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  2. List of unsolved problems in chemistry - Wikipedia

    en.wikipedia.org/wiki/List_of_unsolved_problems...

    Protein folding problem: Is it possible to predict the secondary, tertiary and quaternary structure of a polypeptide sequence based solely on the sequence and environmental information? Inverse protein-folding problem: Is it possible to design a polypeptide sequence which will adopt a given structure under certain environmental conditions?

  3. Femtochemistry - Wikipedia

    en.wikipedia.org/wiki/Femtochemistry

    Femtochemistry is the area of physical chemistry that studies chemical reactions on extremely short timescales (approximately 10 −15 seconds or one femtosecond, hence the name) in order to study the very act of atoms within molecules (reactants) rearranging themselves to form new molecules (products).

  4. Frustrated Lewis pair - Wikipedia

    en.wikipedia.org/wiki/Frustrated_Lewis_pair

    pcy 3 + b(c 6 f 5) 3 + c 2 h 4 → cy 3 p + ch 2 ch 2 b − (c 6 f 5) 3 For acid-base pairs to behave both nucleophilically and electrophilically at the same time offers a method for the ring-opening of cyclic ethers such as THF, 2,5-dihydrofuran, coumaran, and dioxane.

  5. Assignment problem - Wikipedia

    en.wikipedia.org/wiki/Assignment_problem

    This is an unbalanced assignment problem. One way to solve it is to invent a fourth dummy task, perhaps called "sitting still doing nothing", with a cost of 0 for the taxi assigned to it. This reduces the problem to a balanced assignment problem, which can then be solved in the usual way and still give the best solution to the problem.

  6. Crossover experiment (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Crossover_experiment...

    A second complex, Pd(transphos)(CH 3) 2 was locked in a trans-confirmation by “transphos,” a chelating phosphine with a rigid aromatic linker. [19] The complexes with cis-methyl groups were already known to undergo reductive elimination to form ethane. A crossover experiment was performed on both Pd(dppe)(CH 3) 2 and Pd(PPh 3) 2 (CH 3) 2 ...

  7. Chemical kinetics - Wikipedia

    en.wikipedia.org/wiki/Chemical_kinetics

    Chemical kinetics, also known as reaction kinetics, is the branch of physical chemistry that is concerned with understanding the rates of chemical reactions. It is different from chemical thermodynamics, which deals with the direction in which a reaction occurs but in itself tells nothing about its rate.

  8. Substitution reaction - Wikipedia

    en.wikipedia.org/wiki/Substitution_reaction

    The two reactions are named according tho their rate law, with S N 1 having a first-order rate law, and S N 2 having a second-order. [2] S N 1 reaction mechanism occurring through two steps. The S N 1 mechanism has two steps. In the first step, the leaving group departs, forming a carbocation (C +). In the second step, the nucleophilic reagent ...

  9. Environmental chemistry - Wikipedia

    en.wikipedia.org/wiki/Environmental_chemistry

    Environmental chemistry is the scientific study of the chemical and biochemical phenomena that occur in natural places. It should not be confused with green chemistry , which seeks to reduce potential pollution at its source.