ChemPaths: Learning to Meander. Last Updated (Sunday, 23 August 2009 13:07) Written by Administrator This site is the Student Access Portal of many of the Chemistry Education Digital Library collections!
ChemPaths is the Student Portal of the Chemical Education Digital Library ( The ChemEd DL ), and has been built to assist instructors in providing a means to bring all of these multimedia resources into one cohesive package ready for student-use. Dynamic Periodic Table. Definitions of the SI units: The twenty SI prefixes. Activation, Deactivation and Regioselectivity in Electrophilic Aromatic Substitution - [www.rhodium.ws] Here are some data illustrating the influence of substituents groups on the rates and the regioselectivities of various electrophilic aromatic substitution reactions.
![Activation, Deactivation and Regioselectivity in Electrophilic Aromatic Substitution - [www.rhodium.ws]](http://cdn.pearltrees.com/s/pic/th/regioselectivity-electrophilic-23570854)
The trend discussed in class is shown qualitatively in the chart below, which progresses from most deactivating to most activating: What do we mean by “strong”, “medium” or “weak” activating or deactivating effects? A few specific numbers will give you a sense of the general trend. Note that these are relative rates: the reaction rate for benzene has been taken to be “1” for each case, but you should not assume that this means that bromination and nitration of benzene have the same rate. The free chemical database. Chempendix.