Host-guest complexation. 35. Spherands, the first completely preorganized ligand systems

Autor:	Carolyn B. Knobler, Emily F. Maverick, Kenneth N. Trueblood, S. Bruce Brown, Roger C. Helgeson, Donald J. Cram, Takahiro Kaneda
Rok vydání:	1985
Předmět:	Electron pair Ligand Stereochemistry Aryl Radical Cryptand General Chemistry Crystal structure Ring (chemistry) Biochemistry Catalysis Crystallography chemistry.chemical_compound Colloid and Surface Chemistry chemistry X-ray crystallography
Zdroj:	Journal of the American Chemical Society. 107:3645-3657
ISSN:	1520-5126 0002-7863
Popis:	k2Cs2 = (~~~IU,/KSH+)~~C S~CH+C~,~~,+~,) Abstract: Spherands 1-5 and the related macrocycle 6 which are described in this paper are composed mainly of four to six aryloxy units attached to one another in such a way that the orbitals of the unshared electron pairs of their oxygens line an enforced cavity. These ligand systems strongly complex only Li+ and Na+ ions and reject K', Ca2+, and Mg2+ ions. Their syntheses, representative crystal structures, and a qualitative survey of their binding properties are reported. The critical ring closures of these 18-membered-ring systems involved oxidations of appropriate bisaryllithiums with Fe(acac)3 in refluxing benzene or THF to aryl radicals which coupled with one another-a reaction invented for construction of these hosts. The crystal structure of 1 clearly shows its unoccupied cavity lined with electron pairs. The crystal structures of l-LiC1 and l.NaCH3S04 indicate that no conformational reorganization of the host was involved in complexation. The crystal structures of the complexes of the polycyclic hosts 4.LiFeCI4 and 5.LiCI show the ligating systems to be highly strained and to contain severe oxygen-xygen compression.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::5637a76b7b8ee8b0a6f1836f46a8cb15 https://doi.org/10.1021/ja00298a040 Zobrazit plný text záznamu