Acetophenone Azine Research Articles

Sensitization properties of acetophenone azine, a new skin sensitizer identified in textile.

Acetophenone azine (CAS no. 729-43-1) present in sports equipment (shoes, socks and shin pads) has been suspected to induce skin allergies. Twelve case reports of allergy in children and adults from Europe and North America were published between 2016 and 2021. The objective of this study was to confirm that acetophenone azine is indeed a skin sensitizer based on in vitro/ in vivo testings derived from the Adverse Outcome Pathway (AOP) built for skin sensitization by OECD in 2012. Acetophenone azine was tested in vitro according to the human cell line activation test (h-CLAT) and the ARE-Nrf2 Luciferase Test (KeratinoSens) and in vivo using the Local Lymph Nodes Assay (LLNA). Both the h-CLAT and the KeratinoSens were positive whereas the LLNA performed at 5, 2.5 and 1% (wt/vol) of acetophenone azine, was negative. Based on these results, acetophenone azine was considered as a skin sensitizer. This was recently confirmed by its classification under the CLP regulation.

Synthesis of Symmetrical Acetophenone Azine Derivatives as Colorimetric and Fluorescent Cyanide Chemosensors

Cyanide is a highly toxic anion and poison to the environment. Therefore, fast, effective, and efficient analysis methods to detect cyanide are needed. Herein, symmetrical chemosensor of 2’-hydroxy acetophenone azine (1) and 2’,4’-dihydroxy acetophenone azine (2) has been synthesized tested as colorimetric and fluorescent cyanide chemosensor. The azines were produced from the condensation of acetophenone derivatives with hydrazine hydrate in ethanol under reflux or ultrasonic irradiation methods. Colorimetric and fluorescent chemosensor tests showed selectivity to acetate and cyanide anions in DMSO. The limit of detection (LOD) for colorimetric measurement of cyanide anion was 9.68×10–4 M for compound (1) and 9.63×10–5 M for compound (2), while the fluorescent method showed 15.90×10–4 M for compound (1) and 8.95×10–5 M for compound (2), respectively. In addition, test paper-strips containing sensor 2 indicated noticeable results for 'naked eye' detection of cyanide in an aqueous medium.

Acetophenone Azine: The 2021 American Contact Dermatitis Society Allergen of the Year.

The American Contact Dermatitis Society chose acetophenone azine (AA) as the 2021 Allergen of the Year. Acetophenone azine is an emerging contact allergen that often is associated with the use of sports equipment and footwear. The pattern of dermatitis initially starts locally at the site of contact but can develop into a generalized dermatitis. Strong suspicion is necessary to diagnose AA allergy, and patch testing should be completed with AA and to potentially relevant sports equipment and/or shoes. Acetophenone azine is not yet available as a commercial patch-test preparation, but the optimal concentration is 0.1% in acetone or petrolatum. This column serves as an introduction to AA as an emerging allergen and highlights diagnosis, management, and patch testing for AA contact allergy.

Acetophenone Azine.

Acetophenone azine (CAS 729-43-1) was recently discovered as a potent allergen in shin pads and footwear containing the foam elastomer ethyl vinyl acetate. The compound is probably not intentionally added to ethyl vinyl acetate but is likely the result of reactions between other additives that take place during the manufacturing process. A patch testing concentration of 0.1% in acetone or petrolatum is recommended. Acetophenone azine should be part of patch testing shoe series, as well as plastics and glues series. The compound is not currently available from patch testing materials suppliers, a situation that hopefully will be corrected.

Crystal structure and DFT studies of 4-methyl-N-(1-phenylethyl)-N′-(1-phenylethylidene)benzenesulfono-hydrazide: evidence of a carbene insertion in the formation of acetophenone azine from acetophenone p-toluensulfonylhydrazone

The crystal structure of 4-Methyl-N-(1-phenylethyl)-N′-(1-phenylethylidene) benzene sulfonohydrazide is disclosed, which is obtained from direct reaction between acetophenone tosylhydrazone and potassium tert-butoxide. Reaction mechanisms and the corresponding energy barriers were assessed through DFT calculations at the B3LYP/6-31G(d,p) level of theory and showed that this compound plays an important role as an intermediate in the formation of acetophenone azine from acetophenone p-toluensulfonylhydrazone through a carbene insertion on this last compound.

