Magnetic and Sorption Properties of Supramolecular Systems Based on Pentanuclear Copper(II) 12‐Metallacrown‐4 Complexes and Isomeric Phthalates: Structural Modeling of the Different Stages of Alcohol Sorption

Abstract

·14H 2 O (2). Molecules in the structures of 1, 1a and 2 are held together by noncovalent interactions, and the lattices contain voids filled with water molecules. Compounds 1 and 1a differ in the mode of mphthalate coordination, solvent type, and crystal lattice content. Desolvated 1 and 2 sorb gaseous MeOH and EtOH. Whereas the MeOH sorption capacity was very similar for 1 and 2 (about 0.14 cm 3 /g at PP S -1 = 0.9, where P is the current methanol pressure and P S the saturation vapor pressure of

Supramolecular Maleate Adducts of Copper(II) 12‐Metallacrown‐4: Magnetism, EPR, and Alcohol Sorption Properties

“…A detailed description of the structural features of the [Cu 5 (ahpha) 4 (DMF) 2 ] 2+ cations is given in the Supporting Information, since its structure is typical of previously reported copper(II) 12‐metallacrown‐4 complexes , , , . In contrast to known complexes based on the [Cu 5 (ahpha) 4 ] 2+ cation, the carboxylate anions in 1 are not coordinated to metal ions in the metallacrown unit. The [Cu 5 (ahpha) 4 ] 2+ cations are located quite close to each other and form “stacks”, but they are not interacting via long Cu–O contacts (like previously reported systems, , ) – there are no oxygen atoms of one cation over Cu 2+ ions of another cation at all.…”

“…It might be noted, that beside solvent composition, the crystallization mode (diffusion of diethyl ether or slow evaporation) can influence the formation of different compounds as previously observed for metallacrowns. [22b], …”

“…Previously, we have shown that assemblies based on [Cu 5 (ahpha) 4 ] 2+ (ahpha 2– is the dianion of 3‐amino‐3‐hydroximinopropane hydroxamic acid) with [Cr(C 2 O 4 ) 3 ] 3– or m ‐ or p ‐phthalates are able to absorb alcohols or n ‐hexane , . Sorption of alcohols by these complexes was not a classical physical adsorption, but a type of host–guest interaction, between alcohol molecules and structural elements of the supramolecular lattice , . However, several issues remained unclear.…”

“…However, several issues remained unclear. It was shown that the pentanuclear cations formed dimers, trimers, or 1D stacks in the crystal lattice, with long Cu–O bonds/contacts [between 2.427(1) and 2.988(3) Å], but the persistence of such metallacrown oligomers in solution has not been verified. Comparison of crystal structures of different solvates has given some understanding of the changes which could occur in the metallacrown‐based supramolecular system during their interaction with alcohols, but the data were insufficient for conclusions to be made about the generality of the reported phenomenon.…”

Crystal structure of N-hydroxyquinoline-2-carboxamide monohydrate

“…They are widely used in the preparation of metallacrowns (Golenya et al, 2012a;Gumienna-Kontecka et al, 2013;Safyanova et al, 2015) and as building blocks for synthesis of metal-organic frameworks and coordination polymers (Gumienna-Kontecka et al, 2007;Golenya et al, 2014;Pavlishchuk et al, 2010Pavlishchuk et al, , 2011.…”