Inclusion of Cavitands and Calix[4]arenes into a Metallobridged para‐(1H‐Imidazo[4,5‐f][3,8]phenanthrolin‐2‐yl)‐Expanded Calix[4]arene

Abstract

A hunter hunted! A highly preorganized, deep metallocavitand of nanoscale dimensions containing rhenium atoms at the four corners can be readily synthesized from a simple formyl‐substituted calix[4]arene and 3,8‐phenanthroquinone. Unsubstituted calix[4]arenes and cavitands without substituents on the lower rim are the ideal guests for such an expanded calixarene (see picture), and are included with binding constants of 103–105 M−1.

Structures of 1-hydrophenanthroimidazoles: building blocks in the synthesis of expanded-ring bis(imidazoles)

“…The water molecule acts as both a donor (O-H) and an acceptor (O) to form two hydrogen bonds (Table 2), one to the N(amine) H atom of molecule (IIb) and the other to the N(imine) atom of molecule (IIa). In (II), the NÁ Á ÁO distances (Table 2) in the N(imine)Á Á ÁH-O(H 2 O)Á Á ÁH-N(amine) fragments are shorter than the corresponding N(imine)Á Á ÁO(H 2 O) and N(amine)Á Á ÁO(H 2 O) distances in similar hydrogen-bond networks, in which they are in the ranges 2.770-2.914 and 2.802-2.946 Å , respectively, for the imine and amine linkages [Cambridge Structural Database (CSD), Version 5.30; Allen, 2002] (Botana et al, 2007;Freire et al, 2003;Fridman et al, 2006;Meng et al, 2006;Molina et al, 1998;Zhang et al, 2005). In (II), the hydrogen bonds lead to polymer chains consisting sequentially of molecules of (IIa), (IIb) and water.…”

Neutral discrete metal–organic cyclic architectures: Opportunities for structural features and properties in confined spaces

“…The Re(I) cavitand, C 129 H 135 Br 4 N 21 O 30 Re 4 (154) as a host, which could encapsulate appropriate cavitands and calix [4]arenes, was reported by de Mendoza's group, where a functionalized macrocyclic cavity was created through the reaction of 3,8-phenanthrolinoimidazolylcalix [4]arene (L132) with [Re(CO) 5 Br] in refluxing THF [264]. Compound 154 featured a square structure with diagonal distances of 16.0 and 16.7Å with each side being 11.56Å (Fig.…”

Supramolecular Chemistry and Mechanochemistry of Macromolecules: Recent Advances by Single-Molecule Force Spectroscopy

“…In recent years, the development of supramolecular chemistry is usually related to the finding of new acceptors, including cyclodextrins [114], calixarenes [115], cucurbiturils [116], and pillararenes [117], which have frequently been used in the supramolecular systems. Since the concept of "supramolecular polymer" was proposed [2], the interest of supramolecular chemistry has been extended from the host-guest recognition interactions to the discovery of polymerization methods and functional materials with different applications, which include stimuli responsiveness, self-healing, and environmental adaptation [3,[118][119][120].…”