cyclo-Tetra-μ-fluorido-1:2κ2 F;2:3κ2 F;3:4κ2 F;1:4κ2 F-octa­nitrato-1κ8 O,O′;3κ8 O,O′-tetra­kis­(1,10-phenanthroline)-2κ4 N,N′;4κ4 N,N′-2,4-dichromium(III)-1,3-dineodymium(III) methanol tetra­solvate monohydrate

In the title compound, [Cr(2)Nd(2)F(4)(NO(2))(8)(C(12)H(8)N(2))(4)]·4CH(3)OH·H(2)O, two cis-difluoridobis(1,10-phenanthroline)chromium(III) fragments containing octa-hedrally coordinated chromium(III) bridge via fluoride ions to two tetra-nitratoneodymate(III) fragments, forming an uncharged tetra-nuclear 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 tetra-nuclear complex is centered at a fourfold rotoinversion axis, with the Cr and Nd atoms situated on two perpendicular twofold rotation axes. The uncoordinated water mol-ecule resides on a fourfold rotation axis. The four methanol solvent mol-ecules 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.