Crystal structures, magnetic properties, and absorption spectra of nickel(II) thiocyanato complexes: a comparison of different coordination geometries

2003 ◽  
Vol 81 (11) ◽  
pp. 1168-1179 ◽  
Author(s):  
Bruno Larue ◽  
Lan-Tâm Tran ◽  
Dominique Luneau ◽  
Christian Reber
Keyword(s):  
Magnetic Properties ◽  
Crystal Structures ◽  
Absorption Spectra ◽  
Exchange Coupling ◽  
Molecular Magnetism ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Space Group ◽  
Trigonal Bipyramidal ◽  
Ferromagnetic Interactions

Thiocyanatonickel(II) compounds with composition {(AsPh4)2[Ni(NCS)4]} 1, {(Cat)[Ni(NCS)4]} 2, {(AsPh4)4 [Ni2(NCS)8]} 3, {(Cat)2[Ni2(NCS)8]·2CH3NO2} 4, and {(Et4N)4[Ni(NCS)6]} 5 (Cat2+ = (p-xylylenebis(triphenyphosphonium))2+) were prepared. The crystal structures of compounds 1, 3, and 4 were determined. Compound 1 crystallizes in the monoclinic C2/c space group with a = 22.761(2) Å, b = 15.055(1) Å, c = 15.054(1) Å, β = 108.915(1)°, V = 4879.9(6) Å3, and Z = 4. Compound 3 crystallizes in the triclinic P–1 space group with a = 11.2183(6) Å, b = 14.2551(8) Å, c = 16.629(1) Å, α = 79.326(1)°, β = 73.605(1)°, γ = 75.496(1)°, V = 2451.0(2) Å3, Z = 2. Compound 4 crystallizes in the monoclinic P21/n space group with a = 13.1148(9) Å, b = 27.128(2) Å, c = 14.882(1) Å, β = 114.056(2)°, V = 4834.8(6) Å3, Z = 4. The magnetic properties of compounds 1-4 were studied over the 2–300 K temperature range. Compounds 1 and 2 with monometallic [Ni(NCS)4]2– complex units have similar magnetic properties, in agreement with nickel(II) ions in pseudo-tetrahedral environments. Compounds 3 and 4 with bimetallic [Ni2(NCS)8]4– complex units exhibit magnetic properties, which are indicative of Ni(II)–Ni(II) ferromagnetic interactions with zero-field splitting effects caused by the pseudo-square-pyramidal or pseudo-trigonal-bipyramidal coordination environments of the nickel(II) ion in compounds 3 and 4, respectively. The structures and magnetic results for all compounds are correlated with NIR–UV–vis absorption spectra.Key words: nickel(II) thiocyanato complexes, crystal structures, paramagnetism, molecular magnetism, exchange coupling, absorption spectroscopy.

Iron(II) complexes containing thiophene-substituted “bispicen” ligands — Spin-crossover, ligand rearrangements, and ferromagnetic interactions

2010 ◽  
Vol 88 (9) ◽  
pp. 954-963 ◽  
Author(s):  
Haojin Cheng ◽  
Brandon Djukic ◽  
Hilary A. Jenkins ◽  
Serge I. Gorelsky ◽  
Martin T. Lemaire
Keyword(s):  
Magnetic Properties ◽  
Density Functional ◽  
Spin Crossover ◽  
Variable Temperature ◽  
Density Functional Theory Calculations ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Magnetic Analysis ◽  
Ferromagnetic Chain ◽  
Ferromagnetic Interactions

The synthesis and characterization of three new tetradentate “bispicen-type” ligands containing a substituted thiophene heterocycle are described [2,5-thienyl substituents = H (7), Ph (8), or 2-thienyl (9)]. Iron(II) bis(thiocyanate) coordination complexes containing 7–9 were prepared, and the electronic and variable-temperature magnetic properties of complexes containing 7 (10) and 9 (12) are described. Complex 10 features a gradual and incomplete spin crossover in the solid state, and 12 remains high-spin over the entire temperature range. Complex 11 is extremely unstable and rearranges to another iron(II) complex (13), which was structurally characterized. The temperature-dependent magnetic properties of 13 are described as a one-dimensional ferromagnetic chain, with interchain antiferromagnetic interactions and (or) zero-field splitting dominant at low temperatures. The magnetic analysis is corroborated by the molecular packing and density functional theory calculations, which suggest intermolecular interactions between coordinated thiocyanate ligands bearing a significant spin density.

