Probe molecules apopinenes

Experimental data has been sought to substantiate some of the ideas developed from these models. One of these utilized an interesting probe molecule, (+)apopinene, 25, (Eqn. 3.3) which has a number of special characteristics. The... 

An additional, newly developed method for the characterization of metal surfaces is the use of sterically complex organic probe molecules. Comparisons of the transformations of c/i-cyclododecene (2,51) and (+)-apopinene (52,68, 69) on glassy and crystalline metals distinguish certain surface features of the catalysts (see details in Section III,C,1). 

Further detailed examinations were carried out by Smith and coworkers using the probe molecule, (+)-apopinene (6,6-dimethyl-l/ ,5R-bicy-clo[3.1.1]heptene-2), which is sensitive to catalytic sites of differing surface coordination. (+)-Apopinene was developed to differentiate between different catalyst preparations and to trace minor alterations in the morphology of metallic catalysts. The Pd-Si and Pd-Ge alloys examined show the lowest ratios of isomerization (double-bond migration) to addi-... 

Another approach in surface characterization of metal catalysts by alkene transformations is the use of (-l-)-apopinene (23) as the probe molecule194,196. Due to its peculiar geometry this molecule can expose only one face of its double bond to a catalyst surface. 

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