The guanidinium t-diaqua-bis(oxalato)chromate(III) dihydrate complex: synthesis, crystal structure, EPR spectroscopy and magnetic properties

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Idelle Nono Kamga ◽  
Augustin Nkwento Nana ◽  
Bridget Ndoye Ndosiri ◽  
Frédéric Capet ◽  
Michel Foulon ◽  
...  

Abstract A new salt (CH6N3)[t-Cr(C2O4)2(H2O)2]·2H2O (1) (CH6N3 + = guanidinium cation) has been synthesized and characterized by single-crystal X-ray diffraction, FT-IR and UV–Vis spectroscopies, elemental and thermogravimetric analyses. In the crystal structure of 1, the chromate(III) ion lies on an inversion center in the form of an elongated octahedron. The coordination sphere consists of four oxygen atoms of two chelating oxalato ligands in the equatorial plane and two axial oxygen atoms of water ligands. The structural feature of focal interest in the structure of 1 is the formation of pillars of [Cr(C2O4)2(H2O)2]− complex anions and CH6N3 + guanidinium cations, with the next-neighbor cations rotated by an angle of 60° relative to each other. O–H···O and N–H···O hydrogen bonds play an important role in the construction of the three-dimensional network. The electron paramagnetic resonance (EPR) and magnetic properties of 1 have also been investigated.

1997 ◽  
Vol 52 (2) ◽  
pp. 256-258 ◽  
Author(s):  
Evgeni V. Avtomonov ◽  
Rainer Grüning ◽  
Jörg Lorberth

Abstract The crystal structure of the title compound has been determined by X-ray diffraction methods. Due to the Lewis acidic character of the iodine substituent a “zig-zag” chain is formed via intermolecular interactions (2.933(4) A) between iodine and oxygen atoms of theocarbamate moiety. A three-dimensional network is formed through hydrogen-bridging (2.04 A) between NH-groups and the oxygen atoms of the neighbouring carbamate group of the next molecule.


2012 ◽  
Vol 67 (1) ◽  
pp. 1-4
Author(s):  
Dirk Mahlmeister ◽  
Elisabeth Irran

The new telluric acid adduct (RbCl)3 ・ Te(OH)6 was prepared by dissolving RbCl and Te(OH)6 in the molar ratio of 3 : 1 in deionized water at r. t. and slow evaporation of the solvent in air. The crystal structure of the colorless crystals was determined with single-crystal X-ray diffraction (trigonal space group: R3̄c (no. 167), a = 14.4392(8), c = 10.4301(16) Å , Z = 6). In (RbCl)3 ・ Te(OH)6, the rubidium atom is surrounded by five chlorine and four oxygen atoms in form of an irregular tricapped trigonal prism. Each tellurium atom is octahedrally surrounded by six oxygen atoms. The Te(OH)6 octahedra and the RbCl5O4 polyhedra are linked to a dense three-dimensional network which is additionally strengthened by hydrogen bonds.


2017 ◽  
Vol 73 (11) ◽  
pp. 1003-1009 ◽  
Author(s):  
Ning Li ◽  
Binrong Yao ◽  
Chunhua Wang ◽  
Qingguo Meng ◽  
Guige Hou

Four new 3,4-dihydro-1-benzoxepin-5(2H)-one derivatives, namely (E)-4-(5-bromo-2-hydroxybenzylidene)-6,8-dimethoxy-3,4-dihydrobenzo[b]oxepin-5(2H)-one, (7), (E)-4-[(E)-3-(5-bromo-2-hydroxyphenyl)allylidene]-6,8-dimethoxy-3,4-dihydrobenzo[b]oxepin-5(2H)-one, (8), (E)-4-(5-bromo-2-hydroxybenzylidene)-6-hydroxy-8-methoxy-3,4-dihydrobenzo[b]oxepin-5(2H)-one, C18H15BrO5, (9), and (E)-4-[(E)-3-(5-bromo-2-hydroxyphenyl)allylidene]-6-hydroxy-8-methoxy-3,4-dihydrobenzo[b]oxepin-5(2H)-one, (10), have been synthesized and characterized by FT–IR, NMR and MS. The structure of (9) was confirmed by single-crystal X-ray diffraction. Crystal structure analysis shows that molecules of (9) are connected into a one-dimensional chain in the [010] direction through classical hydrogen bonds and these chains are further extended into a three-dimensional network via C—H...O interactions. The inhibitory activities of these compounds against protein–tyrosine kinases (PTKs) show that 6-hydroxy-substituted compounds (9) and (10) are more effective for inhibiting ErbB1 and ErbB2 than are 6-methoxy-substituted compounds (7) and (8). This may be because (9) and (10) could effectively bind to the active pockets of the protein through intermolecular interactions.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2123
Author(s):  
Maria Râpă ◽  
Maria Stefan ◽  
Paula Popa ◽  
Dana Toloman ◽  
Cristian Leostean ◽  
...  

