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• Selective colorimetric recognition of cyanide ion in both solution and solid states. • Fast response to CN– (< 5 s). • Water percentage has a key role in the cyanide's recognition mechanism. • Recognition mechanism was investigated by IR soectroscopy. A novel chemosensor based on Nifuroxazide Cr(III) complex was developed for recognizing CN– over other tested anions e.g., F–, Cl–, Br–, I–, CH 3 COO–, NO 2 –, PO 4 3–, and SCN– in DMSO–H 2 O (9:1, v/v) and THF. Without any interference from the tested anions, UV–vis spectroscopy was used to investigate the recognition of CN–. The deprotonated species that resulted from the ionization of the phenolic group may be the cause of the color shift that occurred after adding CN– to the solution of the Cr(III) complex. The charge transfer interaction between the electron-donor unit and the electron-deficient nitro-furan moiety was improved as a result of the ionization of the phenolic group. The fact that the developed color vanishes in protic polar solvents e.g., H 2 O, CH 3 OH, and C 2 H 5 OH may lend credence to this assumption. The Lambert–Beer's law was obeyed in the concentration ranges of 3.4 × 10−3–3.4 × 10−5 M and 1.0 × 10−4–5.0 × 10−6 M in DMSO–H 2 O (9:1, v/v) and THF, respectively, reflecting the significant role of the solvent in controlling the sensitivity of the developed probe. The electronic transitions were investigated by executing time-dependent density functional theory calculations. [Display omitted] [ABSTRACT FROM AUTHOR]

[Co(FBZ) 2 (H 2 O)]·2NO 3 ·0.5H 2 O ( 1 ), [Ni(FBZ) 2 X 2 ]·zH 2 O (X = Cl ​− , z = 0.5 ( 2 ) and X = CH 3 COO − , z = 1 ( 3 )) and [Cu(FBZ) 2 (H 2 O) (NO 3 )]·NO 3 ·1.5H 2 O ( 4 ) (FBZ = methyl-5-(Phenylthio) benzimidazole-2-carbamate; Fenbendazole) complexes were synthesized and characterized by elemental analysis, thermal, IR, EPR, UV–Vis, magnetic and conductance measurements. Geometry optimization, molecular electrostatic potential maps and natural bond orbital analysis were carried out at DFT/B3LYP/6-31G ∗ level of theory. FBZ behaves as a neutral bidentate ligand via the pyridine-type nitrogen of the benzimidazole moiety and the carbamate group. Three-step ionization with pK a values of 3.38, 4.06 and 10.07 were reported for FBZ. The coordination of FBZ to the metal ions led to an increase in the antibacterial activity against the tested Staphylococcus aureus and Escherichia coli bacteria. [ABSTRACT FROM AUTHOR]

A simple, sensitive and rapid method was developed for the quantitative analysis of sparfloxacin in its pharmaceutical formulations through the formation of charge transfer complexes with π-acceptor systems. The Lambert–Beer’s law was obeyed in the concentration ranges of 7–70 and 10–50 μg/mL sparfloxacin for 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and tetracyanoquinodimethane. Structural characterization of the isolated solid CT complexes was carried out by IR, 1 H NMR, UV–Vis. and MS. The experimental studies were complemented by quantum chemical calculations at DFT level of theory. The electronic structures were investigated by TD-DFT calculations. Natural bond orbital analysis and molecular electrostatic potential maps were helpful in assigning the CT route. The formation constant, molar extinction coefficient, oscillator strength, dipole moment, standard free energy and ionization potential were calculated. [ABSTRACT FROM AUTHOR]