Structural and topological analysis of some isobutyl acetophenone azines sprouting out their asymmetrization effect

In this research, three asymmetrical p-isobutyl acetophenone azine 1-3 named 1-(1-(4-isobutylphenyl)ethylidene)-2-(1-phenylethylidene) hydrazine, 1-(1-(4-isobutylphenyl)ethylidene)-2-(1-4-nitrophenylethylidene) hydrazine, 1-(1-(4-isobutylphenyl)ethylidene)-2-(1-4-methoxyphenylethylidene) hydrazine respectively are prepared and characterized by elemental analyses, FT-IR and NMR spectral studies. The stable optimized conformers of the asymmetrical azines (1-3) are predicted using density functional theory (DFT) method. The theoretical IR frequencies are found to be in good agreement with the experimental values. The asymmetrization effect is observed for the three azines 1-3 from their natural population analysis. The comparative analysis of the computed structural properties of the asymmetrical azines (1-3) and symmetrical p-isobutyl acetophenone azine is accomplished. The topological properties of electronic charge density are analyzed employing Atoms In Molecules (AIM) theory. The electron density (ρ) and Laplacian (∇ρ2) properties indicates the presence of two CH⋯N intramolecular bridges in the methoxy substituted asymmetrical azine 3 which paves way for the reduction of electron density in the aromatic systems of the azine 3. Nonlinear optical behavior of the asymmetrical azines is also examined by the theoretically predicted values of dipole moment (μ), polarizability (α0) and first hyperpolarizability (βtot). The α0 and βtot values clearly depicted that the azine 2 is found to have a good non-linear optical (NLO) property than 1 and 3. The azine 2 is found to be NLO active when it had been subjected to experimental second harmonic generation (SHG) test. The UV–Visible methods are also used to characterize the synthesized azines 1-3.

High pressure study of acetophenone azine

High pressure Raman spectra of acetophenone azine (APA) have been measured up to 17.7 GPa with a diamond anvil cell. Two crystalline-to-crystalline phase transformations are found at pressures about 3.6 and 5.8 GPa. A disappearance of external modes and the C–H vibration at pressures higher than 8.7 GPa suggests that the sample undergoes a phase transition to amorphous or orientationally disordered (plastic) state, and the amorphization was completed at about 12.1 GPa. The disordered state is unstable and, then, a polymerization transformation reaction occurs with a further pressure increase. After the pressure has been released, the polymerization state can remain at the ambient condition, indicating that the virgin crystalline state is not recovered. The results show that the phenomenon underlying the pressure induced phase transition of APA may involve profound changes in the coordination environments of the symmetric aromatic azine.

Study of ac electrical conductivity and dielectric properties of ortho-hydroxy acetophenone azine thin films

AC electrical conductivity measurements were carried out in the temperature range 290–473 K over the frequency range 0.1–20 kHz of vacuum deposited Ortho-hydroxy acetophenone azine films. It was found that the ac electrical conductivity increases with frequency according to the relation σac(ω) = A ωs. The values of the dielectric constant, \({\acute{\varepsilon}}\), slightly changed in higher frequencies irrespective of temperature change, whereas its value increases in higher temperature with the decrease in frequency. Also, the dielectric loss, ɛ′′, and tan δ, has been found to increase with raise in temperature and decrease in frequency. The obtained experimental data has been analyzed with reference to various theoretical models. The analysis shows that the correlated barrier hopping (CBH) model is the most appropriate mechanism for the ac electrical conduction in these films.

Perfect polar stacking of parallel beloamphiphile layers. Synthesis, structure and solid-state optical properties of the unsymmetrical acetophenone azine DCA

Extraordinary high degrees of polar order can be achieved by a rational design that involves the polar stacking of parallel beloamphiphile monolayers (PBAM). This strategy is exemplified by the acetophenone azines MCA (4-methoxy-4'-chloroacetophenone azine) and DCA (4-decoxy-4'-chloroacetophenone azine). The beloamphiphile design aims to achieve strong lateral interactions by way of arene-arene, azine-azine, arene-azine and halogen-bonding interactions. Dipole-induced interactions and halogen bonding dominate interlayer interactions and halogen bonding is shown to effect the layer stacking. Crystals of DCA contain PBAMs with perfect polar order and perfect polar layer stacking, while crystals of MCA features perfect polar order only in one of two layers and layer stacking is polar but not entirely perfect. We report the synthesis of the beloamphiphile DCA, its crystal structure, and we present a comparative discussion of the structures and intermolecular interactions of MCA and DCA. Absorbance and photoluminescence measurements have been carried out for solutions of DCA and for DCA crystals. DCA exhibits a broad emission centered at 2.5 eV when excited with UV radiation. The nonlinear optical response was studied by measuring second harmonic generation (SHG). Strong SHG signals have been observed due to the polar alignment and the DCA crystal's NLO response is 34 times larger than that of urea. Optimization of the beloamphiphile and systematic SAR studies of the polar organic crystals, which are now possible for the very first time, will further improve the performance of this new class of functional organic materials. The materials are organic semiconductors and show promise as blue emitters, as nonlinear optical materials and as OLED materials.

