557-42-6Relevant academic research and scientific papers
Tripodal ligands: Design of distorted coordination polyhedra in biomimetic metal complexes. Crystal structures of [Zn(SCN)(ntb)](SCN) · iPrpOH and [Fe(acac)(ntb)](ClO4)2 · 2 CH2Cl2 · iPrpOH, ntb = N-tris(2-benzimidazolylmethyl)amine
Nazikkol, Cetin,Wegner, Rainer,Bremer, Johannes,Krebs, Bernt
, p. 329 - 336 (1996)
The tripodal ligand N-tris(2-benzimidazolylmethyl)amine (ntb) was used for the preparation of zinc(II) and iron(III) complexes, [Zn(SCN)(ntb)](SCN) · iPrpOH (1) and [Fe(acac)(ntb)](ClO4)2 · 2 CH2Cl2 · iPrpOH (2). 1 has a highly distorted trigonal-bipyramidal ZnN5 coordination geometry. The donor atoms are nitrogens of one amine, three benzimidazoles and one SCN-. A striking feature of the complex is the length of the Zn-Namine bond of 2.539(6) A. The octahedral N4O2 coordination sphere of the iron in 2 is less distorted than that of the zinc in 1. The metal is surrounded by an amine and three benzimidazole nitrogens of the ligand and two oxygens of the bidentate acetylacetonate co-ligand. The Fe-O bond lengths differ by about 0.1 A. As for the unusual long Zn-N bond in 1 this is a result of a trans effect. 1 crystallizes in the space group P1 with: a = 9.530(1) A, b = 13.402(1) A, c = 13.578(2) A, α = 98.83(1), β = 95.19(1), γ = 101.21(1)°, Z = 2; 2 is also triclinic, space group P1, with: a = 9.875(6) A, b = 12.929(10) A, c = 18.635(15) A, α = 94.95(8)°, β = 101.01(6)°, γ = 111.09(4)°, Z = 2. Johann Ambrosius Barth 1996.
Cd(II) and Zn(II) thiocyanate coordination compounds with 3-ethylpyridine: Synthesis, crystal structures and properties
Neumann, Tristan,Jess, Inke,Dos Santos Cunha, Cesar,Terraschke, Huayna,N?ther, Christian
, p. 115 - 123 (2018)
Reaction of Cd(NCS)2 and Zn(NCS)2 with 3-ethylpyridine leads to the formation of compounds of compositions M(NCS)2(3-ethylpyridine)4 (M=Cd, 1-Cd; Zn, 1-Zn) and M(NCS)2(3-ethylpyridine)2 (M=Cd, 2-Cd; Zn, 2-Zn). 1-Cd and 1-Zn are isotypic and form discrete complexes in which the metal cations are octahedrally coordinated by two trans-coordinating N-bonded thiocyanate anions and four 3-ethylpyridine co-ligands. In 2-Cd the cations are also octahedrally coordinated but linked into chains by pairs of μ-1,3-bridging anionic ligands. 2-Zn is built up of discrete complexes, in which the Zn cation is tetrahedrally coordinated by two N-bonded thiocyanate anions and two 3-ethylpyridine co-ligands. Compounds 1-Cd, 2-Cd and 2-Zn can be prepared in a pure state, whereas 1-Zn is unstable and transforms on storage into 2-Zn. If 1-Cd and 1-Zn are heated, a transformation into 2-Cd, respectively 2-Zn is observed. Luminescence measurements reveal that 1-Cd, 2-Cd and 2-Zn emit light in the blue spectral range with maxima at, respectively, 21724, 21654 and 22055 cm-1, assigned to ligand-based luminescence.
Crystal structure solid-state cross polarization magic angle spinning 13C NMR correlation in luminescent d10 metal-organic frameworks constructed with the 1,2-bis(1,2,4-triazol-4-yl)ethane ligand
Habib, Hesham A.,Hoffmann, Anke,Hopped, Henning A.,Sieinfeld, Gunther,Janiak, Christoph
, p. 2166 - 2180 (2009)
Hydrothermal reactions of 1,2-bis(1,2,4-triazol-4-yl)ethane (btre) with copper(ll), zinc(ll), and cadmium(ll) salts have yielded the dinuclear complexes [Zn2CI4(μ2-btre)2] (1) and [Zn2Br4(μ
Trimorphism of Zn(NCS)2(4-dimethylaminopyridine)2: Crystal Structures, Thermodynamic Relations, and Comparison with the Co(II) Polymorphs
Neumann, Tristan,Jess, Inke,Germann, Luzia S.,Dinnebier, Robert E.,N?ther, Christian
, p. 1134 - 1143 (2019)
Reaction of Zn(NCS)2 with 4-dimethylaminopyridine (DMAP) leads to the formation of three polymorphic modifications of Zn(NCS)2(DMAP)2 (I-Zn, II-Zn, and III-Zn), of which only the crystal structure of I-Zn is reported in literature. In all three modifications the Zn(II) cations are tetrahedrally coordinated by two terminal N-bonded thiocyanate anions and two DMAP ligands forming discrete complexes, which differ in the dihedral angle between the DMAP ring planes and the arrangement of the complexes in the crystals. All three modifications show melting, and the thermodynamic relations and the transition behavior were investigated by temperature-dependent X-ray powder diffraction, differential scanning calorimetry, thermomicroscopy, and solvent-mediated conversion experiments. These reveal that I-Zn and II-Zn as well as II-Zn and III-Zn are related by enantiotropism, whereas I-Zn and III-Zn are related by monotropism. The thermodynamic transition temperature between I-Zn and II-Zn is much lower than that between the isotypic Co(II) modifications I-Co and II-Co reported recently.
