scholarly journals Syntheses, Characterization, and X-ray Crystal Structure of Binuclear Lanthanide Complexes Assembled with Schiff Base and Acetate

2021 ◽  
pp. 81-95
Author(s):  
Mbossé Ndiaye-Gueye ◽  
Amar Diop ◽  
Papa Aly Gaye ◽  
Ibrahima Elhadji Thiam ◽  
Farba Bouyagui Tamboura ◽  
...  
Keyword(s):  
Schiff Base ◽  
Intermolecular Hydrogen Bond ◽  
Methanol Solution ◽  
Tridentate Ligand ◽  
Water Molecules ◽  
Binuclear Complexes ◽  
Asymmetric Unit ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
X Ray

Herein we reported the binuclear complexes of the 1-(pyridin-2-yl)-2-(pyridin-2-ylmethylene)hydrazine ligand (HL) [Ln2(HL)2(CH3COO)6].n(H2O) (Ln = Y, Pr, Gd and Er). The binuclear complexes are characterized by IR and physical measurement. Spectroscopic evidence indicated that the Schiff base HL behave an N3 coordination tridentate ligand. The complexes are formulated as [{Ln(1-(pyridin-2-ylmethylidene-kN)-2-(pyridin-2-yl-kN)hydrazine-kN1)(h2-OOCH3)2}{h1:h2:m2-OOCH3}2{Ln(1-(pyridin-2-ylmethylidene-kN)-2-(pyridin-2-yl-kN)hydrazine-kN1))(h2-OOCH3)2}].n(H2O). The structure of the praseodymium complex was elucidated by X-ray diffraction analysis. Suitable crystals were grown by slow evaporation of methanol solution. The asymmetric unit of the compound contains two neutral ligand molecules, two Pr3+ ions, four acetate anions acting in h2-OOCH3 mode, two acetate anions acting in h1:h2:m2-OOCH3 mode, and three uncoordinated water molecules. The praseodymium atom is ten coordinated and the coordination sphere is best described as a distorted bicapped square antiprism. The PrIII···PrIII distance is 4.2777(6) Å and the bridging angle Pr—O—Pr and O—Pr—O are respectively 115.8(3)° and 64.2(3)°. The structure is consolidated by intra and intermolecular hydrogen bond.

scholarly journals Characterization and Structural Analysis of Genkwanin, a Natural Product from Callicarpa americana

Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 491
Author(s):  
Gina Porras ◽  
John Bacsa ◽  
Huaqiao Tang ◽  
Cassandra L. Quave
Keyword(s):  
Natural Compound ◽  
Methanol Solution ◽  
Asymmetric Unit ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Spectroscopic Analyses ◽  
Independent Molecules ◽  
High Degree

The natural compound Genkwanin (systematic name: 5-hydroxy-2-(4-hydroxyphenyl)-7-methoxychromen-4-one) C16H12O5 (1) is a non-glycosylated flavonoid isolated from Callicarpa americana. Microcrystals of Genkwanin were prepared by slow evaporation of a methanol solution under low temperature conditions. The structure of 1 was determined based on spectroscopic analyses, one-dimensional NMR, HRESIMS and was confirmed by single-crystal X-ray diffraction. The crystals grow as very thin needles with an extremely high aspect ratio and with the long axis (along the y-axis) corresponding to the very short unit cell b-axis. There are two independent molecules in the asymmetric unit with two different conformations and modes of packing in the crystal. One molecule has a higher degree on non-planarity than the other. The short stacking distance and separation between the molecules implies a high degree of co-planarity consistent with a conjugated system. The crystal structure is non-centrosymmetric but achiral.

scholarly journals Synthesis and structural peculiarities of gallium Complexes with novel paullone derivatives

2008 ◽  
Vol 6 (3) ◽  
pp. 340-346 ◽  
Author(s):  
Werner Ginzinger ◽  
Vladimir Arion ◽  
Gerald Giester ◽  
Markus Galanski ◽  
Bernhard Keppler
Keyword(s):  
Schiff Base ◽  
Tridentate Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gallium Chloride ◽  
Structural Peculiarities ◽  
Gallium Complex ◽  
Gallium Complexes

Abstract9-Bromo-7,12-dihydroindolo[3,2-d][1]benzazepin-6-ylhydrazine was reacted with 2-acetylpyridine to give a Schiff base as a potential tridentate ligand. The reaction of this ligand with gallium chloride afforded complexes of 1:1 and 2:1 stoichiometry. The results of X-ray diffraction studies of the ligand and both gallium complexes are reported and compared with the data for a related gallium complex with a Schiff base obtained from 9-bromo-7,12-dihydroindolo[3,2-d][1]benzazepin-6-ylhydrazine and 2-hydroxybenzaldehyde.

