Homoselenacalix[4]arenes: synthetic exploration and metallosupramolecular chemistry

Abstract

Homoselenacalix [4]arenes were synthesized by a [2 + 2] reductive coupling protocol favouring the cyclotetramers. The inner and outer-rim decoration was varied and a bicyclic derivative was prepared by a similar one-pot procedure. Conformational analysis in solution and the solid state showed noticeable differences between the homoselenacalix[4]arenes and the analogous homothiacalix[4]arenes and provided insight into the metal binding potential of the Se-bridged macrocycles. The homoselenacalix[4]-arenes were found to bind Ag(I). Complexation was visualized in the solid state and different packing networks were formed depending on the counter ions applied.

Different supramolecular interactions mediated by Br atoms in the crystal structures of three anisole derivatives

“…Ethyl 3,5-bis(hydroxymethyl)-4-methoxybenzoate, (I), was synthesized from ethylparaben (Haba et al, 2005;Thomas et al, 2012). 4-Bromo-2,6-bis(hydroxymethyl)anisole, (II), and 4-bromo-2,6-bis(bromomethyl)anisole, (III), were prepared from 4-bromophenol according to literature procedures (Leroy et al, 1988;Tashiro et al, 1989;Gonzá lez-Bulnes et al, 2013).…”

“…All three are important educts for a wide range of molecules and materials. Compound (I) has been used in the synthesis of selenacalixarenes (Thomas et al, 2012), while compounds (II) and (III) have been used in the preparation of rotaxanes (Hirose, Nishihara et al, 2007;Hirose, Ishibashi et al, 2007), supramolecular ligands (Li et al, 1988;Xu et al, 2012;Sookcharoenpinyo et al, 2012), cyclophanes (Yamato et al, 2002(Yamato et al, , 2006Shimizu et al, 2009), macrocycles (Akine et al, 2000(Akine et al, , 2005Sharghi et al, 2001), crown ethers (Hirose et al, 2003) and pyrene derivatives (Tashiro et al, 1989).…”

Selenacalix[4]selenophene: Synthesis, Structure, and Gel Formation of Cyclic Selenoether of Selenophene

“…Longer C–S bonds and less bulky substituents on the aromatic moieties provide larger cavities and higher conformational flexibility, which is considered advantageous for creating sophisticated structures for functionalization . Nonetheless, the synthesis and evaluation of the selenium-containing calix­[ n ]­arene family are limited to just a few examples. − …”

“…Owing to their electron donating properties, high polarizability, and coordination ability, macrocycles containing selenium atoms can be applied in redox materials, optoelectronic devices, and molecular receptors. − Furthermore, relatively larger van der Waals radii of selenium than other chalcogen atoms endows the formation of a three-dimensional network in the solid state. The resultant packing network provides a favorable molecular array for hole/electron transportation.…”

“… More recently, selenacalix[4]­thiophenes 2a and 2b were prepared by employing nucleophilic and electrophilic substitution reactions . Several other types of selenacalix­[ n ]­arene derivatives comprising various aromatic scaffolds have also been synthesized. , Nevertheless, to the best of our knowledge, the synthesis of selenacalix[4]­selenophene ( 4 ), which is the most prototypical selenium isologue, has not yet been achieved due to the lack of efficient cyclization methods.…”