Mesoscale Chemistry A Workshop Summary (2015) / Chapter Skim
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3 Catalysis
3 Catalysis
Pages 9-24
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From page 9... ...
The tools available in mechanical engineering, fluid control, and synthesis provide a greater ability to design structures with varying pore diameters and shapes to create catalysts reliably for specific functions, but key synthetic challenges remain. Processes developed for the semiconductor industry, such as atomic layer deposition, are being employed to build mesoscale catalyst structures via a bottom-up strategy.
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From page 10... ...
. It is able to creating small organic constructs that can bind metal bind and release oxygen using a confined cobalt ions and promote intermolecular hydrogen bonding atom within a suitable molecular complex.
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From page 11... ...
t transfer and proton mov vement. The ese data aree takes advantage o the interfa between t s of ace two of the s supporting the develo opment of a better r Strepptavidin subuunits, known as the vestibu and is ule, u understanding of the therm g modynamics an kinetics of nd f attem mpting to tun the local en ne nvironment aaround the t the oxidation reaction an how the key reactive n nd e vestiibule to alter the mesoscal interaction in order le ns intermediate could form in a biological active site.
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From page 12... ...
She added that a colleague of hers has s dieleectric potentia of the acti site. Shaw said that als ive w c created activ site mim ve mics that re eproduce the e there are many th e hings about t environment of the the f function of the pendan amines (Figure 3-3)
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From page 13... ...
are two g general meth hods for w don't ha we ave good control of in molecular c i r appr roaching the wwork, either f from the "top down" or c catalysts," sai Shaw, wh said that the important id ho t t the " "bottom up." A top-dow approach t control " wn to lesson when considering all of th dynamics n g he s meso oscale comple exity takes a molecular caatalyst and d described so far is th o hat the inte eraction andd inser it into an already form protein structure, rts n med c cooperativity of the activ site with the protein ve h n such as the wo h ork that Bor rovik discuss sed using s scaffold is nec cessary to gennerate functio on. Strepptavidin.
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From page 14... ...
relay using arginine instead of glycine, which adds Going forward, Shaw and her colleagues plan to guanidinium functionality in the outer coordination add more complexity by using peptides instead of sphere, raises the overpotential slightly but increases amino acids in the outer shell and to employ the reaction rate by about an order of magnitude, she computational methods to inform future designs. said (Dutta, Roberts, and Shaw 2014)
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From page 15... ...
. hydr rophilic, pos sitively char rged, and n negatively M Moreover, thi enzyme is capable of ca is atalyzing this s charg residues around and n ged near the activ site and ve r reaction withhout releasing toxic reac ctive oxygen n many water m y molecules th hat are str rategically s species (Figu 3-4)
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From page 16... ...
. Lu and his work by many research groups has created the colleagues have since used these proteins to generate means to produce modified myoglobin molecules the first experimental support for what is known as a that can be used to explore how well-characterized Marcus inverted region that has been proposed to be changes in the protein's structure affect those important in tuning the forward and backward mesoscale interactions and catalytic activity (Lu et electron transfer rates that create the charge al.
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From page 17... ...
As is the case catalytic activity by modifying the chemical with the homogeneous catalytic systems that the first composition of the internal pore wall using three speakers described, controlling key features of pentafluorophenyl propyl groups, which creates a the heterogeneous catalysts that she studies requires hydrophobic environment inside the pores and consideration of the environment surrounding the enhances catalytic activity. It appears that this active sites.
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From page 18... ...
One feature of controlling the chemistry within the pore. this strategy, he said, is that it runs at equilibrium Controlling the environment surrounding active sites conditions throughout the reaction process, so even in the pore has proven difficult, and so too has been when there is a significant amount of solid material understanding the effect that the reaction products formed, the reaction of the smaller soluble units have on the constrained environment inside a pore.
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From page 19... ...
eliminating all catalytic activity since reactants could A new third approach that Stair and his not reach the nanoparticle. However, this coating has collaborators are developing is to create materials a high water and hydroxyl content and heating the using the atomic layer deposition process developed material generated pores in the deposited layers that by the semiconductor industry as a bottom-up reached down to the nanoparticle.
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From page 20... ...
e n e Labo oratory started the discussi by asking the panel d ion g c chiral cavitie from Do es onna Blackm mond of the e for th thoughts on the statem in the Department heir s ment S Scripps Resea arch Institute Stair expla e, ained that thee of Energy report that, w when thinkin about ng p premise here is that creat ting a spiral of functionall meso oscale phenom mena, the density of atom is more ms g groups in th cavity co he ould create binding sites b s impo ortant than th specific po he ositions of tho atoms ose c capable of disscriminating between two enantiomers. b e (BES SAC Subco ommittee on Mesoscale Science n Stair conccluded his pr resentation by noting that y t 2012 He added that it was his opinion based on 2)
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From page 21... ...
r right sequenc to facilitate the reaction Jenks said ce e n. d G Garrett then asked if t there is a d difference t that her work has shown that transport dynamics is k t t s betw ween mesoscale environm mental effect around ts t tremendously important and that one challenge is a s activ sites and c ve confinement.
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From page 22... ...
added that TEM is good at seeing something solid Yong Wang from PNNL asked Stair to elaborate but poor at seeing voids in structures. on the kind of design rules he would like to see Lu said that his group is exploring the possibility developed to help guide the use of atomic layer of using the optical and magnetic properties of the deposition.
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From page 23... ...
Jenks added he would like to have a better understanding of how that there just is not enough knowledge yet to know to take advantage of the local confinement, which is how understanding the atomic structure is impacting an entropic effect to make systems function better. the macroscale behavior of a system.
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