Thermogravimetric and differential thermal analyses of fluorescein dye in inert and static air atmosphere

Journal of Thermal Analysis and Calorimetry - Fluorescein dye was prepared and characterized on the basis of microanalytical methods, FTIR, NMR and UV–visible spectroscopy in order to ensure...     

A metal-free visible light promoted three-component facile synthesis of 4-oxo-tetrahydroindoles in ethanol–water

A mild and efficient visible light–mediated one-pot multicomponent tandem approach to construct 4-oxo-tetrahydroindoles in ethanol–water medium at room temperature has been described. The characteristics of reported methodology are the utilization of visible light, an ideal source of energy to generate C C and C N bonds from commercially available substrates namely dimedone, phenacyl bromides, and amines. The presented protocol is highly compatible for developing 4-oxo-tetrahydroindole derivatives with improved selectivity and high yields. Moreover, metal-free synthesis, environmental friendly solvent, easy workup process, high atom economy, cost-effectiveness, short reaction time, and broad substratescope are the major advantages of reported protocol.     

Synthesis,spectral characterization,DFT studies and biological activity of novel Ligand 1‐(2‐cyclohexyl thioethyl) piperidine and its complexes with group 12 metal chlorides

C₆H₁₁S^‐Na⁺ (generated insitu by reaction of NaOH with C₆H₁₁SH) on treatment with 1‐(2‐chloroethyl) piperidine hydrochloride under N₂ atmosphere resulted in (1‐(2‐cyclohexyl thioethyl) piperidine) ( L ¹ ) as orange solid. It's complexes having the formula [ZnCl₂. L¹] ( 1 ), [CdCl₂. (L¹)] ( 2 ) and [HgCl₂. L¹] ( 3 ) have been prepared. L ¹ and its complexes 1‐3 were characterized on the basis of physico‐chemical and spectral (FT‐IR, Mass, ¹H, ¹³C and DEPT 135^o NMR) studies. Powder XRD diffraction pattern reveals the crystalline nature of L¹ and complex 1 . Complexes 1‐3 adopt distorted tetrahedral geometry showing bidentate mode of coordination through S and N. Using DFT‐based optimization of structures, the HOMO‐LUMO energy gaps and molecular electrostatic potential maps (EPM) of compound L¹ and complexes 1‐ 3 were theoretically calculated at the B3LYP/6‐311G (d, p) level of theory. HOMO‐LUMO energy gap was calculated which allowed the calculation of relative properties like chemical hardness, chemical inertness, chemical potential, nucleophilicity and electrophillicity index of the synthesized products. The experimentally obtained IR and NMR results showed a good correlation with those of the theoretical ones. Ligand L ¹ and complexes 1‐3 display significant antibacterial and antifungal activity.     

Intuitionistic fuzzy quasi-ideals of ordered semigroups

In this paper we define intuitionistic fuzzy quasi-ideals of ordered semigroups. The main result of the paper is a characterization of quasi-ideals in terms of intuitionistic fuzzy quasi-ideals. We also characterize left simple, right simple, and completely regular ordered semigroups in terms of intuitionistic fuzzy quasi-ideals. We study the decomposition of left and right simple ordered semigroups using intuitionistic fuzzy quasi-ideals.     

Investigation of structural and optical properties of 100 MeV F7+ ion irradiated Ga10Se90-xAlx thin films

Present work focuses on the effect of swift heavy ion (SHI) irradiation of 100 MeV F⁷⁺ ions by varying the fluencies in the range of 1 × 10¹² to 1 × 10¹³ ions/cm² on the morphological, structural and optical properties of polycrystalline thin films of Ga₁₀Se_90-xAl_x (x = 0, 5). Thin films of ~300 nm thickness were deposited on cleaned Al₂O₃ substrates by thermal evaporation technique. X-ray diffraction pattern of investigated thin films shows the crystallite growth occurs in hexagonal phase structure for Ga₁₀Se₉₀ and tetragonal phase structure for Ga₁₀Se₈₅Al₅. The further structural analysis carried out by Raman spectroscopy and scanning electron microscopy verifies the defects or disorder of the investigated material increases after SHI irradiation. The optical parameters absorption coefficient (α), extinction coefficient (K), optical band gap (E_g) and Urbach’s energy (E_U) are determined from optical absorption spectra data measured from spectrophotometry in the wavelength range 200–1100 nm. It was found that the values of absorption coefficient and extinction coefficient increase while the value of optical band gap decreases with the increase in ion fluence. This post irradiation change in the optical parameters was interpreted in terms of bond distribution model.     

Identification of novel thiourea-stilbene-triazine conjugates as persuasive lymphoid tyrosine phosphatase inhibitors

A library of novel thiourea-based symmetrical stilbene-triazines ( 5a-i ) was synthesized in an effort to develop new protein tyrosine phosphatase LYP inhibitors. The versatile nature of 2,4,6-trichloro-1,3,5-triazine allows considerable scope for derivatization and hence exploration of structure activity relationships. A convenient and versatile three-step synthetic approach involved the successive replacement of the two chloro groups of 2,4,6-trichloro-1,3,5-triazine by a variety of substituents for structural modification. The newly synthesized derivatives were subjected to tyrosine phosphatase LYP inhibition studies. The results for the in vitro bioassays were promising with the identification of compound 5k and 5l having a 4-methyl and 4-methoxy substituent on phenyl ring, as the lead and selective candidate for LYP inhibition with an IC₅₀ value of 2.1 ± 0.05 μM and 28 ± 3.3 μM, respectively. Moreover, docking studies were carried out to determine the possible interaction sites of thiourea-based stilbene-triazine compounds with Lymphoid Tyrosine Phosphatase. Results of docking computations further ascertained the inhibitory potential of compound 5k and 5l . The results indicated that the compound 5k may serve as a structural model for the design of most potent LYP inhibitors.     

