Search results for "Pyramid"
showing 10 items of 410 documents
A novel octacyanido dicobalt(iii) building block for the construction of heterometallic compounds
2019
The first bimetallic octacyanido complex of CoIII, (PPh4)2[Co2(μ-2,5-dpp)(CN)8] (1), was synthesized and used as a metalloligand with [Mn(MAC)(H2O)2]Cl2·4H2O to give a new {CoIIIMnII} heterometallic chain of formula [MnII(MAC)(μ-NC)2Co2III(μ-2,5-dpp)(CN)6]n·7nH2O (2) (PPh4+ = tetraphenylphosphonium cation; 2,5-dpp = 2,5-bis(2-pyridyl)pyrazine and MAC = 2,13-dimethyl-3,6,9,12,18-pentaazabicyclo-[12.3.1]octadeca-1(18),2,12,14,16-pentaene). Both compounds were characterized by single-crystal X-ray diffraction. Compound 1 contains a diamagnetic 2,5-dpp-bridged dicobalt(III) unit with four peripheral cyanide ligands at each cobalt center achieving a six-coordinate surrounding, the electroneutral…
Solid state polymerization causing transition to a ferromagnetic state. Crystal structures and magnetic properties of [Cu2(dpp)(H2O)(dmso)Cl4]·dmso a…
2001
The preparation, crystal structures and variable-temperature magnetic susceptibility data for [Cu2(dpp)(H2O)(dmso)Cl4]·dmso (1a) and [Cu2(dpp)Cl4]n (2) (dpp = 2,3-bis(2-pyridyl)pyrazine, dmso = dimethyl sulfoxide) are reported. 1a consists of dinuclear dpp-bridged molecules with chlorine, water and dmso serving as terminal ligands. The two copper atoms are crystallographically independent, with distorted square pyramidal and trigonal bipyramidal coordination geometries, respectively. In a first approximation 2 may be described as a chain compound with out-of-plane mono-μ-chloro bridges (Cu–Cl–Cu–Cl). Only one of the crystallographically independent copper atoms participates in this chain fo…
Triorganotin(IV) derivatives of 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid. Synthesis, spectroscopic characterization, …
2010
Triorganotin(IV) complexes of the 7-amino-2-(methylthio)[1,2,4]triazolo[1,5-a]pyrimidine-6-carboxylic acid (HL), Me 3 SnL(H 2 O), ( 1 ), [ n -Bu 3 SnL] 2 (H 2 O), ( 2 ), Ph 3 SnL(MeOH), ( 3 ), were synthesized by reacting the amino acid with organotin(IV) hydroxides or oxides in refluxing methanol. The complexes have been characterized by elemental analysis, 1 H, 13 C and 119 Sn NMR, IR, Raman and 119 Sn Mossbauer spectroscopic techniques. Single crystal X-ray diffraction data were obtained for compounds ( 2 ) and ( 3 ). Ph 3 SnL(MeOH) presents a trigonal bipyramidal structure with the organic groups on the equatorial plane and the axial positions occupied by a ligand molecule, coordinated …
Amyloid Beta-Mediated Changes in Synaptic Function and Spine Number of Neocortical Neurons Depend on NMDA Receptors
2021
Onset and progression of Alzheimer’s disease (AD) pathophysiology differs between brain regions. The neocortex, for example, is a brain region that is affected very early during AD. NMDA receptors (NMDARs) are involved in mediating amyloid beta (Aβ) toxicity. NMDAR expression, on the other hand, can be affected by Aβ. We tested whether the high vulnerability of neocortical neurons for Aβ-toxicity may result from specific NMDAR expression profiles or from a particular regulation of NMDAR expression by Aβ. Electrophysiological analyses suggested that pyramidal cells of 6-months-old wildtype mice express mostly GluN1/GluN2A NMDARs. While synaptic NMDAR-mediated currents are unaltered in 5xFAD …
Innovations sociales et création de valeur partagée au sein des entreprises
2017
This work focuses on social innovations that are likely to create shared value, that is, to seek commercial success that has the potential to generate benefits for the society. This shared value deals with the wellbeing of low-income consumers and poor people. These innovations are also a lever to reduce the pressures that can be exerted by stakeholders in the social-political sphere (regulatory authorities and soft power), if the company does not reduce the negative externalities produced by its activities.
