(Pyrrole-2,5-Diyl)-Bis(Nitronyl Nitroxide) and-Bis(Iminonitroxide): Specific Features of the Synthesis, Structure, and Magnetic Properties

In contrast to diradicals connected by alternant hydrocarbons, only a few studies have addressed diradicals connected by nonalternant hydrocarbons and their heteroatom derivatives. Here, the synthesis, structure, and magnetic properties of pyrrole-2,5-diyl–linked bis(nitronyl nitroxide) and bis(iminonitroxide) diradicals are described. The diradicals show characteristic electron spin resonance spectra in dilute glassy solutions, from which conclusions about the presence of distinct conformations, their symmetry, and interspin distance were made. X-ray diffraction analysis of the diradicals revealed that paramagnetic moieties lie in the plane of the pyrrole ring, because of the formation of an intramolecular hydrogen bond, ONO…H−N, with O…H distances of 2.15–2.23 Å. The N–O groups participating in the formation of H-bonds have greater bond lengths (~1.29 Å) as compared with nonparticipating groups (~1.27 Å). The nitronyl nitroxide and iminonitroxide diradicals showed an intramolecular antiferromagnetic interaction, with J = −77.3 and −22.2 cm−1, respectively (H = −2JS1⋅S2).

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Synthesis and Complexation Properties of 2-Hydroxy-5-methoxyphenylphosphonic Acid (H3L1). Crystal Structure of the [Cu(H2L1)2(Н2О)2] Complex

Russian Journal of General Chemistry ◽

10.1134/s1070363221110074 ◽

2021 ◽

Vol 91 (11) ◽

pp. 2176-2186

Author(s):

G. S. Tsebrikova ◽

Yu. I. Rogacheva ◽

I. S. Ivanova ◽

A. B. Ilyukhin ◽

V. P. Soloviev ◽

...

Keyword(s):

Crystal Structure ◽

Hydrogen Bond ◽

Methoxy Group ◽

Protonation Constants ◽

Water Molecules ◽

X Ray Diffraction ◽

X Ray ◽

The Stability ◽

Intramolecular Hydrogen ◽

Oxygen Atoms

Abstract 2-Hydroxy-5-methoxyphenylphosphonic acid (H3L1) and the complex [Cu(H2L1)2(H2O)2] were synthesized and characterized by IR spectroscopy, thermogravimetry, and X-ray diffraction analysis. The polyhedron of the copper atom is an axially elongated square bipyramid with oxygen atoms of phenolic and of monodeprotonated phosphonic groups at the base and oxygen atoms of water molecules at the vertices. The protonation constants of the H3L1 acid and the stability constants of its Cu2+ complexes in water were determined by potentiometric titration. The protonation constants of the acid in water are significantly influenced by the intramolecular hydrogen bond and the methoxy group. The H3L1 acid forms complexes CuL‒ and CuL24‒ with Cu2+ in water.

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ZnO Varistor Defective Gd and Pr Ions

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.332.51 ◽

2012 ◽

Vol 332 ◽

pp. 51-61

Author(s):

M. El-Hofy ◽

A. El-Taabl ◽

A.M. Abdel Aziz ◽

M. Elkhatib

Keyword(s):

Magnetic Properties ◽

Ternary System ◽

Binary Systems ◽

Chemical Formula ◽

X Ray Diffraction ◽

X Ray ◽

Zno Varistor ◽

Spin Resonance ◽

The Difference ◽

Scanning Electron

To the best of our knowledge the difference in the magnetic properties of ions like Gd (7.94 μB) and Pr (3.58 μB) on the electrical properties of ZnO-varistor have not been studied. To clarify this effect, the binary systems, ZnO-Gd2O3, ZnO-Pr6O11and the ternary system ZnO-Gd2O3-Pr6O11were studied. The ceramics were prepared according to the chemical formula; (100-X) mol% ZnO - (X) mol% Y, where X = 0.5, 1, 2, 3.5, 5, 6, 7.5, 9 and 15, Y is Gd2O3, Pr6O11or Gd2O3 +Pr6O11. The samples have been sintered at 1200°C, 1250°C, 1300°C, 1350°C and 1400°C for 1 hr. X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDAX), (JxE), (CxV) and Electron Spin Resonance (ESR) have been studied and discussed. Utilizing J-E characteristics, the non-linearity coefficient (α), leakage current (Lg) and breakdown electric field (Eo) have been determined. In the present study, the effect of the magnetic properties on the non-linearity parameters was not clear and the non-linearity characteristics mainly depend upon the microstructure of the system. The ternary system (94%ZnO-4%Pr6O11- 2%Gd2O3) is superior to the binary systems, and can readily serve as a high-voltage varistor.