Zn(NCS)2-3-cyanopyridine Coordination Compounds: Synthesis, Crystal Structures, and Thermal Properties
Jochim, Aleksej,Jess, Inke,N?ther, Christian
, p. 212 - 218 (2019)
The reaction of different stoichiometric amounts of Zn(NCS)2 with 3-cyanopyridine in different solvents leads to the formation of several new coordination compounds, which were structurally characterized and investigated for their thermal behavior. In Zn(NCS)2(3-cyanopyridine)4 (1) and Zn(NCS)2(3-cyanopyridine)2(H2O)2·(3-cyanopyridine)2 (2) the zinc cations are octahedrally coordinated by two terminally N-bonded thiocyanate anions and four 3-cyanopyridine (1) or two 3-cyanopyridine and two water molecules (2) within slightly distorted octahedra. Zn(NCS)2(3-cyanopyridine)2 (3) and Zn(NCS)2(3-cyanopyridine)2·(H2O)0.5 (3-H2O) also form discrete complexes but with tetrahedrally coordinated Zn cations. Upon heating compound 1 decomposes without the formation of any intermediate compound. In contrast, compound 2 loses the water molecules in the first step and transforms into compound 1. Surprisingly, upon further heating a second TG step is observed, in which compound 3 is formed as an intermediate, which is not observed if compound 1 is heated directly. The tetrahedral complex 3 melts leading to the formation of an amorphous phase. If the hemihydrate 3-H2O is heated, it transforms into 3 via melting and crystallization but there are hints that a metastable phase might form as intermediate on water removal.
Zinc coordination polymers with 1-(3-aminopropyl)-imidazole as bridging bidentate unit
Arnold, Ulrich,Walter, Olaf,D?ring, Manfred
, p. 327 - 333 (2006)
The reaction of Zn(SCN)2 with one or two equivalents of 1-(3-aminopropyl)-imidazole (api) yields the coordination polymers [Zn(SCN) 2(api)]n (1) and [Zn(SCN)2(api) 2]n (2), respectively. Single-crystal X-ray diffraction analysis reveals one-dimensional polymeric chain structures for both compounds. The structure of 1 consists of tetrahedral Zn(SCN)2(api)2 units linked by one molecule 1-aminopropyl imidazole in an unsymmetric mode, i.e., each metal center is coordinated by an imidazole nitrogen as well as a nitrogen of the aminopropyl group. The metal ions in 2 display an octahedral coordination geometry with each Zn(SCN)2(api)2 unit linked by two molecules of the imidazole, thus, exhibiting two imidazole and two amino groups in the coordination sphere. The polymers were further characterized by IR-, 1H NMR- and 13C NMR-spectroscopy.
Selective Synthesis and Thermodynamic Relations of Polymorphic Co(NCS)2-4-Dimethylaminopyridine Coordination Compounds
Neumann, Tristan,Jess, Inke,Pielnhofer, Florian,N?ther, Christian
, p. 4972 - 4981 (2018)
Reaction of Co(NCS)2 with 4-dimethylaminopyridine (DMAP) leads to the formation of four new compounds. The crystal structures of Co(NCS)2(DMAP)2(H2O)2·2H2O (1), Co(NCS)2(DMAP)2(MeOH)2 (2) and Co(NCS)2(DMAP)2(MeCN)2 (3) consist of discrete simple solvato complexes in which the Co cations are octahedrally coordinated by two terminally N-bonded thiocyanate anions, two DMAP ligands as well as two solvato ligands. Co(NCS)2(DMAP)2 (4/II) also forms discrete complexes, but the Co cations are tetrahedral coordinated by two anionic ligands and two DMAP ligands. Upon heating, the hydrate 1 transforms into 4/II, whereas the methanol solvate 2 transforms into a new polymorphic modification of Co(NCS)2(DMAP)2 (4/I). For structure determination the corresponding Zn(NCS)2 compound was prepared that is isotypic to 4/I. Solvent mediated conversion experiments prove that 4/II represents the thermodynamic stable form at room-temperature and density functional theory (DFT) calculations indicate that this form is also stable at 0 K. Upon heating both modifications show melting with the higher melting polymorph 4/I having the lower melting enthalpy. Temperature dependent X-ray powder diffraction shows that 4/II transforms into 4/I upon heating. All experimental results indicate, that both modifications are related by enantiotropism.