scholarly journals Crystal Structures and Magnetic Properties of Two New Cobalt(II) Complexes with Triazole-Substituted Nitronyl and Imino Nitroxide Radicals

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Jing Chen ◽  
You-Juan Zhang ◽  
Kun-Tao Huang ◽  
Qiang Huang ◽  
Jun-Jie Wang
Keyword(s):  
Magnetic Properties ◽  
Metal Ions ◽  
Crystal Structures ◽  
Magnetic Measurements ◽  
Nitroxide Radicals ◽  
Triclinic Space Group ◽  
Space Group ◽  
Imino Nitroxide

Two new cobalt(II) complexes of formula [Co(hfac)2(NITphtrz) 1 and Co(hfac)2(IMphtrz) 2] have been prepared and characterized structurally [where NITphtrz = 4,4,5,5-tetramethyl-2-(2-phenyl-1,2,3-triazole-4-yl)imidazoline-1-oxyl-3-oxide and IMphtrz = 4,4,5,5-tetramethyl-2-(2-phenyl-1,2,3-triazole-4-yl)imidazoline-1-oxyl]. All of the complexes crystallize in an isomorphous triclinic space group P1- with the Co(II) ion octahedrally coordinated via the bidentate chelating mode. The magnetic measurements show that two complexes exhibit antiferromagnetic interactions between the metal ions and the nitroxide radicals.

New Thiostannates Synthesized Under Solvothermal Conditions: Crystal Structures of (trenH)2Sn3S7 and {[Mn(tren)]2Sn2S6}

2012 ◽  
Vol 67 (10) ◽  
pp. 1098-1106 ◽  
Author(s):  
Nicole Pienack ◽  
Diana Schinkel ◽  
Angela Puls ◽  
Marie-Eve Ordolff ◽  
Henning Lühmann ◽  
...  
Keyword(s):  
Band Gap ◽  
Crystal Structures ◽  
Bond Formation ◽  
Lattice Parameters ◽  
Triclinic Space Group ◽  
Space Group ◽  
Trigonal Bipyramidal ◽  
Solvothermal Conditions

The two new thiostannate compounds (trenH)2Sn3S7 (1) and {[Mn(tren)]2Sn2S6} (2) (tren=tris-2-aminoethylamine) were obtained under solvothermal conditions. Compound 1 crystallizes in the hexagonal space group P63/mmc with a=13.2642(19), c=19.078(3) Å, V =2906.9(7) Å3. The layered [Sn3S7]2- anion is constructed by Sn3S4 semi-cubes sharing common edges. The layers are characterized by large hexagonal pores with dimensions of about 11×11 Å2. Compound 2 crystallizes in the triclinic space group P1̄ with lattice parameters a=7.6485(7), b=8.1062(7), c=12.1805(11) Å, α =97.367(11), β =103.995(11), γ = 108:762(10)°, V =676.17(10) Å3. The [Sn2S6]4- anion is composed of two edge-sharing SnS4 tetrahedra and joins two Mn2+-centered complexes by Mn-S bond formation. The Mn2+ cation is in a trigonal-bipyramidal environment of four N atoms of the tren ligand and one S atom of the thiostannate anion. Both compounds are semiconductors with a band gap of 2:96 eV for 1 and of 2:75 eV for 2.

scholarly journals [CrIII8NiII6]n+ Heterometallic Coordination Cubes

2021 ◽  
Author(s):  
Helen O'Connor ◽  
Sergio Sanz ◽  
Aaron Scott ◽  
Mateusz Pitak ◽  
Wim Klooster ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Direct Current ◽  
Zero Field ◽  
Modular Approach ◽  
Zero Field Splitting ◽  
Heterometallic Clusters ◽  
Related Family ◽  
Weak Exchange ◽  
Ferromagnetic Interactions ◽  
Weak Ferromagnetic

