Tetraguanidinium bis[citrato(3−)]cuprate(II) dihydrate

Abstract

The asymmetric unit of the title compound, (CH6N3)4[Cu(C6H5O7)2]·2H2O, contains one-half of a centrosymmetric CuII complex anion, two guanidinium cations and a water mol­ecule. The CuII ion, lying on a crystallographic inversion center, is hexa­coordinated with two citrate anions in a distorted octahedral geometry. An intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal structure, mol­ecules are linked into a three-dimensional framework by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds.

Citric Acid as Multidentate Flexible Ligand for Multinuclear Late‐3 d‐Metal Complexes and Single‐Molecule Magnets

“…[26] CitH 2 ligands are only found in [M II (citH 2 ) 2 ] 2À (M=Fe [27] and Zn [28] ). The [M II (citH) 2 ] 4À structure has been reported for M=Mn, [29] Co, [30,31] Cu, [32,33] and Zn [34,35] with different countercations. [Fe III (citH*)(cit)] 4À is a rare case having citH* 3À ligand in late-3d-metal complexes, [12] which can be attributed to the high Lewis acidity of Fe(III).…”