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One-dimensional lanthanide chain bridged by nitronyl nitroxide radical ligand: structure and magnetic properties

E3S Web of Conferences ◽

10.1051/e3sconf/202018504052 ◽

2020 ◽

Vol 185 ◽

pp. 04052

Author(s):

Hui Yang Dong ◽

Me Zhu

Keyword(s):

Variable Temperature ◽

Nitroxide Radical ◽

Antiferromagnetic Interaction ◽

Nitronyl Nitroxide ◽

X Ray Diffraction ◽

Monoclinic System ◽

One Dimensional ◽

X Ray ◽

Ligand Structure ◽

Radical Ligand

In order to synthesize the molecular magnetic material, the complex{Nd(hfac)3(NIT-5MeThien)}n(NIT-5MeThien=2-(5-Methyl-2ˊ-thienyl)-5--4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide) has been synthesized by the reaction using radical ligand and Nd(hfac)3•2H2O. X-ray diffraction analysis showed that the compound belongs to the monoclinic system and constituted by Nd(hfac)3 and NIT-5MeThien to obtain a one-dimensional chain which nitroxide radical acted as a bridged ligand through the N-O groups. Variable temperature magnetization of complex was shown the antiferromagnetic interaction between Nd(III) ion and nitroxide radical.

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(3-Ammonio-2,2-dimethyl-propyl)carbamate Dihydrate

Molbank ◽

10.3390/m1015 ◽

2018 ◽

Vol 2018 (3) ◽

pp. M1015

Author(s):

Jaqueline Heimgert ◽

Dennis Neumann ◽

Guido Reiss

Keyword(s):

Hydrogen Bond ◽

Raman Spectroscopy ◽

Acetic Acid ◽

Hydrogen Bonds ◽

Chain Structure ◽

X Ray Diffraction ◽

Intermolecular Hydrogen Bonds ◽

X Ray ◽

Title Molecule ◽

Intramolecular Hydrogen

(3-Ammonio-2,2-dimethylpropyl)carbamate dihydrate was synthesised. The title compound was characterised by single crystal X-ray diffraction and IR-/Raman-spectroscopy. It has been demonstrated that a mixture of dilute acetic acid and 2,2-dimethyl-1,3-diaminopropane is able to capture CO2 spontaneously from the atmosphere. An intramolecular hydrogen bond stabilises the conformation of the ylide-type title molecule. Intermolecular hydrogen bonds between all moieties connect them to a strand-type chain structure.

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Friedel–Crafts-type reaction of pyrene with diethyl 1-(isothiocyanato)alkylphosphonates. Efficient synthesis of highly fluorescent diethyl 1-(pyrene-1-carboxamido)alkylphosphonates and 1-(pyrene-1-carboxamido)methylphosphonic acid

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.11.266 ◽

2015 ◽

Vol 11 ◽

pp. 2451-2458 ◽

Cited By ~ 9

Author(s):

Anna Wrona-Piotrowicz ◽

Janusz Zakrzewski ◽

Anna Gajda ◽

Tadeusz Gajda ◽

Anna Makal ◽

...

Keyword(s):

Hydrogen Bond ◽

Solid State ◽

Fluorescence Quantum Yield ◽

Fold Increase ◽

Methylphosphonic Acid ◽

Efficient Synthesis ◽

X Ray Diffraction ◽

X Ray ◽

Type Reaction ◽

Intramolecular Hydrogen

Friedel–Crafts-type reaction of pyrene with diethyl 1-(isothiocyanato)alkylphosphonates promoted by trifluoromethanosulfonic acid afforded diethyl 1-(pyrene-1-carbothioamido)alkylphosphonates in 83–94% yield. These compounds were transformed, in 87–94% yield, into the corresponding diethyl 1-(pyrene-1-carboxamido)alkylphosphonates by treatment with Oxone®. 1-(Pyrene-1-carboxamido)methylphosphonic acid was obtained in a 87% yield by treating the corresponding diethyl phosphonate with Me3Si-Br in methanol. All of the synthesized amidophosphonates were emissive in solution and in the solid state. The presence of a phosphonato group brought about an approximately two-fold increase in solution fluorescence quantum yield in comparison with that of a model N-alkyl pyrene-1-carboxamide. This effect was tentatively explained by stiffening of the amidophosphonate lateral chain which was caused by the interaction (intramolecular hydrogen bond) of phosphonate and amide groups. The synthesized phosphonic acid was soluble in a biological aqueous buffer (PBS, 0.01 M, pH 7.35) and was strongly emissive under these conditions (λem = 383, 400 nm, τ = 18.7 ns, ΦF > 0.98). Solid-state emission of diethyl 1-(pyrene-1-carboxamido)methylphosphonate (λmax = 485 nm; ΦF = 0.25) was assigned to π–π aggregates, the presence of which was revealed by single-crystal X-ray diffraction analysis.

