Diphenyl Methylene Research Articles

Design, Synthesis and Anti-Bacterial Activity Evaluation of Indole-Based Benzophenone and Their Derivatives

Indole and benzophenone moiety are of significant interest to investigators because they are found in many natural products and pharmacologically active compounds. They represent versatile synthetic building blocks. The benzophenone and indole scaffolds are special structures in medicinal chemistry because these compounds are found in several biologically active natural products, compounds containing indole and benzophenone exhibit anticancer, antiinflammatory, antimicrobial, and antiviral activities. In this study, derivatives of 2-(diphenyl methylene) hydrazine, containing both indole and benzophenone moieties were successfully synthesized. The structural elucidation of the synthesized compounds were done using spectroscopic techniques like IR, 1HNMR, and 13CNMR. The synthesized target compounds were investigated for their in vitro antibacterial activity against two bacterial strains; staphylococcus aureus (S. auras), and Escherichia coli (E. coli) using the disc diffusion method. All synthesized target compounds showed no significant activity against Staphylococcus aureus (S. aureus) but exhibited moderate activity against Escherichia coli (E. coli). Among all the synthesized compounds, 2-(diphenyl methylene)-1-((1-tosyl-1H-indol-3-yl) methylene) hydrazine (BHT) (7b) showed a good inhibition at a concentration of 50 μg/mL with a zone of inhibition of 21.7 mm against Escherichia coli (E.coli) which was comparable with standard drug Ceftriaxone with the zone of inhibition of 26 mm. Thus, this compound could be considered as a lead molecule to design and develop novel antibacterial drugs.

Evaluation of photostability of azelnidipine tablets and structure determination of its photoproducts

Photo-exposure has a crucial effect on the natures of photosensitive pharmaceuticals in addition to their contents in medicines through the photodegradation. Generated photoproducts might be more bioactive and contribute to the expression of adverse side effects. This study aimed to clarify the photochemical behavior of medicines of azelnidipine, which is a member of dihydropyridine antihypertensive drugs, by the evaluation of its photostability and the determination of chemical structures of generated photoproducts. Calblock® tablets and its altered forms (powders and suspensions) were UV-irradiated by a black light. Residual amounts of active pharmaceutical ingredients (APIs) were monitored by high-performance liquid chromatography. The chemical structures of two photoproducts were determined by electrospray ionization tandem mass spectrometry. API of Calblock® tablets was photodegraded with the generation of several photoproducts. Its photodegradability was more significant when Calblock® tablets were crushed or suspended. Structural determination revealed that two photoproducts were benzophenone and a pyridine derivative. It was speculated that these photoproducts were generated by the elimination of diphenyl methylene radical and additional chemical reaction including oxidation and hydrolysis. Azelnidipine was photosensitive and its photodegradation in Calblock® tablets was promoted by the change of the dosage form. This difference might be derived from the light emission efficiency. This study suggests that API contents of Calblock® tablets might decrease when tablets or its altered forms are exposed to sunlight irradiation with the generation of benzophenone, which is a toxicological potent.

Modular Synthesis of Tetraurea and Octaurea Macrocycles Encoded with Specific Monomer Sequences

Modular Synthesis of Tetraurea and Octaurea Macrocycles Encoded with Specific Monomer Sequences

Controlled (Co)Polymerization of Methacrylates Using a Novel Symmetrical Trithiocarbonate RAFT Agent Bearing Diphenylmethyl Groups.

Herein, we report a novel type of symmetrical trithiocarbonate chain transfer agent (CTA) based diphenylmethyl as R groups. The utilization of this CTA in the Reversible Addition-Fragmentation chain Transfer (RAFT) process reveals an efficient control in the polymerization of methacrylic monomers and the preparation of block copolymers. The latter are obtained by the (co)polymerization of styrene or butyl acrylate using a functionalized macro-CTA polymethyl methacrylate (PMMA) previously synthesized. Data show low molecular weight dispersity values (Đ < 1.5) particularly in the polymerization of methacrylic monomers. Considering a typical RAFT mechanism, the leaving groups (R) from the fragmentation of CTA should be able to re-initiate the polymerization (formation of growth chains) allowing an efficient control of the process. Nevertheless, in the case of the polymerization of MMA in the presence of this symmetrical CTA, the polymerization process displays an atypical behavior that requires high [initiator]/[CTA] molar ratios for accessing predictable molecular weights without affecting the Đ. Some evidence suggests that this does not completely behave as a common RAFT agent as it is not completely consumed during the polymerization reaction, and it needs atypical high molar ratios [initiator]/[CTA] to be closer to the predicted molecular weight without affecting the Đ. This work demonstrates that MMA and other methacrylic monomers can be polymerized in a controlled way, and with “living” characteristics, using certain symmetrical trithiocarbonates.

