Supramolecular Motifs in s‐Block Metal‐Bound Sulfonated Monoazo Dyes, Part 1: Structural Class Controlled by Cation Type and Modulated by Sulfonate Aryl Ring Position

Abstract

The solid-state structures of 43 Li, Na, K, Rb, Mg, Ca and Ba salts of para- and meta-sulfonated azo dyes have been examined and can be categorised into three structural classes. All form alternating organic and inorganic layers, however, the nature of the coordination network that forms these layers differs from class to class. The class of structure formed was found to be primarily governed by metal type, but can also be influenced by the nature and position of the organic substituents. Thus, for the para-sulfonated azo dyes, Mg compounds form solvent-separated ion-pair solids; Ca, Ba and Li compounds form simple coordination networks based on metal-sulfonate bonding; and Na, K and Rb compounds form more complex, higher dimensional coordination networks. Compounds of meta-sulfonated azo dyes follow a similar pattern, but here, Ca species may also form solvent-separated ion-pair solids. Significantly, this first attempt to classify such dyestuffs using the principles of supramolecular chemistry succeeds not only for the simple dyes used here as model compounds, but also for more complex molecules, similar to modern colourants.

Influence of cations on the partition behavior of perfluoroheptanoate (PFHpA) and perfluorohexanesulfonate (PFHxS) on wastewater sludge

“…Similar observation was also found in our previous study on the adsorption of PFASs onto alumina, which showed that magnesium had less interaction with PFAS species (Wang and Shih, 2011). Kennedy et al (2004) suggested that the higher covalent nature of magnesium relative to calcium may lead to stronger direct hydration and thus reduced its interactions with the PFAS species and sludge.…”

Supramolecular Structure in s‐Block Metal Complexes of Sulfonated Monoazo Dyes: Discrepant Packing and Bonding Behavior of ortho‐Sulfonated Azo Dyes

“…Kennedy et al. describes the creation, by synthesis and subsequent single‐crystal diffraction analysis, of an initial database of 43 solid‐state structures of Li, Na, K, Rb, Mg, Ca, and Ba salts of para‐ and meta ‐monosulfonated azo dyes and their subsequent categorization into three structural classes 1. Note that despite the common commercial usage of sulfonated azo compounds only one of these 43 structures was known prior to this work 2.…”

Carboxylate–phenolate tautomerism in 5-[(nitrophenyl)diazenyl]salicylate anions

“…Alternating layers of anions and cations were also observed in crystals of sodium 5-[(4-nitrophenyl)diazenyl]salicylate trihydrate (Yatsenko & Paseshnichenko, 2014), but the contacts between the anions are shorter than in (I) and stacks of anions are recognizable within the layers. Layered structures with alternating polar and apolar zones are typical for the salts of sulfonated azo dyes (Kennedy et al, 2004).…”