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Damir A Safin - One of the best experts on this subject based on the ideXlab platform.
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a novel paramagnetic coordination polymer fabricated from co ncs 2 and 2 Pyridinecarbaldehyde isonicotinoylhydrazone
Inorganica Chimica Acta, 2021Co-Authors: Ghodrat Mahmoudi, Ali Akbar Khandar, Farhad Akbari Afkhami, Atakan Toprak, Fedor I Zubkov, Jonathan M White, Julia Klak, Damir A SafinAbstract:Abstract We report on a mixed cobalt(II)/cobalt(III) heteroleptic coordination polymer of the salt-like structure {[(CoIIIL2)2CoII(NCS)2][CoII(NCS)4]}n∙a(solvent) (1∙a(solvent)), obtained by a reaction of Co(NCS)2 with 2-Pyridinecarbaldehyde isonicotinoylhydrazone (HL). Complex 1∙a(solvent) contains 15.52% of solvent molecules, which fits to six molecules of EtOH per one [(CoIIIL2)2CoII(NCS)2][CoII(NCS)4] species, and the structure of the crystals can be assigned to the {[(CoIIIL2)2CoII(NCS)2][CoII(NCS)4]}n∙6EtOH composition. 1∙a(solvent) was found to be stable after drying at 80 °C for several days, yielding a solvent-free complex 1. The FTIR data of both structures supports the complete loss of solvents after drying, while the general framework remains intact. As evident from the comparison of the experimental X-ray powder diffraction data of 1 with the calculated powder pattern generated from the single crystal X-ray data of 1∙a(solvent), the former complex partially loses its crystallinity; however, the experimental powder pattern resembles the calculated one. Thus, the overall structure of 1 is similar to that of 1∙a(solvent). The crystal structure of 1∙a(solvent) is constructed from the V-shaped (CoIIIL2)+ cations, where the metal ion is N4S2-coordinated by two L. These (CoIIIL2)+ cations are interlinked through CoII(NCS)2 molecules by coordination via free 4-pyridyl nitrogen atoms, yielding a 1D polymeric cationic chain {[(CoIIIL2)2CoII(NCS)2]2+}n, which are interlinked into a 3D framework through a bunch of bifurcated (N)C–S⋯π(2-Py) and linear (NN)C–H⋯O non-covalent interactions. Due to such 3D aggregation, a half of rhombohedral cells are filled by the interlayered [CoII(NCS)4]2– anions, while the other half of cells is free from non-volatile species and filled with volatile solvent molecules, yielding 1D tubular voids, which occupy about 17% of unit cell volume. Direct current variable-temperature magnetic susceptibility measurements on a polycrystalline sample of 1∙a(solvent) were carried out in the temperature range 1.8–300 K. The magnetic behaviour of 1∙a(solvent) indicates the presence of magnetic anisotropy of the CoII ions and/or very weak intermolecular exchange interactions. The surface and pore properties of 1 and HL were calculated by N2 adsorption at 77 K. In addition, CO2 adsorption properties of 1 and HL at different temperatures were determined. It was found that 1 increased both textural and CO2 adsorption properties.
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non covalent interactions induced supramolecular architecture of hg ncs 2 with 3 Pyridinecarbaldehyde nicotinoylhydrazone
Inorganica Chimica Acta, 2020Co-Authors: Juan D Velasquez, Ghodrat Mahmoudi, Damir A Safin, Ennio Zangrando, Barbara Miroslaw, Jorge EcheverriaAbstract:Abstract In this work we have synthesized and characterized a new HgII complex [Hg(HL)(NCS)2]2, fabricated from Hg(NCS)2 and 3-Pyridinecarbaldehyde nicotinoylhydrazone (HL). Single-crystal X-ray crystallography reveals the formation of a dinuclear heteroleptic discrete structure with half of the molecule, [Hg(HL)(SCN)2], in the asymmetric unit. The ligand HL coordinates the HgII center in an unexpected monodentate fashion via the pyridine nitrogen of the nicotinic moiety. Molecules are aggregated through intermolecular N–H∙∙∙N hydrogen bonds and additional weak Hg∙∙∙N interactions. Molecules of complex aggregate into a 2D supramolecular layer with a four-connected uninodal sql (Shubnikov tetragonal plane net) topology due to intermolecular N–H∙∙∙N hydrogen bonds. When the Hg∙∙∙N interactions are excusively considered, a similar layer is formed revealing a three-connected uninodal hcb (Shubnikov hexagonal plane net) topology. Further considering both the intermolecular N–H∙∙∙N hydrogen bonds and Hg∙∙∙N interactions, the structure of complex can be extended into a 3D supramolecular framework with an eight-connected uninodal bcu (body centered cubic) topology. We have also applied DFT calculations as well as MEP, QTAIM, NCI and NBO analyses to shed light on interactions in the crystal structure of the complex. Among others, reciprocal n → π* interactions between the nitrogen lone pairs and empty antibonding π* C–N orbitals of the NCS– anions have been determined.