New fluorescent compounds based on zinc thiocyanate: Influence of structure on spectral properties
Swiatkowski, Marcin,Kruszynski, Rafal
, p. 1144 - 1150 (2017)
New coordination compounds based on zinc thiocyanate, namely (acetone thiosemicarbazone- κ2N1,S)bis(isothiocyanato-κN)zinc(II) monohydrate, [Zn(NCS)2- (C4H9N3S)].H2O, (I), and diaquatetrakis(urea-κO)zinc(II) tetrakis(isothiocyanato- κN)zinc(II), [Zn(CH4N2O)4(H2O)2][Zn(NCS)4], (II), were synthesized and studied by UVVis, fluorescence and IR spectroscopy. Coordination salt (II) forms a rare system composed of two different coordination units of the same metal and it is the first example of a compound with two completely different zinc coordination units, of which one contains a tetrakis(urea)zinc unit. Both (I) and (II) possess fluorescence properties and produce blue and green emissions, respectively, upon irradiation with violet light. The spectral properties were correlated with the observed molecular and supramolecular structures. The acetone thiosemicarbazone ligand of (I) exhibits (upon coordination) red shifts of bands corresponding to N=C and C=S stretching vibration frequencies, which is not typical for chelating molecules.
Synthesis, Crystal Structures, and Properties of M(NCS)2-3-aminomethylpyridine Coordination Compounds (M = Cd, Zn)
Neumann, Tristan,Germann, Luzia S.,Moudrakovski, Igor,Dinnebier, Robert E.,dos Santos Cunha, Cesar,Terraschke, Huayna,N?ther, Christian
, p. 1904 - 1912 (2017)
Reaction of Cd(NCS)2 or Zn(NCS)2 with 3-aminomethylpyridine (3-AMPy) leads to the formation of five compounds with the compositions [Cd(NCS)2(3-AMPy)2·(3-AMPy)]n (1-Cd), [M(NCS)2(3-AMPy)2]n [M = Cd (2-Cd), Zn (2-Zn)] [Cd(NCS)2(3-AMPy)]n (3-Cd), and [Zn(NCS)2(3-AMPy)]2 (3-Zn). In 1-Cd the Cd cations are linked by the 3-AMPy ligands into layers that consist of rings, built up of four Cd cations and four 3-AMPy ligands. These layers are stacked to form channels, in which the 3-AMPy solvate molecules are located. In the isotypic compounds 2-Cd and 2-Zn the metal cations are also linked into layers by the 3-AMPy ligands with an identical layer topology as that in 1-Cd, but a completely different conformation of the 3-AMPy ligand. In the most 3-AMPy deficient compound 3-Cd, the Cd cations are linked by μ-1,3-bridging thiocyanate anions and 3-AMPy ligands into chains, that are further connected into layers by additional anionic ligands. In 3-Zn two Zn cations are linked by pairs of 3-AMPy ligands into discrete dimers. Thermoanalysis and X-ray powder diffraction (XRPD) investigations show that upon heating 1-Cd transforms into 2-Cd and 2-Zn into 3-Zn. The compounds 2-Cd, 3-Cd, 2-Zn, and 3-Zn present ligand-based luminescence in the blue-green spectral range with maxima between 21276 and 21795 cm–1.
The influence of the metal cation and the N-donor ligand on the reactivity and structures of Cd and Zn coordination compounds with 3-bromopyridine and 3-chloropyridine
W?hlert, Susanne,Jess, Inke,N?ther, Christian
, p. 243 - 251 (2013)
Reaction of cadmium thiocyanate and zinc thiocyanate with an excess of 3-bromopyridine and 3-chloropyridine leads to single crystals of four coordination compounds of composition M(NCS)2(3-bromopyridine) 4 (M = Cd (Cd1-Br), Zn (Zn1-Br)) and M(NCS)2(3- chloropyridine)4 (M = Cd (Cd1-Cl), Zn (Zn1-Cl)). These compounds forms pairs of isotypic compounds (Cd1-Br and Zn1-Br in space group P-1 and Cd1-Cl and Zn1-Cl in space group C2/c) in which the metal cation are octahedral coordinated by two terminal thiocyanato anions and four neutral N-donor ligands into discrete complexes. If less N-donor ligands are used in the synthesis, compounds of composition M(NCS)2(3-bromopyridine)2 (M = Cd (Cd2-Br), Zn (Zn2-Br)) and M(NCS)2(3-chloropyridine)2 (M = Cd (Cd2-Cl), Zn (Zn2-Cl)) are obtained. In the crystal structure of the isotypic compounds Cd2-Br and Cd2-Cl (monoclinic space group P21/c) the metal cations are octahedral coordinated by two N-donor ligands and four thiocyanato anions and are linked into chains by the anionic ligands. In contrast, the Zn compounds Zn2-Br and Zn2-Cl are not isotypic but form similar discrete complexes in which the metal cations are tetrahedral coordinated by two terminal N-bonded thiocyanato anions and two neutral N-donor ligands. On heating compounds 1 half of the ligands are removed and a transformation into compounds 2 is observed. The structures and reactivity of these compounds are discussed and compared with those of related compounds.