Intramolecular‐Locked High Efficiency Ultrapure Violet‐Blue (CIE‐y &lt;0.046) Thermally Activated Delayed Fluorescence Emitters Exhibiting Amplified Spontaneous Emission

AbstractRational manipulation of frontier orbital distribution and singlet‐triplet splitting is crucial to exploit the luminescent properties of organic molecules. To realize ultra‐blue luminescence, both blue‐shifted wavelength peak (λpeak) and narrow full‐width at half‐maximum (FWHM) are required. Herein, a new thermally activated delayed fluorescence (TADF) skeleton by inserting the diphenyl methylene intramolecular‐lock to adjust the torsion angles and restrict the intramolecular relaxation is developed. Two rigid emitters, incorporating phenoxazine (PXZN‐B) and acridine (DMACN‐B) as donors and mesitylboron as an acceptor, exhibit narrow FWHMs (&lt;50 nm) with deep‐blue (0.133, 0.147) and violet‐blue emission (0.151, 0.045), respectively. In particular, the Commission Internationale de l'Eclairage (CIE) coordinates of a DMACN‐B‐based device closely approach the Rec.2020 standard (0.131, 0.046). Moreover, both of the organic light‐emitting diodes (OLEDs) based on PXZN‐B and DMACN‐B show TADF character, with high external quantum efficiencies (EQEs) exceeding 10%. Furthermore, owing to the large orbital overlap, these TADF emitters own a fast S1–S0 transition rate exceeding 108 s–1, thereby exhibiting marked amplified spontaneous emission (ASE) with low thresholds. Therefore, the intramolecular‐lock strategy provides not only innovation for realizing high‐efficiency deep‐blue TADF emission with high color purity but also an avenue for a TADF‐based ASE and lasing application.

Continuous Hydrogenolysis of N-Diphenylmethyl Groups in a Micropacked-Bed Reactor

In recent years, with the advancements in continuous flow technology and the ever-increasing demand for green processes, continuous flow chemistry has become more and more widely adopted in the pha...

Preparation, Characterization and Biological Study of New Derivatives of 1, 3, 4 - Thiadiazoleand Its Complexes with Some Transitional Element Ions.

The current study involved preparation of ligand [2,5-bis-(2-(diphenyl methylene) hydrazineyl)-1,3,4-thiadiazole] (L1) from reacting between thiadiazole derivative [ (2,5-dihydrazineyl-1,3,4 -thiadiazol) and Benzphenone by the ratio (1:2) . Attended the transitional elements ions complexes [Cr+3, Fe+3, Co+3, Ni+2, Cu+2] with ligand (L1) Complexes were diagnosed using the precision analysis of elements (C.H.N), Infrared spectrum (FTIR), Spectrum of Nuclear Magnetic Resonance proton (1H-NMR), Mass spectroscopy, measurement magnetic sensitivity and measurement molar conductivity the results were practical exactly matching with the molecular and structural formulas of the proposed compound .Hyperchem was used to draw ligand (L1) and its complexes and to show the distribution of electronic density. Data obtained indicates that the stereochemistry figure of the complexes [Cr+3, Fe+3, Co+3] was octahedral , the proposed stereochemistry figure of the complexes [Ni+2, Cu+2] is square planer. A study was conducted testing the biological activity for the prepared ligand (L1) and its complexes against two types of bacteria staphylococcus aureus and Escherichia coli compared to the standard inhibitor (Cipro.), the results obtained confirmed that ligand(L1) and their complexes did not show any biological activity towards the bacteria aureus staphylococcus aureus, while the ligand(L1) and their complexes showed different activity twards the second type of bacteria Escherichia coli, some showed greater activity than the standard inhibitor and some showed less activity than the standard inhibitor

Acidic Solvent-free Removal of Amine-protecting Diphenylmethyl Groups in the Presence of Camphorsulfonic Acid

We developed novel reaction conditions for the removal of the diphenylmethyl group, which is one of the most important protecting groups for amines. The reaction was promoted by adding one equivalent of camphorsulfonic acid in aqueous media, and no acidic solvent was required.