Kiet V Truong - One of the best experts on this subject based on the ideXlab platform.
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facile synthesis of 4 oxo 4h quinolizine 2 carboxamide derivatives
Synthetic Communications, 2015Co-Authors: Duy Duc Vo, Cuc Thi Kim Tu, Yen Nguyen Tram Chau, Kiet V TruongAbstract:AbstractA facile synthetic method for the construction of 2-substituted-4-oxo-4H-quinolizine-based core structure has been successfully developed. The synthesis made use of a one-pot Stobbe condensation followed by cyclization starting from the commercially available 2-Pyridinecarbaldehyde. The structure of the formed 4-oxo-4H-quinolizine-2-carboxylate was fully confirmed by mass spectra, 1H NMR and 13C NMR, correlation spectrography, heteronuclear multiple bond correlation, and heteronuclear single quantum coherence (HSQC) spectra. The ethyl carboxylate moiety was then further functionalized via direct aminolysis by a range of amines to afford the corresponding 4-oxo-4H-quinolizine-2-carboxamides 4a–i in moderate to good yields.
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Facile Synthesis of 4-Oxo-4H-quinolizine-2-carboxamide Derivatives
2015Co-Authors: Hue T. B. Bui, Yen Nguyen Tram Chau, Hieu V. Mai, Kiet V TruongAbstract:A facile synthetic method for the construction of 2-substituted-4-oxo-4H-quinolizine based core structure has been successfully developed. The synthesis made use of a one pot Stobbe condensation followed by cyclisation starting from the commercially available 2-Pyridinecarbaldehyde. The structure of the formed 4-oxo-4H-quinolizine-2-carboxylate was fully confirmed by MS, 1H NMR, 13C NMR, COSY, HMBC and HSQC spectra. The ethyl carboxylate moiety was then further functionalized via direct aminolysis by a range of amines to afford the corresponding 4-oxo-4H-quinolizine-2-carboxamides 4a-i in moderate to good yields.
Brian W Skelton - One of the best experts on this subject based on the ideXlab platform.
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crystal structure of imidazo 1 5 a pyridinium based hybrid salt c13h12n3 2 mncl4
Acta Crystallographica Section E: Crystallographic Communications, 2020Co-Authors: Olga Yu Vassilyeva, Elena A Buvaylo, Vladimir N Kokozay, Andrii K Melnyk, Svitlana R Petrusenko, Brian W SkeltonAbstract:A new organic–inorganic hybrid salt [L]2[MnCl4] (I) where L+ is the 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, is built of discrete organic cations and tetrachloridomanganate(II) anions. The L+ cation was formed in situ in the oxidative cyclocondensation of 2-pyridinecarbaldehyde and CH3NH2·HCl in methanol. The structure was refined as a two-component twin using PLATON (Spek, 2020) to de-twin the data. The twin law (−1 0 0 0 − 1 0 0.5 0 1) was applied in the refinement where the twin component fraction refined to 0.155 (1). The compound crystallizes in the space group P21/c with two crystallographically non-equivalent cations in the asymmetric unit, which possess similar structural conformations. The fused pyridinium and imidazolium rings of the cations are virtually coplanar [dihedral angles are 0.89 (18) and 0.78 (17)°]; the pendant pyridyl rings are twisted by 36.83 (14) and 36.14 (13)° with respect to the planes of the remaining atoms of the cations. The tetrahedral MnCl42– anion is slightly distorted with the Mn—Cl distances falling in the range 2.3469 (10)–2.3941 (9) A. The distortion value of 0.044 relative to the ideal tetrahedron was obtained by continuous shape measurement (CShM) analysis. In the crystal, the cations and anions form separate stacks propagating along the a-axis direction. The organic cations display weak π–π stacking. The anions, which are stacked identically one above the other, demonstrate loose packing; the minimum Mn⋯Mn separation in the cation stack is approximately 7.49 A. The investigation of the fluorescent properties of a powdered sample of (I) showed no emission. X-band EPR data for (I) at 293 and 77 K revealed broad fine structure signals, indicating moderate zero-field splitting.
