- Room Temperature Acid-Free Greener Synthesis of Imine Using Cobalt-Doped Manganese Tungstate
-
Facile synthesis of an imine compound through a greener route is still a challenging task. Industrial processes rely on the age-old Schiff reaction for the synthesis of imine, which are reversible and nongreen from an environmental viewpoint. Herein, coba
- Mal, Diptangshu Datta,Pradhan, Debabrata
-
supporting information
p. 2211 - 2218
(2022/01/31)
-
- Additional effect of para-hydroxyl on the reduction potentials of the N-benzylidenebenzenamines
-
The reduction potential ERed of disubstituted N-benzylidenebenzenamines XArCH NArY (abbreviated as XBAY) is a measure of the electron acceptance ability of the Lowest-energy Unoccupied Molecular Orbital (LUMO) in molecule, which is closely related to the electronic effects of substituents X and Y in molecule. Previous studies on the ERed of XBAY reported by Luo, Wang, and Yuan all did not involve these molecules containing hydroxyl. In this work, 28 samples of disubstituted N-benzylidenebenzenamines containing para-hydroxyl, (abbreviated as 4-OHBAY or XBAOH-4′) were synthesized, and their ERed values were measured. Then, 127 compounds were taken as a complicated ERed data set, which involved 28 compounds (4-OHBAY and XBAOH-4′) of this work and 99 compounds XBAY reported by Luo. Based on these data ERed set, through a quantitative regression analysis method and comparison of the factors affecting the ERed, the following results are obtained: (a) Because the phenolic hydroxyl OH can dissociate H+ to form phenolic oxygen anion, the change regularity of ERed of compounds 4-OHBAY and XBAOH-4′ is somewhat different from that of ERed of XBAY compounds without hydroxyl OH. That is, hydroxyl OH has an additional effect on the ERed, which decreases the ERed value. (b) The additional effects of 4-OH on the ERed is different from that of 4′-OH. The effect of hydroxyl OH attached to the aldehyde aromatic ring on the ERed is more than that of OH attached to the amine aromatic ring.
- Cao, Chao-Tun,Zhou, Wei,Cao, Chenzhong
-
-
- New wide-stability four-ring azo/ester/Schiff base liquid crystals: Synthesis, mesomorphic, photophysical, and DFT approaches
-
New four-groups-based azo/ester/Schiff base liquid crystals, ((4-substitutedphenylimino)methyl)phenyl 4-[2-(4-alkoxyhenyl)diazenyl]benzoate, Ina-d, were synthesized and analyzed for their mesomorphic stability and optical activity. In these com
- Ahmed, Hoda. A.,Ahmed, Nagwa H. S.,Hagar, Mohamed,Saad, Gamal R.
-
p. 9643 - 9656
(2020/03/19)
-
- Effect of substituents on the UV spectra of supermolecular system: Silver nanoparticles with bi-aryl Schiff bases containing hydroxyl
-
Effect of substituents on the ultraviolet (UV) spectra of supermolecular system involving silver nanoparticles (AgNPs) and Schiff bases was investigated. AgNPs and 49 samples of model compounds (MC), bi-aryl Schiff bases containing hydroxyl (XBAY, involving 4-OHArCH?NArY, 2-OHArCH?NArY, XArCH?NAr-4′-OH, and XArCH?NAr-2′-OH), were synthesized. The size of AgNPs was characterized by transmission electron microscopy (TEM), and the UV absorption spectra of AgNPs, XBAYs, and MC-AgNPs mixed solutions were measured, respectively. The results show that (1) the size of AgNPs is larger in MC-AgNPs solutions than that in AgNPs solution due to the distribution of MC molecules on the surface of AgNPs; (2) the UV absorption wavelength of XBAYs changes in the action of AgNPs and their wavelength shift exists limitation between XBAY and MC-AgNPs solutions; and (3) the wavelength shift limit of MC-AgNPs (λWSL) is influenced by the substituents X and Y and the position of hydroxyl OH. The wavenumber ΔνWSL of λWSL can be quantified by employing the excited-state substituent constant σexCC and Hammett constant σ of substituents X and Y. Comparing with the 4-OH, the 4′-OH makes the ΔνWSL a red shift, whereas the 2′-OH, comparing with the 2-OH, makes the ΔνWSL a blue shift.