ChemInform Abstract: Two Phenyls Are Better Than One or Three: Synthesis and Application of Terminal Olefin‐Oxazoline (TOlefOx) Ligands.

AbstractA novel terminal olefin‐oxazoline ligand containing two diphenylmethyl groups is used in the highly enantioselective rhodium‐catalyzed conjugate addition of aryl boronic acids to enones.

Highly Stable N3-Substituted Imidazolium-Based Alkaline Anion Exchange Membranes: Experimental Studies and Theoretical Calculations

Imidazolium cations with various N3-substituents (including methyl, butyl, heptyl, dodecyl, isopropyl, and diphenylmethyl groups) were synthesized and investigated in terms of their alkaline stability. The effect of the N3-substituent on the alkaline stability was studied by quantitative 1H NMR spectra and density functional theory (GGA-BLYP) calculations. The isopropyl substituted imidazolium cation ([DMIIm]+) with the highest LUMO energy value exhibited the highest alkaline stability in aqueous NaOH. The [DMIIm]+ cation also exhibited higher alkaline stability than that of a quaternary ammonium cation, benzyltrimethyl-ammonium ([BTMA]+), in CD3OD/D2O NaOH solution at elevated temperatures. This observation inspired the preparation of [DMIIm]+-based alkaline anion exchange membranes (AEMs) which showed high alkaline stability in alkaline solution.

Preparation and Flame Retardancy of Polyurethane/POSS Nanocomposites

Polyurethane/polyhedral oligomeric sisesquioxane (PU/POSS) nanocomposites were synthesized via polymerization utilizing the compatibility between POSS nanoparticles and 4,4′-diphenyl methylene diisocyanate. Scanning electron microscope images and Fourier transform infrared spectra revealed that POSS nanoparticles were dispersed in PU matrix. Thermal gravimetric analysis was employed to investigate the thermal decomposition behavior of PU/POSS nanocomposites at elevated temperatures. Then fire performance was evaluated by limiting oxygen index, underwriters laboratories 94 testing and char residue morphology. These results showed that the addition of POSS promoted the formation of char residues which were covered on the surface of polymer composites, leading to the improvement of thermal stability and flame retardancy.

Microencapsulation of a cooling agent by interfacial polymerization: Influence of the parameters of encapsulation on poly(urethane–urea) microparticles characteristics

A series of polyurea–urethane microparticles containing xylitol were synthesized by interfacial polymerization from reaction between diphenyl methylene diisocyanate (MDI) and xylitol. This research was conducted to clarify the influence of different parameters on the encapsulation process, i.e. during the emulsion formation step and during the shell formation using contact angle measurement, Fourier-transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analyses. By carefully analyzing the influencing factors stirring rate and feeding weight ratio of core/shell monomers, the optimum synthetic conditions were found out. The results show that core/shell weight ratio influences not only the shell formation mechanism but also the mean diameter, microcapsule morphology, the encapsulation yield and the xylitol content. Thus, the choice of a core/shell weight ratio of 77.0–23.0 is the most suitable to obtain high encapsulation yield and xylitol loading content.

Influence of the washings on the thermal properties of polyurea-urethane microcapsules containing xylitol to provide a cooling effect

In this report, the preparation and performance of microcapsules interacting with the absorbed water to promote a cooling effect were investigated. The microcapsules containing xylitol were prepared from xylitol and diphenyl methylene diisocyanate (MDI) by an interfacial polymerization process. The microencapsulated xylitol was characterized by scanning electron microscopy (SEM) to illustrate its porous surface structure and its morphology. The influence of the drying process after washing was analyzed by differential scanning calorimetry (DSC) prior to the determination of the heat of solution. The results show the perspectives of the usage of these microcapsules as a reversible cooling agent for moisture management.

