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Reaction of resorcinarene octols with tris-hydroxymethylmethylamine (TRIS), formaldehyde, and alcohols results in tetraalkoxymethylation of the resorcinol rings. Harsh acylation of aminomethylated resorcinarenes with acid anhydrides leads to the complete acylation of eight hydroxyls and substitution of the amino versus acyloxy groups. Acyloxymethylated resorcinarene 6b can be transformed into a tetrabromomethylated derivative 7 through the reaction with HBr in acetic acid.

The reaction of tetra-p-formyltetra-O-propylcalix[4]arene with phenanthrenequinone in the presence of NH4OAc affords compound 2, a new class of calixarene with an expanded aromatic cavity, that could be stabilized by hydrogen-bonded bridges and/or ion pairing, thus preventing collapse into fully stacked pinched cone conformations as depicted. Two partially protonated calixarenes interdigitate in the solid state to give rise to a self-assembled face-to-face dimer, stabilized by π−π stacking interactions.

Ab initio Hartree−Fock and DFT MO calculations have been used to study the conformations of six [2.2.1]cyclophane π-prismands and the formation of their π-complexes with silver triflate (AgSO3CF3). The lowest energy cyclophane conformations and their silver triflate π-complexes have been calculated with HF/3-21G* and B3LYP/3-21G* levels of theory. The nature of bonding in silver triflate π-complexes has been studied with natural bond orbital analysis (NBO). Energies of the calculated cyclophanes and complexes, together with the formation energies of those complexes, have also been discussed. The results have been compared to available X-ray crystal structures and also to results of the previously published ab initio calculations of slightly larger [2.2.2]cyclophanes and their silver complexes. Calculated and experimental X-ray structures agreed reasonably well, given the rather small 3-21G* basis set. Changes in the bonding between the ligand and Ag⁺ ion were observed, due to an enhanced bonding of the triflate moiety over the silver atom ion in the calculated models. In these complexes the silver ion is bonded to the cyclophane cavity by the bonds formed by σ donation and d−π* back-donation between the silver ion and the hydrocarbon skeleton resulting in variable bonding modes from η¹ to η⁶ per aromatic ring depending on the ligand conformation. In this case the σ donation from the hydrocarbon to the silver ion is the main contribution to the metal−cyclophane bonding. Bonding of the silver ion to the present π-prismands relates by strength to a single moderately strong hydrogen bond and varies between 25 and 50 kJ/mol. Due to the smaller cavity, the more rigid hydrocarbon skeleton, and the presence of the triflate moiety [2.2.1]cyclophanes form different types of interactions with silver ion when compared to previously published [2.2.2]cyclophane π-prismand complexes with Ag⁺ ion.

Sterically hindered tetraaminomethylated resorcarenes form inclusion complexes in CDCl3 with acetonitrile and acetaldehyde, which are kinetically stable on the NMR time scale at 233 K.

Calix[4]arenes bearing one, two, or four 1,8-naphthyl imide groups at the wide rim and bis-calix[4]arenes connected via perylene-bisimide dye spacers have been synthesized. The low-temperature NMR spectrum of the tetranaphthylimide suggests, in agreement with a crystal structure, a C2-symmetrical pinched cone conformation stabilized via face-to-face π−π interactions between opposite naphthylimide groups. UV−vis and fluorescence studies have been carried out for the perylene bis-calix[4]arene dyes.

Aminomethylation of resorcarenes at the wider rim with bulky diisopropylamine and formaline leads to trisubstituted derivatives. Analogous reaction with C2v-symmetrical resorcarene tetratosylate gives the monoaminomethylated compound. Further reactions of remaining unsubstituted resorcinol rings result in new resorcarene derivatives.

A concept is demonstrated for comb-shaped supramolecules based on dodecylbenzenesulfonic acid-doped polyaniline, i.e., PANI(DBSA)0.5, by complexation with zinc dodecylbenzenesulfonate, Zn(DBS)2. Model studies using related protonated single crystalline bipyridine oligomers suggest that Zn(DBS)2 molecules are bonded by Zn²⁺- and water-mediated hydrogen bonds to the sulfonates of PANI(DBSA)0.5. The comb-shaped supramolecules, denoted as PANI(DBSA)0.5[Zn(DBS)2]x with x = 0.25, 0.5, 0.75, 1.0, and 1.5, self-organize as lamellar structures due to the repulsion between the alkyl chains and the polar moieties leading to plasticized materials. So far, the conductivity levels are low, i.e., in the range 10^-7 S/cm, potentially requiring optimization of the lengths and the amounts of side groups. The concept allows generalization to complex functional groups along sulfonic acid protonated polyaniline chains.

Ab initio Hartree−Fock and DFT MO calculations have been used to study the conformations of [2.2.2]cyclophane π-prismands and the formation of π-complexes with silver ion and [2.2.2]cyclophanes. The lowest energy cyclophane conformations have been calculated up to the HF/6-31+G* level of theory. The silver π-complexes of the lowest energy conformations have been calculated with HF/3-21G* and B3LYP/3-21G* levels of theory. The nature of bonding in silver ion π-complexes has been studied with natural bond orbital analysis (NBO). Energies of the calculated cyclophanes and complexes, together with formation energies of those complexes, have also been discussed. The results obtained have been compared to X-ray crystal structures whenever such structures were available. Calculated and experimental X-ray structures agreed reasonably well given provision to the rather small 3-21G* basis set and the omission of triflate anion in the calculation model. The NBO analysis showed that when Ag⁺ is bonded to the cyclophane cavity, the bonds are formed by σ-donation and d−π*-back-donation between the silver ion and the hydrocarbon skeleton, resulting in hexahapto (3×η²) overall π-bonding. This is in agreement with the well-known “bonding−back-bonding” scheme in transition metal carbonyl complexes. In this case the σ-donation from hydrocarbon to silver ion is the main contribution to the metal−cyclophane bonding. One dihapto (η²) bonding to one aromatic ring in the present π-prismands relates by strength to a single strong hydrogen bond, which is up to 100 kJ/mol; thus the strength of this 3×η² bonding in these [2.2.2]cyclophane π-prismands can be compared to three simultaneous strong hydrogen bonds.