Single-Polymer–Particle Growth Kinetics with
Molecular Catalyst Speciation and Single-Turnover Imaging
Quinn
T. Easter
Antonio Garcia
Suzanne A. Blum
10.1021/acscatal.9b00095.s004
https://acs.figshare.com/articles/media/Single-Polymer_Particle_Growth_Kinetics_with_Molecular_Catalyst_Speciation_and_Single-Turnover_Imaging/7853243
The dynamics of the
local environments surrounding molecular polymerization
catalysts plausibly impact turnover kinetics, but the impact of and
nature of such dynamics have previously been obscured by ensemble
averaging. With Grubbs’ second generation ruthenium metathesis
catalyst and a precipitation polymerization system, studies at the
single-particle and -turnover level establish that (1) an inverse
correlation exists between rate and duration of single-polymer–particle
growth of aggregates, consistent with a local environment density
model for the time-variable kinetics; (2) cross-linking additives
produced a small, but detectible, reduction in overall monomer incorporation;
(3) total ruthenium quantity within the polymer particles (as characterized
by energy dispersive X-ray spectroscopy) is differentiable from the
quantity that is catalytically active (as characterized by in situ
fluorescence microscopy), providing catalyst speciation information;
and (4) time-resolved enyne metathesis reactions can be imaged, corresponding
to single turnovers at individual molecular catalysts during polymer
growth under synthetically relevant conditions. These findings identify
and characterize reactivity distributions likely arising from the
dynamics of local environments. As such, these data provide reactivity
information that is unavailable through traditional ensemble analytical
methods that obscure this type of information through averaging.
2019-03-04 00:00:00
dynamic
environment density model
polymerization catalysts
precipitation polymerization system
catalyst speciation information
energy dispersive X-ray spectroscopy
Molecular Catalyst Speciation
generation ruthenium metathesis catalyst
reactivity information
impact turnover kinetics
polymer growth
time-variable kinetics
turnover level
reactivity distributions
Single-Turnover Imaging
monomer incorporation
ruthenium quantity
ensemble
polymer particles