Three new heterometallic [CrIII8NiII6] coordination cubes of formulae [CrIII8NiII6L24(H2O)12](NO3)12 (1), [CrIII8NiII6L24(MeCN)7(H2O)5](ClO4)12 (2) and [CrIII8NiII6L24Cl12] (3) (where HL = 1-(4-pyridyl)butane-1,3-dione), were synthesised using the paramagnetic metalloligand [CrIIIL3] and the corresponding NiII salt. The magnetic skeleton of each capsule describes a face-centred cube in which the eight CrIII and six NiII ions occupy the eight vertices and six faces of the structure, respectively. Direct current magnetic susceptibility measurements on (1) reveal weak ferromagnetic interactions between the CrIII and NiII ions, with JCr-Ni = +0.045 cm-1 . EPR spectra are consistent with weak exchange, being dominated by the zero-field splitting of the CrIII ions. Excluding wheel-like structures, examples of large heterometallic clusters containing both CrIII and NiII ions are rather rare, and we demonstrate that the use of metalloligands with predictable bonding modes allows for a modular approach to building families of related polymetallic complexes. Compounds (1)-(3) join the previously published, structurally related family of [MIII8MII6] cubes, where MIII = Cr, Fe and MII = Cu, Co, Mn, Pd. <br>

Characterization of the Phenanthrene-Tetrachlorophthalic Anhydride (P/TCPA) 1:1 Charge-Transfer Crystal: Spectroscopic and Structural Investigations

1987 ◽  
Vol 42 (6) ◽  
pp. 622-629 ◽  
Author(s):  
J. Krzystek ◽  
J. U. von Schütz ◽  
H. C Wolf ◽  
R.-D. Stigler ◽  
J. J. Stezowski
Keyword(s):  
Charge Transfer ◽  
Low Temperature ◽  
Structural Model ◽  
Emission Spectra ◽  
Optical Emission ◽  
Delayed Fluorescence ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Structural Investigations ◽  
Space Group

The 1:1 phenanthrene-tetrachlorophthalic anhydride (P/TCPA) charge-transfer complex crystalizes with monoclinic symmetry, space group P21, with two magnetically inequivalent stacks in the unit cell. The noncentrosymmetric space group is very unusual for CT-complexes. The optical emission spectra at low temperature are characterized by a strong CT phosphorescence and a weak CT fluorescence and delayed fluorescence.The S1 band lies at 22 800 ± 100 cm-1, the T1 band at 21 200 ± 100 cm-1. Above 15 K triplet excitons, moving along the stacks are revealed by ESR. They have a CT character of about 30%, coinciding with that of the shallow X-traps found by ODMR at low temperatures. A further trap, with zero-field-splitting (zfs) parameters of D = ± 0.0617, E = + 0.0116 cm-1 has a much larger CT character of 50% as found in the isolated complex in low-temperature glass [1]. A structural model is proposed.

Structural influences on the exchange coupling and zero-field splitting in the single-molecule magnet [MnIII6MnIII]3+

2012 ◽  
Vol 41 (41) ◽  
pp. 12942 ◽  
Author(s):  
Veronika Hoeke ◽  
Maik Heidemeier ◽  
Erich Krickemeyer ◽  
Anja Stammler ◽  
Hartmut Bögge ◽  
...  
Keyword(s):  
Single Molecule ◽  
Exchange Coupling ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Single Molecule Magnet

Solid State Coordination Chemistry of Pyridinedicarboxylic Acid Isomers. I Copper(II) Disodium Bis(pyridine-2,3- dicarboxylate) Octahydrate and Copper(II) Pyridine-3,4-dicarboxylate 3·5 Hydrate

1999 ◽  
Vol 52 (3) ◽  
pp. 205 ◽  
Author(s):  
Elsa E. Sileo ◽  
Daniel Vega ◽  
Mará T. Garland ◽  
Ricardo Baggio ◽  
Miguel A. Blesa
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Crystal Structures ◽  
Monoclinic Space Group ◽  
Thermal Dependence ◽  
Magnetic Susceptibility Data ◽  
Space Group ◽  
Susceptibility Data ◽  
Pyridinedicarboxylic Acid ◽  
State Coordination

The crystal structures of Na2Cu(2,3-pydc)2.8H2O (1) and Cu(3,4-pydc).3·5H2O (2) (pydc = pyridinedi- carboxylato) are presented. Compound (1) is monoclinic, space group C 2/c, with a 21·274(1), b 6 ·114(1), c 17·136(1) Å, β 101·62(1)°, Z 4, Dc 1·776 g cm-3 ; compound (2) is also monoclinic, space group P 21/c, with a 7·272(2), b 11·319(3), c 25·453(9) Å, β 90·58(1)°, Z 4, Dc 1·850 g cm-3 . Their stereochemistries are analysed, and compared with other copper(II) pyridine-2,6-dicarboxylates. Ligand constraints are shown to determine the crystal structures and the magnetic properties. Thermal dependence of magnetic susceptibility data and t.g., d.t.g. and d.t.a. measurements are also presented.

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