scholarly journals First Cobalt(II) Spin Crossover Compound with N4S2-Donorset

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 855 ◽  
Author(s):  
Fabian Fürmeyer ◽  
Danny Münzberg ◽  
Luca M. Carrella ◽  
Eva Rentschler

Herein we report the synthesis and characterization of a novel bis-tridentate 1,3,4-thiadiazole ligand (L = 2,5-bis[(2-pyridylmethyl)thio]methyl-1,3,4-thiadiazole). Two new mononuclear complexes of the type [MII(L)2](ClO4)2 (with M = FeII (C1) and CoII (C2)) have been synthesized, containing the new ligand (L). In both complexes the metal centers are coordinated by an N4S2-donorset and each of the two ligands is donating to the metal ion with just one of the tridentate pockets. The iron(II) complex (C1) is in the low spin [LS] state below room temperature and shows an increase in the magnetic moment only above 300 K. In contrast, the cobalt(II) complex (C2) shows a gradual spin crossover (SCO) with T1/2 = 175 K. To our knowledge, this is the first cobalt(II) SCO complex with an N4S2-coordination.

RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13245-13255
Author(s):  
Mehdi Davoodi ◽  
Fatemeh Davar ◽  
Mohammad R. Rezayat ◽  
Mohammad T. Jafari ◽  
Mehdi Bazarganipour ◽  
...  

New nanocomposite of zeolitic imidazolate framework-67@magnesium aluminate spinel (ZIF-67@MgAl2O4) has been fabricated by a simple method at room temperature with different weight ratios.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Evelyn Carolina Martínez Ceballos ◽  
Ricardo Vera Graziano ◽  
Gonzalo Martínez Barrera ◽  
Oscar Olea Mejía

Poly(dichlorophosphazene) was prepared by melt ring-opening polymerization of the hexachlorocyclotriphosphazene. Poly[bis(2-hydroxyethyl-methacrylate)-phosphazene] and poly[(2-hydroxyethyl-methacrylate)-graft-poly(lactic-acid)-phosphazene] were obtained by nucleophilic condensation reactions at different concentrations of the substituents. The properties of the synthesized copolymers were assessed by FTIR,1H-NMR and31P-NMR, thermal analysis (DSC-TGA), and electron microscopy (SEM). The copolymers have a block structure and show twoTg's below room temperature. They are stable up to a temperature of 100°C. The type of the substituents attached to the PZ backbone determines the morphology of the polymers.


2004 ◽  
Vol 69 (8-9) ◽  
pp. 641-649 ◽  
Author(s):  
Fouzia Rafat ◽  
M.Y. Siddiqi ◽  
K.S. Siddiqi

Reaction of [M(ppn)2]X2 (where M = Cu(II), Ni(II), Co(II) and ppn = 1,3-diaminopropane) with formaldehyde and ethylenediamine in methanol results in the ready formation of a 16-membered macrocyclic complex. The complexes were characterized by elemental analysis, IR, EPR, electronic spectral data magnetic moments and conductance measurements. The Cu(II), Ni(II) and Co(III) complexes are coordinated axially with both pendant groups of the hexadentate macrocycle. These pendant donors are attached to the macrocycle by a carbon chain. The electrical conductivities of the Cu(II) and Ni(II) chelates indicated them to be 1:2 electrolytes whilst those of Co(III) is a 1:3 electrolyte in DMSO. The EPR spectrum of the copper complex exhibited G at 3.66, which indicates a considerable exchange interaction in the complex. Spectroscopic evidence suggests that in all of the complexes the metal ion is in an octahedral environment.


2020 ◽  
Author(s):  
Joel D. Smith ◽  
George Durrant ◽  
Daniel Ess ◽  
Warren Piers

<div>The synthesis and characterization of an iridium polyhydride complex (Ir-H4)</div><div>supported by an electron-rich PCP framework is described. This complex readily loses molecular</div><div>hydrogen allowing for rapid room temperature hydrogen isotope exchange (HIE) at the hydridic</div><div>positions and the α-C-H site of the ligand with deuterated solvents such as benzene-d6, toluene-d8</div><div>and THF-d8. The removal of 1-2 equivalents of molecular H2 forms unsaturated iridium carbene</div><div>trihydride (Ir-H3) or monohydride (Ir-H) compounds that are able to create further unsaturation</div><div>by reversibly transferring a hydride to the ligand carbene carbon. These species are highly active</div><div>hydrogen isotope exchange (HIE) catalysts using C6D6 or D2O as deuterium sources for the</div><div>deuteration of a variety of substrates. By modifying conditions to influence the Ir-Hn speciation,</div><div>deuteration levels can range from near exhaustive to selective only for sterically accessible sites.</div><div>Preparative level deuterations of select substrates were performed allowing for procurement of</div><div>>95% deuterated compounds in excellent isolated yields; the catalyst can be regenerated by</div><div>treatment of residues with H2 and is still active for further reactions.</div>


Author(s):  
U. Mahaboob Basha ◽  
D. Mohana Krishnudu ◽  
P. Hussain ◽  
K. Manohar Reddy ◽  
N. Karthikeyan ◽  
...  

In the current work epoxy resin is chosen as matrix, treated Sacharum offinarum ( SugarCane) fiber, Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler are chosen as reinforcement. Room temperature cured Epoxy System filled with Sacharum offinarum fiber and Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler are synthesised by mechanical shear mixer, then kept in a Ultra sonic Sonicator for better dispersion of Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler in the matrix. Different weights of modified Pennisetum typhoides (Jowar)/ Fillet miller (Ragi) filler (1,2,3,4,5 gm wt) has been incorporated into the Epoxy matrix in order to study the variation of Mechanical and Thermal properties.


2010 ◽  
Vol 3 (2) ◽  
pp. 70-73 ◽  
Author(s):  
Sentot Budi Rahardjo

Cu (II) complexs with 1,4,8-tris(2-hidroxymethyl)-11-methyl-1,4,8,11-tetraazacyclotetradecane (L) have been synthesized with chemical formula of [CuL](ClO4) (experimental Cu = 32.7 %, H = 6.4%, theoritical Cu = 32.6 %, H = 6.4 %). Its magnetic moment of 1.90 BM indicated that the complexs is paramagnetic and there are no Cu-Cu bonding. This complexs is stable with the value of log k [CuL]2+ = 17.3(2). Visible spectra of [CuL]2+ showed that single wide peak at λmax of 628 nm (ε = 164 dm3.mol-1.cm-1) and indicated of E9 - T29 transition. The IR spectra and the conductancy data indicated that the ClO4 was not coordinated to Cu.   Keywords: tembaga (II), senyawa kompleks, paramagnetik


2014 ◽  
Vol 11 (2) ◽  
pp. 477-485 ◽  
Author(s):  
Baghdad Science Journal

In this study, chalcones were synthesis by condensing 2-acetylpyridine with aromatic aldehyde derivatives in dilute ethanolic potassium hydroxide solution at room temperature according to Claisen-Schmidt condensation. After that, new heterocyclic derivatives such as Oxazine, Thiazine and Pyrazol were synthesis by reaction between chalcones with urea, thiourea and hydrazine hydrate respectively scheme 1. All these compounds wrer characterization by FTIR, 1H-NMR spectroscopy and elemental analysis.


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