@article {2630, title = {A new [4]carceplex, and a crystal structure and dynamic combinatorial chemistry of a [5]carceplex}, journal = {Tetrahedron}, volume = {65}, number = {35}, year = {2009}, note = {ISI Document Delivery No.: 485CQTimes Cited: 1Cited Reference Count: 16Sun, Jianyu Patrick, Brian O. Sherman, John C.}, month = {Aug}, pages = {7296-7302}, type = {Article}, abstract = {A new [4]carceplex (2-guest) is reported. It is composed of two cavitands linked by four disulfide bonds. It forms twistomers, which interconvert on a millisecond timescale. The energy barrier for interconversion of twistomers is guest-dependent. Formation of [4]carceplex 2-guest is template dependent. The selectivity in templates is flat relative to most previous related template work. Larger kin [5]carceplex 1.guests were reinvestigated. A crystal structure confirms the twist between the hemispherical cavitands. Use of a redox buffer allowed dynamic combinatorial chemistry to be performed between pairs of templates. (C) 2009 Elsevier Ltd. All rights reserved.}, keywords = {carceplex, Disulfide, Dynamic combinatorial chemistry, Guest release, HEMICARCEPLEXES, MOLECULES, supramolecular, TEMPLATION}, isbn = {0040-4020}, url = {://000269098700012}, author = {Sun, J. Y. and Patrick, B. O. and Sherman, J. C.} } @article {736, title = {Molecules that can{\textquoteright}t resist templation}, journal = {Chemical Communications}, number = {14}, year = {2003}, note = {ISI Document Delivery No.: 696EETimes Cited: 26Cited Reference Count: 47}, pages = {1617-1623}, type = {Article}, abstract = {The encapsulation of molecules or ions has captured the interest of a variety of researches, including those using zeolites, fullerenes, micelles, clathrates, and metal coordination complexes. Multiple hemispherical units have been used to create organic cages that can bind guests reversibly or irreversibly. Often such cages will only form in the presence of a guest, which acts as a template. This article summarizes some of the work in this field.}, keywords = {CAPSULES, CARCEPLEXES, CAVITANDS, CONTAINER COMPOUNDS, CRYSTAL-STRUCTURE, HEMICARCEPLEXES, HOST-GUEST COMPLEXATION, PHASE, REVERSIBLE ENCAPSULATION, SHELL CLOSURE}, isbn = {1359-7345}, url = {://000183872700002}, author = {Sherman, J.} } @article {461, title = {Synthesis and conformational dynamics of ortho-xylyl-bridged-[4]cavitands}, journal = {Tetrahedron}, volume = {58}, number = {4}, year = {2002}, note = {ISI Document Delivery No.: 515QLTimes Cited: 10Cited Reference Count: 24}, month = {Jan}, pages = {787-798}, type = {Article}, abstract = {ortho-Xylyl-[4]cavitands 2 to 6 were synthesized from bromoresorcin[4] arenes 1. Cavitands 2 to 6 show C-4nu symmetry in their H-1 NMR spectra at higher temperatures. Dynamic H-1 NMR studies of 2 to 6 indicate the C-4nu symmetry is due to fast interconversion of rectangular C-2nu isomers. This is supported by the crystal structure of 2a, which shows a C-2nu rectangular structure. The activation energy barriers for 2a and 2b were measured by quantitative 1D NOESY (EXSY) experiments. The results were analyzed by the initial rate approximation and matrix calculations. The activation energy barrier was found to depend strongly on the size of the upper rim group (Br, H, OH, CN). In addition, replacing the phenolic proton of tetrol derivatives 4a and 4b with metal ions raises the energy barrier further, likely via bridging metal cations. The two tetrabromo compounds (2a and 2b) reveal a sensitivity of the activation barrier to the feet of the cavitands. Cavitand 6 may act as a hub for radially expanded cavitands. The advantages of the 1D NOESY experiments over the more commonly used two-dimensional experiments are discussed. (C) 2002 Elsevier Science Ltd. All rights reserved.}, keywords = {1D NOESY (EXSY), CARCEPLEXES, CAVITANDS, CHEMICAL-EXCHANGE, DEEP-CAVITY CAVITANDS, dynamic H-1 NMR, EXCHANGE, HEMICARCEPLEXES, KINETICS, MAGNETIC-RESONANCE SPECTROSCOPY, NMR}, isbn = {0040-4020}, url = {://000173506800019}, author = {Naumann, C. and Patrick, B. O. and Sherman, J. C.} } @article {4225, title = {Templation in the formation of carceplexes}, journal = {Journal of Organic Chemistry}, volume = {63}, number = {12}, year = {1998}, note = {ISI Document Delivery No.: ZV170Times Cited: 30Cited Reference Count: 20}, month = {Jun}, pages = {4103-4110}, type = {Article}, abstract = {The formation of carceplexes and hemicarceplexes involves an assembly process whereby a molecular template is entrapped between two bowl-shaped molecules. The process can be highly selective such that a million-fold range in template recognition has been realized. The relative template abilities, or template ratios, for 34 molecules in forming carceplex a guest is described. Species with one, two, and three bridges linking the two "bowls" are reported and were used to delineate the guest-determining step of the reaction. The effect of base and solvent on the reaction are also described, and a discussion of the reaction mechanism is presented.}, keywords = {HEMICARCEPLEXES, MOLECULAR ENCAPSULATION}, isbn = {0022-3263}, url = {://000074277100048}, author = {Chapman, R. G. and Sherman, J. C.} }