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A new class of blue-light triggered carbon monoxide releasing molecules based on Mn(CO) 3 Br(N,S) ((N,S) = N,S-bidentate thiourea ligands) has been reported in this work. The 1 H and 13 C NMR analysis indicated that the thioureas coordinate to Mn(I) in the thione form. The stability test and the ability to derive CO to DMSO and myoglobin solution upon the exposure to 468 nm light source have been investigated. The benzothiazole-thiourea-CORM released only one CO equivalent, while the pyridine-analogs offered two molecules at the same experimental conditions. Natural bond orbital analysis has been carried out to give details about the hybridization of Mn C and C O bonds, natural charge, electronic arrangement of metal ion and strength of interaction between Mn(I) and the coordination sites. Both functional, B3LYP and CAM-B3LYP compare well with the experimental findings, where the longest wavelength band is assigned to MLCT. [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]

New cis-platin analogs Pd II and Pt II complexes of (1H-benzimidazol-2-ylmethyl)-N-(4-chloro-phenyl)-amine (L Cl ) and (1H-benzimidazol-2-ylmethyl)-N-(4-iodo-phenyl)-amine (L I ) were prepared as potential antitumor compounds, characterized (elemental analysis, TG/DTA, FT IR, 1 H NMR, MS, UV–Vis. and conductance measurements) and tested for their cytotoxic activities against MCF7, HCT and HEPG2. The antibacterial activity was tested on against Staphylococcus aureus , Bacillus subtilis , Streptococcus faecalis , Escherichia coli , Pseudomonas aeruginosa and Neisseria gonorrhea . The effect of the aniline substituent on the toxicity was discussed. The experimental studies were complemented by quantum chemical calculations. TD-DFT calculations were carried out to understand the electronic structure and to explain the related experimental findings. Natural bond orbital analysis was performed to provide details about the electronic arrangement, type of hybridization and the nature of bonding. [ABSTRACT FROM AUTHOR]

[ZnL 2 ]·4EtOH ( 1 ), [PdL(EtOH) 2 ]·Cl ( 2 ) and [PtL(EtOH)Cl] ( 3 ) (HL = N-(2-thiazolyl)-1H-benzotriazole-1-carbothioamide complexes have been synthesized, and characterized by elemental analysis, IR, 1 H NMR, UV–Vis, and TGA. In complex 1 , the thiazole N and C–S − donor sites of two deprotonated ligand molecules are coordinated to Zn(II) forming a tetrahedral structure, while in case of 2 and 3 , the benzotriazole N and C–S − are participated in the coordination spheres of square planar complexes. Optimized structures, natural bond orbital analysis, molecular electrostatic potential maps, and frontier molecular orbitals have been obtained by DFT/B3LYP/LANL2DZ method. Time-dependent DFT calculations have been performed to assign the electronic spectra. The complexes in comparison to HL have been screened for their antimicrobial and cytotoxicity activities. Complex 2 (3.08 μg/mL) is more potent than HL and the other complexes that may be attributed to its ionic nature and presence of two easily replaceable ethanol molecules. The capacity of complexes to slow down the proliferation of the MCF7 cell line has been achieved by down regulation of the vascular endothelial growth factors using RT-PCR technique. [ABSTRACT FROM AUTHOR]

Abstract: Three sulfadimidine metal complexes (M Fe(III), Cu(II), and Ag(I)) were prepared, characterized, and examined as neutral carriers for the determination of SCN− using modified carbon paste electrode. These sensors were successfully applied in the pure samples, and biological fluids. The electrode mechanism was investigated by UV–vis and FT IR. The experimental studies were complemented by quantum chemical calculations at DFT/B3LYP level of theory. The best performance was observed for Cu(II) electrode (C) containing 7.0% complex, 53.0% o-nitrophenyloctyl ether, 37.0% graphite and 3.0% cetylpyridinium chloride, and also for Fe(III)-electrode (A) having 6.0% complex, 52.0% o-nitro phenyloctyl ether, 40.5% graphite and 2.5% cetylpyridinium chloride. [Copyright &y& Elsevier]

Highlights: [•] New mono- and binuclear CuII complexes of a sulfamethazine Schiff-base were prepared. [•] Correlation between the experimental and theoretical work was performed. [•] Mononuclear complex is less toxic than free ligand, while the binuclear one is inactive. [•] E LUMO, ΔE, dipole moment and polarizability correlate well with experimental LC50. [Copyright &y& Elsevier]

