3634-86-4Relevant articles and documents
Macrocyclic nonviral vectors: High cell transfection efficiency and low toxicity in a lower rim guanidinium calix[4]arene
Bagnacani, Valentine,Sansone, Francesco,Donofrio, Gaetano,Baldini, Laura,Casnati, Alessandro,Ungaro, Rocco
supporting information; experimental part, p. 3953 - 3956 (2009/06/18)
(Figure Presented) New multivalent cationic lipids, one of them showing high efficiency and low toxicity in cell transfection, have been obtained by attaching guanidinium groups at the lower rim of calix[4]arenes.
Molecular Design and Characterizations of New Calixarene-based Gelators of Organic Fluids
Aoki, Masayoshi,Nakashima, Kazuaki,Kawabata, Hirosuke,Tsutsui, Satoru,Shinkai, Seiji
, p. 347 - 354 (2007/10/02)
We have found that certain calixarenes having long acyl groups at the p-positions (e.g., 5,11,17,23,29,35,41,47-octadodecanoylcalixarene-49,50,51,52,53,54,55,56-octol: 28C12) act as excellent and unique gelators of various organic solvents (e.g., toluene, carbon tetrachloride, carbon disulfide, hexane, isopropanol, etc.).The sol-gel phase transition temperatures (Tgel) could be determined by the inverted test-tube method or by the DSC method.The change in the aggregation mode at the phase transition temperature was directly observable by an optical microscope: below Tgel the fibrillar network (diameter ca. 1 μm) appeared whereas above Tgel it 'melted' down.It was shown on the basis of these mesurements that the sol-gel phase transition occurs reversibly.The spectroscopic studies using 1H NMR and IR spectroscopy and the comparative experiments using the analogues of 28C12 (nine cyclic and six non-cyclic) established that the prerequisites for the formation of the stable organic gels are (i) the intermolecular C=O...HO hydrogen-bonding interaction to form the three-dimensional network and (ii) the moderate affinity of gelators with solvent molecules.The results offer important strategies useful for the molecular design of new gelators of organic fluids.
