Characterization and kinetics analysis of the thermal decomposition of the humic substance from hazelnut husk

A humic substance was obtained from hazelnut husk using an alkali extraction. The chemical and morphological structure of the humic matter was characterized via elemental analysis, Fourier transform infrared spectrometry (FTIR), nuclear magnetic resonance, Brunauer-Emmet-Teller (BET) analysis, scanning electron microscopy (SEM), and thermogravimetric-FTIR (TG-FTIR). In addition, thermal analysis measurements TG analysis-differential thermogravimetry/differential scanning calorimetry (TGA-DTG/DSC) were performed under dynamic air conditions to better determine the origin, physical and chemical structure, and decomposition process of the humic matter. The Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods were used to calculate the kinetic parameters of the high-temperature decomposition process. It was observed that the activation energy values were almost constant at certain conversion and temperature intervals. In addition, the structure of the humic substance at different temperatures was also investigated via FTIR analysis. It was found that the obtained humic substance had a very stable structure and decomposed at a high temperature. The stability of the humic matter can be a useful tool in the environmental quality research of soil.     

Structure–reactivity relationships of alkyl α‐hydroxymethacrylate derivatives

A series of alkyl α‐hydroxymethacrylate derivatives with various secondary functionalities (ether, ester, carbonate, and carbamate) and terminal groups (alkyl, cyano, oxetane, cyclic carbonate, phenyl and morpholine) were synthesized to investigate the effect of intermolecular interactions, H‐bonding, π–π interactions, and dipole moment on monomer reactivity. All of the monomers except one ester and one ether derivative are novel. The polymerization rates, determined by using photo‐DSC, showed the average trend (aromatic carbamate > hydroxyl > ester > carbonate ～ aliphatic carbamate ～ ether), with several exceptions due to the differences in terminal groups. There is a correlation between the chemical shift differences of the double bond carbons, the calculated dipole moments, and the reactivities only for nonhydrogen bonded monomers. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Potentiometric Studies on Complexation of Cu(II) Ion with Methyl/Nitro-Substituted 1,10-Phenanthrolines and Selected Amino Acids

Protonation constants of methyl/nitro substituted 1,10-phenanthrolines {(m/n-sphen): 4-methyl-phenanthroline (4-mphen), 5-methyl-1,10-phenanthroline (5-mphen), 4,7-dimethyl-1,10-phenanthroline (dmphen), 3,4,7,8-tetramethyl-1,10-phenanthroline (tmphen) and 5-nitro-1,10-phenanthroline (5-nphen)] and the amino acids (aa) l-tyrosine (tyr) and glycine (gly), and their corresponding binary and ternary stability constants with Cu(II), were determined in aqueous 0.1 mol·L^?1 KCl ionic media at 298.15 K. The protonation constants of the ligands and the stability constants of the binary and ternary complexes of Cu(II) with the ligands were calculated from the potentiometric data using the “BEST” software package. The species distribution diagrams were obtained using the “SPE” software package under the experimental conditions described. The order of stability of the ternary complexes in terms of the primary ligands is [Cu(tmphen)(aa)]⁺ > [Cu(dmphen)(aa)]⁺ > [Cu(4-mphen)(aa)]⁺ > [Cu(5-mphen)(aa)]⁺ > [Cu(5-nphen)(aa)]⁺. The stability constants of the ternary complexes decrease in the following order: [Cu(m/n-sphen)(gly)]⁺ > [Cu(m/n-sphen)(tyr)]⁺, which is identical to the sequence found for the binary complexes of Cu(II) with gly and tyr.     

Real-time optical reconstruction of the diffused 3D object using phase information calculated by Continuous Wavelet Transform

We propose the real time optical reconstruction of a three-dimensional (3D) object from a digitally recorded hologram. Phase distribution of the recorded hologram is numerically calculated by 1-dimensional Continuous Wavelet Transform (1D-CWT) for digital reconstruction with phase only information. Also, the phase distribution of 1D-CWT transferred to the spatial light modulator (SLM) is used to obtain optically reconstructed image. It is observed that an efficient real-time analysis can be achieved, if phase of 1D-CWT is used. In the same time, optically reconstructed 3D objects obtained by only phase information are about three times brighter than bleached hologram intensity's. So the minimum power loss can be obtained. Numerical and experimental results are presented.     

Urea dimethacrylates functionalized with bisphosphonate/bisphosphonic acid for improved dental materials

Incorporation of bisphosphonate/bisphosphonic acid groups in dental monomer structures should increase interaction of these monomers with dental tissue as these groups have strong affinity for hydroxyapatite. Therefore, new urea dimethacrylates functionalized with bisphosphonate (1a, 1b) and bisphosphonic acid (2a, 2b) groups are synthesized and evaluated for dental applications. Monomers 1a and 1b are synthesized from 2‐isocyanatoethyl methacrylate (IEM) and two bisphosphonated amines (BPA1 and BPA2), prepared as reported elsewhere. Selective dealkylation of the bisphosphonate ester groups of 1a and 1b using trimethylsilyl bromide (TMSBr) gives monomers (2a and 2b) with bisphosphonic acid functionality. X‐ray diffractometer (XRD), Raman spectroscopy, and X‐ray photoelectron spectroscopy (XPS) analyses of monomer‐treated HAP particles show that 2a induces formation of stable monomer‐calcium salts, similar to 10‐methacryloyloxydecyl dihydrogen phosphate (MDP), with higher chemical interaction than 2b. The photopolymerization studies indicate good copolymerizability with commercial dental monomers. In vitro studies on NIH 3T3 mouse embryonic fibroblast cells have clearly shown that the tested monomers (1b and 2b) are not toxic according to the MTT standards. All these properties make these monomers suitable as biocompatible cross‐linkers/adhesives for dental applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3195–3204     

