1
|
Khakina EA, Denisov GL, Nikovskii IA, Polezhaev AV, Nelyubina YV. Spin State of the Cobalt(II) Complex with N,N'-Disubstituted 2,6-Bis(pyrazol-3-yl)pyridine. RUSS J COORD CHEM+ 2022. [DOI: 10.1134/s1070328422060021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
2
|
Denisov GL, Nikovskii IA, Aliev TM, Polezhaev AV, Nelyubina YV. Spin State of Cobalt(II) 2,6-Bis(pyrazol-3-yl)pyridine Complex with a Redox-Active Ferrocenyl Substituent. RUSS J COORD CHEM+ 2021. [DOI: 10.1134/s1070328421060014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
3
|
Spin State Behavior of A Spin-Crossover Iron(II) Complex with N,N′-Disubstituted 2,6-bis(pyrazol-3-yl)pyridine: A Combined Study by X-ray Diffraction and NMR Spectroscopy. CRYSTALS 2020. [DOI: 10.3390/cryst10090793] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A series of three different solvatomorphs of a new iron(II) complex with N,N′-disubstituted 2,6-bis(pyrazol-3-yl)pyridine, including those with the same lattice solvent, has been identified by X-ray diffraction under the same crystallization conditions with the metal ion trapped in the different spin states. A thermally induced switching between them, however, occurs in a solution, as unambiguously confirmed by the Evans technique and an analysis of paramagnetic chemical shifts, both based on variable-temperature NMR spectroscopy. The observed stabilization of the high-spin state by an electron-donating substituent contributes to the controversial results for the iron(II) complexes of 2,6-bis(pyrazol-3-yl)pyridines, preventing ‘molecular’ design of their spin-crossover activity; the synthesized complex being only the fourth of the spin-crossover (SCO)-active kind with an N,N′-disubstituted ligand.
Collapse
|
4
|
Pankratova Y, Aleshin D, Nikovskiy I, Novikov V, Nelyubina Y. In Situ NMR Search for Spin-Crossover in Heteroleptic Cobalt(II) Complexes. Inorg Chem 2020; 59:7700-7709. [PMID: 32383584 DOI: 10.1021/acs.inorgchem.0c00716] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Here we report the first successful attempt to identify spin-crossover compounds in solutions of metal complexes produced by mixing different ligands and an appropriate metal salt by variable-temperature nuclear magnetic resonance (NMR) spectroscopy. Screening the spin state of a cobalt(II) ion in a series of thus obtained homoleptic and heteroleptic compounds of terpyridines (terpy) and 2,6-bis(pyrazol-3-yl)pyridines (3-bpp) by using this NMR-based approach, which only relies on the temperature behavior of chemical shifts, revealed the first cobalt(II) complexes with a 3-bpp ligand to undergo a thermally induced spin-crossover. A simple analysis of NMR spectra collected from mixtures of different compounds without their isolation or purification required by the current method of choice, the Evans technique, thus emerges as a powerful tool in a search for new spin-crossover compounds and their molecular design boosted by wide possibilities for chemical modifications in heteroleptic complexes.
Collapse
Affiliation(s)
- Yanina Pankratova
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991 Moscow, Russia.,Moscow State University, Leninskie gory, 1, 119991 Moscow, Russia
| | - Dmitry Aleshin
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991 Moscow, Russia.,Mendeleev University of Chemical Technology of Russia, Miusskaya pl., 9, 125047 Moscow, Russia
| | - Igor Nikovskiy
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991 Moscow, Russia
| | - Valentin Novikov
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991 Moscow, Russia.,Moscow Institute of Physics and Technology, Institutskiy per., 9, Dolgoprudny 141700, Moscow Region, Russia
| | - Yulia Nelyubina
- A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991 Moscow, Russia
| |
Collapse
|
5
|
Blinou DO, Nikiforov AA, Gurzhiy VV, Minkovich AE, Maksimov MY, Panina NS, Belyaev AN, Eremin AV. Complexes [Ni2(μ-OH2)(μ-O2CCH(CH3)2)2L2–4((CH3)2CHCO2)2]: Synthesis, Structure, and Mass Spectrometric Studies. RUSS J COORD CHEM+ 2020. [DOI: 10.1134/s1070328420020037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|