Acid-base chemistry oxide character

In Chapter 9 we established the first five components of our interconnected network of ideas for understanding the periodic table. These included the periodic law, the uniqueness principle, the diagonal effect, the inert-pair effect, and the metal-nonmetal line. These components are summarized individually and collectively in colored figures located on the front inside cover of the book The icons for each component are shown there as well as on the bookmark pullout in the back of the text. In Chapter 10 we discussed hydrogen and the hydrides (as well as basic nuclear processes). In Chapter 11 we discussed the chemistry of oxygen, reviewed and extended our knowledge of the nature of water and aqueous solutions, and added a sixth component to our network the acid-base character of oxides and their corresponding hydroxides and oxoacids. The network with this additional component is shown in color on the top left side of the back inside cover of the book. 

I4w9 List and briefly explain two examples from Group 3A chemistry that illustrate the variation of the acid-base character of the oxides going down the group. 

The first part of the book examines the crystal and electronic structure, stoichiometry and composition, redox properties, acid-base character, and cation valence states, as well as new approaches to the preparation of ordered TMO with extended structure of texturally defined systems. The second part compiles practical aspects of TMO applications in materials science, chemical sensing, analytical chemistry, solid-state chemistry, microelectronics, nanotechnology, environmental decontamination, and fuel cells. The book examines many types of reactions — such as dehydration, reduction, selective oxidations, olefin metathesis, VOC removal, photo- and electrocatalysis, and water splitting — to elucidate how chemical composition and optical, magnetic, and structural properties of oxides affect their surface reactivity in catalysis. 

Metal oxides belong to a class of widely used catalysts. They exhibit acidic or basic properties, which make them appropriate systems to be used as supports for highly dispersed metal catalysts or as precursors of a metal phase or sulfide, chloride, etc. Simple metal oxides range from essentially ionic compounds with the electropositive elements to covalent compounds with the nonmetals. However, taking into account the large variety of metal oxides, the principal objective of this book is to examine only metal oxides that are more attractive from the catalytic point of view, and most specifically transition metal oxides (TMO). In particular, TMO usually exhibit nonstoichiometry as a consequence of the presence of defective structures. The interaction of TMO with surfaces of the appropriate carriers develop monolayer structures of these oxides. The crystal and electronic structure, stoichiometry and composition, redox properties, acid-base character and cation valence sates are major ingredients of the chemistry investigated in the first part of the book. New approaches to the preparation of ordered TMO with extended structure of texturally well defined systems are also included. 

Before providing an overview of the acid-base properties of metal oxide surfaces, a brief systematic description of their bulk and stmctural properties and surface chemistry is needed. According to basic inorganic chemistry concepts, the oxides of non-metals as well as the oxides of the metals in very high oxidation states are defined as acidic oxides and anhydrides, respectively, the oxides of metals as basic oxides, and the oxides having both acidic and basic characters are denoted as amphoteric. 

Softer Lewis bases have to be applied in etch baths for oxides and salts of metals or semiconductors with a softer Lewis acid character of their cations. Materials consisting of compounds of heavier metals frequently become dissolvable in the presence of higher halogenide imis like chloride or bromide. So, Cu(l) which is not well solvated in water as the unbound ion becomes dissoluble in the presence of, for example, chloride ions by forming Cu(l) chlorocomplexes. The choice of suitable complex ligands depends on the particular coordination chemistry of the heavier metals or semiconductors inside the oxidic or saltlike functional materials. In some cases, ammonia or amines are suitable. So, the formatiOTi of a silver diamine complex can be used for the etching of Ag(l) compounds,... 

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