The electrospun nanosystems containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and 1 wt% Fe doped ZnO nanoparticles (NPs) (with the content of dopant in the range of 0–1 wt% Fe) deposited onto polylactic acid (PLA) film were prepared for food packaging application. They were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), antimicrobial analysis, and X-ray photoelectron spectrometry (XPS) techniques. Migration studies conducted in acetic acid 3% (wt/wt) and ethanol 10% (v/v) food simulants as well as by the use of treated ashes with 3% HNO3 solution reveal that the migration of Zn and Fe falls into the specific limits imposed by the legislation in force. Results indicated that the PLA/PHBV/ZnO:Fex electrospun nanosystems exhibit excellent antibacterial activity against the Pseudomonas aeruginosa (ATCC-27853) due to the generation of a larger amount of perhydroxyl (˙OOH) radicals as assessed using electron paramagnetic resonance (EPR) spectroscopy coupled with a spin trapping method.


2015 ◽  
Vol 71 (1) ◽  
pp. 48-52 ◽  
Author(s):  
José J. Campos-Gaxiola ◽  
Susana P. Arredondo Rea ◽  
Ramón Corral Higuera ◽  
Herbert Höpfl ◽  
Adriana Cruz Enríquez

Two organic–inorganic hybrid compounds have been prepared by the combination of the 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium cation with perhalometallate anions to give 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium tetrachloridocobaltate(II), (C12H12N2)[CoCl4], (I), and 4-[(E)-2-(pyridin-1-ium-2-yl)ethenyl]pyridinium tetrachloridozincate(II), (C12H12N2)[ZnCl4], (II). The compounds have been structurally characterized by single-crystal X-ray diffraction analysis, showing the formation of a three-dimensional network throughX—H...ClnM−(X= C, N+;n= 1, 2;M= CoII, ZnII) hydrogen-bonding interactions and π–π stacking interactions. The title compounds were also characterized by FT–IR spectroscopy and thermogravimetric analysis (TGA).


2020 ◽  
Vol 76 (8) ◽  
pp. 1369-1372
Author(s):  
Abdessalem Badri ◽  
Inmaculada Alvarez-Serrano ◽  
María Luisa López ◽  
Mongi Ben Amara

Na2.22Mn0.87In1.68(PO4)3, sodium manganese indium tris(phosphate) (2.22/0.87/1.68), was obtained in the form of single crystals by a flux method and was structurally characterized by single-crystal X-ray diffraction. The compound belongs to the alluaudite structure type (space group C2/c) with general formula X(2)X(1)M(1)M(2)2(PO4)3. The X(2) and X(1) sites are partially occupied by sodium [occupancy 0.7676 (17) and 1/2] while the M(1) and M(2) sites are fully occupied within a mixed distribution of sodium/manganese(II) and manganese(II)/indium, respectively. The three-dimensional anionic framework is built up on the basis of M(2)2O10 dimers that share opposite edges with M(1)O6 octahedra, thus forming infinite chains extending parallel to [10\overline{1}]. The linkage between these chains is ensured by PO4 tetrahedra through common vertices. The three-dimensional network thus constructed delimits two types of hexagonal channels, resulting from the catenation of M(2)2O10 dimers, M(1)O6 octahedra and PO4 tetrahedra through edge- and corner-sharing. The channels are occupied by Na+ cations with coordination numbers of seven and eight.


