Size-dependent encapsulation selectivity of alkaline earth metal ions in distorted octahedral and dicapped Ni(II) metallacryptate with L-isoleucine
Full article
| Journal |
Journal of Molecular Structure
ISSN: 0022-2860
, E-ISSN: 1872-8014
|
| Output data |
Year: 2026,
Volume: 1351,
Article number
: 144164,
Pages count
:
DOI:
10.1016/j.molstruc.2025.144164
|
| Authors |
Savarets Alexander R.
1
,
Maximova Anna D.
2
,
Dolotov Roman A.
1
,
D’yakonov Vladimir A.
1
,
Dolzhenko Vladimir D.
3,1
|
| Affiliations |
| 1 |
N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47 Leninskii pr., 119991 Moscow, Russian Federation
|
| 2 |
Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, 31 Leninskii pr., 119991 Moscow, Russian Federation
|
| 3 |
Department of Chemistry, M. V. Lomonosov Moscow State University, 1 Lenin’s Hills, 119991 Moscow, Russian Federation
|
|
Funding (1)
|
1
|
N. D. Zelinsky Institute of Organic Chemistry Russian Academy of Sciences
|
|
The study of size selectivity of cryptands and crown ethers towards metal ions is one of the most interesting and promising directions in supramolecular chemistry. In this work the metallacryptates [MNi6(Ile)12](ClO4)2 (M = Ba2+, Sr2+; Ile = l-isoleucine) (2–3) and the complex [Ca2Ni6(Ile)12(CH3OH)6(H2O)3](ClO4)4 (4) were synthesized for the first time. The composition and structure of the obtained compounds were studied by single-crystal X-ray diffraction (SCXRD), IR-spectroscopy, CHN analysis, electrospray ionization mass spectrometry (ESI-MS) and energy-dispersive X-ray spectroscopy (EDX). The time-dependent dynamics of self-assembly of metallacryptates 2–3 was investigated by PCA method. The intermediate complex ion [MNi5(Ile)10]2+ was discovered, it coexists in solution together with complexes 2–3. The stability constants of the complexes [MNi6(Ile)12]2+ decrease in the series Ba2+ – Sr2+. It is shown that the class of octahedral Ni(II) metallacryptates with amino acids possesses a rigid [Ni6(AA)12] framework (AA = amino acids) and exhibits very high size and charge selectivity towards the central atom, showing no binding affinity for monovalent cations and Mg2+. Significant changes in the crystal radius across the series of alkaline earth metal ions (M2+) allowed us to investigate the size selectivity of octahedral M(II)-Ni(II) metallacryptates with l-isoleucine. Complexes 2–3 belong to the class of octahedral metallacryptates. The possibility of the existence of 4 was previously denied in the literature. Changes in structural parameters correlate well with the electronic structure, investigated by quantum chemical calculations and UV–Vis spectroscopy within the ligand field theory.