123264-03-9

Upstream product

• 96107-95-8 calix[6]arene 
• 112-82-3 hexadecanyl bromide 

Relevant academic research and scientific papers

Dopamine-selective response in membrane potential by homooxacalix[3]arene triether host incorporated in PVC liquid membrane

Selectivities of membrane potential changes for catecholamines and inorganic cations were investigated with lipophilic derivatives of calix[6]arene and related hosts incorporated in poly(vinyl chloride) (PVC) matrix liquid membranes. Homooxacalix[3]arene triether displayed an excellent selectivity for dopamine against other catecholamines (adrenaline, noradrenaline) and also against inorganic cations (K+, Na+).

Assembly and disassembly of Langmuir-Blodgett films on poly[1- (trimethylsilyl)-1-propyne]: The uniqueness of calix[6]arene multilayers as permeation-selective membranes

A series of calix[6]arene-based surfactants have been synthesized, which contain amide oxime head groups on their upper rim and 5,5-dimethylhexyl (I), n-octyl (II), n-dodecyl (III), and n-hexadecyl (IV) groups on their lower rim. Composite membranes that were fabricated from Langmuir-Blodgett (LB) multilayers derived from each surfactant plus poly[1-(trimethylsilyl)-1- propyne] (PTMSP) cast film showed a significant increase in their selectivity toward helium and nitrogen, relative to bare PTMSP. In sharp contrast, analogous composites that were prepared with LB multilayers of conventional single chain surfactants [arachidic acid (AA), cadmium arachidate (AA/Cd2+) and stearoamideoxime (SA)] exhibited permeation properties that were identical with those of bare PTMSP. When a polymeric surfactant [poly(1- octadecene-co-maleic anhydride), POM] is used for LB film construction, a modest increase in selectivity was observed. These findings, together with an analysis of representative composites by X-ray photoelectron spectroscopy, provide compelling evidence for the presence of intact, calix[6]arene-based LB assemblies on the surface of PTMSP; with the conventional single chain surfactants, however, disassembly and absorption into the bulk phase of the support is favored. The results of this study highlight the need for having individual surfactant molecules span individual pores on the surface of the support and strong intermolecular forces between neighboring surfactants to produce relatively defect-free LB films.

Perforated Monolayers: Design and Synthesis of Porous and Cohesive Monolayers from Mercurated Calixarenes1

Mercuration of a series of O-alkylated calixarenes (produced via reaction of tetrahydroxycalixarene, pentahydroxycalixarene hexahydroxycalixarene, and heptahydroxycalixarene with n-bromobutane and with n-bromohexadecane) affords an homologous series of calixarene-based surfactants that form stable monolayers at the air-water interface.Surface pressure-area isotherms, measured for each calixarene, yield limiting areas that are in excellent agreement with values predicted from space-filling models, if it is assumed that the base of each calixarene is parallel and the alkyl chains are perpendicular to the water surface.Introduction of malonic acid to the aqueous subphase results in a substantial increase in the coheresiveness of films derived from calixarene-, calixarene-, and calixarene-based surfactants, as judged by changes in surface viscosity.X-ray photoelectron spectroscopic analysis of a Langmuir-Blodgett film, produced from a malonic acid stabilized calixarene monolayer, shows a carboxylate/mercury ratio of 0.9.This value is in excellent agreement with a model that assumes that all of the bound malonate acts as a bridge between adjacent calixarene subunits in an hexagonally packed array.Water evaporation studies, carried out at the air-water interface, reveal that each of the calixarene-, calixarene-, and calixarene-based monolayers, in the presence and in the absence of malonic acid, maintains a porous structure that offers little resistance to the permeation of water, relative to a densely packed aliphatic monolayer of surfactant.