Conversion of 3‐carbethoxy‐4‐methyl coumarin derivatives into several new annelated coumarin derivatives

AbstractThe reaction of ethyl esters of 4‐methyl‐2‐oxo‐2H‐1‐benzo (naphtho) pyran‐3‐carboxylic acids (1) with aromatic aldehydes in the presence of piperidine yielded 4‐styryl‐3‐carboxamidopiperidyl coumarin derivatives 4. The reaction of hydrazine hydrate with 1 gave acetophenone hydrozone derivatives 5 and acetophenone azine derivatives 6. The reaction of 1 with primary amines afforded compounds 7–9. And the treatment of la with Grignard reagents afforded 3‐aroyl‐4‐methyl coumarin derivatives 10.

Synthesis and structural study of the ligand o-OH acetophenone azine and its Cu(II), Ni(II), Co(II) and Zn(II) complexes

The ligand o-hydroxy acetophenone azine (APA) was identified as bulk material and as deposited thin films by X-ray diffraction (XRD) to be single-phase polycrystalline of the monoclinic structure. The unit cell lattice constants were determined to be a=1.578 nm, b=1.394 nm and c=0.640 nm, as well as its plane angles are α= γ=90°, β=132.8°. Coordination compounds of the ligand o-hydroxy APA and its complexes with the divalent transition metal ions Cu(II), Ni(II), Co(II) and Zn(II) were prepared and characterized by elemental analysis, conductometric measurements, UV/Visible, FT infrared spectra, thermogravimetric (TGA) analysis and magnetic measurements. The ligand acts in a bidentate or tridendate manner forming neutral 1:1 and 2:1 metal to ligand ratio. The formed complexes have the formulae [Cu(II)L(H 2O)]·3H 2O, [Ni(II)L(H 2O)]·2H 2O, [Zn(II)L(H 2O)]·2H 2O and [Co 2L(CH 3COO) 2·4H 2O] where L is the ligand.

Structural and optical studies on ortho-hydroxy acetophenone azine thin films

The bulk material and deposited thin films of ortho-hydroxy acetophenone azine (o-HAcPhAz) were identified by X-ray diffraction (XRD) to be single phase polycrystalline of the monoclinic structure. The unit cell lattice constants were determined to be a = 1.578 nm, b = 1.394 nm and c = 0.64 nm, as well as its plane angles as α = 90°, β = 123.8° and γ = 90°. FTIR spectra of the bulk and thin films of the compound under investigation were assigned in the wave number range 4000–500 cm−1. It was revealed that they were similar to each other. The optical constants (the refractive index, n, and the extinction coefficient, k) of the compound thin films were determined from the measured transmittance, T, and reflectance, R, at normal incidence of light in the spectral range 200–2100 nm. The plot of the absorption coefficient (α) versus hν, gave three intense bands and a shoulder which were designated as A (232.3 nm), B (299.5 nm) and C (440.6 nm, 404.8 nm, sh). The observed A and B bands were attributed to π π* transitions, while the C-bands were attributed to π* ← σ(n). The optical high frequency dielectric constant (∈1, ∈2) as well as the real and imaginary parts of the optical conductivity (σ1, σ2) were determined. The plots of both ∈1, ∈2, σ1 and σ2 versus hν reveal the same obtained optical transitions. Also, the relationships between both of surface, volume and surface/volume energy losses against hν gave the same optical transtions.

Molecular properties of a bis(ketoiminato)-bis(tricarbonyliron) complex obtained by symmetric cleavage from acetophenone azine. Idealized symmetry in anti and syn isomers studied by X-ray diffraction, NMR and density functional theory

Distinct anti and syn isomers of the bis(μ2-acetophenoniminato)-bis(tricarbonyliron) obtained from iron dodecacarbonyl and 1,4-dimethyl-1,4-diphenyl-2,3-diazabuta-1,3-diene by symmetric cleavage of the azine have been compared in terms of molecular deviations from symmetry. The study was carried out by the analysis of intra- and intermolecular close contacts in crystals, quantum chemical DFT calculations for the isolated molecules and by NMR in solution. In the crystalline state the intramolecular contacts and also the symmetry perturbations were more strongly expressed in the syn form as compared with anti, and the same relation was perceived in the DFT-optimized single molecules. However, in solution only symmetric conformations were observed for both isomers anti and syn by 1H and 13C NMR at room temperature and at −70°C.

Synthesis of Acetophenone Azine

Abstract Conditions for preparing acetophenone azine via the oxidative dimerization of acetophenone imine anion are investigated.

