53193-22-9Relevant articles and documents
Intrinsic and Extrinsic Control of the p Ka of Thiol Guests inside Yoctoliter Containers
Cai, Xiaoyang,Kataria, Rhea,Gibb, Bruce C.
supporting information, p. 8291 - 8298 (2020/05/28)
Despite decades of research, there are still many open questions surrounding the mechanisms by which enzymes catalyze reactions. Understanding all the noncovalent forces involved has the potential to allow de novo catalysis design, and as a step toward this, understanding how to control the charge state of ionizable groups represents a powerful yet straightforward approach to probing complex systems. Here we utilize supramolecular capsules assembled via the hydrophobic effect to encapsulate guests and control their acidity. We find that the greatest influence on the acidity of bound guests is the location of the acidic group within the yoctoliter space. However, the nature of the electrostatic field generated by the (remote) charged solubilizing groups also plays a significant role in acidity, as does counterion complexation to the outer surfaces of the capsules. Taken together, these results suggest new ways by which to affect reactions in confined spaces.
Odd-even effects in charge transport across n-alkanethiolate-based SAMs
Baghbanzadeh, Mostafa,Simeone, Felice C.,Bowers, Carleen M.,Liao, Kung-Ching,Thuo, Martin,Baghbanzadeh, Mahdi,Miller, Michael S.,Carmichael, Tricia Breen,Whitesides, George M.
supporting information, p. 16919 - 16925 (2015/02/05)
This paper compares rates of charge transport across self-assembled monolayers (SAMs) of n-alkanethiolates having odd and even numbers of carbon atoms (nodd and neven) using junctions with the structure MTS/SAM//Ga2O3/EGaIn (M = Au or Ag). Measurements of current density, J(V), across SAMs of n-alkanethiolates on AuTS and AgTS demonstrated a statistically significant odd-even effect on AuTS, but not on AgTS, that could be detected using this technique. Statistical analysis showed the values of tunneling current density across SAMs of n-alkanethiolates on AuTS with nodd and neven belonging to two separate sets, and while there is a significant difference between the values of injection current density, J0, for these two series (log|J0Au,even| = 4.0 ± 0.3 and log|J0Au,odd| = 4.5 ± 0.3), the values of tunneling decay constant, β, for nodd and neven alkyl chains are indistinguishable (βAu,even = 0.73 ± 0.02 ?-1, and βAu,odd= 0.74 ± 0.02 ?-1). A comparison of electrical characteristics across junctions of n-alkanethiolate SAMs on gold and silver electrodes yields indistinguishable values of β and J0 and indicates that a change that substantially alters the tilt angle of the alkyl chain (and, therefore, the thickness of the SAM) has no influence on the injection current density across SAMs of n-alkanethiolates.
