scholarly journals Bis(triphenylphosphine)iminium Salts of Dioxothiadiazole Radical Anions: Preparation, Crystal Structures, and Magnetic Properties

Crystals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 30 ◽  
Author(s):  
Paweł Pakulski ◽  
Mirosław Arczyński ◽  
Dawid Pinkowicz
Keyword(s):  
Magnetic Properties ◽  
Crystal Structures ◽  
Magnetic Materials ◽  
Exchange Coupling ◽  
Crystal Packing ◽  
Stable Radical ◽  
Radical Anions ◽  
Iminium Salts ◽  
Redox Active ◽  
Derivatives Of

Phenanthroline dioxothiadiazoles are redox active molecules that form stable radical anions suitable for the construction of supramolecular magnetic materials. Herein, the preparation, structures and magnetic properties of bis(triphenylphosphine)iminium (PPN) salts of [1,2,5]thiadiazole[3,4-f][1,10]phenanthroline 1,1-dioxide (L), [1,2,5]thiadiazole[3,4-f][4,7]phenanthroline 1,1-dioxide (4,7-L), 5-bromo-[1,2,5]thiadiazolo[3,4-f][1,10]phenanthroline 2,2-dioxide (BrL), and 5,10-dibromo-[1,2,5]thiadiazolo[3,4-f][1,10]phenanthroline 2,2-dioxide (diBrL) are reported. The preparation of new bromo derivatives of the L: 5-bromo-[1,2,5]thiadiazolo[3,4-f][1,10]phenanthroline 2,2-dioxide (BrL) and 5,10-dibromo-[1,2,5]thiadiazolo[3,4-f][1,10]phenanthroline 2,2-dioxide (diBrL)—suitable starting materials for further derivatization—are described starting from a commercially available and cheap 1,10-phenanthroline. All PPN salts show antiferromagnetic interactions between the pairs of radical anions, which in the case of PPN(diBrL) are very strong (−116 cm−1; using Ĥ = −2JSS type of exchange coupling Hamiltonian) due to a different crystal packing of the anion radicals as compared to PPN(L), PPN(4,7-L), and PPN(BrL).

Filling the gap between the quantum and classical worlds of nanoscale magnetism: giant molecular aggregates based on paramagnetic 3d metal ions

2016 ◽  
Vol 45 (6) ◽  
pp. 1597-1628 ◽  
Author(s):  
Constantina Papatriantafyllopoulou ◽  
Eleni E. Moushi ◽  
George Christou ◽  
Anastasios J. Tasiopoulos
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Metal Ions ◽  
Crystal Structures ◽  
Magnetic Materials ◽  
Metal Clusters ◽  
Molecular Aggregates ◽  
Bottom Up ◽  
Paramagnetic Metal

The syntheses, structures and magnetic properties of giant molecular 3d and 3d/4f paramagnetic metal clusters are surveyed. Such complexes combine fascinating crystal structures, interesting magnetic properties and sizes comparable to those of classical magnetic nanoparticles providing a powerful bottom-up approach to nanoscale magnetic materials.

Oxalato-Bridged Dinuclear Copper(II) Complexes ofN-Alkylated Derivatives of 1,4,7-Triazacyclononane: Synthesis, X-ray Crystal Structures and Magnetic Properties

2006 ◽  
Vol 2006 (23) ◽  
pp. 4872-4878 ◽  
Author(s):  
Matthew J. Belousoff ◽  
Bim Graham ◽  
Boujemaa Moubaraki ◽  
Keith S. Murray ◽  
Leone Spiccia
Keyword(s):  
Magnetic Properties ◽  
Crystal Structures ◽  
Dinuclear Copper ◽  
X Ray ◽  
Derivatives Of

Phase behaviour and crystal structures of 2′,3′-difluorinated p-terphenyl derivatives

2021 ◽  
Vol 77 (7) ◽  
Author(s):  
Sakuntala Gupta ◽  
Partha Pratim Das ◽  
Przemysław Kula ◽  
Emmanuele Parisi ◽  
Roberto Centore
Keyword(s):  
Crystal Structures ◽  
Crystal Packing ◽  
Phase Behaviour ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Space Group ◽  
X Ray ◽  
Independent Molecules ◽  
Derivatives Of

The crystal structures of difluorine derivatives of p-terphenyls (nTm) have been determined by single-crystal X-ray diffraction. For the unsymmetrical substituted compounds 2′,3′-difluoro-4-methyl-p-terphenyl (1T0, C19H14F2) and 4-ethyl-2′,3′-difluoro-4′′-methyl-p-terphenyl (1T2, C21H18F2), the crystal structure is disordered, with molecules statistically entering the crystal in up and down orientations, with full superposition of all the atoms, except for those of the terminal groups (H/methyl for 1T0 and methyl/ethyl for 1T2). For triclinic 2′,3′-difluoro-4,4′′-dimethyl-p-terphenyl (1T1, C20H16F2), with the space group P\overline{1}, the two crystallographically independent molecules have the same conformation, which is different from monoclinic 1T0 (space group C2) and 1T2 (space group C2/c). A common feature of the conformation of the three compounds is the noncoplanar twisted arrangement of the three rings of the p-terphenyl moiety. Two-dimensional (2D) Hirshfeld fingerprint plots are consistent with H...H and C...H contacts in the crystal packing. For the three compounds, the phase behaviour has been investigated by POM (Petra/Osiris/Molinspiration) and differential scanning calorimetry (DSC) analysis. 1T2 is mesogenic, with enantiotropic nematic behaviour.

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.

scholarly journals Exchange coupling and single molecule magnetism in redox-active tetraoxolene-bridged dilanthanide complexes

2018 ◽  
Vol 9 (5) ◽  
pp. 1221-1230 ◽  
Author(s):  
Peng Zhang ◽  
Mauro Perfetti ◽  
Michal Kern ◽  
Philipp P. Hallmen ◽  
Liviu Ungur ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ab Initio ◽  
Single Molecule ◽  
Epr Spectroscopy ◽  
Exchange Coupling ◽  
Redox Active

The magnetic properties of the title complexes were studied by EPR spectroscopy, magnetometry and ab initio calculations.

Syntheses, crystal structures and magnetic properties of five new manganese(ii) complexes: influence of the conformation of different alkyl/aryl substituted malonate ligands on the crystal packing

CrystEngComm ◽  
2014 ◽  
Vol 16 (13) ◽  
pp. 2766 ◽  
Author(s):  
Mariadel Déniz ◽  
Irene Hernández-Rodríguez ◽  
Jorge Pasán ◽  
Oscar Fabelo ◽  
Laura Cañadillas-Delgado ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Crystal Structures ◽  
Crystal Packing ◽  
Alkyl Aryl
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