Crystal and molecular structures of black (cat)(2)[Fe-III(eta(3)-dipic)(NCS)(3)] (cat = C9H7NH; C10H9NH); (HNC10H8NH)[Fe-III(dipic)(NCS)(3)], and (C6H7NH)[Fe-III(eta(3)-dipic)(H2O)(NCS)(2)] (dipic pyridine-2,6-dicarboxylate (-2); C9H7NH = quinolinium; C10H9NH = 3-methylisoquinolinium; HNC10H8NH = 4,4-bipyridinium; C6H7NH = 2-picolinium) were determinated. These complexes crystallized in monoclinic crystal class. Each Fe(III) atom is six coordinated. The octahedron is build up unsymmetrically, one half side is creates by terdentate dipic-O-1,N-2,O-3 ligand and the other half by three monodentate (NCS)(3) or (NCS)(2)(H2O) donor ligands. The terdentate dipic-O-1,N-2,O-3 ligand forms a pair of five-membered metallocyclic rings with the common central N-2 atom of pyridine ((OC2NC3O)-O-1-N-2-O-2) with the mean value of O-Fe-N bite angles of 75.5 degrees. The mean value of trans O-1-Fe3O bond angles is 150.8 degrees in complexes with an inner coordination spheres FeO2N4 and FeO3N3. The mean value of sum of all three ((Fe-O-1) + (Fe-N-2) + (Fe-O-3)) bond distances is 6.217 angstrom (FeO2N4) and 6.183 angstrom (FeO3N3). The opposite side in FeO2N4 is created by three monodentate NCS groups with the sum of Fe-N(x3) bond distances of 6.050 angstrom and in the FeO3N3 two NCS groups with water create opposite side with the sum of (Fe-N(x2) + Fe-O) bond distances of 6.183 angstrom. One polymorph of complex (C10H9NH)(2)[Fe-III(dipic)(NCS)(3)] contains two crystallographically independent molecules differ mostly by degree of distortion in Fe-L bond distances and L-Fe-L bond angles and are examples of distortion isomerism. The data of the complexes are compare and discuses with the data of familiar iron(III) complexes. The intermolecular interactions of all compounds are studied by Hirshfeld surface analysis. (C) 2020 Elsevier Ltd. All rights reserved.

Abstract The new iron(II) complex [Fe(bpta)2(EtOH)2(NCS)2] (bpta = 3,3’-(1,2,4-thiadiazole-3,5-diyl) dipyridine; EtOH = ethanol) has been prepared by refluxing Fe(NCS)3 or Fe(NCS)2 with thionicotinamide in an ethanol solution and characterized by elemental analysis, infrared spectroscopy, thermal decomposition and X-ray structural analysis. The characterized compound is a mixture of three regioisomers resulting from differential coordination by the 3- and 5-position 2-pyridyl groups. The bpta ligand was generated in situ by the oxidation dimerization of thionicotinamide. X-ray single-crystal diffraction revealed that the crystal structure is centrosymmetric and the complex crystallizes in the triclinic space group P-1. The iron(II) atom lies in the centre of symmetry and it is octahedrally coordinated by two nitrogen atoms from two thiocyanate anions and two oxygen atoms from ethanol molecules in the equatorial plane and two nitrogen atoms of pyridine rings from two bpta ligands in the axial positions. This complex represents the second example of metal complex with bpta.

New ionic manganese(II/III), manganese(III) and iron(II/III) complexes of the formula [MnII(H2O)2(phen)2]{[MnIII(dipic)2]}2·7H2O, (dmphenH)[MnIII(dipic)2]·2H2O, (2,2′-bipyH)[MnIII(dipic)2]·3H2O, (4,4′-bipyH)[MnIII(dipic)2]·4H2O, [FeII(phen)3]{[FeIII(dipic)2]}2·4.83H2O and [FeII(2,2′-bipy)3]{[FeIII(dipic)2]}2·6.11H2O where dipic2−=pyridine-2,6-dicarboxylate anion, phen=1,10-phenanthroline, dmphenH=2,9-dimethyl-1,10-phenanthrolinium cation, 2,2′-bipyH=2-(2-pyridyl)pyridinium cation, 4,4′-bipyH=4-(4-pyridyl)pyridinium cation, have been prepared and characterized by the single-crystal X-ray structure analysis, infrared spectroscopy, and by magnetic susceptibility and magnetization measurements. A zero field splitting was found in the Mn(III) dipicolinates while an antiferromagnetic exchange interaction was present in the Fe(III) dipicolinates.

