A Nonanuclear Iron(II) Single‐Molecule Magnet

Abstract

Single-molecule magnets (SMMs) have attracted considerable interest in recent times.[1] Although molecular, these species display superparamagnetic properties normally seen in mesoscale magnetic particles and thus can function as magnetizable entities below their blocking temperature. As a consequence, they represent the ultimate limit of miniaturization for data-storage domains in magnetic media.[1] Quantum tunneling of magnetization (QTM) effects [2] have led to the proposal that SMMs could be exploited as qubits in quantum computing.[3] The existence of SMM behavior was first noted ten years ago in the complex [Mn 12 O 12 (O 2 CMe) 16 (H 2 O) 4 ] (S = 10, D = À0.50 cm À1 = À0.72 K), [4] which represents the most extensively studied SMM.[1] Another compound that has been investigated for its SMM behavior is [{Fe 8 O 2 (OH) 12 (tacn) 6 }Br 7 ·H 2 O]Br·8 H 2 O (tacn = 1,4,7-triaza-

Secondary building units, nets and bonding in the chemistry of metal–organic frameworks

“…69). 167 A square-antiprism SBU is composed in the same manner as the twisted rectangular prism described above (Fig. 70).…”

Coordination Dependence of Magnetic Properties within a Family of Related [FeII2] Complexes of a Triazine‐Based Ligand

“…Slow evaporation of the solvent from the reaction mixture resulted in the formation of light green crystals of a new complex, the formula of which was confirmed to be [Fe 2 (dpyatriz) 2 (2) by single-crystal X-ray diffraction (see below) and elemental analysis. Thus, Equation (1) could serve to describe the formation of 2, only replacing CH 3 CN and ClO 4 -by CH 3 OH and BF 4 -, respectively. In contrast with 1, however, this compound was found to be stable in air.…”

“…[2,3] Another example is the exploitation of the potential of certain ligand systems to propagate ferromagnetic interactions between paramagnetic metals with the aim of generating high-spin molecules or magnetically ordered materials. Among such ligand frameworks are (end-on) N 3 -groups [4,5] and m-phenylene links (the latter usually facilitating ferromagnetism through a spin-polarisation mechanism). [6,7] Even more desirable in the preparation of versatile functional materials are systems capable of exhibiting different properties by introducing subtle changes of environment or of chemical nature.…”

“…The versatility of this ligand has been demonstrated by the diversity of some of the coordination compounds obtained. Thus, the reaction with Cu(NO 3 ) 2 produces a magnetically exchanged 1D coordination polymer, [9] whereas a similar reaction involving CuCl 2 allows the characterisation of the trinuclear discrete molecule [(CuCl) 3 (dpyatriz) 2 ]-[CuCl 4 ]Cl. [10] The same process, using Zn(NO 3 ) 2 , leads to the formation of the tetranuclear molecular species [Zn 4 (dpyatriz) 2 (NO 3 ) 8 ].…”

A novel high-spin heterometallic Ni12K4cluster incorporating large Ni–azide circles and an in situ cyanomethylated di-2-pyridyl ketone

“…The acetonitrile and dpk in the synthesis of 1 prefer undergoing an unprecedented reaction (Scheme S1{), different from previously reported phenomena. [6][7][8] Moreover, our synthetic route to b-hydroxy nitriles suggests that it may be potentially useful for the addition of nitrile anions to cluster is located on a crystallographic inversion centre. There are six crystallographically unique (but chemically similar) Ni atoms, two unique K atoms, one carbonato, three unique dpkMeCN-H ligands, six unique N 3 2 ions, three unique acetates and one aqua ligand in the structure of 1 (Fig.…”