Impact of Halogenido Coligands on Magnetic Anisotropy in Seven-Coordinate Co(II) Complexes

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F17%3A73583707" target="_blank" >RIV/61989592:15310/17:73583707 - isvavai.cz</a>

Výsledek na webu

<a href="http://pubs.acs.org/doi/ipdf/10.1021/acs.inorgchem.7b00235" target="_blank" >http://pubs.acs.org/doi/ipdf/10.1021/acs.inorgchem.7b00235</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.inorgchem.7b00235" target="_blank" >10.1021/acs.inorgchem.7b00235</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Impact of Halogenido Coligands on Magnetic Anisotropy in Seven-Coordinate Co(II) Complexes

Popis výsledku v původním jazyce

The structural and magnetic features of a series of mononuclear seven-coordinate Co-II complexes with the general formula [Co(L)X-2], where L is a 15-membered pyridine-based macrocyclic ligand (3,12,18-triaza-6,9-dioxabicyclo[12.3.1]octadeca-1(18),14,16-triene) and X = Cl- (1), Br- (2), or I- (3), were investigated experimentally and theoretically in order to reveal how the corresponding halogenido coligands in the apical positions of a distorted pentagonalbipyramidal coordination polyhedron may affect the magnetic properties of the prepared compounds. The thorough analyses of the magnetic data revealed a large easy-plane type of the magnetic anisotropy (D &gt; 0) for all three compounds, with the D-values increasing in the order 35 cm(-1) for 3 (I-), 38 cm(-1) for 1 (Cl-), and 41 cm(-1) for 2 (Br-). Various theoretical methods like the Angular Overlap Model, density functional theory, CASSCF/CASPT2, CASSCF/NEVPT2 were utilized in order to understand the observed trend in magnetic anisotropy. The D-values correlated well with the Mayer bond order (decreasing in order Co-I &gt; Co-Cl &gt; Co-Br), which could be a consequence of two competing factors: (a) the ligand field splitting and (b) the covalence of the CoX bond. All the complexes also behave as field-induced single-molecule magnets with the spin reversal barrier U-eff increasing in order 1 (Cl-) &lt; 2 (Br-) &lt; 3 (I-); however, taking into account the easy-plane type of the magnetic anisotropy, the Raman relaxation process is most likely responsible for slow relaxation of the magnetization. The results of the work revealed that the previously suggested and fully accepted strategy employing heavier halogenido ligands in order to increase the magnetic anisotropy has some limitations in the case of pentagonalbipyramidal Co-II complexes.

Název v anglickém jazyce

Impact of Halogenido Coligands on Magnetic Anisotropy in Seven-Coordinate Co(II) Complexes

Popis výsledku anglicky

The structural and magnetic features of a series of mononuclear seven-coordinate Co-II complexes with the general formula [Co(L)X-2], where L is a 15-membered pyridine-based macrocyclic ligand (3,12,18-triaza-6,9-dioxabicyclo[12.3.1]octadeca-1(18),14,16-triene) and X = Cl- (1), Br- (2), or I- (3), were investigated experimentally and theoretically in order to reveal how the corresponding halogenido coligands in the apical positions of a distorted pentagonalbipyramidal coordination polyhedron may affect the magnetic properties of the prepared compounds. The thorough analyses of the magnetic data revealed a large easy-plane type of the magnetic anisotropy (D &gt; 0) for all three compounds, with the D-values increasing in the order 35 cm(-1) for 3 (I-), 38 cm(-1) for 1 (Cl-), and 41 cm(-1) for 2 (Br-). Various theoretical methods like the Angular Overlap Model, density functional theory, CASSCF/CASPT2, CASSCF/NEVPT2 were utilized in order to understand the observed trend in magnetic anisotropy. The D-values correlated well with the Mayer bond order (decreasing in order Co-I &gt; Co-Cl &gt; Co-Br), which could be a consequence of two competing factors: (a) the ligand field splitting and (b) the covalence of the CoX bond. All the complexes also behave as field-induced single-molecule magnets with the spin reversal barrier U-eff increasing in order 1 (Cl-) &lt; 2 (Br-) &lt; 3 (I-); however, taking into account the easy-plane type of the magnetic anisotropy, the Raman relaxation process is most likely responsible for slow relaxation of the magnetization. The results of the work revealed that the previously suggested and fully accepted strategy employing heavier halogenido ligands in order to increase the magnetic anisotropy has some limitations in the case of pentagonalbipyramidal Co-II complexes.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Inorganic Chemistry

ISSN

0020-1669

e-ISSN

—

Svazek periodika

56

Číslo periodika v rámci svazku

9

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

5076-5088

Kód UT WoS článku

000400633200035

EID výsledku v databázi Scopus

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