5 - Chemical Reactions and (Retro)synthesis Flashcards
(20 cards)
What is a chemical reaction?
A transformation of molecules involving breaking and forming bonds.
What is the equation form of a chemical reaction?
aA + bB → cC + dD, where reactants are on the left and products on the right.
What does the Gibbs free energy equation ΔG = ΔH - TΔS determine?
Whether a reaction is thermodynamically favorable.
What does a negative ΔG indicate?
The reaction happens spontaneously.
What affects the rate of a chemical reaction (kinetics)?
Concentration, surface area, pressure, temperature, and catalysts.
What does a catalyst do?
Lowers activation energy and speeds up a reaction without being consumed.
What is chemical synthesis?
The artificial execution of chemical reactions to obtain desired products.
What is retrosynthesis?
The process of breaking down a target molecule into simpler precursor structures.
What is CASP?
Computer-Assisted Synthesis Planning.
What is a reaction template?
A generalized blueprint that shows how substructures in reactants become products.
What are template-free models in ML for synthesis?
Sequence-to-sequence models (like transformers) that directly predict reactions.
What are template-based models in ML for synthesis?
Neural-symbolic systems that apply learned rules to predict products.
What is Monte Carlo Tree Search (MCTS) used for in retrosynthesis?
To explore reaction pathways like moves in a game.
How is reinforcement learning used in retrosynthesis?
To guide reaction pathway search by maximizing success through learning.
What is the Modern Hopfield Network used for in reaction prediction?
To retrieve the most suitable reaction template from memory.
What is the role of reaction datasets like USPTO or ORD?
They provide reaction examples for training synthesis models.
What challenge exists with complex reaction rules?
They may not generalize well to new reactants.
Why is retrosynthesis considered a ‘game’ in ML?
Because it involves states, actions, and rewards, like in game theory.
What is reaction translation in ML?
Using DL to translate between products and reactants like languages.
Why is synthesis planning complex?
It involves multiple steps, conditions, and optimization choices.
