John Leopold Speier

Homogeneous Catalysis of Hydrosilation by Transition Metals

Publisher Summary This chapter describes numerous ways in which soluble complexes of transition metals act as catalysts for the hydrosilation of organic compounds, especially substituted and unsubstituted unsaturated hydrocarbons. The term “hydrosilation” can be used to describe an addition reaction in which compounds with one or more Si–H bonds add to any reagent. The chapter focuses on the effects of structure on reactivity during hydrosilation in homogeneous solutions of platinum catalysts, and point out similarities and differences that are observed with other catalysts. Commonly, when chloroplatinic acid is the source of the catalyst for hydrosilation and sometimes when salts of other metals are used, no effect is observed for some time after it has been added to a mixture of reagents. Then, rather suddenly a rapid reaction can ensue. This “induction period” can in some cases last for a relatively long time, even for hours. An induction period, followed by a very fast exothermic reaction leads to difficult situations when large amounts of reagents are employed. Homogeneous catalysis with metals other than platinum and hydrosilation of acetylenes is also discussed in this chapter.

Destruction of microorganisms by contact with solid surfaces

Abstract Solids upon which organic or inorganic cations had been chemisorbed killed microorganisms at a rate described by a second order rate expression −dS dt = K [surface area/milliliter][S] in which S = concentration of viable organisms/milliliter in an aqueous medium. Cations that have no antimicrobial activity in solution were capable of forming antimicrobial surfaces.

Equilibria between MexSiCl4−x, x=3, 2, 1, 0 and alkyl carboxylate esters

Abstract At 150°C equilibria are established between chlorosilanes and alkyl esters according to the equation: Me x SiCl 4- x + RCOOR′ → Me x Si(O 1 2 ) y (OOCR) z-y Cl 4- x-y-z + y RCOCl + z R′Cl When x = 3, y = 0, z = 0.56, when x = 1, y = 0.26, z = 098 When x = 1, y = z = 0.56; when x = 0, y = z = 0.53 Lewis acid salts such as ZnCl 2 or FeCl 3 are effective catalysts for the reactions leading to mixtures of these compounds.