Structural and optical analysis of 60Co gamma-irradiated thin films of polycrystalline Ga10Se85Sn5

The present study focuses on the effects of gamma irradiation on structural and optical properties of polycrystalline Ga₁₀Se₈₅Sn₅ thin films with a thickness of ～300?nm deposited by the thermal evaporation technique on cleaned glass substrates. X-ray diffraction patterns of the investigated thin films show that crystallite growth occurs in the orthorhombic phase structure. The surface study carried out by using the scanning electron microscope (SEM) confirms that the grain size increases with gamma irradiation. The optical parameters were estimated from optical transmission spectra data measured from a UV–vis-spectrophotometer in the wavelength range of 200–1100?nm. The refractive index dispersion data of the investigated thin films follow the single oscillator model. The estimated values of static refractive index n₀, oscillator strength E_d, zero frequency dielectric constant ε₀, optical conductivity σ_optical and the dissipation factor increases after irradiation, while the single oscillator energy E_o decreases after irradiation. It was found that the value of the optical band gap of the investigated thin films decreases and the corresponding absorption coefficient increases continuously with an increase in the dose of gamma irradiation. This post irradiation changes in the values of optical band gap and absorption coefficient were interpreted in terms of the bond distribution model.     

Defensive Mechanisms in Cucurbits against Melon Fly (Bactrocera cucurbitae) Infestation through Excessive Production of Defensive Enzymes and Antioxidants

Melon fly (Bactrocera cucurbitae) is the most common pest of cucurbits, and it directly causes damage to cucurbit fruits in the early developmental stage. The infection of fruit tissues induces oxidative damage through increased generation of cellular reactive oxygen species. The effects of melon fly infestation on the production of defensive enzymes and antioxidant capabilities in five cucurbit species, namely, bottle gourd, chayote, cucumber, snake gourd, and bitter gourd, were investigated in this study. The total phenolic and flavonoid content was considerably higher in melon fly infestation tissues compared to healthy and apparently healthy tissues. The chayote and bottle gourd tissues expressed almost 1.5- to 2-fold higher phenolic and flavonoid contents compared to the tissues of bitter gourd, snake gourd, and cucumber upon infestation. Defensive enzymes, such as peroxidase (POD), superoxide dismutase (SOD), polyphenol oxidase (PPO), and catalase (CAT), were high in healthy and infected tissues of chayote and bottle gourd compared to bitter gourd, snake gourd, and cucumber. The activity of POD (60–80%), SOD (30–35%), PPO (70–75%), and CAT (40–50%) were high in infected chayote and bottle gourd tissue, representing resistance against infestation, while bitter gourd, snake gourd, and cucumber exhibited comparatively lower activity suggesting susceptibility to melon fly infection. The antioxidant properties were also high in the resistant cucurbits compared to the susceptible cucurbits. The current research has enlightened the importance of redox-regulatory pathways involving ROS neutralization through infection-induced antioxidative enzymes in host cucurbit resistance. The melon fly infestation depicts the possible induction of pathways that upregulate the production of defensive enzymes and antioxidants as a defensive strategy against melon fly infestation in resistant cucurbits.     

N-fuzzy Filters in Ordered Semigroups

In this paper we define N-fuzzy filters,N-fuzzy bi-ideal subsets and N-fuzzy bi-filters of ordered semigroups and characterize ordered semigroups in terms of N-fuzzy filters, N-fuzzy bi-ideal subsets and N-fuzzy bi-filters.We establish relationship of N-fuzzy filters and prime N-fuzzy ideals of ordered semigroups. Also we discuss the relationship of N-fuzzy bi-filters and prime N-fuzzy bi-ideal subsets of ordered semigroups.     

Synthesis of Symmetric Bridged Bis-Pyrazolone Based Metal Complex Acid Dyes and their Applications on Leather

Our present investigation aims at the synthesis and application of new, symmetric bridged bis-pyrazolone based acid dyes. The bis-pyrazolone compounds were accomplished from bis- hydrazine of 4,4′-Diaminostilbene-2,2′-disulfonic acid and ethyl acetoacetate. The bis-pyrazolones have been coupled with diazonium salts of o-hydroxyl aromatic amines which resulted in ligand dyes. The intermediate ligand dyes were treated with 3d transition metals to achieve the targeted metal complex acid dyes. The structures of investigated compounds were confirmed with the help of spectroscopic techniques. Dyes were applied on leather and their application parameters including their light fastness, wash fastness and rubbing fastness were determined.

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Graphical Abstract Symmetric brymmetric Bridged bis-Pyrazolone based Metal Complex Acid