ИСТИНА

In this work, EMS studies were performed using 57CoII complexes with alkylresorcinols (ARs; 1,3-dihydroxybenzenes with methyl or hexyl substituents in positions 5 or 4, respectively; chemical analogues of microbial autoinducers with adaptogenic functions) in circumneutral aqueous media (measured at T = 80 K in rapidly frozen solutions) and in the dried state. The parameters of the main nucleogenic 57FeII components (quadrupole doublets), which represent the parent 57CoII coordination, calculated from the spectra (at 80 K) were in the following ranges: isomer shift (vs. α-Fe), δ = 0.69–0.96 mm/s; quadrupole splitting, Δ = 2.5–3.0 mm/s (relative spectral area Sr ≥ 64%). Besides that, additional lower-intensity lines corresponding to the stabilised daughter 57FeIII components (featuring after-effects) were observed with δ ~ 0.2 mm/s, Δ = 0.8–1.1 mm/s. In the dried state, both δ and Δ values tended to slightly decrease. The EMS data obtained may be attributed to a distorted tetrahedral coordination of 57CoII in the parent high-spin 57CoII–AR complexes (at high [AR]:[57CoII] ratios applied). ARs may form coordination bonds via one of the two OH-groups of ARs (being in the meta-position), evidently involving also water molecules as additional ligands.