Multiarm star triblock terpolymers via sequential double click reactions

Multiarm star triblock terpolymers were obtained by using two different click reactions sequentially: Cu(I) catalyzed azide–alkyne and Diels–Alder. The synthetic strategy is described as follows: (poly(methyl methacrylate))_n‐(polystyrene)_m‐poly(divinyl benzene)) ((PMMA)_n‐(PS)_m‐polyDVB) multiarm star diblock copolymer was first obtained from an azide–alkyne click reaction of (alkyne‐PS)_m‐polyDVB multiarm star polymer with α‐anthracene‐ω‐azide PMMA (anth‐PMMA‐N₃), followed by a Diels–Alder click reaction of the anthracene groups at the star periphery with α‐maleimide poly (tert‐butyl acrylate) (PtBA‐MI) or α‐maleimide poly(ethylene glycol) (PEG‐MI) leading to target (PtBA)_k‐(PMMA)_n‐(PS)_m‐polyDVB and (PEG)_p‐(PMMA)_n‐(PS)_m‐polyDVB multiarm star triblock terpolymers. The hydrodynamic diameter of individual multiarm star triblock terpolymers were measured by dynamic light scattering (DLS) to be ～24–27 nm in consistent with the atomic force microscopy (AFM) images on silicon substrates. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1557–1564, 2010     

Synthesis,characterization, crystal structure,and antimicrobial studies of 2-morpholinoethyl-substituted benzimidazolium salts and their silver(I)-N-heterocyclic carbene complexes

Research on Chemical Intermediates - This article describes synthesis of N-morpholinoethylbenzimidazole (1), 2-morpholinoethyl-substituted benzimidazolium salts (NHC precursors, 2a–c), and...     

Solvatochromic rotaxane molecular shuttles

A strongly fluorescent bistable rotaxane is described in which the relative position of the macrocyclic ring with respect to a solvatochromic fluorophore gives a strong response in the spectral domain.     

Affinity of a new copper(II) complex to DNA/BSA and antioxidant/radical scavenging activities: crystal structure of [Cu(4,7-diphenyl-1,10-phenanthroline)(leucine)(NO3)(H2O)]

A new copper(II) complex, [Cu(Bphen)(Leu)(NO₃)(H₂O)] (Bphen = 4,7-diphenyl-1,10-phenanthroline, leu = L-leucine), has been synthesized and characterized by IR spectroscopy, CHN analysis, and single-crystal X-ray diffraction techniques. The CT-DNA binding properties of the complex have been investigated by both absorption and emission spectroscopy. The binding parameters for the fluorescence Scatchard plot were also determined. Further, the interaction of the complex with bovine serum albumin (BSA) has been investigated using absorption and emission spectroscopy. The thermodynamic parameters, free energy change (ΔG), enthalpy change (ΔH), and entropy change (ΔS), were calculated by the van’t Hoff equation and discussed. The distance between BSA and the complex has been obtained according to fluorescence resonance energy transfer. Conformational changes of BSA have been observed from synchronous fluorescence. Antioxidant and radical scavenging activities of the complex were determined by various in vitro assays such as 1,1-diphenyl-2-picryl-hydrazyl free radicals (DPPH˙), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radicals (ABTS˙⁺), and reducing ability determination by H₂O₂ scavenging methods.     

Synthesis and investigation of spectroelectrochemical properties of peripherally tetra-substituted phthalocyanine bearing 3-(4-{[3-(trifluoromethyl)benzyl]oxy}phenyl)propan-1-ol and its metallo compounds

In this study, the new compounds; 3-(4-{[3-(trifluoromethyl)benzyl]oxy}phenyl)propan-1-ol 3 was prepared by the reaction of 4-(3-hydroxypropyl)phenol 1 with 1-(bromomethyl)-3-(trifluoromethyl)benzene 2 and 4-[3-(4-{[3 (trifluoromethyl)benzyl]oxy}phenyl)propoxy] phthalonitrile 5 was synthesized by the reaction of 4-nitrophthalonitrile 4 with 3-(4-{[3-(trifluoromethyl)benzyl]oxy}phenyl)propan-1-ol 3. Novel peripherally tetra substituted H₂Pc 6, Co(II) 7, Cu(II) 8, Ni(II) 9 and Fe(II) 10 phthalocyanines, which have peripheral positions with 4-[3-(4-{[3 (trifluoromethyl)benzyl]oxy}phenyl)propoxy] groups, were synthesized and all of the new compounds characterized by IR, ¹H NMR, ¹³C NMR, UV–Vis, mass spectroscopies and elemental analysis. The electrochemical and spectroelectrochemical investigation of the phthalocyanines carrying 4-[3-(4-{[3 (trifluoromethyl)benzyl]oxy}phenyl)propoxy] groups were studied using various electrochemical techniques in DMF on a glassy carbon electrode. Cyclic voltammetry and square wave voltammetry studies show that the complexes have either metal based or ligand-based diffusion controlled electron transfer properties. To shed more light on the electron-transfer steps of the complexes and assignments of the redox couples were carried out by spectroelectrochemical measurements. The color changes during spectral changes of redox species were recorded with in situ electrocolorimetric measurements. The electrochemical and in situ UV–Vis spectral change of complexes indicated their applicability in the fields of the electrochemical technologies.