Temperature Dependent Part kTR of the Reaction Rate

The temperature dependent part
kTR of the reaction rate is given by

                                                                kTR = k(T) - k(T = 0) - kTG(T) ,

k(T) is the measured acridine T1 triplet state decay rate and kTG(T) ist the intramolecular triplet to ground state decay rate at
temperature T.

In the limit  of low temperatures k(T = 0) = kTR(T = 0) + kTG(T = 0) = 13.88 s-1 (ODMR data point at 1.5 K)
with kTG(T) = 28.75 s-1exp(-501.5 K/T) (from acridine-d9 data in fluorene-d8D2 below 200 K)

For the H-transfer a value of kTR(T = 0) = 1.25 s-1  could be evaluated separately from the low temperature  (< 200 K) pressure dependent measurements. For the D-transfer this was not possible, as in this case kTR(T = 0) is expected to be substantially  smaller.

To obtain the complete H-transfer reaction rate
the value of kTR(T = 0) = 1.25 s-1 should be added to the temperature dependent rate data kTR presented here.

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