Head-to-Head Linked Double Calix[4]arenes:  Convenient Synthesis and Complexation Properties

Abstract

Combination of calix[4]arenes functionalized at the upper rim at the 5- and 17-positions with amino and formyl groups, respectively, gives a new series of "head-to-head" linked double calix[4]arenes in nearly quantitative yield. The X-ray structure of a modified double calix[4]arene is reported. The novel, highly preorganized receptor molecules complex silver(I) ions (K(ass) = 9.5 x 10(5) M(-)(1) in CDCl(3)); the selectivity of complexation was studied by supported liquid membrane transport experiments and chemically modified field effect transistor measurements.

Removal of chromate and phosphate anion from aqueous solutions using calix[4]aren receptors containing proton switchable units

“…The phenolic-OH of the calixarenes lower rim can be further functionalized to feasibly give various ionic receptors [18,19]. The introduction of two or four different groups as ester [20,21], keto, amide [22,23] on the phenolic-OH groups of calixarenes fixes this macrocycle in the "cone" structure giving metal selective cation receptors [24,25]. Selective calixarene-based receptors for cations and neutral molecules have been synthesized in the past decade [26].…”

Selective Complexation of Hg2+by Biscalix[4]arene Nitriles

“…In these compounds, two (or more) calixarene units are linked at their upper or lower rims through one or more spacer elements (12,13). Various structural motifs have been used as spacers, including alkyl, alkenyl, and alkynyl chains, diesters, diamines, metallacenes, polyethers, sulfides, and diimines (14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24).…”

A Novel Fluorescent Sensor for Fe3+ and Cr3+ based on a calix[4]arene bearing two coumarin units

“…Only one signal of the imino-protons (CH=N at 7.70 ppm) shows that the C=N bonds adopt the E-configuration, in accord with the literature. 21 The complexation behaviour of calix [4]arene 1 towards different heavy and transition metal cations (Ni 2+ , Cr 3+ , Pb 2+ , Cd 2+ , Cu 2+ , Zn 2+ , Ag + , Hg 2+ , Co 2+ , Fe 2+ , Fe 3+ , Mn 2+ , Ca 2+ and Scheme 1 Synthesis of compound 1.…”