A new organic-inorganic hybrid salt pipéridinium trans-diaquabis(oxalato)chromate(III) tetrahydrate, (C 5 H 10 NH 2 )[Cr(C 2 O 4 ) 2 (H 2 O) 2 ]•4H 2 O (1), has been synthesized in water and characterized by FTIR and UV-Vis spectroscopies, elemental and thermal analyses and by single-crystal X-ray diffraction. 1 crystallizes in the orthorhombic non-centrosymmetric space group Cmc2 1 with the unit cell parameters a = 7.4329(3), b = 9.9356(5), c = 23.6756(11) Å, α = β = γ = 90˚, V = 1748.45(14) Å 3 and Z = 4. The structure of 1 consists of [Cr(C 2 O 4 ) 2 (H 2 O) 2 ] − mononuclear anions, piperidinium cations and uncoordinated water molecules. The Cr III ion in the complex [Cr(C 2 O 4 ) 2 (H 2 O) 2 ] − is coordinated in a slightly distorted octahedral environment by four O atoms from two chelating oxalate dianions in the equatorial plane, and two O atoms from trans-coordinated water molecules occupying the apical positions. In the crystal, N-H⋯O and O-H⋯O hydrogen bond interactions connect the components into a 3-D framework. The IR spectrum of 1 is consistent with the presence of the various molecular building constituents, namely oxalato and aqua ligands, piperidinium cations and solvent water molecules. The UV-Vis spectrum shows two absorption bands around 564 and 416 nm which are

A novel organic-inorganic chromium(III) hybrid salt, triethylammonium trans-diaquabis(oxalato-κ 2 O 1 ,O 2)chromate(III), (C 6 H 16 N)[Cr(C 2 O 4) 2 (H 2 O) 2 ] (1), has been synthesized in aqueous solution and characterized by elemental and thermal analyses, FTIR and UV-Vis spectroscopies, and by single crystal X-ray structure determination. Compound 1 crystallizes in the orthorhombic system, Pbcn space group with the unit cell parameters a = 11.1776(10), b = 7.6105(10), c = 17.5654(2) Å, α = β = γ = 90˚, V = 1494.24(3) Å 3 , Z = 4 and Z' = 1/2. The structure of 1 consists of [Cr(C 2 O 4) 2 (H 2 O) 2 ] − mononuclear anions and triethylammonium [(C 2 H 5) 3 NH] + cations. In the anionic unit, the Cr III ion is six coordinated, in a distorted octahedral geometry, by four equatorial O atoms of two oxalate anions acting as chelating ligands and two O atoms from trans-coordinated water molecules occupying the apical positions with longer metal-oxygen distances. In the solid, O-H … O and N-H … O intra and inter molecular hydrogen bonding interactions connect the components into a 3D network. The triethylammonium cations are disordered among two possible orientations with occupancies rates around 50% for C4, N1, C1a, C1b, C4 ii , N1 ii , C1a ii , C1b ii

Source of material-is six-coordinated in a slightly distorted octahedral coordination environment defined by two chelating bidentate oxalate anions in the equatorial plane and two aqua ligands in apical trans position (Fig.)