- Cao, Chao-Tun,Cheng, Shimao,Zhang, Jingyuan,Cao, Chenzhong
-
-
- Iron-Catalyzed Nitrene Transfer Reaction of 4-Hydroxystilbenes with Aryl Azides: Synthesis of Imines via C=C Bond Cleavage
-
C=C bond breaking to access the C=N bond remains an underdeveloped area. A new protocol for C=C bond cleavage of alkenes under nonoxidative conditions to produce imines via an iron-catalyzed nitrene transfer reaction of 4-hydroxystilbenes with aryl azides is reported. The success of various sequential one-pot reactions reveals that the good compatibility of this method makes it very attractive for synthetic applications. On the basis of experimental observations, a plausible reaction mechanism is also proposed.
- Peng, Yi,Fan, Yan-Hui,Li, Si-Yuan,Li, Bin,Xue, Jing,Deng, Qing-Hai
-
p. 8389 - 8394
(2019/10/16)
-
- Abnormal effect of hydroxyl on the longest wavelength maximum in ultraviolet absorption spectra for bis-aryl Schiff bases
-
Two sets of bis-aryl Schiff bases that contain 4(or 4′)-OH and 2(or 2′)-OH were synthesized. The first set consists of 4-HOArCH=NArY and XArCH=NArOH-4′, and the second set consists of 2-HOArCH=NArY and XArCH=NArOH-2′. Their ultraviolet absorption spectra were measured and investigated. A very interesting phenomenon was observed by analyzing their wave number νmax (cm?1) of longest wavelength maximum λmax (nm) of ultraviolet. Compared with the change regularity of the νmax of XArCH=NArY (where the X and Y excluded OH), the 4′-position hydroxyl (4′-OH) and 2′-position hydroxyl (2′-OH) have abnormal performance. The details are the following: the 4′-OH contributes an additional red shift to the νmax of XArCH=NArOH-4′ (λmax increase), whereas the 2′-OH contributes an additional blue shift to the νmax of XArCH=NArOH-2′ (λmax decrease). In addition, there are ortho steric effects of all 2-OH and 2′-OH on the νmax for 2-HOArCH=NArY and XArCH=NArOH-2′, and the ortho steric effect contributes a red shift to their νmax. These experimental facts can provide an important theoretical reference for us using aryl Schiff base compounds as optical materials and performing the molecular design.
- Cao, Chao-Tun,Zhou, Wei,Cao, Chenzhong
-
-
- Non-symmetric chiral liquid crystal dimers. Preparation and characterisation of the (S)-(benzylidene-4′-substitutedaniline)-2″-methylbutyl-4?(4″″-phenyloxy)-benzoateoxy)hexanoates
-
The properties of six chiral non-symmetric dimers belonging to the family of (S)-(benzylidene-4′-substitutedaniline)-2″-methylbutyl-4?(4″″-phenyloxy)benzoate-oxy)hexanoates are described. The terminal substituents on the 4-benzylidene-4′-substituted fragm
- Yeap, Guan-Yeow,Osman, Faridah,Imrie, Corrie T.
-
p. 118 - 125
(2016/02/12)
-
- Synthesis of novel Schiff Bases containing acryloyl moiety and the investigation of spectroscopic and electrochemical properties
-
A novel Schiff bases and their acryloyl derivatives were synthesized through the reaction of p-hydroxybenzaldehyde in order of with aniline, p-chloroaniline, p-nitroaniline, p-methylaniline and p-aminobenzoic acid. The structures of these compounds were characterised spectroscopic techniques such of IR, 1H NMR, 13C NMR and Mass spectroscopy. π→π?and n→π?transitions were determined via UV-vis spectroscopy studies performed in EtOH, CHCl3, and DMF. Furthermore, the inhibition efficiencies of these new compounds were investigated on the surface of steel within the solution of 0.1 M NaCl, 0.1 M NaOH and 0.10 M H2SO4 solution via cyclic voltammetry and Tafel extrapolation methods.
