Preparation and characterization of azaindolyl-azaindole and structure of its halogen-free dicationic cluster containing the µ4-oxotetracopper(II) core

1994 ◽  
Vol 72 (11) ◽  
pp. 2339-2347 ◽  
Author(s):  
Jacques Poitras ◽  
André L. Beauchamp

Refluxing NbCl5 and excess 7-azaindole (Haza) in benzene yielded a solid mixture containing NbCl5(Haza), NbCl4(Haza)2, the azaindolium ion (H2aza)+, and the azaindolyl-azaindolium ion (H2aza-aza)+. The neutral (Haza-aza) molecule was obtained from the hydrolysed mixture and shown by X-ray diffraction (monoclinic, P21/c, a = 10.025, b = 13.758, c = 8.416 Å, β = 102.89°, Z = 4, R = 0.035) to result from the coupling of two azaindole units via N7—C6′. This compound was the only oxidation product detected, but concurrent formation of other niobium- and (or) azaindole-containing products keeps the yield of Haza-aza low. Dark green crystals of [Cu4O(aza-aza)4]Cl2•6.5H2O were obtained from (Haza-aza) and CuCl2 in wet methanol. The crystal structure (monoclinic, C2/c, a = 17.704, b = 25.240, c = 14.457 Å, β = 116.14°, Z = 4, R = 0.051) shows the presence of a tetranuclear dicationic cluster consisting of a µ4-oxide ion surrounded by a tetrahedron of Cu(II) atoms. A distorted square-planar coordination is achieved about each copper atom by (aza-aza)− ligands each bridging two copper atoms and providing a third nitrogen donor to one of them. For each such cation, the unit cell also includes two chloride ions and 6.5 disordered lattice water molecules. The 1H NMR and infrared spectroscopy data are discussed.

2018 ◽  
Vol 22 (09n10) ◽  
pp. 814-820
Author(s):  
Yingying Jia ◽  
Ling Xu ◽  
Bangshao Yin ◽  
Mingbo Zhou ◽  
Jianxin Song

Beginning with 5,10,15-triarylporphyrin-nickel complex, five meso-to-meso directly linked porphyrin-diazaporphyrin triads were successfully prepared for the first time through a series of reactions including formylation via Vilsmeier–Haack reaction, condensation with pyrrole, bromination with [Formula: see text]-Bromosuccinimide (NBS), oxidation with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), metal-templated cyclization of dibromodipyrrin-metal complexes with NaN[Formula: see text] and demetalization. All these triads were comprehensively characterized by [Formula: see text]H NMR, high-resolution mass spectrometry and UV-vis absorption. In addition, the structure of compound 6Ni was unambiguously determined by X-ray diffraction analysis, which showed that the two dihedral angles are both 86.65 (4)[Formula: see text] between each mean plane of porphyrin and that of central diazaporphyrin The UV-vis absorption spectra disclosed that the longest wavelengths of Soret bands and Q bands for these triads were observed at 429 and 642 nm, respectively. In contrast to diazaporphyrin-porphyrin dyads, diazaporphyrin dimers and diazaporphyrin monomers reported previously the molar extinction coefficients, particularly for triad 8Ni are much higher.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4364
Author(s):  
Rutaba Amjad ◽  
Bismillah Mubeen ◽  
Syed Shahbaz Ali ◽  
Syed Sarim Imam ◽  
Sultan Alshehri ◽  
...  

The use of biomaterials in the synthesis of nanoparticles is one of the most up-to-date focuses in modern nanotechnologies and nanosciences. More and more research on green methods of producing metal oxide nanoparticles (NP) is taking place, with the goal to overcome the possible dangers of toxic chemicals for a safe and innocuous environment. In this study, we synthesized copper nanoparticles (CuNPs) using Fortunella margarita leaves’ extract, which reflects its novelty in the field of nanosciences. The visual observation of a color change from dark green to bluish green clearly shows the instant and spontaneous formation of CuNPs when the phytochemicals of F. margarita come in contact with Cu+2 ions. The synthesis of CuNPs was carried out at different conditions, including pH, temperature, concentration ratio and time, and were characterized with UV-Vis absorption spectra, scanning electron microscope (SEM) and X-ray diffraction (XRD). The UV-Vis analysis reveals the surface plasmon resonance property (SPR) of CuNPs, showing a characteristic absorption peak at 679 nm, while SEM reveals the spherical but agglomerated shape of CuNPs of the size within the range of 51.26–56.66 nm.


2002 ◽  
Vol 06 (03) ◽  
pp. 198-202 ◽  
Author(s):  
José L. Sosa-Sánchez ◽  
Alberto Galindo ◽  
Dino Gnecco ◽  
Sylvain Bernès ◽  
George R. Fern ◽  
...  

