P-methyl Phenyl Research Articles

Syntheses, crystal structure, luminescent properties and Hirshfeld surface of a set of triazole-based salts

To further investigate and explore the new luminescent materials, three new salts with triazole-based skeletons, namely, [HCNT]+X− (X = BS (1), PS (2) and SS∙H2O (3)) [CNT = 4-((1H-1,2,4-triazol-1-yl)methyl)benzonitrile, BS= benzene-sulfonic acid, PS = p-methyl phenyl sulfonic acid, SS = sulfosalicylic acid], have been prepared through the CNT and three sulfonic acids, respectively. Compounds 1-3 have been characterized by single–crystal X–ray diffraction, IR, UV-Vis, EA, powder X-ray diffraction (PXRD) and thermogravimetric analysis (TGA). In the target compounds, hydrogen bonds (N/O/C–H⋯O/N) and stacking interactions can be evidently observed, through which a three-dimensional framework will be built. The luminescent spectra of these compounds show that the maximal emission peaks in compounds 1-3 can be found to be 452, 441 and 472 nm, respectively. Compared with the free CNT, the emission maxima of compounds 1-3 are obviously red-shifted about 135, 124 and 155 nm, respectively. The Hirshfeld surface analysis further confirms that the C∙∙∙C close contacts can account for the photoluminescent spectra.

Syntheses, crystal structure, luminescent behaviors and Hirshfeld surface of salts with imidazole and benzimidazole-yl scaffolds

To explore the new photoluminescent materials, two new salts with imidazole and benzimidazole moieties, namely, [HIBI]+Z− (Z= MBS– (1) and BS– (2) [IBI = 2-((1H-imidazol-1-yl)methyl)-1H-benzimidazole, MBS = p-methyl phenyl sulfonic acid, BS= benzene-sulfonic acid], were obtained through reacting IBI and phenyl sulfonic acids by slow evaporation method, respectively. Compounds 1 and 2 have been characterized by single-crystal X-ray diffraction, IR, powder X-ray diffraction (PXRD) and thermogravimetric analyses (TGA). In both compounds, a set of hydrogen bonds (C/N–H⋯O) can be evidently observed, through which a three-dimensional framework will be fabricated. The luminescent spectra show that the emission maximal peaks in compounds 1 and 2 can be observed to be 460 and 477 nm, respectively. By comparison with the free IBI, the emission maxima of compounds 1 and 2 are obviously red-shifted about 151 and 168 nm, respectively. The Hirshfield surface analysis further confirms that the C∙∙∙C close contacts can account for the photoluminescent spectra.

Antimicrobial and antioxidant evaluation of newly synthesized nanomaterials of potential anticorrosion properties based on Co (II), Ni (II), Cu (II) and Zn (II) nano complexes of N-(p-methyl phenyl)-N-Benzoyl thiourea

Antimicrobial and antioxidant evaluation of newly synthesized nanomaterials of potential anticorrosion properties based on Co (II), Ni (II), Cu (II) and Zn (II) nano complexes of N-(p-methyl phenyl)-N-Benzoyl thiourea

Studies in Solute-Solute and Solute-Solvent Interaction of Some Substituted Ketimine Drugs in 75 % Dichloromethane Water Mixture under Different Temperature by Viscometric Technique

The computation of densities, specific viscosities of 5- Bromo-2-hydroxy-4-chloro (p-methyl phenyl) ketimine (L1) and 5- Bromo-2-hydroxy-4-chloro (p-amino phenol) ketimine (L2) drugs in 75% (DCM + water) mixture at the temperature range (308 to 314 K) are reported. The investigational data shows, the effect of temperature on viscosity of solute in DCM + water mixtures which gives idea about the molecular interactions present in different solutions. Considerable molecular interactions have been observed between the substituted ketimines drugs and DCM + water mixture. The experimental data at different temperature range (308 to 314 K) are used to investigate thermodynamic properties such as free energy change (∆G), enthalpy change (∆H) and entropy change (∆S) of substituted ketimines drugs in 75% (DCM + water) mixture. The experimental data gives the idea about effect of temperature on the molecular interaction and structural changes in solute.

Evaluation of the stability of rigid poly(vinyl chloride)/biologically active phthalimido phenyl urea composites using thermogravimetric analysis

