Publisher Summary This review is concerned with the neglected class of inorganic compounds, which contain ions of the same element in two different formal states of oxidation. Although the number of references cited in our review show that many individual examples of this class have been studied, yet they have very rarely been treated as a class, and there has never before, to our knowledge, been a systematic attempt to classify their properties in terms of their electronic and molecular structures. In the past, systems containing an element in two different states of oxidation have gone by various names, the terms “mixed valence,” nonintegral valence,” “mixed oxidation,” “oscillating valency,” and “controlled valency” being used interchangeably. Actually, none of these is completely accurate or all-embracing, but in our hope to avoid the introduction of yet another definition, we have somewhat arbitrarily adopted the phrase “mixed valence” for the description of these systems. The concept of resonance among various valence bond structures is one of the cornerstones of modern organic chemistry.

Mixed Valence Chemistry-A Survey and Classification

Reaction of 2,3,6,7,10,11-hexaaminotriphenylene with Ni2+ in aqueous NH3 solution under aerobic conditions produces Ni3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene), a new two-dimensional metal–organic framework (MOF). The new material can be isolated as a highly conductive black powder or dark blue-violet films. Two-probe and van der Pauw electrical measurements reveal bulk (pellet) and surface (film) conductivity values of 2 and 40 S·cm–1, respectively, both records for MOFs and among the best for any coordination polymer.

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High Electrical Conductivity in Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2, a Semiconducting Metal–Organic Graphene Analogue

Metal–organic frameworks (MOFs) are intrinsically porous extended solids formed by coordination bonding between organic ligands and metal ions or clusters. High electrical conductivity is rare in M...

Electrically Conductive Metal-Organic Frameworks.

The industrial preparation of many chemicals relies on the unparalleled rate and selectivity enhancements offered by metal compounds in solution. In many cases, the best catalysts rely on the scarcest elements, such as rhodium, iridium, and platinum. The cost of these materials has long driven efforts to make soluble catalysts out of cheaper, more Earth-abundant metals ( 1 ), often by modifying their reactivity with their surrounding ligands. This is especially true for catalyzing reduction-oxidation, or redox, reactions, which are critical not only in catalysis but in energy generation and storage. Such reactions usually change the oxidation state of the metal in solution. We discuss why there can be advantages to having the redox changes occur in the ligands instead.

https://science.sciencemag.org/content/sci/327/5967/794.full.pdf

Radical Ligands Confer Nobility on Base-Metal Catalysts

The chiral architectures from macromolecular building blocks were discussed. The conformational dynamics of the helicity and their effect on the (photo)physical properties of the polymers and the induction of helicity in the polymer chain were elaborated. The influence of kinetics on the macromolecular secondary structure and the use of multiple interactions in the hierarchical organization of macromolecules to well-defined supramolecular assemblied were also examined.

Chiral Architectures from Macromolecular Building Blocks

The Myth of Nickel(III) and Nickel(IV) in Planar Complexes1

The Toluenedithiolate and Maleonitriledithiolate Square-Matrix Systems

The Electronic Structures of Square-Planar Metal Complexes. II. The Complexes of Maleonitriledithiolate with Copper(II), Nickel(II), Palladium(II), and Platinum(II)

James H. Waters

Papers

The Myth of Nickel(III) and Nickel(IV) in Planar Complexes1

The Toluenedithiolate and Maleonitriledithiolate Square-Matrix Systems

The Electronic Structures of Square-Planar Metal Complexes. II. The Complexes of Maleonitriledithiolate with Copper(II), Nickel(II), Palladium(II), and Platinum(II)

The Electronic Structures of Square-Planar Metal Complexes. IV. A Square-Planaar Rhodium(II) Complex

A Stable Paramagnetic Complex of Gold1