The synthesis and spectroscopic characterization of a new soluble silicon(IV) phthalocyanine complex is presented. The compound shows an increased solubility compared to its SiPcCl 2 precursor and this allowed solution 1 H NMR characterization. The assignment of the 1 H NMR signals for the axial ligands is greatly facilitated due to the anisotropic high ring current effects from the macrocycle. In addition, good quality crystals were grown from this more soluble material for molecular structure determination by single-crystal X-ray diffraction analysis. The molecular structure determination shows that the complex crystallizes in a non-centrosymmetric space group due to the inherent chirality of the naproxene ligands. Bond lengths and angles fit well to other analogous compounds previously reported.


2017 ◽  
Vol 72 (8) ◽  
pp. 573-577 ◽  
Author(s):  
Seyed Ghorban Hosseini ◽  
Keyvan Moeini ◽  
Mohammed S.M. Abdelbaky ◽  
Santiago García-Granda

AbstractIn this work, a coordination polymer formed from 4,5-diamino-3-methyl-4H-1,2,4-triazol-1-ium chloride (DAMT·HCl) and HgCl2 formulated as [Hg5(μ-DAMT)2(μ-Cl)6(μ3-Cl)2Cl2]n has been prepared and characterized by elemental analysis, FT-IR, 1H NMR spectroscopy, and single-crystal X-ray diffraction. X-ray analysis of the complex revealed an organic-inorganic hybrid coordination polymer containing three different mercury atoms with coordination numbers of 4 (HgN(μ-Cl)2(μ3-Cl)), 5 (Hg(μ-Cl)3(μ3-Cl)Cl), and 6 (HgN2(μ-Cl)2(μ3-Cl)2) and seesaw, octahedral, and square pyramidal geometries, respectively. The polymeric chains are extended to a three-dimensional (3D) array by C–H···Cl and N–H···Cl interactions. In addition to these hydrogen bonds, there are Hg···Cl interactions with the mercury atoms with coordination numbers 4 and 5 to complete their pseudo-square planar and -octahedral geometries, respectively.


1993 ◽  
Vol 48 (4) ◽  
pp. 409-417 ◽  
Author(s):  
Rostislav D. Lampeka ◽  
Zamira D. Uzakbergenova ◽  
Victor V. Skopenko

Mixed complexes of Co(III) with 2-oximinopropionic (H2A) or 2-oximino-3-phenylpropionic (H2B) acid and different amine (imidazole, benzimidazole, pyridine, β-picoline, γ-picoline) are reported. Characterization of the complexes was based upon elemental analysis, conductivity and JR, 1H NMR, and electronic absorption spectra, and X-ray diffraction analysis. The organic ligands behave as O,N donors via the carboxyl oxygen and the oxime nitrogen atoms. A trans-octahedral structure has been assigned to the bis(2-oximinocarboxylato)bis(amine)cobalt(III) on the basis of 1H NMR data.The crystal and molecular structures of the complexes trans-[bis(2-oximinopropionato)bis-(imidazole)]- (I) and trans-[bis(2-oximinopropionato)bis(pyridine)]cobalt(III) (II) were determined. I crystallizes in space group P2/n with a = 14.1 67(2), b = 8.774(1), c = 14.785(2) Å,β = 113.37(1)°, Z = 4, Dcalc = 1.568 g · cm-3. II crystallizes in space group P1̄ with a = 9.122(2), b = 10.038(2), c = 11.759(2) Å, α = 69.95(1)°, β = 67.47(2)°, γ = 69.49(2)°, Ζ = 2, Dcalc = 1.547 g cm-3. The structures were refined to unweighted R factors of 0.036 and 0.028, respectively. The coordination sphere around Co is pseudo-octahedral with the 2-oximinopropionato ligands occupying four equatorial positions, and the amines in axial positions.


Author(s):  
ROGER GUILARD ◽  
VIRGINIE PICHON-PESME ◽  
HASSANE LACHEKAR ◽  
CLAUDE LECOMTE ◽  
ALLY M. AUKAULOO ◽  
...  

The synthesis and characterization of three monomeric aluminum porphycenes with anionic or σ-bonded axial ligands is reported. The investigated compounds are represented as ( EtioPc ) Al ( CH 3) and ( EtioPc ) AlX where EtioPc represents the dianion of etioporphycene and X = Cl − or OH −. Each synthesized complex was characterized by mass spectrometry. 1 H NMR, IR and UV-visible spectroscopies as well as by electrochemistry. Comparisons are made between the properties of complexes in the aluminum etioporphycene series and related chloro- or methyl σ-bonded Al ( III ) porphyrins containing octaethylporphyrin ( OEP ) or tetraphenylporphyrin ( TPP ) macrocycles. Comparisons are also made between the currently investigated compounds and a previously reported Al ( III ) μ-oxo dimer, [( EtioPc ) Al ]2 O . In addition, the crystal and molecular structure of ( EtioPc ) Al ( CH 3) was determined by X-ray diffraction. The molecular structure of this methyl-σ-bonded aluminum etioporphycene provides the first structural data for an aluminum porphycene compound. The aluminum(III) atom in ( EtioPc ) Al ( CH 3) is pentacoordinated and is located 0.54 Å from the plane of the four N -nitrogens.


