Dipole moments and spectroscopic properties of methyl-4-nitropyridine N-oxides

Puszko, Aniela; Wasylina, L.; Pawełka, Z.

doi:10.1007/bf00817252

Cited by 9 publications

(12 citation statements)

References 22 publications

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“…Compound 6 was inactive. The activity of 0 and 1 was found to be close to the international criterion for synthetic Table 7 IC 50 value for compounds against various cell lines [lg/dm 3 ] compounds (IC 50 value lower than 4 lg/cm 3 [19]). It is concluded that increasing number of methyl groups in the ligand (2-7) causes a decrease in activity.…”

Section: Antiproliferative Activitymentioning

confidence: 98%

“…1 and 2. The structure consists of a 122.01(7) C(2)-C(3)-C (4) 114.98(7) C(2)-C(3)-C (7) 120.06(7) C(4)-C(3)-C (7) 124.93(8) C(5)-C(4)-C (3) 122.63(8) C(5)-C(4)-N (2) 115.80(7) C(3)-C(4)-N (2) 121.57(7) C(4)-C(5)-C (6) 120.06(7) N(1)-C(6)-C (5) 117.49(7) N(1)-C(6)-C (8) 118.86(8) C(5)-C(6)-C (8) 123.65 (8) Symmetry transformations used to generate equivalent atoms: #1 Àx, Ày, Àz.…”

Section: Crystal Structure Analysismentioning

confidence: 99%

“…Such a wide scope of applications can be attributed to the unusual structure of these compounds [5]. It was found that in the molecule of 4-nitropyridine N-oxide (npn, Scheme 1), a specific ''communication'' between the electron withdrawing (NO 2 ) and the electrodonating (NO) group located in the para position is taking place through the p-electron system of the ring [3].…”

Section: Introductionmentioning

confidence: 99%

“…4-Nitropyridine N-oxide and its methyl derivatives are an important group of compounds due to their potential biological applications as radiosensitizers, cytotoxins [1,2], antifungal [3], antibacterial, anti-inflammatory and tranquilizing substances [4,5]. Such a wide scope of applications can be attributed to the unusual structure of these compounds [5].…”

Section: Introductionmentioning

confidence: 99%

“…The coordination geometry is square-planar with O(1)-Cu-Cl and O(1)-Cu-Cl#1 angles being 85.57(3) and 94.43(3) Å , respectively (Table 3). The Cu-O and CuCl distances are equal to 1.962(1) and 2.2333(4) Å , respectively, in agreement with other copper complexes with monomeric pyridine N-oxides[26].…”

mentioning

confidence: 99%

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Methyl-substituted 4-nitropyridine N-oxides as ligands: Structural, spectroscopic, magnetic and cytotoxic characteristics of copper(II) complexes

Puszko

Wasylina

Pełczyńska

et al. 2007

Journal of Inorganic Biochemistry

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Section: Antiproliferative Activitymentioning

confidence: 98%

Section: Crystal Structure Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Methyl-substituted 4-nitropyridine N-oxides as ligands: Structural, spectroscopic, magnetic and cytotoxic characteristics of copper(II) complexes

Puszko

Wasylina

Pełczyńska

et al. 2007

Journal of Inorganic Biochemistry

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Polar aspects of intramolecular interactions in 2‐amino‐5‐nitro‐4‐methylpyridines and 2‐amino‐3‐nitro‐4‐methylpyridines

Wandas

Puszko

Pawełka

2000

Journal of Heterocyclic Chem

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The dipole moments of twelve 2‐N‐substituted amino‐5‐nitro‐4‐methylpyridines (I‐XII) and three 2‐N‐substituted amino‐3‐nitro‐4‐methylpyridines (XIII‐XV) were determined in benzene. The polar aspects of intramolecular charge‐transfer and intramolecular hydrogen bonding were discussed. The interaction dipole moments, μint, were calculated for 2‐N‐alkyl(or aryl)amino‐5‐nitro‐4‐methylpyridines. Increased alkylation of amino nitrogen brought about an intensified push‐pull interaction between the amino and nitro groups. The solvent effects on the dipole moments of 2‐N‐methylamino‐5‐nitro‐4‐methyl‐(I), 2‐N,N‐dimethylamino‐5‐nitro‐4‐methyl‐ (II) and 2‐N‐methylamino‐3‐nitro‐4‐methylpyridines (XIII) were different. Specific hydrogen bond solute‐solvent interactions increased the charge‐transfer effect in I, but it did not disrupt the intramolecular hydrogen bond in XIII.