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copper ii complex of the 2 Pyridinecarbaldehyde aminoguanidine schiff base crystal structure and catalytic behaviour in mild oxidation of alkanes
Inorganic Chemistry Communications, 2017Co-Authors: Elena A Buvaylo, Vladimir N Kokozay, Olga Yu Vassilyeva, Brian W Skelton, Oksana V Nesterova, Armando J L PombeiroAbstract:Abstract The new neutral dichloro-copper(II) Schiff base complex [CuCl2L]·dmf 2, where L results from condensation of 2-Pyridinecarbaldehyde and aminoguanidine, was prepared, while the ligand itself was isolated in its protonated form as the dinitrate salt (H2L)(NO3)2 1. Extended conjugation is responsible for the planarity of the H2L2 + cation in 1. On coordination, L forms two fused 5-membered chelate rings occupying three equatorial positions of the distorted square pyramidal copper polyhedron in 2. The catalytic investigations disclosed a prominent activity of the copper compound 2 towards oxidation of cyclohexane with hydrogen peroxide in the presence of various promoters (nitric and acetic acids, pyridine and pyrrole), showing overall yields of products (cyclohexanol and cyclohexanone) up to 21% based on the substrate.
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divalent manganese cobalt and nickel chloride complexes with neutral n2 and n3 based ligands derived from 2 Pyridinecarbaldehyde synthesis structural features and spectroscopic studies
Polyhedron, 2016Co-Authors: Elena A Buvaylo, Olga Yu Vassilyeva, Andrii K Melnyk, Vladimir V Trachevsky, Brian W SkeltonAbstract:Abstract A series of dihalide M(II) mononuclear complexes in a cis configuration, Mn(HL1)2Cl2·CH3OH·H2O (1), Co(HL1)2Cl2·CH3OH·H2O (2), Ni(HL1)2Cl2·2H2O (3) and CoL2Cl2·0.5dmf (4) (HL1 – Schiff base ligand 4-N-(2′-pyridylimine)benzoic acid; L2 – pyridin-2-yl(3-(pyridin-2-yl)imidazo[1,5-a]pyridin-1-yl) methanone, both formed in situ from 2-Pyridinecarbaldehyde), have been obtained as single crystals and characterized by elemental analysis, IR and EPR spectroscopy, and single-crystal X-ray diffraction techniques. The neutral M(L1)2Cl2 and CoL2Cl2 molecules in 1–3 and 4, respectively, show no crystallographically imposed symmetry with the metal atoms in a MN4Cl2 distorted octahedral (1–3) and CoN3Cl2 (4) elongated trigonal–bipyramidal geometries. In the crystal lattice molecules of 1–3 are arranged in columns propagating along the c axis; the structure of 4 can be described as layers of CoL2Cl2 and dmf molecules alternating along the a axis. The minimum M⋯M separations in a column (1–3) and inside a layer (4) are above 8 A. The X-band solid-state EPR spectra of 1 at room temperature and 77 K exhibit broad fine structure signals at 1600 and 3000 G (geff ∼ 4.14 and 2.22, respectively) resulting from ZFS of the spin states for the high-spin d5 metal ion. The solid-state EPR spectra of 2 are temperature dependent showing a wide unresolved line at geff ∼ 2.09 at room temperature and a very broad signal (ΔHpp = 2500 G) at geff ∼ 4.21 at 77 K. The Ni analogue 3 is EPR-silent. The EPR spectra of 4 at both temperatures show a broad asymmetrical signal centred at g ∼ 2 suggesting the low-spin configuration; the line width is nearly independent of temperature.