• Square-pyramidal Zn(II) azide complexes. • Based on TDDFT calculations, the lowest E transition is assigned to LLCT (N 3 →Terpy). • NBO analysis supported charge transfer from coordination sites toward Zn(II). • MEP maps showed that azido ligands have roles in the cycloaddition reaction. Square-pyramidal Zn(II) azide complexes with the formula of [Zn n (N 3) 2n L] (n = 1; L = 4′-(2-pyridyl)-2,2′:6′,2′'-terpyridine (LPy), 4′-(4-phenylmorpholine)-2,2′:6′,2′'-terpyridine (LMorph), and n = 2; L = 1,4- bis (2,2′:6′,2′'-terpyridin-4′-yl)benzene (LBPY)) were synthesized, and structurally characterized using different spectroscopic and analytical tools. Ground-state geometry optimization and harmonic vibrational analysis were carried out at two different levels of theory (B3LYP/LANL2DZ and CAM-B3LYP/def2-SVP) to gather insights into the local minimum structures. Natural bond orbital (NBO) analyses revealed that the electronic population of the 3d orbitals of Zn(II) ion is corresponding to the oxidation state of Zn(I), not Zn(II), in agreement with the ligand to metal charge transfer. Molecular electrostatic potential energy maps showed that the azido ligand may act as a nucleophile in the cycloaddition coupling with electron poor dipolar molecules. The electronic structure and transitions were investigated by executing time dependent density functional theory (TDDFT) calculations. [Display omitted] [ABSTRACT FROM AUTHOR]

• Acid dissociation constants fit well with Hammett constant. • Introduction of a substituent reduces the toxicity compared to the unsubstituted one. • Solvatochromism behaviour is mainly attributed to solvent dipolarity/polarizability. • Structural activity relationship is recognized by correlating toxicity to total energy. A series of (1H-benzimidazol-2-ylmethyl)-N-(4-phenyl)amine derivatives incorporating different electron-donating and withdrawing groups (X = 4 OCH 3 (1), 4 CH 3 (2), H (3), 4 Cl (4), and 4 Br (5)) on the para -position of the phenyl substituent was prepared, characterized and screened for their potential antimicrobial activity against some microbes. The substituent effect on the spectroscopic data (vibrational modes and NMR resonances) is well established by fitting with the Hammett constant. The unsubstituted derivative 4 exhibited comparable activity (MIC = 0.26 μM) to the standard tetracycline (MIC = 0.18 μM) against Staphylococcus aureus. Introduction of a substituent to the phenyl ring led to diminishing of the antibacterial activity. The substituent effect on the electron structure of 1–5 was investigated by TDDFT calculations. The acid dissociation constants of the ionizable NH group correlate well with Kubota's σ− parameter (R2 = 0.9196). The solvatochromism behavior of 1–5 , in solvents of different polarity and hydrogen-bond tendency, was investigated by linear solvation–energy relationship equation analysis. Correlation between various quantum chemical descriptors, and antibacterial activity was carried out to verify a structural activity relation for this series of benzimidazole derivatives. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• Sixteen compounds of novel benzylidene-quinazolinone hybrids derivatives were designed and synthesized. • The target compounds were tested in vivo for their anti-hyperglycemic effects against STZ-induced hyperglycemic rats. • In vitro α-glucosidase inhibitory activity was evaluated. • A homology model of α-glucosidase was built. • Molecular docking studies were carried out. A novel series of benzylidene-quinazolinone hybrids 8 a,b and 10 a-n were designed, synthesized, and evaluated for their in vitro α -glucosidase inhibitory effect aiming to discover efficient anti-diabetic agents. The synthesized compounds were assessed for their in vivo anti-hyperglycemic activities against STZ-induced hyperglycemic rats. Five compounds (10 m , 10 f , 10 c , 10 d and 8 b) demonstrated potent activities with percent reduction in blood glucose levels of 43.07, 40.14, 39.83, 37.04 and 36.16, respectively. The most active members were further evaluated in vitro for their α -glucosidase inhibitory binding affinities. Among them, Compound 10 m containing 4-hydroxybenzylidene moiety and compound 10 f with 4-chlorobenzylidene moiety connected to the acetohydrazide demonstrated the most potent inhibitory activities towards α -glucosidase with IC 50 values of 561 and 610 µM, respectively. Molecular docking study was performed in order to understand the molecular interactions between the molecule and enzyme. [ABSTRACT FROM AUTHOR]