Supramolecular interactions between chiral ions: Synthesis and characterization of [MII(bpy)3][VO(O2)(ox)(bpy)]⋅7H2O (M=Fe and Ni)

Heterometallic Copper-Vanadium Compounds: Crystal Structures of Polymers [Cu(im)4(V2O4(mand)2)] n and [Cu(im)4(V2O4((S)-mand)2)] n ·2nH2O (im = imidazole, mand = mandelato2-)

ABSTRACT

Two new 1D polymeric heterometallic copper-vanadium compounds were prepared. The polymers are constructed from [Cu(im)₄]²⁺ cations that are coordinated to two terminal oxido ligands of [V₂O₄(mand)₂]^2- anions. The stronger coordination in [Cu(im)₄V₂O₄(mand)₂] _n (1) that contains the racemic mandelato ligand is manifested by a shorter Cu‒O bond distance 2.4095(12) Å, while the weaker interaction in [Cu(im)₄(V₂O₄((S)-mand)₂)] _n ·2nH₂O (2) is exhibited by Cu‒O bond distances 2.4547(16) Å and 2.5413(16) Å. The vanadate anion in compound 2 carries only the (S)-enantiomer of the initial mandelic acid and differs from the anion in 1 in parallel cis orientation of the phenyl groups of the mandelato ligand. FT-IR spectroscopy was used for the confirmation of the coordination mode of mandelato ligand. Strong bands corresponding to the vibrations of carboxyl groups can be observed around 1650 and at 1344 cm^-1. The stretching vibration of deprotonated hydroxyl group in the mandelato ligand occurs at 1045 and 1065 cm^-1 for 1 and 2, respectively. In addition, the very strong, characteristic band corresponding to ν(V=O) vibration can be observed at 931 cm^-1 for 1 and 925 cm^-1 for 2, as well as in Raman spectrum.

GRAPHIC ABSTRACT

The polymeric structures of two new vanadium-copper heterometallic complexes are constructed from [Cu(imidazole)₄]²⁺ cations that are coordinated to two terminal oxido ligands of [V₂O₄(mandelato)₂]^2- anions with different orientation of the phenyl groups depending on the chirality of the mandelato ligand.

Low-dimensional compounds containing cyanide groups. XXV. Synthesis, spectroscopic properties and crystal structures of two ionic iron(II) complexes with tricyanomethanide: tris(1,10-phenanthroline-κ(2)N,N')iron(II) bis(tricyanomethanide) and tris(2,2'-bipyridine-κ(2)N,N')iron(II) bis(tricyanomethanide) sesquihydrate

Two new diamagnetic coordination compounds, [Fe(phen)3][C(CN)3]2, (I), and [Fe(bpy)3][C(CN)3]2·1.5H2O, (II), have been synthesized and characterized by single-crystal X-ray diffraction analysis, and IR and UV-Vis spectroscopy (phen is 1,10-phenanthroline, C12H8N2, and bpy is 2,2'-bipyridine, C10H8N2). Both compounds are ionic with distorted octahedral [Fe(phen)3](2+) or [Fe(bpy)3](2+) complex cations, with average Fe-N distances of 1.977 (2) and 1.971 (3) Å, respectively, and two uncoordinated planar tricyanomethanide, or [C(CN)3](-), counter-anions balancing the positive charges of the cations. Solvent water molecules and tcm anions in (II) are linked via O-H...N hydrogen bonds into negatively charged layers and the interlayer space is filled by [Fe(bpy)3](2+) cations. The structures of (I) and (II) are stabilized by π-π interactions between the stacked aromatic rings of the phen ligands of two adjacent cations and by O-H...N hydrogen bonds, respectively, and also by π-π stacking interactions between phen and tcm units in (I).