Jump to main content
Jump to site search


Bulky ligands shape the separation between the large spin carriers to condition field-induced slow magnetic relaxation

Author affiliations

Abstract

Crystal engineering of magnetic relaxation in supramolecular networks based on almost isotropic cyanido-bridged {Mn9[W(CN)8]6L8(solv)8} clusters decorated by bulky 4,4′-di-tert-butyl-2,2′-bipyridine (But2bpy) and 4,7-diphenyl-1,10-phenanthroline (Ph2phen) ligands is presented. The three new compounds {MnII9[WV(CN)8]6(But2bpy)8(MeOH)8}·Pri2O·13MeOH (1), {MnII9[WV(CN)8]6(But2bpy)8(MeOH)6(H2O)2}·4Pri2O·2H2O (1a), and {MnII9[WV(CN)8]6(Ph2phen)8(MeOH)8}·29MeOH·6H2O (2) were characterized structurally and magnetically. Compound 1 exhibits unequivocal domination of repulsive intercluster contacts operating between the side But groups leading to intercluster distances exceeding 10 Å in all three dimensions. Compound 1a reveals a 1-dimensional (1D) supramolecular chain structure with very close intercluster distances of 6.7 Å realized through the direct W–CN⋯HO–Mn hydrogen bonds along the chain, further isolated by the above repulsive But⋯But synthons. Compound 2 shows significant separation in all three directions with the intercluster distances close to 10, 12 and 13.5 Å. However, in contrast to 1, these separations are accompanied by indirect hydrogen bond arrays and local π–π interactions of potential to assist in the transfer of weak magnetic interactions. The dc magnetic data show the signature of S = 39/2 in the ground state, which is typical in this group of compounds. The high-spin clusters are accompanied by different intercluster interactions, illustrated by the effective zJ′ values of +0.010 cm−1 (1), +0.008 cm−1 (1a) and +0.001 cm−1 (2). The low temperature ac susceptibility measurements revealed a temperature- and field-dependent magnetic relaxation time for all 1, 1a and 2 compounds (τ1, τ1a-fast, and τ2-fast in the range 10−3–10−4 s). In contrast and only in the case of 1a and 2, an additional temperature independent slow process was detected (τ1a-slow and τ2-slow located between 0.1 s and 1 s). The magnetic relaxations were correlated with the obtained supramolecular networks, indicating the significant role of dipolar fields, weak non-covalent interactions, hydrogen bonds and π–π interactions.

Graphical abstract: Bulky ligands shape the separation between the large spin carriers to condition field-induced slow magnetic relaxation

Back to tab navigation

Supplementary files

Publication details

The article was received on 02 Oct 2019, accepted on 16 Nov 2019 and first published on 18 Nov 2019


Article type: Paper
DOI: 10.1039/C9DT03903A
Dalton Trans., 2020, Advance Article

  •   Request permissions

    Bulky ligands shape the separation between the large spin carriers to condition field-induced slow magnetic relaxation

    J. Kobylarczyk, M. Liberka, P. Konieczny, S. Baran, M. Kubicki, T. Korzeniak and R. Podgajny, Dalton Trans., 2020, Advance Article , DOI: 10.1039/C9DT03903A

Search articles by author

Spotlight

Advertisements