Crystal structure and photolysis spin-trapping EPR investigations of aqua(2-methoxycarbonylethyl)cobaloxime and its β-cyclodextrin inclusion complex †

Abstract

Aqua(2-methoxycarbonylethyl)cobaloxime 1 and its β-cyclodextrin inclusion complex 2 were synthesized and characterized by 1 H NMR and X-ray crystallography. Structural and conformational comparisons between the inclusion complex and the guest compound are made. The rearrangement reaction of the methoxycarbonylethyl radical was observed in the anaerobic photolysis of aqua(2-methoxycarbonylethyl)cobaloxime in the absence and presence of β-cyclodextrin by using the EPR spin-trapping technique. The changes of EPR parameters indicate that the formed spin adduct could be included in the β-cyclodextrin's cavity.

The structure and modified properties of a self-dimerised Cu(ii) inclusion complex in γ-cyclodextrins

“…To this end, cyclodextrins (CDs), which are cyclic oligosaccharides consisting of d -glucose subunits, 4 are widely used because their hydrophobic cavities can accommodate organic compounds, polyoxometalates, metal clusters and coordination complexes, 5,6 whose redox, spin, and luminescence properties are modified as a result of their confinement. 7–9 In fact, a search in the CCDC database (updated in June 2022) resulted in more than 350 articles reporting the crystal structure of inclusion complexes of CDs. In contrast, reports on CD inclusion complexes with more than one guest molecule are scarce.…”

Jørgensen Complex within a Molecular Container: Selective Encapsulation of trans-[Co(en)2Cl2]+ into Cucurbit[8]uril and Influence of Inclusion on Guest's Properties

“…Inclusion of transition metal complexes into various molecular containers (cyclodextrins, calixarenes, cucurbiturils) represents a rare phenomenon in supramolecular chemistry. The first examples of such host−guest complexes, the inclusion compounds of ferrocene within the cavity of α-, β-, and γ-cyclodextrins, were reported in the 1980s. − The majority of inclusion compounds with metal complexes known to date exhibits an organometallic complex (metallocenes, − olefin metal complexes, − metal alkyls, , carbonyls , ) encapsulated inside the cavity of a macrocyclic host. Investigation of these types of compounds is very important, because encapsulation can substantially affect the geometry of the guest, its thermal stability, ,,,,− magnetic and photochemical − properties, electrochemical behavior, − and reactivity.…”