Search results for "Pentamer"
showing 3 items of 13 documents
A resorcinol derived calix[5]arene with C5-symmetry
1994
Abstract Condensation of 2,4-dihydroxy-3-hydroxymethyl benzophenone (4) in dioxane/H2SO4 gave the cyclic pentamer 5, a calix[5]arene with regular incorporation of the resorcinol units via their 2- and 6-positions. The structure follows from the 1H NMR and mass spectra and was further confirmed by single crystal X-ray analysis. Dynamic NMR in C2D2Cl4 gave a surprisingly high barrier of ΔG‡ = 17.3 kcal/mol for the cone-to-cone ring inversion.
Schrittweise synthesen und eigenschaften einiger cyclopentamerer aus methylenverbrückten (5-alkyl-2-hydroxy-1,3-phenylen)-bausteinen
1981
Three cyclopentamers (2a–c) and a chainlike pentanuclear oligomer (3a) were prepared by stepwise syntheses. The molecules of the cyclic compounds with 20 links contain o,o′-methylene bridged 2-hydroxy-5-methyl-1,3-phenylene or 2-hydroxy-5-tert-butyl-1,3-phenylene units in a strictly defined manner. The properties of the cyclic pentamer 2a and the chainlike pentanuclear oligomer 3a were compared. They differ by their solubilities, melting points, IR and 1H NMR spectra (pseudorotation) and fragmentation behaviour shown by their mass spectra. The pseudorotation of the cyclic compounds were quantitatively studied.
Entrapment of a linear water pentamer into a uranyl-salophen dimer in the solid state
2019
In the solid state, uranyl-salophen complex 1, decorated with bipyridyl sidearms, self-assembles from moist acetonitrile into dimeric species displaying a confined water pentamer, as observed by X-...