6533b872fe1ef96bd12d2d1f
RESEARCH PRODUCT
Stufenweise darstellung eines cycloheptamers aus p-kresol, 4-tert-butylphenol und formaldehyd. Vergleich mit einem phenolischen, heptanuklearen kettenoligomer
Günter HappelHermann Kämmerersubject
chemistry.chemical_compoundChloroformchemistryRing flipPolymer chemistryMass spectrumProton NMRPseudorotationMethyleneRing (chemistry)Oligomerdescription
A phenolic cycloheptamer (11) and an analogous chain oligomer (10) with nearly the same structure were gained by stepwise syntheses. The cycloheptamer has a higher melting point and a better solubility in chloroform. In contrast to the chain oligomer his infrared spectrum indicates a stronger association of the hydroxyl groups which is not influenced by the solvent. The mass spectra announce a preferred statistical cleavage along the chain of compound 10 and a great stability of the ring of 11 which preferentially loses his substituents. The 1H NMR spectra confirm the constitutions of the chain (10) and ring compound (11). The cycloheptamer is distinguished by a ring inversion or a pseudorotation, seen by the NMR signals of the methylene protons. The activation energy of the pseudorotation is determined.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1980-10-01 | Die Makromolekulare Chemie |