Template Synthesis Flashcards
What is the kinetic template effect? Give an example.
Synthetic method, works by organising molecular components using template. Example: crown ether synthesis by Williamson ether synthesis around a potassium ion. Reacting groups brought in close proximity and compound preorganised.
Template catalyses reaction by stabilising cyclic intermediate, increasing rate of reaction = kinetic effect.
How do you recognise a template effect?
Organisation of molecular components by template, accompanying chemical reactions include significant spatial, topological or geometric control.
What is the thermodynamic template effect?
All possible products in an equilibrium. Metal binds to ligand with most suitability = macrocycle, hence removing from equilibria. By Le Chatelier’s Principle, equilibria shifts to produce more of the macrocycle.
What is high dilution synthesis?
Lab scale trick. Keep the concentrations of reactants very low. Based on ratio between rates of cyclisation and polymerisation being approximately = k/[X-Y]. Thus rate of cyclisation increases by decreasing [X-Y]
