Tri- and tetranuclear heteropivalate complexes with core {Fe2Ni O} (x = 1, 2): Synthesis, structure, magnetic and thermal properties

Coordination Polymer Based on a Triangular Carboxylate Core {Fe(μ3-O)(μ-O2CR)6} and an Aliphatic Diamine

Interaction of the pre-organized complex of iron(II) trimethylacetate and 1,10-phenanthroline (phen) [Fe2(piv)4(phen)2] (1) (piv = (Me)3CCO2-)) with 1,6-diaminohexane (dahx) in anhydrous acetonitrile yielded a 1D coordination polymer [Fe3O(piv)6(dahx)1.5]n (2) and an organic salt of pivalic acid (H2dahx)(piv)2 (3). The structure of the obtained compounds was determined by single-crystal X-ray diffraction analysis. The phase purity of the complexes was determined by powder X-ray diffraction analysis. According to the single-crystal X-ray analysis, coordination polymer 2 is formed due to the binding of a triangular carboxylate core {Fe3(μ3-O)(μ-piv)6} with an aliphatic diamine ligand. Thermal behavior was investigated for compounds 1 and 2 in an argon atmosphere.

Pentanuclear clusters resembling the cubane-dangler connectivity in the native oxygen-evolving center of photosystem II

A series of pentametallic "cubane-plus-dangler" complexes have been target synthesized. Among them, the [Fe3Ni2] aggregate strongly resembled the native oxygen-evolving center by mimicking the "cubane-plus-dangler" skeleton, the aqua binding site, and the connectivity between the pendent ion and the parent cubane. Our synthetic strategy that uses tri-substituted methanol as the "cubane-generator" and carboxylate as the pendant ligand provides a feasible approach for accessing model compounds of biological catalyst systems.

A new heterometallic pivalate {Fe8Cd} complex as an example of unusual "ferric wheel" molecular self-assembly

The interaction of the pivalate complexes of iron(iii), [Fe3O(Piv)6(H2O)3]·HPiv, and cadmium(ii), [Cd(Piv)2], in Et2O resulted in one more type of "ferric wheel" family complex, namely [Fe8(Piv)16{Cd(Piv)2}(μ-OH)8]·Et2O (1). The complex is an octanuclear iron(iii) wheel with a {Cd(Piv)2} moiety asymmetrically incorporated into the ring.

Some aspects of the formation and structural features of low nuclearity heterometallic carboxylates

Heterometallic carboxylate complexes are of paramount interest in pure and applied coordination chemistry. Despite that plurality of such type compounds have been published to date, synthetic aspects of their chemistry often remain in the shadow of intriguing physical properties manifesting by these species. Present review summarizes reliable data on direct synthesis of low nuclearity molecular compounds as well as coordination polymers on their base with carboxylate-bridged {M2Mg} (M = Co2+, Ni2+, Cd2+), {M2Li2} (M = Co2+, Ni2+, Zn2+, VO2+), {M2Ln2} and {M2Ln} (M = Cu2+, Zn2+, Co2+) metal cores. Structural features and stabilization factors are considered and principal outcomes are confirmed by quantum-chemical calculations. Particular attention is paid to consideration of ligand-exchange reactions that allow controllable modification of heterometallic metal core under mild conditions giving diverse molecular complexes with modified ligand environment or Metal-Organic Frameworks with permanent porosity.