Efficient DNA Cleavage Induced by Copper(II) Complexes of Hydrolysis Derivatives of 2,4,6‐Tri(2‐pyridyl)‐1,3,5‐triazine in the Presence of Reducing A…
2007
The reaction of 2,4,6-tri(pyridyl)-1,3,5-triazine (ptz) and copper(II) salts in dmf/water (1:1) results in the hydrolysis of ptz and formation of the anions bis(2-pyridylcarbonyl)amide (ptO2–) and bis(2-pyridylamine)amide (ptN2–), which are found in the complexes [Cu(ptN2)(OAc)]·3H2O (1), [Cu(ptO2)(OAc)(H2O)]·H2O (2), [Cu(ptN2)(for)]·3H2O (3) (for = formate), [Cu(ptO2)(for)(H2O)] (4), [Cu(ptO2)(benz)]·H2O (5) (benz = benzoate), and [Cu(ptO2)F(H2O)]2·3H2O (6). This report includes the chemical and spectroscopic characterization of all these complexes along with the crystal structures of 4–6. The coordination spheres of CuII in 4 and 5 are best described as distorted tetragonal square pyramid…
Polynuclear copper(II) complexes with hexadentate Schiff base directed by the counter ion. Syntheses, crystal structures and magnetic properties
2018
Abstract Four new complexes, [Cu 9 L 6 ( µ 3 -ClO 4 ) 2 ](ClO 4 ) 4 ·4CHCl 3 1 , [Cu 3 L 2 (H 2 O) 2 ](ClO 4 ) 2 ·3H 2 O 2 , [Cu 6 L 4 (N 3 ) 2 ](ClO 4 ) 2 3 and [Cu 2 L(CH 3 COO) 2 ] 4 , where H 2 L stands for the Schiff base N , N ′-bis[(2-hydroxybenzilideneamino)-propyl]-piperazine, were obtained and structurally characterized. Compounds 1 , 2 and 3 contain the Cu 3 L 2 2+ entities in which L 2− acts in an unsymmetrical mode with N 3 O donor set wrapped around marginal copper(II) and with the remained NO sets bound to the central copper ion. The marginal copper(II) ions are in distorted square pyramidal environment, whereas that of the central one is square planar. In 1 , the peripheral …
Anion modulated structural variations in copper(II) complexes with a semicarbazone Schiff base: Synthesis, characterization and self assembly
2014
Abstract Two copper(II) complexes, [Cu(L)N3]n (1) and [Cu(HL)2](I3)ClO4 (2), where HL = 2-pyridylaldehydesemicarbazone, have been prepared and characterized by elemental analysis, IR and UV–Vis spectroscopy and single crystal X-ray diffraction studies. Complex 1 crystallizes in monoclinic space group P21/a, whereas, complex 2 crystallizes in triclinic space group P-1. Complex 1 is a stair-like coordination polymer with square pyramidal geometry of copper(II), whereas, complex 2 is a mononuclear cationic bis-ligand complex of octahedral copper(II). Lower coordination ability of tri-iodide or perchlorate compared to azide may be related with variations of the structures of the complexes.
A new linear double phenoxide-bridged trinuclear Cu(II) Schiff base complex: Synthesis, crystallographic elucidation, magneto-structural correlation …
2014
Abstract The tetradentate (ONNO) donor Schiff base ligand LH2, derived from the condensation of salicylaldehyde and 1,3-diaminopropane, has been synthesized and reacted with CuBr2 to yield a trinuclear complex with the molecular formula [Cu3L2Br2]. Single crystal X-ray diffraction study reveals that the two terminal copper atoms adopt a square pyramidal geometry, whereas the central copper atom, situated at the inversion centre, is surrounded by four phenoxide oxygen atoms in a square planar fashion. Variable temperature magnetic susceptibility measurement study shows strong antiferromagnetic intra-trimer interactions between the copper centers with a J value of −302 cm−1. EPR study of the …
Self-assembly of extended Schiff base amino acetate skeletons, 2-{[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)]amino}phenylpropionate and 2-{[(E)-1-(2-h…
2007
The organotin(IV) compounds, [Ph 3 SnL 1 H] n · nCCl 4 ( 1 ), [Me 2 SnL 2 (OH 2 )] ( 2 ), [ n Bu 2 SnL 2 ] ( 3 ), [Ph 2 SnL 2 ] n ( 4 ), [Ph 3 SnL 2 H] n ( 5 ) and [Ph 3 SnL 3 H] n ( 7 ) (L 1 = 2-{[(2 Z )-(3-hydroxy-1-methyl-2-butenylidene)]amino}phenylpropionate and L 2−3 = 2-{[( E )-1-(2-hydroxyaryl)alkylidene]amino}phenylpropionate), were synthesized by treating the appropriate organotin(IV) chloride(s) with the potassium salt of the ligand in a suitable solvent, while [ n Bu 2 SnL 3 (OH 2 )] ( 6 ) was obtained by reacting the acid form of L 3 (generated in situ) with n Bu 2 SnO. These complexes have been characterized by 1 H, 13 C, 119 Sn NMR, ESI-MS, IR and 119m Sn Mossbauer spectro…