxide chemistry. Synthetic pathways employed in our laboratories to obtain alkoxide and aryloxide complexes of the actinides include (1) metathesis of the iodide ligands in Ul 3(THF) 4 and Thl 4(THF) 4 with potassium salts of the desired ligand, or (2) protonolysis of metal-nitrogen or metal-carbon bonds by alcohols or phenols. The rich structural and reaction chemistry of these new complexes is described along with prospects for future developments in the field.

Molecular structure of hydrocarbon monolayers on metal surfaces

Recent studies of the molecular structure and chemical bonding of organic monolayers on metal surfaces are reviewed. Most of the research is concentrated on alkenes and alkynes adsorbed on platinum and rhodium. The applications of low-energy electron diffraction, high-resolution electron energy loss spectroscopy, and thermal desorption spectroscopy provided most of the structural and bonding information in studies that utilized single-crystal metal surfaces. Hydrocarbon monolayers exhibit a rich and diverse structural chemistry that may be correlated to analogous organometallic clusters. Alkylidyne (==C(CH/sub 2/)/sub n/CH/sub 3/) bonding predominates near 300 K on Pt and Rh although a variety of different molecular conformations is found. Perhaps the most pronounced characteristic of the organic monolayers is the temperature-dependent variation of their structure and bonding. The bonding also varies markedly across the periodic table; much stronger for the early transition metals (W, Fe) and much weaker on Ag and Cu than on Pt and Rh. These temperature- and metal-dependent trends are altered to some extent when considering different crystallographic planes for the metal surface. Finally the possible directions that this field of research may take are discussed.