Syntheses, Structures, Thermal and Photoluminescence Properties of Two Zn(II) and Cd(II) Coordination Polymers Constructed from Taurine-derived Schiff Base and 4,4’-Bipyridine Ligands

2012 ◽  
Vol 67 (8) ◽  
pp. 774-782 ◽  
Author(s):  
Wei-Ting Guo ◽  
Zhi-Min Miao ◽  
Yun-Long Wang
Keyword(s):  
Schiff Base ◽  
Coordination Polymers ◽  
Tridentate Ligand ◽  
Supramolecular Architecture ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Monodentate Ligand ◽  
Metal Centers ◽  
X Ray ◽  
Ethanesulfonic Acid

Two chain-like coordination polymers, namely, {[Zn(saes)(4,4'-bipy)(H2O)]·H2O}n (1) and {[Cd (Hsaes)2(4,4'-bipy)(H2O)2]·2H2O}n (2), where H2saes=2-(2-hydroxybenzylideneamino)ethanesulfonic acid and 4,4'-bipy=4,4'-bipyridine, have been synthesized and characterized by singlecrystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric and photoluminescence analysis. X-Ray diffraction analyses indicate that 1and 2display octahedral metal centers with N3O3 and N2O4 donor sets, respectively. The Schiff base serves as a common N,O'-tridentate ligand in 1, and as a unique O-monodentate ligand in 2. In the crystal, both 1and 2form a 3D supramolecular architecture by O-H···O, C-H···O interactions or π···π stacking. The thermal and solid-state photoluminescence properties of both complexes have been investigated

A new organically templated magnesium sulfate: structure, spectroscopic analysis, and thermal behaviour

2014 ◽  
Vol 68 (2) ◽  
Author(s):  
Dhouha Hassan ◽  
Walid Rekik ◽  
Houcine Naïli ◽  
Tahar Mhiri
Keyword(s):  
Thermal Decomposition ◽  
Hydrogen Bonds ◽  
Magnesium Sulfate ◽  
Spectroscopic Analysis ◽  
Water Molecules ◽  
Supramolecular Network ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray

AbstractA new magnesium sulfate templated by 2-methylpiperazine, (C5H14N2)[Mg(H2O)6](SO4)2, was prepared by the slow evaporation method. The obtained crystals were investigated by the Raman and FTIR spectroscopy and crystallographically characterised by single-crystal X-ray diffraction. The compound crystallises in the monoclinic system, space group P21/n. Supramolecular network of this hybrid material consists of Mg2+ cations octahedrally coordinated by six water molecules, sulfate tetrahedra and protonated and disordered diamine linked together by two types of hydrogen bonds: OW—H…O and N—H…O. Dehydration of the title compound takes place in three steps. Thermal decomposition of the anhydrous phase consists in the loss of the organic moiety and one sulfate group leading to the formation of magnesium sulfate.

Supercell and subcell description of the crystal structure of triammonium bis(O-phospho-L-serinate) trihydrate

2006 ◽  
Vol 62 (5) ◽  
pp. 919-925 ◽  
Author(s):  
Małgorzata Hołyńska ◽  
Iwona Bryndal ◽  
Tadeusz Lis
Keyword(s):  
Crystal Structure ◽  
Diffraction Pattern ◽  
Water Molecules ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Data Set ◽  
Space Group ◽  
X Ray ◽  
Average Structure ◽  
Structure Solution

The X-ray diffraction pattern obtained for a crystal of triammonium bis(O-phospho-L-serinate) trihydrate at 100 K displays the presence of weak superstructure reflections with odd l indices. Omission of the superstructure reflections leads to orthorhombic Laue symmetry. The structure may be solved and refined in the space group P212121 as an average structure omitting the weak reflections. The model reveals the presence of O-phospho-L-serinate monoanions, ammonium cations and partly disordered water molecules. The structure solution for the whole data set could be obtained only in the space group P21. There are two monoanions and two dianions of O-phospho-L-serinate per asymmetric unit, as well as six ordered ammonium cations and six water molecules.

