Versatility of the Amino Group in Hydrazone‐Based Molecular and Supramolecular Systems

Abstract

Hydrazone‐based systems have been, and continue to be, widely studied in the field of supramolecular chemistry due to the chemical versatility of their triatomic C=N‐N structure, whose amino nitrogen commonly bears a methyl group or a hydrogen atom. Herein we review the conformational, configurational, and constitutional dynamics of these systems, focusing on the particularly important role of the N−H group of the hydrazone framework in each of those processes observed in molecular and supramolecular systems published in recent decades. Due to the enormous diversity of supramolecular architectures and molecular entities, the most representative synthetic methodologies to obtain them are described.

Efficient multigram procedure for the synthesis of large hydrazone-linked molecular cages

“…1). Our new structures (especially compound 13, which contains 6 p-quarterphenyl linkers), represent some of the largest tetrahedral porous organic cages created 13,[30][31][32][33] to date (Scheme 2). Notably, the largest cage (13) can now be synthesized with only a single chromatographic purification step, which provides a practical path to gram-scale quantities of the common vertex syn-9 (Scheme 1).…”

Synthesis and Crystal Structure Studies of a New Complex of Co (III)-Schiff Base Derivative Derived from Isonicotinohydrazide

“…In recent years, the chemical properties and biological activity of acylhydrazones have attracted much attention from chemists [1,2]. Acylhydrazones, due to their azometine moieties -C=N-NH-CO-, are good intermediates in the synthesis of various heterocyclic compounds [3][4][5][6][7][8] and they are also effective organic compounds in their own right due to their biological activities [9] and their chemical and industrial versatility [10][11][12][13].…”

Effect of twisted molecular geometry on the solid-state emissions of an anthracene fluorophore

“…the relative orientation of the anthracene motif and 4-hydroxyphenyl group. [41][42][43][44][45][46] Using this system, we sought to elucidate how the presence of a hydrazone CN linkage could influence the packing behaviour of anthracene motifs. In particular, we inquired whether the hydrazone CN linkage could adopt cisoid and transoid geometries in the solid (Scheme 1), and if such structures could be isolated.…”