Search results for "Inorganic chemistry"
showing 10 items of 7339 documents
A spin-crossover complex based on a 2,6-bis(pyrazol-1-yl)pyridine (1-bpp) ligand functionalized with a carboxylate group
2014
Combining Fe(ii) with the carboxylate-functionalized 2,6-bis(pyrazol-1-yl)pyridine (bppCOOH) ligand results in the spin-crossover compound [Fe(bppCOOH)2](ClO4)2 which shows an abrupt spin transition with a T1/2 of ca. 380 K and a TLIESST of 60 K due to the presence of a hydrogen-bonded linear network of complexes.
Conformational Control of Metallocene Backbone by Cyclopentadienyl Ring Substitution: a New Concept in Polyphosphane Ligands Evidenced by “Through-Sp…
2009
The present study deals with the conformational control of the metallocene backbone within ferrocenyl polyphosphane ligands and their performance in the highly topical palladium-catalyzed heteroaromatics arylation by direct C−H activation. New substituted cyclopentadienyl rings were synthesized, which allowed the assembling of original tri- and diphosphanes. The bulky cyclopentadienyl lithium salts diphenylphosphino-3-(triphenyl)methylcyclopentadienyllithium (4) and 1,2-bis(diphenylphosphino)-4-(triphenyl)methylcyclopentadienyllithium (5) were prepared in excellent yield. The assembling of these new hindered cyclopentadienyl salts (Cp) with other Cp fragments was performed in order to prepa…
Nonanuclear Spin-Crossover Complex Containing Iron(II) and Iron(III) Based on a 2,6-Bis(pyrazol-1-yl)pyridine Ligand Functionalized with a Carboxylat…
2016
The synthesis and magnetostructural characterization of [Fe(III)3(μ3-O)(H2O)3[Fe(II)(bppCOOH)(bppCOO)]6](ClO4)13·(CH3)2CO)6·(solvate) (2) are reported. This compound is obtained as a secondary product during synthesis of the mononuclear complex [Fe(II)(bppCOOH)2](ClO4)2 (1). The single-crystal X-ray diffraction structure of 2 shows that it contains the nonanuclear cluster of the formula [Fe(III)3(μ3-O)(H2O)3[Fe(II)(bppCOOH)(bppCOO)]6](13+), which is formed by a central Fe(III)3O core coordinated to six partially deprotonated [Fe(II)(bppCOOH)(bppCOO)](+) complexes. Raman spectroscopy studies on single crystals of 1 and 2 have been performed to elucidate the spin and oxidation states of iron …
Synthesis and characterization of binuclear μ-oxalato nickel(II), copper(II) and zinc(II) complexes with 3,3′-diamino-N-methyl-dipropylamine or trans…
1999
Abstract New binuclear complexes of the type [(Ni(Medpt)NO3)2ox] (1) (Medpt=3,3′-diamino-N-methyl-dipropylamine, H2ox=oxalic acid), [(Ni(dach)2)2ox]NO3·2H2O (2) (dach=trans-1,2-diaminocyclohexane), [(Cu(Medpt))2ox]X2·yH2O (X=NO3, y=2 2/3 (3); X=ClO4, y=0 (4)) and [(Zn(dach)2)2ox](ClO4)2·2H2O (5) have been prepared and characterized by IR and UV–Vis spectroscopies. Spectroscopic data are consistent with oxalate-bridged structures between six-coordinated (N3O3 or N4O2) Ni(II) (compounds 1 or 2), five-coordinated (N3O2) Cu(II) (compounds 3 and 4) or six-coordinated (N4O2) Zn(II) (compound 5). The crystal structure of [(Cu(Medpt))2ox](NO3)2·2 2/3 H2O (3) has been determined by single-crystal X-…
Long-range electronic connection in picket-fence like ferrocene–porphyrin derivatives
2012
The effects of a direct connection between ferrocene and porphyrin units have been thoroughly investigated by electrochemical and spectroscopic methods. These data not only reveal that substitution of the porphyrin macrocycle by one, two, three or four ferrocenyl groups strongly affects the electronic properties of the porphyrin and ferrocenyl moieties, they also clearly demonstrate that the metallocene centres are "connected" through the porphyrin-based electronic network. The dynamic properties of selected ferrocene-porphyrin conjugates have been investigated by VT NMR and metadynamic calculations. 1,3-Dithiolanyl protecting groups have been introduced on the upper rings of the ferrocene …
Remote Control by π-Conjugation of the Emissive Properties of Fischer Carbene-BODIPY Dyads.
2016
The synthesis, structure, and complete characterization of mono- and bimetallic dyads joining Fischer carbene complexes and BODIPY chromophores are reported. In these organometallic species, the Fischer carbene complex is attached to the BODIPY moiety through a p-aminophenyl group linked at the C8 carbon atom of the BODIPY core. The photophysical properties, namely the corresponding UV/vis absorption and emission spectra of these new metal-carbene complexes, are analyzed and discussed. It is found that whereas the absorption of the considered dyads strongly resembles that of the parent 4-anilinyl-substituted BODIPY, the fluorescence emission is significantly reduced in these species, very l…
Catalytic activity of biscobalt porphyrin-corrole dyads toward the reduction of dioxygen
2009
A series of biscobalt cofacial porphyrin-corrole dyads bearing mesityl substituents at the meso positions of the corrole ring were investigated as to their electrochemistry, spectroelectrochemistry, and CO binding properties in nonaqueous media and then applied to the surface of a graphite electrode and tested as electrocatalysts for the reduction of dioxygen to water or hydrogen peroxide in air-saturated aqueous solutions containing 1 M HClO(4). The catalytic reduction of O(2) with the same dyads was also investigated in the homogeneous phase using 1,1'-dimethylferrocene as a reductant in PhCN containing HClO(4). The examined compounds are represented as (PMes(2)CY)Co(2), where P = a porph…
Electrochemically-driven conformational shift in mono- and di-copper constrained macrotricyclic cyclen receptors
2008
International audience; An electrochemical study of mono- and di-copper constrained cyclen macrotricycles is presented. Electrochemical data in DMF solution indicate that the reduction of dinuclear complexes occurs in two steps in the -0.4 to -0.8 V vs.AgCl/Ag potential range yielding CuII CuI and CuI CuI species further reduced to Cu metal at highly negative potentials. Mononuclear complexes are reduced in two steps to CuI and Cu metal. Electrochemical data suggest that reduction of both mononuclear and dinuclear complexes approach a square scheme involving electrochemically-driven conformational shifts for metal ions. The presence of endo- and exo-forms of the complexes are revealed by ch…
The Chemo- and Stereoselective Formation of Pallado- and Platinocryptophanes
2019
International audience