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One-Pot Synthesis of Trifluoromethylated Pyrazol-4-yl-pyrrole-2,5-dione Derivatives

Synthesis ◽

10.1055/s-0037-1611837 ◽

2019 ◽

Vol 51 (17) ◽

pp. 3345-3355 ◽

Cited By ~ 4

Author(s):

Fangchong Yuan ◽

Wenwen Duan ◽

Zeyu Li ◽

Xi Luo ◽

Min Zhang ◽

...

Keyword(s):

Hydrogen Bond ◽

Diffraction Analysis ◽

Spectral Methods ◽

Aromatic Aldehydes ◽

X Ray Diffraction ◽

One Pot ◽

X Ray ◽

Effect Of Solvents ◽

Intramolecular Hydrogen ◽

Strong Intramolecular Hydrogen Bond

Efficient and convenient one-pot, three-component reactions of pyrrolidone, aromatic aldehydes and 1-phenyl-3-trifluoromethyl-5-pyrazolone afforded highly functionalized trifluoromethylated pyrazol-4-ylpyrrole-2,5-dione derivatives in good yields. The effect of solvents on the reaction efficiency and yield was briefly investigated. The structures of products were determined by spectral methods and X-ray diffraction analysis. The latter showed that the products formed have a strong intramolecular hydrogen bond, which made them particularly stable and the corresponding annulated products were not obtained by treatment with dehydrating reagents.

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Diethyl 2-Benzimidazol-1-ylsuccinate–Picric Acid (1/1) – An Inclusion Molecular Complex

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768197008562 ◽

1997 ◽

Vol 53 (6) ◽

pp. 961-967 ◽

Cited By ~ 41

Author(s):

P. Zaderenko ◽

M. S. Gil ◽

P. López ◽

P. Ballesteros ◽

I. Fonseca ◽

...

Keyword(s):

Hydrogen Bond ◽

Hydrogen Bonding ◽

Molecular Complex ◽

Picric Acid ◽

X Ray Diffraction ◽

Nmr Studies ◽

X Ray ◽

H Nmr ◽

Intramolecular Hydrogen ◽

C Nmr

The crystal structure of the diethyl 2-benzimidazol-1-ylsuccinate–picric acid (1/1) molecular complex has been determined by X-ray diffraction analysis. Diethyl 2-benzimidazol-l-ylsuccinate molecules form channels along the a axis, in which the picric acid molecules are located. The benzimidazole moiety and the phenol group are held together by hydrogen bonding between the hydrogen of the phenol and the N3 atom of benzimidazole. Additionally, this hydrogen forms an intramolecular hydrogen bond with one O atom of the ortho-nitro group, thus producing a bifurcated hydrogen bond. 1H NMR spectra in DMSO-d 6 solution and CP/MAS solid 13 C NMR studies of this 2-benzimidazol-1-ylsuccinate–picric acid (1/1) molecular complex, as well as those of dimethyl, diethyl, di-n-butyl and 1-n-butyl-4-ethyl 2-imidazol-1-ylsuccinates, diethyl 2-pyrazol-1-ylsuccinate, ethyl imidazol-1-ylacetate, ethyl pyrazol-1-ylacetate and ethyl pyrazol-l-ylsuccinate, suggest that the picric acid linkage depends on the nature of the azole. Actual proton transfer is deduced for the imidazole derivatives, but only weak hydrogen bonding could be inferred for pyrazole derivatives.

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Solvates of acotiamide hydrochloride: characterization and phase transformation

Acta Crystallographica Section B Structural Science Crystal Engineering and Materials ◽

10.1107/s2052520619013428 ◽

2019 ◽

Vol 75 (6) ◽

pp. 1106-1114 ◽

Cited By ~ 1

Author(s):

Guoshun Zhang ◽

Na Wang ◽

Xiaoqing Shang ◽

Lifeng Zhang ◽

Ruili Wang ◽

...