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hybrid organic inorganic chlorozincate and a molecular zinc complex involving the in situ formed imidazo 1 5 a pyridinium cation serendipitous oxidative cyclization structures and photophysical properties
Dalton Transactions, 2015Co-Authors: Elena A Buvaylo, Vladimir N Kokozay, Olga Yu Vassilyeva, R P Linnik, Brian W SkeltonAbstract:Two novel compounds, the organic–inorganic hybrid [L]2[ZnCl4] (1) and the coordination complex LZnCl3 (2), where L is the 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium cation, were prepared using the oxidative condensation–cyclization of 2-Pyridinecarbaldehyde and CH3NH2·HCl in methanol in the presence of Zn2+ cations. The metal-free interaction of the organic components afforded the salt [L][Cl]·1.5H2O (3). The use of methylamine hydrochloride instead of its aqueous solution is believed to be responsible for the cyclocondensation with the formation of L instead of the expected Schiff base ligand. Compounds 1–3 have been obtained as single crystals and characterized by elemental analysis, IR, NMR spectroscopy, and single-crystal X-ray diffraction techniques. The structure of 1 is described as layers of cations and anions stacked along the c-axis, with the minimum Zn⋯Zn distance being 8.435 A inside a layer. In the crystal lattice of 3, the cations are arranged in stacks propagating along the a-axis; the 1D H-bonding polymer built of chloride ions and water molecules runs parallel to a column of stacked cations. The organic cations in salts 1 and 3 show various patterns of π–π stacking. The discrete molecular structure of 2 shows coordination of a Zn atom to the Npyridyl atom, which enables one of the chloride atoms attached to the metal centre to interact with a π-system of the positively charged imidazolium ring. Numerous C–H⋯Cl contacts in 1–3 are seen as space-filling van der Waals interactions of minor importance in determining crystal packing. The 1H NMR studies suggest that the Zn–N coordination found in the solid-state structure of 2 is not retained in dmso, and 1, 2 and 3 are completely dissociated in solution. The emission spectra of 1 and 2 (λmax = 455 and 445 nm, respectively) exhibit red-shifts of fluorescence wavelength when compared to 3 and differ in the shapes and maxima of the emission as well as in relative fluorescence intensity.
Guy R G Rudolph - One of the best experts on this subject based on the ideXlab platform.
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some aspects of the coordination chemistry of 2 Pyridinecarbaldehyde azine 2 paa the crystal structure of a complex with manganese ii cis mncl2 2 paa 2
Polyhedron, 1998Co-Authors: Dennis A Edwards, Grace M Hoskins, Mary F Mahon, Kieran C Malloy, Guy R G RudolphAbstract:Abstract In the complex cis-[MnCl2(2-paa)2], (2-paa = 2-Pyridinecarbaldehyde azine) each 2-paa behaves as a bidentate chelating ligand using adjacent pyridyl and azine nitrogen donor atoms. Twisting about the NN bonds removes the remaining two nitrogen donor atoms of each 2-paa away from the vicinity of the metal centre. This complex is the first to be reported containing two bidentate 2-paa ligands. Only one previous example of a metal complex involving a single bidentate 6-methyl-2-paa ligand has been examined structurally. The complexes [Mn2Cl4(2-paa)], [Zn2(NO3)4(2-paa)] · 2H2O and [Ag2(NO3)2(2-paa)] have also been isolated, NMR evidence indicating that in the zinc and silver complexes the 2-paa ligands act in a double bidentate coordination mode.
Hajime Ishii - One of the best experts on this subject based on the ideXlab platform.
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synthesis and properties of 3 4 and 5 nitro 2 Pyridinecarbaldehyde 2 pyridylhydrazones and characterization of their metal complexes
ChemInform, 1993Co-Authors: Tsugikatsu Odashima, Kei Sakakura, Katsunori Kohata, Hajime IshiiAbstract:Three hydrazones, 3-, 4-, and 5-nitro-2-Pyridinecarbaldehyde 2-pyridylhydrazones, were synthesized. Their properties and reactivities with metal ions and the extraction and characteristics of the resultant complexes have been investigated and compared with one another. As a result, useful information on the molecular design of highly sensitive hydrazone reagents has been obtained.
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synthesis and properties of hydrazones from 3 and or 5 nitro 2 pyridylhydrazine and heterocyclic aldehydes characterization of their complexes and extraction spectrophotometric determination of traces of nickel with 2 Pyridinecarbaldehyde 3 5 dinitro
Analytica Chimica Acta, 1993Co-Authors: Tsugikatsu Odashima, Hajime IshiiAbstract:Abstract Four new hydrazones, 2-Pyridinecarbaldehyde 3-nitro-2-pyridylhydrazone, 2-Pyridinecarbaldehyde 3,5-dinitro-2-pyridylhydrazone (PA-3,5-NPH), 2-quinolinecarbaldehyde 5-nitro-2-pyridylhydrazone and 6-phenanthridinecarbaldehyde 5-nitro-2-pyridylhydrazone, were synthesized. Their properties and reactivities with metal ions and the properties of the resultant complexes were investigated spectrophotometrically and compared mutually and with those of 2-Pyridinecarbaldehyde 5-nitro-2-pyridylhydrazone. Useful information on the molecular design of the hydrazone reagent was obtained. A highly sensitive and practical extraction-spectrophotometric method for the determination of nickel with PA-3,5-NPH was developed and applied successfully to the determination of nickel in steel samples.