Four novel phthalimido phenyl urea derivatives, prepared by a low temperature solution condensation reaction between N-[4-(chlorocarbonyl) phenyl] phthalimide and either of phenyl urea, p-methyl phenyl urea, o-chloro phenyl urea or p-carboxy phenyl urea, have been investigated as antimicrobial thermal stabilizers for rigid PVC. They were characterized by FTIR, 1H-NMR, mass spectra, elemental analysis and antimicrobial activity. Their antibacterial activities against Bacillis subtilis and Streptococcus pneumoniae as Gram-positive bacteria and against Salmonella typhimurium as Gram-negative bacteria and their antifungal activities against Aspergillus fumigatus, and Geotricum candidum were evaluated using the agar well diffusion technique. The results indicated that these derivatives showed good antibacterial activity as judged by their high inhibition zone diameter and low minimum inhibition concentration. These derivatives are more potent against Gram-positive bacteria than against Gram-negative bacteria. The results also indicated that these derivatives have effective antifungal activity. The carboxy derivative exhibited the highest antimicrobial activity relative to the other derivatives. Their stabilizing efficiency is evaluated using thermogravimetric technique in nitrogen, and by the extent of discoloration as well as by the change in the molecular weight of the degraded polymer. The results reveal the greater stabilizing efficiency of these derivatives relative to dibasic lead carbonate (DBLC), cadmium-barium-zinc (Cd-Ba-Zn) stearate complex and di-n-octyltin bis (isooctylmercaptoacetate) (n-octyltin mercaptide, n-OTM) reference thermal stabilizers. This is well illustrated by the higher initial decomposition temperature, and lower rates both of weight loss and discoloration as well as decreasing in degree of chain scission of the polymer during degradation relative to those of the reference stabilizers. Moreover, the stabilizing efficiency is influenced by the nature of the substituent group in the aryl moiety of the phenyl urea part of these derivatives. While, the methyl derivative is characterized by a greater efficiency relative to those of the chloro and carboxy derivatives, the non-substituted derivative lies between these two cases.

Synthesis, structure and photoluminescence properties of functionalized azoimine ligands and their nickel complexes

The new ligands 2-hydroxy-5-methyl-3-(2-aryldiazenyl)phenylimino)methyl)benzaldehyde HLa, 2, and ethyl-2-cyano-3-(2-hydroxy-5-methyl-3-(-(2-aryldiazenyl)phenylimino)methyl)phenyl)acrylate, HLb, 3, [where aryl is phenyl for HLa1, 2a, and HLb1, 3a; p-methyl phenyl for HLa2, 2b, and HLb2; 3b, and p-chloro phenyl for HLa3, 2c, and HLb3, 3c] were prepared. The newly synthesized ligands are abbreviated as HLa and HLb where H represents the dissociable proton upon complexation. The reactions of HLa and HLb with hydrated nickel acetate afforded the new complexes of compositions [(La)2Ni] and [(Lb)2Ni], respectively. Both type of ligands bind the Ni(II) centres in tridentate (N,N,O) fashion being uninegative anion by the way of phenolic proton dissociation during complexation. The complexes were characterized by analytical and spectroscopic studies. X-ray structures of [(Lb1)2Ni] was determined to confirm the molecular species unequivocally. The photoluminescence properties of the ligand and complexes were studies along with the effect of several anions.

Conformation analysis and computation of energy barrier to rotation about C[sbnd]N bond in para-methylphenyl carbamate and its solvent dependence in comparison with tertiary carbamates and tertiary amides

Barrier to rotation about conjugated CN bond in p-Methyl phenyl carbamate (PMPC) was computed 14–16kcal/mol at three levels of HF, B3LYP and MP2 using 6-311++G∗∗ basis set. The solvent effect and energy barriers about CN bond in PMPC were compared to the case of tertiary carbamates and tertiary amides. Moreover, it is shown that in primary carbamates such as PMPC and tertiary amides isomerisation process passes through TS2 and TS1 respectively, while in tertiary carbamates goes through a combination of both TSs. Furthermore, X-ray analysis which is reported for the first time for primary aryl carbamates demonstrated that the inclusive plane of carbamate functional group is perpendicular to the plane of phenyl ring. The results of computations are completely in agreement with the X-ray data.

Improved thiophene solution selectivity by Cu2+, Pb2+ and Mn2+ ions in pervaporative poly[bis(p-methyl phenyl) phosphazene]desulfurization membrane

Due to interfacial defects and agglomeration, role of metal ions in mixed matrix membrane during pervaporation is not fairly demonstrated and not fully taken advantage of. Through surface modification of pristine PMePP membrane and the followed ion exchange treatments, PMePP-M membranes containing Cu2+, Mn2+, or Pb2+ ions were obtained. X-ray photoelectron spectroscopy (XPS) analysis confirms the successful exchange of Cu2+, Mn2+, or Pb2+ ions onto the membrane surface. Pervaporation results show that the removal of thiophene from model gasoline by pristine PMePP membrane or modified PMePP membranes is a solution-diffusion controlled process while it shifts to a solution controlled process for PMePP-M membranes. It provides important evidence for the facilitated thiophene mass transport via metal ions. PMePP-M membranes show superior selectivity in a Robeson type plot and their performance locates above the upper bound of literature reported thiophene permeability and selectivity. In the meantime, it is proved that post-treatment and control of oxidation temperature can compensate the decrease of pervaporative flux caused by the change in surface hydrophobicity and the introduction of electric charge.