Keyword(s):

Thermal Analysis ◽

Hydrogen Bond ◽

Phase Transformation ◽

Fourier Transform ◽

Infrared Spectroscopy ◽

X Ray Diffraction ◽

X Ray ◽

Structural Types ◽

Benzene Rings ◽

Intramolecular Hydrogen

Five novel crystals of acotiamide hydrochloride (AH) with solvates dimethyl formide (DMF), dimethyl sulfoxide (DMSO), ethyl acetate (EA) and water (W) [1AH-1W-1DMF, 1AH-1DMSO-I, 1AH-1DMSO-II, 1AH-1W-1DMSO and 2AH-2DMSO-1EA] were characterized using single-crystal X-ray diffraction, powder X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy. The five crystals can be divided into four distinct structural types based on analysis of their similarities; 1AH-1W-1DMF and 1AH-1W-1DMSO are isostructural. The benzene rings in 1AH-1DMSO-I, 1AH-1DMSO-II and 2AH-2DMSO-1EA can rotate 180°, and the intramolecular hydrogen bond changes from an OH...C=O bond to an NH...OH bond relative to what is seen in 1AH-1W-1DMF and 1AH-1W-1DMSO. Phase transformation experiments show that a humidity-induced phase transformation is closely tied to moisture content.

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Planarity of benzoylthiocarbazate tuberculostatics. III. Diesters of 3-(2-hydroxybenzoyl)dithiocarbazic acid

Acta Crystallographica Section C Structural Chemistry ◽

10.1107/s2053229616020556 ◽

2017 ◽

Vol 73 (2) ◽

pp. 84-90 ◽

Cited By ~ 2

Author(s):

Małgorzata Szczesio ◽

Andrzej Olczak ◽

Ida Mazerant ◽

Katarzyna Gobis ◽

Henryk Foks ◽

...

Keyword(s):

Hydrogen Bond ◽

Aromatic Ring ◽

Mutual Orientation ◽

Drug Resistant ◽

X Ray Diffraction ◽

X Ray ◽

Resistant Strains ◽

Intramolecular Hydrogen ◽

Drug Resistant Strains ◽

Tuberculostatic Agents

Searches for new tuberculostatic agents are important considering the occurrence of drug-resistant strains ofMycobacterium tuberculosis. The structures of three new potentially tuberculostatic compounds, namely isopropyl methyl (2-hydroxybenzoyl)carbonohydrazonodithioate, C12H16N2O2S2, (Z)-benzyl methyl (2-hydroxybenzoyl)carbonohydrazonodithioate, C16H16N2O2S2, and dibenzyl (2-hydroxybenzoyl)carbonohydrazonodithioate propan-2-ol monosolvate, C22H20N2O2S2·C3H8O, were determined by X-ray diffraction. The mutual orientation of the three main fragments of the compounds, namely an aromatic ring, a dithioester group and a hydrazide group, can influence the biological activity of the compounds. In all three of the structures studied, the C(=O)NH group is in theanticonformation. In addition, the presence of the hydroxy group in theorthoposition of the aromatic ring in all three structures leads to the formation of an intramolecular hydrogen bond stabilizing the planarity of the molecules.

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Properties of a strong intramolecular OHO hydrogen bond in 2-(N,N-diethylamino-N-oxymethyl)-4,6-dichlorophenol

Canadian Journal of Chemistry ◽

10.1139/v86-304 ◽

1986 ◽

Vol 64 (9) ◽

pp. 1850-1854 ◽

Cited By ~ 15

Author(s):

A. Koll ◽

M. Rospenk ◽

L. Sobczyk ◽

T. Glowiak

Keyword(s):

Hydrogen Bond ◽

Hydrogen Bonds ◽

Diffraction Study ◽

Mannich Base ◽

Direct Method ◽

Uv Spectra ◽

X Ray Diffraction ◽

Intramolecular Hydrogen Bonds ◽

X Ray ◽

Intramolecular Hydrogen

The crystals of 2-(N,N-diethylamino-N-oxymethyl)-4,6-dichlorophenol chosen as a representative of the Mannich base N-oxides were found to be monoclinic, P21/c space group, with a = 11.729(3), b = 16.232(4), c = 13.689(3) Å, β = 107.37(3)°, and Z = 8. The structure solved by the direct method was refined to R = 0.033 for 3170 independent reflections. Two slightly different molecules denoted as A and B in the unit cell with very short (2.42 and 2.40 Å) OHO intramolecular hydrogen bonds were detected. Both a X-ray diffraction study and the ir and uv spectra indicate a symmetric type of bridge in this compound.

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