Observation on the Fragmentation of Some Tosylhydrazones Using Electrochemically Generated Superoxide Ion

Abstract Superoxide ion (O2\ewdot) generated in situ by electrochemical reduction of molecular oxygen in dimethylformamide (DMF) at mercury cathode, behaves as a mild effective base to deprotonate the acidic hydrogen from tosylhydrazones of benzophenone (1), benzaldehyde (2), cyclohexanone (3), benzoin (4), acetophenone (5), and benzil (6) finally affording tetraphenylethene (1a), trans-stilbene (2a), cyclohexene (3a), deoxybenzoin (4a), acetophenone azine (5a), and 4,5-diphenyl-1-tosylamino-1,2,3-triazole (6a) respectively in good to excellent yield.

Photoinitiated amino-group formation in a polymer matrix and its application to polymer surface modification

Photochemical reactions of pendent acyloxyimino (AOI) groups in copolymers of acryloyl acetophenone oxime (AAPO) with styrene (St) or methyl methacrylate (MMA) were investigated in the solid phase AAPO(26.3)-St films with 10 wt.% benzophenone as a sensitizer were irradiated at 366 nm at room temperature under air. After irradiation alkylimino groups and double bonds were introduced into the copolymers and their yields were 68% and 29% rspectively. The alkylimino groups could be converted into amino groups by hydrolysis with water very easily. The quantum yields of photodecomposition of AOI groups and of formation of amino groups were 0.70 and 0.48 respectively. The yields of amino groups did not depend on the atmosphere employed during irradiation, irradiation wavelengths or residual casting solvents in the films, but depended on the content of AOI groups in the copolymers: the yield decreased with an increase in AOI groups. This was explained by assuming that the increase in the content of AOI groups in a polymer matrix facilitated the formation of acetophenone azine by the mutual recombination of amino radicals, which depressed the formation of alkylimino groups. This assumption was verified. It was found that when the amino groups in irradiated AAPO-St(or MMA) were changed into ammonium groups, the wettability of the copolymer surface was modified remarkably and that they made it possible for an acid dye to dye the copolymer surface.

Thermolysis of the sodium salt of tricarbonyl(acetophenone)chromium p-tosylhydrazone

Thermolysis of the sodium salt of tricarbonyl(acetophenone)chromium p-tosylhydrazone was carried out at 116–118 °C in pyridine, both in the presence and absence of 1,1-diphenyl-ethylene and cyclohexene. The products, separated by column chromatography, were shown by analyses to be acetophenone azine, symmetrical and unsymmetrical tricarbonyl(acetophenone azine)chromium complexes, and a diastereomeric mixture of hexacarbonyl(2,3-diphenylbutane)-dichromium and 1-tricarbonyl(phenyl)chromium-1-methyl-2,2-diphenylcyclopropane. The formation of these compounds has been rationalised by the combination of a diazo intermediate and tricarbonyl(methylphenylcarbene)chromium. Their stereochemistry has been discussed in the light of various spectroscopic results.

A spectroscopic study of two hydrazine derivatives and some of their metal complexes

o-Aminobenzaldehyde and o-aminoacetophenone react with hydrazine hydrate to form monoazines. Their structures and electronic spectra are discussed together with mo calculations. 1:1 complexes are formed between Co(II), Ni(II), Cu(II) and the deprotonated benzaldehyde azine (AZ) also with the neutral form of the acetophenone azine (MeAZ). Zn(II) forms a 1:1 complex with deprotonated MeAZ only. Magnetic and spectroscopic studies of the complexes show that the Co(II), Ni(II) and Cu(II) complexes have distorted octahedral structures, the AZ complexes being more distorted than the MeAZ ones.

Mass spectrometry—III: Further studies of the unimolecular decomposition of acetophenone azine in the gas phase induced by electron‐impact

AbstractMass spectra of acetophenone azine‐d10 (II) and acetophenone azine‐d6 (III) were obtained to ascertain the validity of the proposed mass spectral fragmentation mechanisms proposed for acetophenone azine (I). Data from II and III reveal that the [M –1] ion in the spectrum of I is formed via loss of ring hydrogen. Within experimental uncertainty the major fragmentation reactions of the molecular ion of I, the [M –1] ion, and the [M –15] ion occur without loss of structural identity of the phenyl and methyl moieties. Ionization of I occurs with a high degree of structural integrity.

Mass spectrometry—II: The unimolecular decomposition of benzaldehyde azine in the gas phase induced by electron‐impact

AbstractThe mass spectra of benzaldehyde azine‐α, αA‐d2 (III) and benzaldehyde azine‐d10 (IV) reveal that both ring and α hydrogen are lost from the molecular ion of benzaldehyde azine (II) in forming the [M –1] ion. Data from the spectra of III and IV at 70 eV and reduced ionizing voltages are consistent with the existence of two competing pathways producing [M –1] ions. Rearrangement ions are observed in the spectra of II. Randomization is unimportant in the electron‐impact‐induced fragmentation reactions of II. The rearrangement‐fragmentation reactions for II in general parallel those previously observed for acetophenone azine (I).