- Layered calcium structures of p-phosphonic acid o-methyl-calix[6]arene
-
Hexamethoxy-calix[6]arene has been fully functionalized with p-phosphonic acid groups on the upper rim in57% yield over three steps and has been authenticated in the solid state by X-ray diffraction as either a nitrate salt or one of two calcium complexes. The latter differ by the ratio of calcium ions per calixarene, either 3:1 or 4:1. In both structures, the coordination sphere of the calcium ions is made up of oxygen atoms from the phosphonic acid groups and from water of crystallization, as part of extended polymeric layers in the extended three-dimensional packing. Hirshfeld surface analysis shows extensive O...H and O...Ca interactions for the phosphonic acid moieties in both calcium structures. Matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) of the hexaphosphonic acid shows nanoarrays consisting of up to a maximum of 28 calixarene units.
- Clark, Thomas E.,Martin, Adam,Makha, Mohamed,Sobolev, Alexandre N.,Su, Dian,Rohrs, Henry W.,Gross, Michael L.,Raston, Colin L.
-
-
Read Online
- Synthesis and evaluation of deep cavity imidazolyl calix[n]arenes
-
A series of deep cavity diphenyl imidazolyl calix[n]arenes (4, 6, 8) have been obtained from readily available starting materials through a five step synthetic methodology involving appropriate alkylation of lower rim of preformed calixarene, formylation of the upper rim and subsequent condensation with aryl diketones in the presence of ammonium acetate and glacial acetic acid. Optimized reaction conditions for obtaining the titled derivatives in their cone configuration and their characterization by spectroscopic methods (IR, UV, NMR and FAB mass) have been delineated. The synthesized imidazolyl calixarenes have preliminarily been examined for selective recognition of monovalent metal ions (Li+, Na+, K+, Cs+, Ag+).
- Chawla,Kumar,Pant,Santra,Sriniwas,Kumar,Black, David Stc.
-
experimental part
p. 169 - 178
(2012/05/04)
-
- Molecular design of calixarene-based host molecules for inclusion of C60 in solution
-
Calix[6]arenes bearing N,N-dialkylaniline units or m-phenylenediamine units were synthesized to capture C60 in organic solution: the association constants (7.9-1.1 × 102 dm3mol-1) were the largest values obtained so far, indicating that calix[6]arene acts as an excellent platform to facilitate the cooperative action of the donor groups.
- Araki, Koji,Akao, Kiyotaka,Ikeda, Atsushi,Suzuki, Tsuyoshi,Shinkai, Seiji
-
-
- CALIXARENES 12 THE SYNTESIS OF FUNCTIONALIZED CALIXARENES
-
Procedures are described for the removal of the p-t-butyl groups from p-t-butylcalixarene, p-t-butylcalixarene, and p-t-butylcalixarene and the introduction of functional groups in their place.Although attempts to functionalize the p-positions of the calixarenes have generally failed, the corresponding methyl ethers are amenable to facile acetylation to provide syntheses of the p-acetyl-, p-carboxy-, and p-carbomethoxycalixarenes and calixarenes.Acetylation and benzoylation of calixarene and calixarene occur at the phenolic oxygens rather than the p-positions, leading under most reaction conditions to the completely O-substituted product.Calixarene reacts with benzoyl chloride in the presence of pyridine, however, to yield the tribenzoate.Conversion of the tribenzoate to the corresponding tribenzoyloxy monoallyl ether followed by a Claisen rearrangement and hydrolysis yields monoallylcalixarene, a compound of particular interest because of its potential for the synthesis of calixarenes containing a single substituent on the "upper rim".
- Gutsche, C. David,Lin, Lee-Gin
-
p. 1633 - 1640
(2007/10/02)
-