Poly[bis(p-methyl phenyl) phosphazene] Pervaporative Membranes for Separating Organosulfur Compounds from n-Heptane and Its Surface Functionalization

This work investigates the application of poly[bis(p-methyl phenyl) phosphazene] (PMePP) for separating organosulfur compounds from n-heptane. PMePP was synthesized and characterized by NMR, X-ray photo spectroscopy, thermogravimetric analysis, scanning electron microscopy, and Fourier transformed infrared spectroscopy. Membranes based on PMePP were fabricated and investigated for desulfurization of FCC (fluid catalytic cracking) model gasoline by pervaporation. The effects of operating temperature, feed composition, and feed sulfur content on the performance of PMePP membranes were investigated. The experimental results showed that the PMePP-based membranes are effective for FCC gasoline pervaporative desulfurization. To provide active spots for future grafting modification, the surface functionalization of PMePP was carried out to convert the methyl units into carboxylic units. The surface-functionalized membrane was also investigated for its pervaporation performance, and results showed the increased in enrichment factor and less temperature dependence.

Activation of ortho C–H bond by nickel(II) acetate or sodium tetrachloropalladate(II) in naphthyl imino derivatives of azobenzene

The reactions of 1-{[2-(arylazo)phenyl]iminomethyl}-2-naphthol, H2Lnap [where H represents the dissociable proton upon complexation and aryl groups of H2Lnap are phenyl for H2L1nap; p-methyl phenyl for H2L2nap and p-chloro phenyl for H2L3nap] with nickel acetate tetra hydrate or disodium tetrachloropalladate in methanol afforded M–C(aryl) bonded species of composition [M(Lnap)] (M=Ni(II) and Pd (II)). The dinegative (Lnap)2− ligands bind the Ni(II) or Pd(II) in tetradentate (C, N, N, O) fashion in distorted square planar geometry. Ligands and complexes were characterized by spectroscopic methods. The X-ray structures of H2L1nap, [Ni(L1nap)] and [Pd(L1nap)] were determined to authenticate the characterization. Reactions with metachloroperbenzoic acid (mCPBA), TBHP and hydrogen peroxide leading to oxygen insertion into the M-C bond have been examined. Luminescent properties of ligands and complexes have been reported.

X-ray powder diffraction analysis of a nonlinear optical material N-(p-methoxy benzoyl)-N′-(p-methyl phenyl) thiourea

A nonlinear optical material, N-(p-methoxy benzoyl)-N′-(p-methyl phenyl) thiourea (C16H16N2O2S), has been characterized by X-ray powder diffraction. Experimental values of 2θ corrected for systematic errors, relative peak intensities, values of d, and the Miller indices of 94 observed reflections with 2θ up to 66° are reported. The powder diffraction data and the figure-of-merit are reported. The least-squares refined unit cell parameters are a=25.3291(3) Å, b=11.9478(1) Å, c=10.1407(4) Å, β=103.10(2)°, V=2988.97(6) Å3, Z=8, Dx=1.335(0) g/cm3, with space group P21(4).

The comparative adsorption of aromatics on mercury from water and ethyleneglycol

The interfacial behaviour of benzaldehyde and p-methyl phenyl acetic acid in ethyleneglycol (EG), as well as that of o-dimethyltoluidine in water, has been investigated to obtain a number of adsorption parameters necessary to discuss the reliability, on a quantitative ground, of the “intrinsic” value of Gibbs adsorption energy, Δ G int°, relating, for a group of aromatic derivatives adsorbed on mercury, to the process: A pure+Hg⇌Hg(A adsorbed). It has been shown that this quantity does not depend on the solvent in use, so that it is really “intrinsic” and can be usefully related to structural molecular parameters of the adsorbate alone, allowing the interfacial behaviour to be foreseen a priori. As a consequence the solvation in the adsorption state of the interfacial active species, either in EG and in water, can be considered to contribute little to the whole adsorption Gibbs energy. Eventually, EG itself shows an interfacial activity almost the double of that of water, ∼−50 and ∼−21 kJ mol −1, respectively. So that, within this view the adsorption of aromatics from EG on mercury can be fully rationalized with respect their behaviour on Hg from water.

Characterization and electrical properties of p-methyl phenyl azo ethyl aceto acetate metal chelates

The temperature dependence of the d.c. conductivity, dielectric constant and thermally stimulated depolarization current (TSDC) have been investigated for press-prepared metal-ligand complex samples. The electrical conductivity results are explained by assuming that both ionic and electronic conduction mechanism coexist with different contributions over the whole temperature range of experiments. The dielectric constant ɛ′ shows a sharp peak at a particular transition temperature in all samples. The effect of annealing on dielectric constant of nickel complex sample induces a remarkable reduction in its magnitude. The TSDC spectra have been found to be characterized by two pronounced peaks in cobalt complex and a broad peak for the other complexes. For aged cobalt complex sample, one sees clearly that the longer the ageing time, the smaller the polarization.