10364-04-2Relevant articles and documents
Reactions of Some Bicycloalkyl Iodides with Bromine
Wiberg, Kenneth B.,Pratt, William E.,Matturro, Michael G.
, p. 2720 - 2722 (1982)
The reactions of normally unreactive bicyclic iodides such as 1- and 7-iodonorbornane with bromine has been found to occur readily with the formation of the corresponding bromide.The reaction involves the formation of the complex RI*X2 as an intermediate and is accelerated by polar solvents.The reaction of 1-iodobicyclohexane with bromine led to rearranged products, showing that a cationic intermediate is involved.The data indicate that the IBr2- ion is one of the best of the known leaving groups for SN1 or SN2 reactions.The observation of a rapid reaction of the bridgehead bicyclooctyl iodides with bromine has led to a reexamination of the reaction of 1,4-diiodobicyclooctane with butyllithium.The previous report of the formation and trapping of the propellane in this reaction was found to be incorrect.
Tuning Singlet Fission in π-Bridge-π Chromophores
Kumarasamy, Elango,Sanders, Samuel N.,Tayebjee, Murad J. Y.,Asadpoordarvish, Amir,Hele, Timothy J. H.,Fuemmeler, Eric G.,Pun, Andrew B.,Yablon, Lauren M.,Low, Jonathan Z.,Paley, Daniel W.,Dean, Jacob C.,Choi, Bonnie,Scholes, Gregory D.,Steigerwald, Michael L.,Ananth, Nandini,McCamey, Dane R.,Sfeir, Matthew Y.,Campos, Luis M.
, p. 12488 - 12494 (2017)
We have designed a series of pentacene dimers separated by homoconjugated or nonconjugated bridges that exhibit fast and efficient intramolecular singlet exciton fission (iSF). These materials are distinctive among reported iSF compounds because they exist in the unexplored regime of close spatial proximity but weak electronic coupling between the singlet exciton and triplet pair states. Using transient absorption spectroscopy to investigate photophysics in these molecules, we find that homoconjugated dimers display desirable excited-state dynamics, with significantly reduced recombination rates as compared to conjugated dimers with similar singlet fission rates. In addition, unlike conjugated dimers, the time constants for singlet fission are relatively insensitive to the interplanar angle between chromophores, since rotation about σ bonds negligibly affects the orbital overlap within the π-bonding network. In the nonconjugated dimer, where the iSF occurs with a time constant >10 ns, comparable to the fluorescence lifetime, we used electron spin resonance spectroscopy to unequivocally establish the formation of triplet-triplet multiexcitons and uncoupled triplet excitons through singlet fission. Together, these studies enable us to articulate the role of the conjugation motif in iSF.
SYNTHESIS OF BICYCLO[2.2.2]OCTANE DERIVATIVES
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Paragraph 00105, (2019/05/02)
Provided is a process for the preparation of certain 1,4-bicyclo[2.2.2]octane derivatives. The new synthetic procedure involves treating 1,4-dimethylene cyclohexane with an oxidizing agent in the presence of a transition metal catalyst to afford an oxo-substituted bicyclo[2.2.2]octane species. This intermediate structure can then be further derivatized. The processes of this disclosure thus affords a novel and simplified means for the commercial production of a wide variety of bicyclo[2.2.2]octane derivatives.
Synthesis and PE Spectra of 1-Ethynyl- and 1,4-Diethynylbicyclooctane, and of Related 1,4-Dihalobicyclooctanes
Honegger, Evi,Heilbronner, Edgar,Hess, Nicole,Martin, Hans-Dieter
, p. 187 - 194 (2007/10/02)
The synthesis of 1-ethynylbicyclooctane (1), of 1,4-diethynylbicyclooctane (2), of 1,4-dichloro- (3) and of 1,4-dibromobicyclooctane (4) is reported.The He(1α) photoelectron spectra of 1 and 2 have been assigned using the STO-3G and the HAM/3 procedure, whereas those of 3 and 4 have been interpreted on the basis of an equivalent bond orbital model including spin-orbit coupling.
SYNTHESIS OF BRIDGEHEAD CHLORO-, BROMO- AND IODOBICYCLOOCTANES
Kopecky, Jan,Smejkal, Jaroslav
, p. 2965 - 2970 (2007/10/02)
The paper describes transformations of hydroxy-, acetoxy- or methoxy-bridgehead bicyclooctanes into bridgehead chloro, bromo or iodo derivatives by action of inorganic halides in the medium of orthophosphoric or polyphosphoric acids.