- Silku, Pakize,?zkinali, Sevil,?ztürk, Zeynel,Asan, Abdurrahman,K?se, D. Ali
-
-
- Molecular structure-thermal behaviour relationship of dimers consisting of different terminal substituents and sulphur-sulphur linking group
-
A new series of dimers 6-(4-oxybenzylidine-4′-substituted-aniline)hexyldisulphides containing various terminal substituents (CH3, C2H5, Cl and Br) have been synthesized. The correlation between the molecular structure and
- Yeap, Guan-Yeow,Osman, Faridah,Kamil Mahmood, Wan Ahmad,Takeuchi, Daisuke
-
p. 666 - 672
(2016/02/03)
-
- Symmetrical trimeric star-shaped mesogens based on 1,3,5-trisubstituted benzene incorporating Schiff base and azobenzene fragments as the peripheral units: Synthesis and mesomorphic properties
-
Two series of symmetrical three-armed star-shaped mesogens based on 1,3,5-trihydroxybenzene as a core unit, interconnecting three Schiff base or azobenzene moieties via oxymethylene spacers have been synthesized and characterized by spectroscopic techniqu
- Yeap, Guan-Yeow,Ooi, Yew-Hong,Uchida, Nozomi,Ito, Masato M.
-
p. 847 - 859
(2014/07/07)
-
- GREEN SYNTHESIS OF ARYL ALDIMINES USING ETHYL LACTATE
-
The present invention relates to a method for preparing aryl aldimines. In particular, the present invention relates to methods of preparing aryl aldimines that uses environmentally friendly solvent systems.
- -
-
Page/Page column 5-6
(2011/08/22)
-
- Novel nonsymmetric trimeric liquid crystals exhibiting glassy nematic state at low temperatures
-
Series of nonsymmetric 4-ethyl- and 4-fluoroanilinebenzylidene-2',4'-oxy- bis(4''-halogenoanilinebenzylidene-4'''oxy)alkanes trimers have been synthesized and characterized. Every member in this series possesses either Cl or Br terminal atoms. The molecul
- Yeap, Guan-Yeow,Hng, Tiang-Chuan,Mahmood, Wan Ahmad Kamil,Gorecka, Ewa,Takeuchi, Daisuke,Osakada, Kohtaro
-
experimental part
p. 135 - 152
(2010/03/24)
-
- Synthesis of 4-O- azomethino-D-glucopyranosides
-
The interaction of 2,3,4,6-tetraacetyi-α-D-glucopyranosyl bromide with potassium salt of 4-hydroxybenzylideneanilines under anhydrous conditions and freezing temperature gives benzylideneaniline tetraacetyl-4-O-D- glucopyranosides and corresponding 4-O-be
- Ingle,Upadhyay,Kharche
-
p. 1743 - 1747
(2007/10/03)
-
- Quantitative solid-solid synthesis of azomethines
-
Twenty preparatively useful azomethines have been quantitatively (100% yield at 100% conversion) obtained as hydrates by grinding together solid anilines with solid benzaldehydes without passing through liquid phases. Unlike (acid catalyzed) azomethine syntheses in solution, the solid-solid condensations proceed 'waste-free'. The solid-state mechanisms have been elucidated by atomic force microscopy (AFM) and in part by scanning near-field optical microscopy (SNOM) in three cases. The results indicate long distance migration of the aldehydes into the lattice of the aniline derivatives. Stumpy protrusions are formed at the direct points of contact but also distance sublimation (100 nm range) is succesful in the case of p-chlorobenzaldehyde and p-nitroaniline. Long-range flow of 4-hydroxybenzaldehyde molecules on its (010)-face into contracting crystals of p-toluidine or p-anisidine occurs along two different cleavage planes. Steep hills and valleys are left behind. The molecular migrations through the sites of contact are interpreted in terms of crystals packing. The ease of these solid-solid condensation reactions relies on the crystal packing.
- Schmeyers, Jens,Toda, Fumio,Boy, Juergen,Kaupp, Gerd
-
p. 989 - 993
(2007/10/03)
-
- Polarographic investigations on azomethines: Benzal-p-chloranilines in alkaline medium and effect of substituents on half-wave potentials
-
Polarographic behavior of twenty-four substituted benzal-p-chloranilines has been investigated in 50percent methanol-water medium in alkaline pH range.The experimental conditions for the study were so designed that no appreciable hydrolysis of the Schiff
- Katiyar, Sarvagya S.,Lalithambika, M.
-
p. 961 - 973
(2007/10/02)
-