Occurrence of slow relaxation of the magnetization in a family of copper()/manganese() quasi-isotropic complexes with different ground spin states

• Published in: Dalton transactions : an international journal of inorganic chemistry 2022-11, Vol.51 (46), p.17653-17663
• Main Authors: Pilichos, Evangelos, Font-Bardia, Mercè, Escuer, Albert, Mayans, Júlia
• Format: Article
• Language: English
• Subjects: Copper; Cyclohexane; Ethylene; Magnetic anisotropy; Magnetization; Manganese; Raman spectroscopy
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d2dt02807g

A family of copper( ii )/manganese( ii ) new clusters with the formulas [Cu II Na I (L2)(MeOH)(ClO 4 )] ( 1 ), [Cu II 2 Mn II ( S , S -L3) 2 (MeOH)](ClO 4 ) 2 ( 2 SS ), [{Cu II Mn II (L1)(H 2 O) 2 (MeOH)}{Cu II (L1)} 2 ](ClO 4 ) 2 ( 3 ), [(μ 1,3 -N 3 ) 2 {Cu II Mn II (L2)(H 2 O)} 2 {Cu II (L2) 2 ](ClO 4 )} 2 ( 4 ) and [(μ 1,1 -N 3 ) 2 {Cu II Mn II (L1)(N 3 )} 2 {Cu II Na I (L1)(MeOH)} 2 ](ClO 4 ) 2 ( 5 ) with L1 = N , N ′-ethylene-bis(3-methoxysalicylaldiimine), L2 = N , N ′-ethylene-bis(3-ethoxysalicylaldiimine) and L3 = N , N ′-cyclohexane-bis(3-ethoxysalicylaldiimine), has been synthesized, and structurally and magnetically characterized. Reduced magnetization studies demonstrate that the magnetic anisotropy of the systems is very small. However, dynamic magnetic studies and ultra-low-frequency Raman spectroscopy confirm the slow relaxation of these systems despite their quasi-isotropic nature, enlarging the range of non-anisotropic slow relaxing molecules. Polynuclear systems derived from isotropic cations such as MnII also can exhibit slow relaxation of the magnetization: Cu2Mn, Cu3Mn, Cu4Mn2 and Cu4Na2Mn2 are examples with a variety of S ground states.