Synthesis of Polyurethane and Characterization of its Composites Based on Alfa Cellulose Fibers

Polyurethane (PU) based on polycaprolactone (PCL) and 4,4′ diphenyl methylene diisocyanate (MDI) was synthesized using a two-step method. The PU obtained was then blended with various amounts of cellulose extracted from alfa stems to prepare composite materials. The influence of cellulose on the thermal and mechanical properties of different composites was demonstrated by means of several characterization techniques such as Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM)…

Ruthenium(II)‐Komplexe mit orthometallierten O'Donnell Schiffbasen (Diphenylmethylenglycinester) [1

AbstractRuthenium(II) Complexes of Orthometallated O'Donnell Schiff Bases (Diphenylmethylene Glycine Esters) [1]The reaction of diphenyl methylene glycine esters with [Ru(PPh3)3Cl2] gives the orthometallated complexes [Ru(PPh3)2(Cl){(C6H4)(C6H5)C=NCH2CO2R}] (R = H, Et, CMe3) in which the ester group is coordinated to the ruthenium atom and which were characterized by IR, NMR, MS data and by cyclovoltammetry.

Two new polymorphs of diphenyl(4-pyridyl)methyl methacrylate

The title compound (D4PyMA), C(22)H(19)NO(2), exhibits polymorphism after crystallization by slow evaporation from a binary mixture of chloroform and hexane. Long needle-like crystals have an orthorhombic structure (space group Fdd2), with one molecule in the asymmetric unit, while small tablet-like crystals exhibit a monoclinic crystal structure (space group P2(1)/n), in which two independent but chemically identical molecules comprise the asymmetric unit. The bond lengths and angles are normal, while the torsion angles around the -C-O- bond linking the diphenyl(4-pyridyl)methyl and methacrylate groups show the flexibility of the molecule by way of packing effects. The two polymorphs both contain weak C-H...pi and C-H...O/N contacts but have different conformations.

Alkaline hydrolysis/polymerization of 2,4,6-trinitrotoluene: characterization of products by 13C and 15N NMR.

Alkaline hydrolysis has been investigated as a nonbiological procedure for the destruction of 2,4,6-trinitrotoluene (TNT) in explosives contaminated soils and munitions scrap. Nucleophilic substitutions of the nitro and methyl groups of TNT by hydroxide ion are the initial steps in the alkaline degradation of TNT. Potential applications of the technique include both in situ surface liming and ex situ alkaline treatment of contaminated soils. A number of laboratory studies have reported the formation of an uncharacterized polymeric material upon prolonged treatment of TNT in base. As part of an overall assessment of alkaline hydrolysis as a remediation technique, and to gain a better understanding of the chemical reactions underlying the hydrolysis/polymerization process, the soluble and precipitate fractions of polymeric material produced from the calcium hydroxide hydrolysis of unlabeled and 15N-labeled TNT were analyzed by elemental analysis and 13C and 15N nuclear magnetic resonance spectroscopy. Spectra indicated that reactions leading to polymerization included nucleophilic displacement of nitro groups by hydroxide ion, formation of ketone, carboxyl, alcohol, ether, and other aliphatic carbons, conversion of methyl groups to diphenyl methylene carbons, and recondensation of aromatic amines and reduced forms of nitrite, including ammonia and possibly hydroxylamine, into the polymer. Compared to the distribution of carbons in TNT as 14% sp3- and 86% sp2-hybridized, the precipitate fraction from hydrolysis of unlabeled TNT contained 33% sp3- and 67% sp2-hybridized carbons. The concentration of nitrogen in the precipitate was 64% of that in TNT. The 15N NMR spectra showed that, in addition to residual nitro groups, forms of nitrogen present in the filtrate and precipitate fractions include aminohydroquinone, primary amide, indole, imine, and azoxy, among others. Unreacted nitrite was recovered in the filtrate fraction. The toxicities and susceptibilities to microbial or chemical degradation of the polymeric materials remain unknown.

