Predominantly ligand guided non-covalently linked assemblies of inorganic complexes and guest inclusions

Abstract

Various non-covalently linked inorganic self-assemblies formed by the supramolecular interacting sites located at the ligands are discussed. The impetus for this rapidly growing topic on the construction of robust assemblies is elucidated by select examples that are associated with interesting structures and properties. The review includes discussion on the stabilization of different assemblies of nucleobases in the non-covalent assemblies of inorganic complexes. The participation of the guest molecules in the formation of self-assemblies with hosts to make extra space or voids for intake of the guest, water-assisted assemblies, changes in the structures guided by cations, and aggregation-induced photoluminescence in the self-assemblies of metal complexes are presented. Fine-tuning of non-covalent self-assemblies of metal complexes by changing ligands or by other components, which modify the guest recognition abilities is elucidated. The discussions are based on selected examples of self-assemblies that use supramolecular features of peripheral part of ligands or ligand of a complex that helps one to identify templates for weak interactions and for molecular recognition.

Neutral, Zwitterion, Ionic Forms of 5‐Aminoisophthalic Acid in Cocrystals, Salts and Their Optical Properties

“…[20][21][22][23][24] The electrostatic interactions in the noncovalent self-assemblies of inorganic complexes are common. [25][26][27][28] Among many examples of organic salts forming cocrystals the salts of active pharmaceutical ingredients, [25] carboxylic acid, [20][21][22][23][24] quaternary ammonium [29] and heterocycle containing oximes [30] are well studied. Depending on the reactivity of a base dicarboxylic acids form salts with different stoichiometries.…”

“…Charge‐assisted hydrogen bonds have definite scopes in the synthesis of non‐covalent assemblies . The electrostatic interactions in the non‐covalent self‐assemblies of inorganic complexes are common . Among many examples of organic salts forming cocrystals the salts of active pharmaceutical ingredients, carboxylic acid, quaternary ammonium and heterocycle containing oximes are well studied.…”

Changes in the proportions of an active pharmaceutical through cocrystals

“…The use of metal ions in medicine were well studied (Franz & Metzler-Nolte, 2019), the utilities of second coordination sphere of a metal complex to modulate API contents have not been explored. Second coordination sphere of a metal complex provides complementing free binding sites of ligands of a stable metal complex for supramolecular interactions to accommodate guest molecules or for further coordination (Baruah, 2018). 2,6-Pyridinedicarboxylic acid (abreviated as H 2 pdc) is a biocompatible compound (Powell, 1953) whose neutral form F and two different anionic forms G and H are shown in Figure 2.…”

Adsorption of Polar Volatile Organic Compounds by a Crystalline Network Structure Based on a Bis(benzimidazole)NiCl2 Complex

“…Furthermore, the hydrogen-bond networks can provide hydrogen-bond sites that interact weakly with volatile carbonyl compounds. The characteristics of metal-complex-based hydrogen-bond networks have been investigated for more than two decades (for selected reviews, see refs − ; for recent examples, see refs − ); nevertheless, the adsorption/desorption properties of volatile carbonyl compounds in such networks have not been explored, except in the case of acetone. − Takamizawa et al have measured the adsorption isotherm of acetone in a hydrogen-bond network derived from [Co­(ethylenediamine) 3 ]­Cl 3 . The Beatty group has investigated the desorption of co-crystallized acetone from the crystals of [M­(2,4-pyridine dicarboxylate) 2 ] 2– , where M was Cu or Zn. , Castillo and co-workers have confirmed that a [Cu 2 (μ-adenine) 4 Cl 2 ]­Cl 2 -based hydrogen-bond network can adsorb acetone .…”