The structure determination of a binuclear copper(II) complex of aTetra-Schiff base macrocycle

1976 ◽  
Vol 29 (3) ◽  
pp. 515 ◽  
Author(s):  
BF Hoskins ◽  
NJ McLeod ◽  
HA Schaap
Keyword(s):  
Schiff Base ◽  
Least Squares Method ◽  
Condensation Product ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Binuclear Copper ◽  
Apical Position ◽  
X Ray ◽  
Space Groups

The structure of the complex Lcu2Cl2,6H2O (where LH2 is the tetra-Schiff base macrocycle formed as the condensation product of propane-1,3-diamine and 2-hydroxy-5-methylisophthal- aldehyde in the mole ratio 2: 2) was determined by single-crystal X-ray diffraction methods. The crystals are monoclinic, a 7.720(1), b 17.079(1), c 11.171(1) � and β 91.50(1)�, with two molecules per unit cell. It has proved difficult to resolve the ambiguity between the three possible space groups (C2, Cm, and C2/m) and the initial model has been refined in each using a full-matrix least-squares method. The space group C2/m seems the most likely and the structure is described in it; R 0.049 for the 1369 independent reflections measured using counter methods. The structure analysis has confirmed the anticipated cyclic structure of the ligand with the two copper atoms held together in a binuclear arrangement by the planar N4O2 donor set; the Cu.. .Cu distance is 3.133(1)�. Each copper atom has a distorted square-pyramidal environment with the apical position of each being occupied by a chlorine atom; the two chlorine atoms are on the opposite sides of the macrocycle. The water molecules are not coordinated, but form an extensive system of hydrogen bonding throughout the crystal with discrete binuclear molecules of the LCu2Cl2 complex.

The Crystal Structure of the Pyrimidine Analogue Calcium 5-Ethylidenehydroorotate · 1.5 Hydrate, a Photoproduct of Ethylorotate

1976 ◽  
Vol 31 (9-10) ◽  
pp. 518-523 ◽  
Author(s):  
B Hingerty ◽  
E Kulikowska ◽  
W Saenger ◽  
D Shugar
Keyword(s):  
Crystal Structure ◽  
Calcium Salt ◽  
Direct Methods ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Photochemical Rearrangement ◽  
Pyrimidine Analogue

Abstract X-ray diffraction methods have been employed to establish the crystal structure of a new, unusual pyrimidine analogue, 5-ethylidenehydroorotate, obtained by a photochemical rearrangement of 5-ethylorotate. Crystals of the calcium salt of the title compound are monoclinic, space group Pc, cell constants a=14.631, 6 = 10.038, c = 19.168 Å,β = 137.7°, and contain four molecules, two cations and three water molecules per asymmetric unit. The structure was solved by direct methods and refined to R = 5.2% on the basis of 2653 diffractometer measured data. The four independent molecules represent two pairs of enantiomers with slightly differing conformations linked together by an intricate system of hydrogen bonding and Ca2+-coordination (pentagonal bipyrimidal). The structure of the compound in aqueous medium, as that in the crystal.

scholarly journals Synthesis, Characterization and Crystal Structure of Samarium(III)-(E)-1-phenyl-N-(4H-1,2,4-triazol-4-yl)methanimine Complex

2021 ◽  
pp. 87-94
Keyword(s):  
Schiff Base ◽  
Chemical Structure ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Form Hydrogen Bond ◽  
X Ray ◽  
Mass Spectral ◽  
Cell Parameters ◽  
Ft Ir ◽  
Coordination Water

Samarium-benzylidene Schiff base adduct with the formula [Sm(NO3)3(H2O)3].2L (L= (E)-1-phenyl-N-(4H-1,2,4-triazol-4-yl) methanimine) (1) has been prepared, with two water molecules bonded to the samarium center form hydrogen bond with three molecules of title Schiff base through nitrogen atoms of the triazole rings. The chemical structure was confirmed by means of single-crystal X-ray diffraction (scXRD), FT-IR, electrical conductivity, thermogravimetric analysis (TGA), mass spectrometry and elemental analysis. The title complex 1 crystallizes in the triclinic P-1 space group. The unit cell parameters are a = 10.4045(1) Å, b = 12.5403(1) Å, c = 12.5477(2) Å,  = 96.668(1)o,  = 110.810(1)o,  = 111.567(1)o, V = 1.788 Å3, Z = 2, Rgt(F) = 0.0223, wRref(F2) = 0.0576. The samarium ion is in a distorted capped square antiprism environment, coordinated by three bidentate nitrates and three coordination water molecules. The [Sm(H2O)3(NO3)3] complex and the (E)-1-phenyl-N-(4H-1,2,4-triazol-4-yl)methanimine) moiety (L) are held together via hydrogen interactions to form a 2-D supramolecular framework. It is a non-electrolyte as indicated by its molar conductivity (ΛM= 10.1 S cm2 mol-1) in MeOH at 1.0 mM. The mass spectral results confirm the suggested structure of the investigated adduct.