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Absorption spectra of nitro derivatives. 2-alkylamino-4-nitropicolines and their N-oxides

Lorenc¹,

Puszko²

1998

Chem Heterocycl Compd

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The UV spectra of 15 2-N-substituted 4-nitropicolines and their N-oxides . UV spectroscopy, in particular, has been prominent [3][4][5][6][7][8][9].The importance of the overlapping between the highest occupied molecular orbital (HOMO) of an electron donor and the lowest unoccupied molecular orbital (LUMO) of an electron acceptor in determining the favorable position and spatial direction of a chemical reaction is emphasized by setting up the following auxiliary principles: the principle of positional parallelism between the charge-transfer and the bond-interchange; the principle of narrowing of the interfrontier energy-level separation; and the principle of growing frontier density along the reaction path. These subprinciples work in a cooperative manner to enable us to arrive at this general governing principle: most of the chemical interactions are liable to occur at the positions (at the direction) where the overlapping of the HOMO and LUMO of the respective reactants is at its maximum in an electron-donating reactant, the HOMO predominates in the overlapping interaction with the MO's of the other reactant, whereas the LUMO does in an electron-accepting reactant; in the reactants which possess singly-occupied MO's, these play the part of HOMO or of LUMO, or of both. These particular MO's, HOMO, LUMO, and singly-occupied, are "generalized frontier orbitals" in chemical reactions [10]. Fukui [11] found some parallelism between the LUMO energy level and the fungicidal activity. The properties of 4-nitropyridine N-oxide and its methyl derivatives are especially interesting because of their antifungal activity [12, 13] and optical nonlinearity on the molecular as well as the macroscopic level [14, 15].An indispensable prequisite for achieving large second-order nonlinear optical response in an organic molecule is the existence of intramolecular charge transfer (ICT), resulting from the electron-donor and electron-acceptor groups communicating through a ~'-conjugated molecular framework.In the literature there are no data on the UV spectra of 2-N-substituted 4-nitropyridine N-oxide and their methyl derivatives; there are few data on the spectra of 2-nitraminopyridine [9, 16, 17]. In recent papers the UV spectra of 2-alkylamino-, 2-phenylamino-, 2-morpholyl-3-or -5-nitro-4-, or -6-methylpyridines are reported [8, 9, 18]. The aim of this paper is to determine the mutual communication of NO and NO 2 groups and its modification by the steric effects of the methyl and 2-methylamino group. EXPERIMENTALThe title compounds were prepared as described previously [19]. The UV spectra of 0.1 mM solutions in ethanol were recorded by means of a Specord UV-vis spectrophotometer equipped with a thermostated cell compartment keeping the temperature at 25~ the quartz cell being of 0.097 cm thickness.

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Dipole moments and spectroscopic properties of methyl-4-nitropyridine N-oxides

Cited by 9 publications

References 22 publications

Methyl-substituted 4-nitropyridine N-oxides as ligands: Structural, spectroscopic, magnetic and cytotoxic characteristics of copper(II) complexes

Methyl-substituted 4-nitropyridine N-oxides as ligands: Structural, spectroscopic, magnetic and cytotoxic characteristics of copper(II) complexes

Polar aspects of intramolecular interactions in 2‐amino‐5‐nitro‐4‐methylpyridines and 2‐amino‐3‐nitro‐4‐methylpyridines

Absorption spectra of nitro derivatives. 2-alkylamino-4-nitropicolines and their N-oxides

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