Four ionic iron(III) and manganese(III) dipicolinato complexes of the formula (2-pymeH) [FeIII(dipic)2]⋅[FeIII(H2O)2Cl(dipic)]⋅2H2O, (3-pymeH)[MnIII(dipic)2]⋅1.5H2O, (4-pymeH)[FeIII(dipic)2]⋅2H2O and (4-pymeH)[MnIII(dipic)2]⋅2H2O, where H2dipic = pyridine-2,6-dicarboxylic acid, 2-pyme = 2-pyridinemethanol, 3-pyme = 3-pyridinemethanol, 4-pyme = 4-pyridinemethanol, have been prepared and characterized by the single-crystal X-ray structure analysis, infrared spectroscopy and magnetic measurements. The magnetic data were fitted to a zero-field splitting model revealing a slight magnetic anisotropy for Mn(III) systems. The molecular field correction was consistently formulated and included in the analysis for both, magnetic susceptibility and magnetization data.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The new iron(II) complex [Fe(NCS)(2)(CH3OH)(2)(bpta)(2)] (bpta = 3,5-bis(3-pyridyl)-1,2,4-thiadiazole) has been prepared by refluxing Fe(NCS)(3) or Fe(NCS)(2) with thionicotinamide in methanol solution. It is supposed that the bpta ligand is generated in situ by the oxidative dimerization of thionicotinamide. The complex was characterized by X-ray structural analysis at 150 and 293 K, elemental analysis, spectral and magnetic measurements. The compound crystallizes in the monoclinic P2(1) space group, with unit cell parameters at 293 K: a = 7.869(2), b = 17.056(3), c = 12.637(3) angstrom, beta = 102.88(1)degrees. The crystal structure analysis showed that the iron atom has a distorted octahedral environment with FeN4O2 chromophore. Iron atom is coordinated by two nitrogen atoms from NCS ions, by two oxygen atoms from methanol molecules in the equatorial plane and by two nitrogen atoms of pyridine rings from dpta ligands in axial positions. The crystal lattice forms 2D supramolecular network which is stabilized by a system of hydrogen bonds and pi-pi stacking interactions. Variable-temperature magnetic susceptibility data in the temperature range 1.8-300 K show that the octahedral iron(II) is high-spin S = 2(T-5(2g)) and as a result effects due to zero-field splitting are anticipated at low temperatures. Structural parameters and infrared spectra of similar complexes are compared and discussed. (C) 2014 Elsevier B. V. All rights reserved.

A novel tetranuclear manganese(II/III) complex with anions of pyridine-2,6-dicarboxylic acid (dipicolinic acid) has been synthesised and magneto-structurally characterised. The crystal structure of [MnII2MnIII2(dipic)6(H2O)4]·2CH3OH·4H2O has been determined by single-crystal X-ray diffraction. The tetranuclear complex molecule [MnII2MnIII2(dipic)6(H2O)4] is centrosymmetric and two manganese(II) and two manganese(III) atoms are bridged by four dipicolinate ligands. The complex molecules and uncoordinated water and methanol molecules are connected through hydrogen bonds and they form a 3D supramolecular hydrogen-bonding network.

Four manganese(III) and iron(III) dipicolinato (dipic) complexes were synthetized. The structures show distorted octahedral chromophores MN2O4 (M=Mn(III), Fe(III)). The magnetic data were fitted to a zero-field splitting model revealing a slight magnetic anisotropy.