Metal Complexes of Biologically Important Ligands, CLXXV [1]. Pentamethylcyclopentadienyl Halfsandwich Complexes of Rhodium(III) and Iridium(III) with Schiff Bases from 2-(Diphenylphosphino)- benzaldehyde and α-Amino Acid Esters

2010 ◽  
Vol 65 (6) ◽  
pp. 679-686 ◽  
Author(s):  
Bernhard Schreiner ◽  
Barbara Wagner-Schuh ◽  
Wolfgang Beck
Keyword(s):  
Schiff Base ◽  
Amino Acid ◽  
Schiff Bases ◽  
Ester Group ◽  
Tridentate Ligand ◽  
Molar Ratio ◽  
Amino Acid Esters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acid Esters

The reactions of the chlorido-bridged complexes [Cp*M(Cl)(μ-Cl)]2 (M = Rh, Ir) with Schiff bases (P-N-O) from 2-(diphenylphosphino)benzaldehyde and α-amino acid esters afford the complexes Cp*M(Cl)2(P-N-O) in which the ligands function as monodentate P donors (M = Ir) or as bidentate P-N donors (M = Rh). These complexes can be converted into cationic complexes [Cp*M(Cl)(P-NO)]+ with bidentate P-N ligands by treatment with NH4PF6. The cationic complexes [Cp*M(Cl)(PN- O)]+Cl− have been detected also in solutions of Cp*M(Cl)2(P-N-O). The P-N-coordinated complex [Cp*Rh(Cl)(Ph2P-C6H4-C(H)=N-C(H)(CH2Ph)CO2Me)]+PF6− was characterized by X-ray diffraction. From Cp*M(Cl)2(P-N-O) and AgBF4 or AgPF6 (molar ratio 1 : 2) the dicationic complexes [Cp*M(P-N-O)]2+ are formed in which the ester group is also coordinated to the metal atom. The Schiff base from 2-(diphenylphosphino)benzaldehyde and allylglycine ester acts as a tridentate ligand, however with coordination of the C=C allyl group instead of the ester function.

scholarly journals Mononuclear and Tetranuclear Copper(II) Complexes Bearing Amino Acid Schiff Base Ligands: Structural Characterization and Catalytic Applications

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7301
Author(s):  
Karla-Alejandra López-Gastélum ◽  
Enrique F. Velázquez-Contreras ◽  
Juventino J. García ◽  
Marcos Flores-Alamo ◽  
Gerardo Aguirre ◽  
...  
Keyword(s):  
Schiff Base ◽  
Tridentate Ligand ◽  
Planar Geometry ◽  
X Ray Diffraction ◽  
Schiff Base Ligands ◽  
X Ray ◽  
Square Planar ◽  
Catalytic Applications ◽  
Amino Acid Schiff Base ◽  
Very High

Two new glycine-Schiff base copper(II) complexes were synthesized. Single crystal X-ray diffraction (SCXRD) allowed us to establish the structure of both complexes in the solid state. The glycine-Schiff base copper(II) complex derived from 2′-hydroxy-5′-nitroacetophenone showed a mononuclear hydrated structure, in which the Schiff base acted as a tridentate ligand, and the glycine-Schiff base copper(II) complex derived from 2′-hydroxy-5′-methylacetophenone showed a less common tetranuclear anhydrous metallocyclic structure, in which the Schiff base acted as a tetradentate ligand. In both compounds, copper(II) had a tetracoordinated square planar geometry. The results of vibrational, electronic, and paramagnetic spectroscopies, as well as thermal analysis, were consistent with the crystal structures. Both complexes were evaluated as catalysts in the olefin cyclopropanation by carbene transference, and both led to very high diastereoselectivity (greater than 98%).

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