3922-28-9Relevant articles and documents
Electrostatic Control of Macrocyclization Reactions within Nanospaces
Wang, Kaiya,Cai, Xiaoyang,Yao, Wei,Tang, Du,Kataria, Rhea,Ashbaugh, Henry S.,Byers, Larry D,Gibb, Bruce C.
supporting information, p. 6740 - 6747 (2019/05/06)
The intrinsic structural complexity of proteins makes it hard to identify the contributions of each noncovalent interaction behind the remarkable rate accelerations of enzymes. Coulombic forces are evidently primary, but despite developments in artificial nanoreactor design, a picture of the extent to which these can contribute has not been forthcoming. Here we report on two supramolecular capsules that possess structurally identical inner-spaces that differ in the electrostatic potential (EP) field that envelops them: one positive and one negative. This architecture means that only changes in the EP field influence the chemical properties of encapsulated species. We quantify these influences via acidity and rates of cyclization measurements for encapsulated guests, and we confirm the primary role of Coulombic forces with a simple mathematical model approximating the capsules as Born spheres within a continuum dielectric. These results reveal the reaction rate accelerations possible under Coulombic control and highlight important design criteria for nanoreactors.
Chemical control of double barrier tunnelling in α,ω- dithiaalkane molecular wires
Leary, Edmund,Higgins, Simon J.,Van Zalinge, Harm,Haiss, Wolfgang,Nichols, Richard J.
, p. 3939 - 3941 (2008/09/21)
Single molecule conductance measurements on 1,4-bis-(6-thia-hexyl)-benzene derivatives reveal (i) that benzene rings serve as an effective indentation in the tunnelling barrier, and (ii) that more electron-rich benzene rings give higher conductances, cons
Electrochemical Reduction of 1,6-Dihalohexanes at Carbon Cathodes in Dimethylformamide
Mubarak, Mohammad S.,Peters, Dennis G.
, p. 681 - 685 (2007/10/02)
Cyclic voltammograms for the reduction of 1,6-dibromo-, 1,6-diiodo-, 1-bromo-6-chloro-, and 1-chloro-6-iodohexane at glassy carbon electrodes in dimethylformamide containing tetramethylammonium perchlorate exhibit single irreversible waves that correspond to the reductive cleavage of carbon-bromine or carbon-iodine bonds.When large-scale controlled-potential electrolyses of either 1,6-dibromo- or 1,6-diiodohexane are performed at reticulated vitreous carbon, the principal products are n-hexane (30-45percent), 1-hexene (28-34percent), 1,5-hexadiene (6-16percent), and cyclohexane (7percent), with n-dodecane being another significant species obtained from 1,6-diiodohexane.Because a carbon-chlorine bond is not directly reducible, 1-bromo-6-chloro- and 1-chloro-5-iodohexane give rise mainly to 1-chlorohexane (47-64percent), 6-chloro-1-hexene (20-33percent), and 1,12-dichlorododecane (2-25percent).From these product distributions, and with the aid of experiments done in the presence of deuterium-labeled reagents, we conclude that the electrolytic reduction of 1,6-diiodo- and 1-chloro-6-iodohexane involves both radical and carbanion intermediates, whereas only carbanionic pathways are important for electrolyses of 1,6-dibromo- and 1-bromo-6-chlorohexane.
