Origin and switch of different colors: Thermo-isomerism and crystal structure of (1E,2E)-bis[1-(4-nitrophenyl)ethylidene] hydrazine

Abstract

International audienceA new symmetric branched 4-nitrophenyl hydrazine compound has been prepared in one-step procedure by direct condensation of aromatic ketone with hydrazine in MeOH. The synthesized compound, red isomer, was characterized by IR, 1H and 13C NMR spectroscopy, Elemental analyses, Mass spectrometry and X-ray crystallography. Refluxing in MeOH solution led to thermo-isomerism offering a white isomer product that was characterized by X-ray crystallography. The red isomer crystallizes in the orthorhombic system having space group Pbcn, with a = 12.7612(4), b = 11.5197(3), c = 20.1586(7) Å, V = 2963.42(16) Å 3, Z = 8 while the white isomer crystallizes in the triclinic system having space group P −1, with a = 7.8007(4), 8.5966(7), 12.224 (1) Å, α= 71.133(7), β= 81.281(5), γ= 74.895(5) ∘, V = 746.86(9) Å 3, Z = 2. Molecules of both compounds are twisted at N2–N3 bond with the C7-N2-N3-C9 torsion angle of 155.23(12) and −113.36(18) ∘, respectively. The crystal structures of both compounds are stabilized by weak intramolecular C—H …N contacts and intermolecular C—H …O hydrogen bonding interactions. In addition, π– π stacking interactions are observed between the same aromatic rings of molecules. Graphical Abstract Hydrazone undergoes trans-cis isomerism when heated in an appropriate solvent. The reverse trans-cis thermo-isomerism can be driven also by light or thermally in the dar

Evaluation of inhibitive corrosion potential of symmetrical hydrazine derivatives containing nitrophenyl moiety in 1M HCl for C38 steel: experimental and theoretical studies

“…However, even though the three tested compounds present acceptable inhibitive efficiencies, we can note that in the case of the ortho-and para-positions of the nitro group, the corresponding compounds (SSBO and SSBP) have relatively low inhibition efficiency compared to that where the nitro group in the meta-position (SSBM). As previously described, this is could be attributed to the hydrogen bonding C-H … N and π-bonds interactions in the case of meta-position whereas the threedimensional distance is not helpful to the formation of hydrogen bonding and/or π-bonds interactions in the case of ortho-and para-positions [13].…”

“…Indeed, they present two superimposed capacitive loops. At high frequency a first capacitive loop was attributed to the formation of a film barrier by the inhibitor on the CS surface, while the second at low frequency was related to the charge transfer capacity [13] , [34] . This result was confirmed through the analysis of Bode plots (presence of two-time constants) Fig.…”

“…The choice of these hydrazine derivatives ( SSBs ) to test their anti-corrosive properties is based on the following cautions (a) their synthesis process easy and not expensive, (b) they are formed with high yield, (c) have many biological activities and excellent fluorescent chemosensors for metal ions [13] , (d) they are no poisonous, (e) contain heteroatoms (N and O), (f) contain ortho-, meta- or para-nitro group (with electron-withdrawing) leading to the partial charges on carbon chain of aromatic ring, (g) they are π -conjugated systems with 2,3-diaza group (R-C=N-N=C-R), (h) possess methyl group (with electron-donor) which ensure availability of electron density around nitrogen atoms of 2,3-diaza group, (i) they are symmetrical systems [13] , [14] . The considerations (d), (e), (f), (g), (h) and (i) offer the studied compounds a high ability to form covalent or/and non-covalent bonds with C38 steel and thus forming a protective layer against corrosion.…”

Self‐assembly of unexpected [Mn(2‐(1‐hydrazonoethyl)pyridine)Cl2]n 1D coordination polymer: Synthesis, structural elucidation, and biological studies

“…The results gave sufficient evidence on the way by which the Mn(II) ion coordinating to the ligand L 2 . [ 36 ] It is clear that the free ligand L 2 exhibits two characteristic bands attributed to ν (NH 2 ) at 3365 and 3301 cm −1 that appeared as one band at 3430 cm −1 in the [Mn(L 2 )Cl 2 ] n complex. Also, the strong absorption band observed in the free ligand L 2 at 1641 cm −1 was assigned to ν(C=N) mode, which is found shifted to lower wavenumber of 1623 cm −1 in the spectra of the [Mn(L 2 )Cl 2 ] n complex.…”

Synthesis, molecular structure, spectroscopic investigations and computational study of a potential molecular switch of 2-([1,1’-biphenyl]-4-yl)-2-methyl-6-(4-nitrophenyl)-4-phenyl-1,3 diazabicyclo [3.1.0]hex-3-ene

“…1 Photochromic compounds reversibly change geometrical structure. 2 Although many types of photochromic compounds have been reported, those exhibiting photochromism in solid state are very rare. 3 Depending on the special structure, 1,3diazabicyclo[3.1.0]hex-3-ene derivative crystals show different colour such as blue, purple, yellow, purple, pink, brown, etc.…”