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

Result code in 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>

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10402 - Inorganic and nuclear chemistry

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

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

Publication year

2017

Confidentiality

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

Name of the periodical

Inorganic Chemistry

ISSN

0020-1669

e-ISSN

—

Volume of the periodical

56

Issue of the periodical within the volume

9

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

5076-5088

UT code for WoS article

000400633200035

EID of the result in the Scopus database

—