1993 ◽  
Vol 48 (7) ◽  
pp. 886-892 ◽  
Author(s):  
Adalbert Lossin ◽  
Gerd Meyer

Single crystals of CsPr2(CH3COO)7 were obtained from an acetic acid solution of Pr(CH3COO)3 • H2O and Cs2CO3 in a molar ratio of 4:1 at 120°C. It crystallizes in the triclinic system, PĪ (no. 2), Z = 2, a = 1028.1(5), b = 1034.6(5), c = 1199.4(6) pm, α = 84.82(2), β = 67.07(3), γ = 76.01(2)°, Vm = 343.3(3) cm3/mol, R = 0.031, Rw = 0.027. The crystal structure contains infinite chains, 1∞[Pr2(CH3COO)6], running along the [110] direction. The chains are built up by bridging acetate ions coordinated to two crystallographically different Pr3+ ions which are both surrounded by 9 oxygen ligands. These chains are linked by “intercalated” Cs(CH3COO) to layers parallel (100). Cs+ has contacts to oxygen atoms of neighbouring layers, such that a three-dimensional network is formed.


2019 ◽  
Vol 75 (4) ◽  
pp. 388-397 ◽  
Author(s):  
Sevim Hamamci Alisir ◽  
Necmi Dege ◽  
Recep Tapramaz

Three new diclofenac-based copper(II) complexes, namely tetrakis{μ-2-[2-(2,6-dichloroanilino)phenyl]acetato-κ2 O:O′}bis(methanol-κO)copper(II), [Cu2(μ-dicl)4(CH3OH)2] (1), bis{2-[2-(2,6-dichloroanilino)phenyl]acetato-κ2 O,O′}bis(1-vinyl-1H-imidazole-κN 3)copper(II), [Cu(dicl)2(vim)2] (2), and bis{2-[2-(2,6-dichloroanilino)phenyl]acetato-κ2 O,O′}bis(1H-imidazole-κN 3)copper(II), [Cu(dicl)2(im)2] (3) [dicl is diclofenac (C14H10Cl2NO2), vim is 1-vinylimidazole (C5H6N2) and im is imidazole (C3H4N2)], have been synthesized and characterized by elemental analysis, FT–IR spectroscopy, thermal analysis and single-crystal X-ray diffraction. X-ray diffraction analysis shows that complex 1 consists of dimeric units in which the dicl ligand exhibits a bidentate syn,syn-μ2 coordination mode linking two copper(II) centres. Complexes 2 and 3 have mononuclear units with the general formula [Cu(dicl)2 L 2] (L is vim or im) in which the CuII ions are octahedrally coordinated by two L and two dicl chelating ligands. The L and dicl ligands both occupy the trans positions of the coordination octahedron. The different coordination modes of dicl in the title complexes were revealed by Fourier transform IR (FT–IR) spectroscopy. The spin matching between the copper(II) centres in the dimeric [Cu2(μ-dicl)4(CH3OH)2] units was also confirmed by magnetic data to be lower than the spin-only value and electron paramagnetic resonance (EPR) spectra. The thermal properties of the complexes were investigated by thermogravimetric (TG) and differential thermal analysis (DTA) techniques.


Author(s):  
Stefan Suckert ◽  
Mario Wriedt ◽  
Inke Jess ◽  
Christian Näther

In the crystal structure of the title compound, [Ni(NCS)2(H2O)4]·4C6H8N2, the NiIIcations are coordinated by four water ligands and twotrans-coordinated terminallyN-bonded thiocyanate anions in a slightly distorted octahedral geometry. The asymmetric unit consists of a Ni2+cation located on a centre of inversion, two water molecules and one thiocyanate ligand, as well as two uncoordinated 2,5-dimethylpyrazine ligands in general positions. In the crystal, discrete complex molecules are linked into a three-dimensional network by O—H...N hydrogen bonding between the water H atoms and the 2,5-dimethylpyrazine N atoms.


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