Formation of white light

Dimethyl mercury reacted with hydroxy tellurium pentafluoride at 0° with evolution of methane and quantitative formation of white, crystalline methyl mercury pentafluoro-(oxo)tellurate(Vl), a sublimable, light-sensitive compound2. 

Factors such as reaction temperature, excess of oxygen, water addition, addition of other minor reactants, eg, AlCl to promote the formation of mtile, mixing conditions inside the reactor, and many others influence the quaUty of Ti02 pigment. In general, titanium white pigments produced by the chloride process exhibit better lightness than those produced by the sulfate process. 

Xenon difluoride [4, 5, 7, 8,10] is a white crystalline material obtained through the combination of fluorine and xenon m the presence of light The reagent is commercially available and possesses a relatively long shelf-life when stored cold (freezer) Xenon difluoride is very effective for small-scale fluormation of alkenes and activated nucleophilic substrates. The reactions are usually conducted between 0 °C and room temperature in chloroform or methylene chloride solutions Hydrogen fluoride catalysis is sometimes helpful Xenon difluoride reacts in a manner that usually involves some complexation between the substrate and reagent followed by the formation of radical and radical cation intermediates... 

The simplest azo compound, azobenzene, exists as a mixture (Scheme 4-18) of a stable trans (4.19) and an unstable cis (4.20) form [38,39]. Formation of the cis isomer is induced by exposure to light, the quantum yield of the process depending upon the wavelength of the light employed [40]. The proportion of cis isomer can be appreciable in an equilibrium mixture. Thus a concentration of 24% of this unstable form builds up within a few hours when an acetic acid solution of azobenzene is exposed to sunlight in shallow white trays. Reversion to the trans form occurs readily on heating and is catalysed by a variety of substances that can function as electron donors or acceptors [41]-... 

---