2010 ◽  
Vol 636-637 ◽  
pp. 714-721 ◽  
Author(s):  
K. Kordatos ◽  
A. Ntziouni ◽  
A. Theodoratou ◽  
Maria Perraki ◽  
M. Terrones ◽  
...  

The present work describes the synthesis of nitrogen doped multi-walled carbon nanotubes (CNx CNT). The chosen production method was the catalytic pyrolysis of a solid mixture containing [Ni(DMG)2] and melamine (C3H6N6), under an Αr atmosphere. A series of various experiments were performed, using different proportions of the reaction mixture, in order to optimize the production conditions of nitrogen doped carbon nanotubes. Finally, the produced materials were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX), Raman spectroscopy as well as thermogravimetric analysis (TGA). The obtained data from all the above analyses, showed the formation of nitrogen doped carbon nanotubes of various diameters as well as nanofibers surrounded by byproducts such as aggregations of amorphous carbon and metallic catalyst, depending on the proportion of the reaction mixture.


2015 ◽  
Vol 1094 ◽  
pp. 41-48
Author(s):  
Ri Min Cong ◽  
Huai Qing Yu ◽  
Yan Gong Yang ◽  
Si Yi Yang ◽  
Jiao Li ◽  
...  

A dumbbell-shaped polyrotaxane based on polytetrahydrofuran bis (3-aminopropyl) terminated and α-cyclodextrins using polyamidoamine (PAMAM) dentrimers as bulky stoppers was successfully prepared. The1H NMR results show that the peaks of α-CDs in these polyrotaxanes are broadened compared with pure α-CDs. Wide-angle X-ray diffraction (XRD) measurements of the resulting polyrotaxanes suggest to produce a channel-type crystalline structure of inclusion complex. Thermogravimetric analysis (TGA) of the resultant polyrotaxanes show that α-CDs are significantly stabilized by the formation of the inclusion complexes.


2000 ◽  
Vol 55 (5) ◽  
pp. 373-376 ◽  
Author(s):  
Andrey B. Lysenko ◽  
Oleg V. Shishkin ◽  
Rostislav D. Lampeka

The 1:1 complex of palladium(II) chloride with 2-(2-methyl-3-phenyl-isoxazolidin-5-yl)- pyridine (L) has been prepared and studied by means of elemental analysis, 1H NMR spectroscopy and X-ray diffraction (monoclinic, space group P21/n with parameters: a = 8.141(2), b = 9.750(2),c = 20.691(6)Å ,β = 95.62(3)°,V = 1634.4(7)Å3 ,Z = 4 ;R1= 0.054 and wR2= 0.144 for 3352 unique reflections). A square-planar coordination polyhedron has been established for the palladium atom both in acetone solution and in the solid state. The organic ligand is coordinated toometal in a bidentate manner via nitrogen atoms of the pyridine substituent (Pd-N(2) 2.125(3) Å) and the isoxazolidine heterocycle (Pd-N(l) 2.102(3) Å). The other two coordination positions of palladium are occupied by chlorine atoms (Pd-Cl(l) 2.321(1) and Pd-Cl(2) 2.333(1) Å). The six-membered chelate ring formed by Pd, N(2), C(4), C(1), 0(1) and N (1) possesses a “twist-tub” conformation. The isoxazolidine cycle has an envelope conformation with an equatorial orientation of the methyl group.


2015 ◽  
Vol 30 (4) ◽  
pp. 357-361 ◽  
Author(s):  
Bruno Z. Mascaliovas ◽  
Fernando R.G. Bergamini ◽  
Alexandre Cuin ◽  
Pedro P. Corbi

Synthesis and structural characterization of a novel palladium Pd(II) complex with the amino acid L-citrulline (Cit, C6H13N3O3) are presented in this paper. Elemental analysis indicates a 1:2 metal/ligand molar composition for the complex, with the molecular formula PdC12H24N6O6. The compound was also characterized by infrared (IR) spectroscopic measurements and the crystal structure has been solved by powder X-ray diffraction data with simulated annealing strategy in real space. The Pd(II) complex crystallizes in the triclinic system with space group P-1 and cell parameters a = 4.6493(4) Å, b = 5.222(4) Å, c = 18.040(2) Å, α = 77.41(6)°, β = 94.72(7),° and γ = 101.45(7)°. The crystal structure confirms the presence of Pd(II) ions in a nearly square planar environment and the molecular formula with deprotonated citrulline as proposed by analytical and spectroscopic data.


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