An [FeIII34] Molecular Metal Oxide

Abstract

The dissolution of anhydrous iron bromide in am ixture of pyridine and acetonitrile,i nt he presence of an organic amine,results in the formation of an [Fe 34 ]metal oxide molecule,s tructurally characterised by alternate layers of tetrahedral and octahedral Fe III ions connected by oxide and hydroxide ions.T he outer shell of the complex is capped by ac ombination of pyridine molecules and bromide ions. Magnetic data, measured at temperatures as lowa s0 .4 Ka nd fields up to 35 T, reveal competing antiferromagnetic exchange interactions;DFT calculations showing that the magnitudes of the coupling constants are highly dependent on both the Fe-O-Fe angles and Fe À Od istances.T he simplicity of the synthetic methodology,and the structural similarity between [Fe 34 ], bulk iron oxides,p revious Fe III -oxo cages,a nd polyoxometalates (POMs), hints that muchl arger molecular Fe III oxides can be made.

A New Tetradentate Mixed Aza-Thioether Macrocycle and Its Complexation Behavior towards Fe(II), Ni(II) and Cu(II) Ions

“…The Cu-N bond distances of 3(ClO 4 ) 2 (1.950(3)-1.963(3) Å) are comparable to that in [Cu( [15]ane(phenN 2 )S 2 )(ClO 4 )] + (1.956(5) Å) [47]. On the other hand, the Cu-S bond distances in 3(ClO 4 ) 2 (2.292(1)-2.296(1) Å) are shorter than those in [Cu( [15]ane(phenN 2 )S 2 )(ClO 4 )] + (2.347(2) Å). This again reflects the restricted flexibility of the shorter aliphatic linker in [13]ane(phenN 2 )S 2 .…”

“…The Cu atom is found to be located above the mean plane constructed by the four coordinating atoms of [13]ane(phenN 2 )S 2 by 0.444 Å. The Cu-N bond distances of 3(ClO 4 ) 2 (1.950(3)-1.963(3) Å) are comparable to that in [Cu( [15]ane(phenN 2 )S 2 )(ClO 4 )] + (1.956(5) Å) [47]. On the other hand, the Cu-S bond distances in 3(ClO 4 ) 2 (2.292(1)-2.296(1) Å) are shorter than those in [Cu( [15]ane(phenN 2 )S 2 )(ClO 4 )] + (2.347(2) Å).…”

“…τ ≈ 0 and τ ≈ 1 for square planar and tetrahedral geometry, respectively, in four-coordinated compounds). In comparison with [Ni( [15] -S). These observations are probably originated from the restricted flexibility of the shorter aliphatic linker in [13]ane(phenN 2 )S 2 .…”

“…Coordination chemistry of first-row transition metal ions has attracted considerable attention for decades due to their high biological relevance. Not only do the coordination complexes serve as models to study biologically related metallomolecules, but they also provide insights into biomimetic designs [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. Among a reservoir of ligand designs, macrocycles have been demonstrated to be a valuable type of auxiliary ligand for these studies because (1) many macrocycles are incorporated in naturally-occurring metalloproteins and metalloenzymes, such as porphyrin in haemoglobin and corrin in vitamin B 12 , and (2) the properties of the derived metal complexes can be modulated via modification in the ring size and donor atoms on the macrocyclic ligands.…”