cyclo-Tetra-μ-fluorido-1:2κ2F;2:3κ2F;3:4κ2F;1:4κ2F-octanitrato-1κ8O,O′;3κ8O,O′-tetrakis(1,10-phenanthroline)-2κ4N,N′;4κ4N,N′-2,4-dichromium(III)-1,3-dineodymium(III) methanol tetrasolvate monohydrate

Abstract

In the title compound, [Cr2Nd2F4(NO2)8(C12H8N2)4]·4CH3OH·H2O, two cis-difluoridobis(1,10-phenanthroline)chromium(III) fragments containing octahedrally coordinated chromium(III) bridge via fluoride ions to two tetranitratoneodymate(III) fragments, forming an uncharged tetranuclear square-like core. The fluoride bridges are fairly linear, with Cr—F—Nd angles of 168.74 (8)°. Cr—F bond lengths are 1.8815 (15) Å, slightly elongated compared to those of the parent chromium(III) complex, which has bond lengths ranging from 1.8444 (10) to 1.8621 (10) Å. The tetranuclear complex is centered at a fourfold rotoinversion axis, with the Cr and Nd atoms situated on two perpendicular twofold rotation axes. The uncoordinated water molecule resides on a fourfold rotation axis. The four methanol solvent molecules are located around this axis, forming a cyclic hydrogen-bonded arrangement. The title compound is the first structurally characterized example of unsupported fluoride bridges between lanthanide and transition metal ions.