A New “Offset” Analogue of the Classical Oxime-Bridged [Mn^III₆] Single-Molecule Magnets

Abstract

A new "offset" analogue of the classical [Mn6O2]-core oxime-bridged single-molecule magnets is introduced with a modified stacking arrangement of the [Mn3O] units. Studies of the magnetic properties reveal antiferromagnetic exchange interactions, a spin S = 4 ground state and population of low-lying excited states. Slow relaxation of the magnetization can be detected, with a corresponding energy barrier of 35.8 K. Interpretation of these features is supported with high-frequency EPR studies, quantifying the easy-axis type magnetic anisotropy, leading to a biaxial system. Redox properties investigated by cyclic and differential pulse voltammetry reveal multiple irreversible redox processes.

Covalently Linked Dimer of Mn3 Single-Molecule Magnets and Retention of Its Structure and Quantum Properties in Solution

“…The combined structural and magnetic data for 3 emphasize that this dimeric [Mn 3 ] 2 molecule is distinctly different from all other Mn 6 molecules reported in the literature that can be described as containing two Mn 3 triangular units. − 3 is a [Mn 3 ] 2 dimer of two very weakly coupled Mn 3 SMMs connected by a long dioximate linker, whereas the other Mn 6 molecules contain monatomic oxo bridges and thus much stronger couplings between their two halves, and they are therefore best described as Mn 6 monomers.…”

A review on oxime functionality: an ordinary functional group with significant impacts in supramolecular chemistry

“…Oxm-57 , an oxime derivative with an attached naphthalene moiety, was designed to synthesize several polynuclear metal complexes containing various transition metal ions. 86 The oxime Oxm-57 formed hexnuclear Mn( iii ) complex having [Mn 6 O 2 ]-core with oximato form of Oxm-57 as main building block. The magnetic properties of [Mn( iii ) 6 ]- Oxm-57 complex reveals antiferromagnetic exchange interactions with spin value S = 4 ground state and a population of low-lying excited states.…”

New members of the [Mn6/oxime] family and analogues with converging [Mn3] planes

“…Data collection parameters and structure solution and refinement details are listed in Table 1. Table 1 Crystal and structure refinement data for complexes 1 -5 [35], with the main difference in the latter complex being the presence of two μ4-O 2groups (vs. one in clusters 1 and 2). In Figure 4, the metallic cores of all three types of clusters are given, and it becomes apparent that Type I and Type II complexes are closely related, while Type III clusters are so distorted that the connectivity between the two triangular units is completely different.…”

“…Besides the scientific interest that such molecules possess, it has been proposed that they may be used in various technological applications, such as in computer magnetic storage, in magnetic resonance imaging as contrast agents, and in cooling processes [23,24]. Manganese oximate cluster chemistry has afforded a large family of compounds that function as SMMs; a series of complexes with general formulae [Mn III xO2(R-sao)x(O2CR)1-2(L) [4][5][6] (R= H, Me, Et, Ph, etc; L= solvent and x = 3 or 6) were synthesized and characterized [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], with two representative members of this family that function as SMMs being…”