## Anslyn pp. 355 – 420 Part II (367 – 420)

p. 369 — “In that substitution (for the equilibrium constant) a distribution of states for the transition state is indeed assumed, but it is not a Boltzmann distribution”  — Well, what is it?

p. 374 —  In the Going Deeper segment  “The momentum of the CH2 group as the hydrocarbon recoils from the expelled N2”  — a recoil would push the CH2 group away from N2 giving ii rather than iii.

p. 380 – Connections — trigonal bipyramidal intermediates in cyclic phosphotriesters.  What about something of more biologic interest, the phospho NON cyclic diesters holding the nucleotides of DNA and RNA together.

p. 385 — Lifetime — 1/k  — the term is often bandied about, but I never understood exactly how it was defined ’till now.  Only true for a first order reaction obviously, since the lifetime of an entity in a bimolecular reaction with a second order rate constant will be dependent on the other entity.  You can teach an old dog new tricks !  The units of a first order rate constant k is moles/second, so 1/k is seconds/mole.

p. 390 Steady state kinetics — The equations look very close to Michaelis Menton kinetics which isn’t discussed until pp. 523.

p. 399 — nice to know just what the rate of a diffusion limited reaction is — 10^10 Moles/second

p. 400  Converting an IR stretch 3000 – 1000 cm^-1 to a time.  Cm^-1 is just the number of wavelengths/centimeter  So to convert cm^-1 to  frequency, multiply by the velocity of light in centimeters/second (e.g. 3 * 10^10 cm/sec) to get a frequency of 3 – 9 * 10^13/second.  So one vibration takes from 10 – 100 picoSeconds (or .01 – .10  femtoSeconds.

p. 403 It would be nice to see a derivation of the Marcus equation.

p. 406 — In the Connections section ‘steriod’ should be steroid.

p. 412 — “the shape of the mountain pass (energy of the transition state) is representative of the entropy changes along the reaction coordinate”  — very nice analogy.
Not a lot of comments on 50 pages of Anslyn, but kinetics has always left me cold.  Perhaps it won’t after I get to chapter 14, which is a long 400 pages or so away