Time-Resolved Electron Paramagnetic Resonance Study of the First Excited Triplet States of Dibenzocycloheptadienylidene and Diphenylmethylene Derivatives

Transient triplet electron paramagnetic resonance (EPR) spectra of dibenzocycloheptadienylidene (DBC) and substituted diphenylmethylenes were observed in a rigid glassy matrix at low temperatures. On excitation with the wavelength of the T−T transition of DBC, polarized EPR spectra due to the both ground (T0) and excited (T1) states were observed at a short delay time (180 ns) after the laser pulse. The T1 components in the spectrum decayed faster than the other and diminished at 1 μs after the laser pulse irradiation. The remaining signals after the decay of the T1 state were unambiguously assigned to the T0 state, taking into account the steady-state (SS) EPR results. From analysis of the spectrum of the short-lived triplet species, the zero-field splitting (ZFS) parameters, |D| = 0.201 and |E| = 0.008 cm-1, were determined for the T1 state directly. The parameters obtained were comparable to those of the T1 state of diphenylmethylene (DPM). The polarization patterns of the transient spectra match well with interpretation as anisotropic intersystem crossing induced by the spin−orbit couplings between the Sn and the triplet states. On the basis of the results of magnetophotoselection experiments, we also confirmed that the principal axes in the T0 and T1 states did not differ significantly from each other. The behavior of the methyl-substituted DPM resembles that of DPM and DBC, indicating that the methyl group does not affect the photophysical and photochemical properties of the T0 and T1 states. Although the SS EPR spectra were observed for the T0 state of substituted DPM derivatives, the chemical properties of the excited states were affected by substitution of electron-donating (OCH3) or -withdrawing (CN) groups.

Development of Immunoassays for Biomonitoring of Hexamethylene Diisocyanate Exposure

Hexamethylene diisocyanate (HDI) is used widely to manufacture polyurethanes for paints and coatings. It is an irritant and a chemical asthmagen. The U.S. Occupational Safety and Health Administration time-weighted average permissible exposure limit is 5 ppb and the ceiling limit is 20 ppb. We sought to develop a sensitive and specific immuno-bioassay to supplement workplace air monitoring and detect recent HDI exposure. For this, we produced rabbit antiserum to HDI-adducted keyhole limpet hemocyanin (HDI-KLH). The specificity of the antiserum was demonstrated by its reaction with a variety of HDI-conjugated proteins and the absence of reactions with conjugates of other diisocyanates, namely toluene diisocyanate and diphenyl methylene diisocyanate. Four immunoassays were developed and compared for their ability to detect decreasing quantities of HDI-adducted human serum albumin (HSA) containing 2 mol HDI adduct per mol HSA (HDI(2)-HSA) as determined by matrix-assisted laser desorption time-of-flight (MALDI-TOF) mass spectrometry. The sensitivities of some of the assays are within the range (0.82-45 nM) of current analytic methods. A Western analysis procedure has a sensitivity of 600 nM HDI adduct on HSA. ELISA inhibition assay, in which microtiter plates are coated with the HDI(2)-HSA antigen, has a sensitivity of 300 nM HDI adduct. An immunoblot assay has a sensitivity of 9 nM HDI adduct. The most sensitive bioassay (1.8 nM HDI adduct) is a three-antibody sandwich ELISA in which wells of microtiter plates are coated with the IgG fraction of the anti-HDI-KLH antisera. Compared with analytic methods for HDI biomonitoring, the immunoassays are faster and less costly and accommodate numerous samples simultaneously. The assays have the potential to affect industrial biomonitoring programs significantly.

Functional End-Group Exchange of Nitroxide- or Bromo-Terminated Polystyrene

Nitroxide- and bromo-terminated polystyrenes resulting from “living” free radical polymerization processes have been “functionalized” by a combination reaction with tetraphenylethane based derivatives i.e. 1,1,2,2-tetraphenyl-1,2-bis(trimethylsilyloxy)ethane. The substitution of the terminal moiety by diphenylmethyl groups has been characterized by 1H, 13C and 29Si NMR, ESI and MALDI-TOF mass spectrometry.