Two Ni/Ce complexes based on bicompartmental ligands with field supported slow magnetic relaxation

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388980%3A_____%2F24%3A00599561" target="_blank" >RIV/61388980:_____/24:00599561 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1039/D4NJ03545C" target="_blank" >https://doi.org/10.1039/D4NJ03545C</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d4nj03545c" target="_blank" >10.1039/d4nj03545c</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Two Ni/Ce complexes based on bicompartmental ligands with field supported slow magnetic relaxation

Popis výsledku v původním jazyce

Dinuclear Ni(ii)/Ce(iii) complexes, namely [Ni(o-van-dap)Ce(H2O)(NO3)3] (1) and [Ni(H2O)2(o-van-dmdap)Ce(NO3)3] (2), were synthesized and chemically and spectroscopically characterized. Single crystal X-ray analyses revealed that in both 1 and 2 bicompartmental Schiff base-type ligands (o-van-dap)2- and (o-van-dmdap)2- are present, with neighbouring cis-N2O2 and O4 donor sets. The smaller N2O2 cavity is occupied by the Ni(ii) ions while the larger O4 cavity contains a Ce(iii) ion, both metal ions are linked via a pair of monoatomic O-bridges with the O atoms provided by deprotonated hydroxyl groups. In complex 1 the bridging unit within the Schiff base-type ligand is formed from two carbon atoms, consequently the central Ni(ii) atom has a square-planar geometry, and is thus diamagnetic. In complex 2 the bridging unit within the structure of the ligand is composed of three carbon atoms yielding a larger cavity accommodating a paramagnetic, hexacoordinated Ni(ii) atom, whose coordination sphere is completed by two axial aqua ligands. The Ce(iii) atoms in both 1 and 2 are additionally coordinated by three chelating nitrato co-ligands resulting in coordination number 10 in 2, while another aqua ligand increases the coordination number of the Ce(iii) atom in 1 to 11. Variable temperature dc magnetic studies of both 1 and 2 (2-300 K) corroborate the diamagnetism of the Ni(ii) atom (S = 0) in 1 and paramagnetism of the Ni(ii) atom (S = 1) in 2. The ac magnetic studies showed that both complexes 1 and 2 exhibit field induced slow magnetic relaxation. The obtained values of the energy barriers are Delta/kB = 24.1 K with tau 0 = 6.96 x 10-8 s for 1, and Delta/kB = 9.88 K with tau 0 = 5.36 x 10-7 s for 2. One-atomic elongation of the bridging unit in the bicompartmental ligand induces change of the magnetic character of the Ni(ii) central atoms from S = 0 in 1 to S = 1 in 2, and this change leads to significant differences in the values of the respective Delta/kB parameters. Theoretical ab initio calculations for complexes 1 and 2 were performed to investigate their magnetic properties in detail.

Název v anglickém jazyce

Two Ni/Ce complexes based on bicompartmental ligands with field supported slow magnetic relaxation

Popis výsledku anglicky

Dinuclear Ni(ii)/Ce(iii) complexes, namely [Ni(o-van-dap)Ce(H2O)(NO3)3] (1) and [Ni(H2O)2(o-van-dmdap)Ce(NO3)3] (2), were synthesized and chemically and spectroscopically characterized. Single crystal X-ray analyses revealed that in both 1 and 2 bicompartmental Schiff base-type ligands (o-van-dap)2- and (o-van-dmdap)2- are present, with neighbouring cis-N2O2 and O4 donor sets. The smaller N2O2 cavity is occupied by the Ni(ii) ions while the larger O4 cavity contains a Ce(iii) ion, both metal ions are linked via a pair of monoatomic O-bridges with the O atoms provided by deprotonated hydroxyl groups. In complex 1 the bridging unit within the Schiff base-type ligand is formed from two carbon atoms, consequently the central Ni(ii) atom has a square-planar geometry, and is thus diamagnetic. In complex 2 the bridging unit within the structure of the ligand is composed of three carbon atoms yielding a larger cavity accommodating a paramagnetic, hexacoordinated Ni(ii) atom, whose coordination sphere is completed by two axial aqua ligands. The Ce(iii) atoms in both 1 and 2 are additionally coordinated by three chelating nitrato co-ligands resulting in coordination number 10 in 2, while another aqua ligand increases the coordination number of the Ce(iii) atom in 1 to 11. Variable temperature dc magnetic studies of both 1 and 2 (2-300 K) corroborate the diamagnetism of the Ni(ii) atom (S = 0) in 1 and paramagnetism of the Ni(ii) atom (S = 1) in 2. The ac magnetic studies showed that both complexes 1 and 2 exhibit field induced slow magnetic relaxation. The obtained values of the energy barriers are Delta/kB = 24.1 K with tau 0 = 6.96 x 10-8 s for 1, and Delta/kB = 9.88 K with tau 0 = 5.36 x 10-7 s for 2. One-atomic elongation of the bridging unit in the bicompartmental ligand induces change of the magnetic character of the Ni(ii) central atoms from S = 0 in 1 to S = 1 in 2, and this change leads to significant differences in the values of the respective Delta/kB parameters. Theoretical ab initio calculations for complexes 1 and 2 were performed to investigate their magnetic properties in detail.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

New Journal of Chemistry

ISSN

1144-0546

e-ISSN

1369-9261

Svazek periodika

48

Číslo periodika v rámci svazku

41

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

11

Strana od-do

17750-17760

Kód UT WoS článku

001325703100001

EID výsledku v databázi Scopus

2-s2.0-85205921973