[MnLCl(H2O)3]·H2O complex (HL=4-amino-N-(4,6-dimethyl-2-pyrimidinyl)benzenesulfonamide, sulfamethazine) has been synthesized and characterized by elemental analysis, TG/DTA, MS, FT-IR, UV–Vis, magnetic, electrochemical, and X-ray powder diffraction. The experimental studies were complemented by quantum chemical calculations at DFT/B3LYP level of theory. Sulfamethazine behaves as a mono-negatively bidentate ligand and interacts with Mn(II) ion through sulfonamidic (N15) and pyrimidic (N23) nitrogen atoms. Electronic structures were investigated using TD-DFT method and the descriptions of frontier molecular orbitals and the relocation of the electron density were determined. The voltammogram of NaL shows one irreversible one-electron process due to oxidation of p-amino group, and one anodic peak characteristic of reduction of - SO2 group. The synthesized complex, in comparison to the parent drug, was screened for its antibacterial activity. [ABSTRACT FROM AUTHOR]

Abstract: Ru(III) and Pt(II) complexes of sulfamethazine drug have been synthesized as antibacterial agents, aiming to enhance the biological activity of sulfamethazine drug against resistance development of some organisms and to throw more light about the debatable coordination behavior of sulfamethazine, and their structures were elucidated by several experimental and theoretical tools. Sulfamethazine acts as a bidentate ligand through sulfonamidic (N15) and pyrimidic (N23) nitrogen atoms. AC magnetic susceptibility measurements of RuIII complex showed anti-ferromagnetic behavior in 80–212K with a Néel temperature at 128K. Electrochemical studies revealed that –NH2 and –SO2 groups remain intact in complex formation. Antibacterial activity and structural activity relationship (SAR) showed that activity decreases with complex formation due to increase the energy of lowest unoccupied molecular orbital (E LUMO), dipole moment, and charge on sulfonamidic nitrogen (N15) as a result of formation of covalent M-sulfonamidic bond, which in turn suppress the activity. [Copyright &y& Elsevier]

Abstract: [MLCl2] (L = (1H-benzimidazol-2-ylmethyl)-N-(4-bromo-phenyl)-amine; M = Pd & Pt) and [PdL(OH2)2]∙2X∙zH2O (X = Br, I, z = 2; X = SCN, z = 1; X = NO3, z = 0) complexes have been synthesized as potential anticancer compounds and their structures were elucidated using elemental analysis, spectral, thermal analysis and X-ray powder diffraction. The benzimidazole (L) crystallizes in the space group P21/c with a = 8.6660(3) Å, b = 16.6739(7) Å, c = 9.8611(4) Å and β = 113.505(3) ° and forms an infinite chain structure with a trans-zigzag type along the crystallographic axis "a", through the intermolecular H–bond. FT-IR and 1H NMR studies revealed that the ligand L is coordinated to the metal ion via the pyridine-type nitrogen (Npy) of the benzimidazole ring and secondary amino group (NHsec). Quantum mechanical calculations of energies, geometries, vibrational wavenumbers, and 1H NMR of the benzimidazole L and its complexes were carried out by DFT/B3LYP method combined with 6–31G(d) and LANL2DZ basis sets. Natural bond orbital (NBO) analysis and frontier molecular orbitals (FMO) were performed at B3LYP/LANL2DZ level of theory. The benzimidazole L, in comparison to its metal complexes was screened for its antibacterial activity. The complexes showed cyctotoxic effects against human breast cancer (MCF7), hepatocarcinoma (HepG2) and colon carcinoma cells (HCT). The platinum complex (6) exhibited a moderate antitumor activity against MCF7 with IC50 = 10.2 μM comparing to that reported for cis-platin 9.91 μM. [Copyright &y& Elsevier]

Abstract: [MLCl2]·zH2O (L=(1H-benzimidazol-2-ylmethyl)-N-phenyl amine; M=Pd, z =0; M=Pt, z =1) and [PdL(OH2)2]·2X·zH2O (X=Br, I, NO3, z =0; X=SCN, z =1) complexes were synthesized as potential anticancer compounds and characterized by elemental analysis, spectral and thermal methods. FT-IR and 1H NMR studies revealed that the benzimidazole L is coordinated to the metal ions via the pyridine-type nitrogen (Npy) of the benzimidazole ring and secondary amino group (NHsec). Quantum mechanical calculations of energies, geometries, vibrational wavenumbers, and 1H NMR of the benzimidazole L and its complexes were carried out by density functional theory using B3LYP functional combined with 6-31G(d) and LANL2DZ basis sets. Natural bond orbitals (NBOs) and frontier molecular orbitals were performed at B3LYP/LANL2DZ level of theory. The synthesized ligand, in comparison to its metal complexes was screened for its antibacterial activity. The benzimidazole L is more toxic against the bacterium Staphylococcus aureus (MIC=58μg/mL) than the standard tetracycline (MIC=82μg/mL). The complexes showed cytotoxicity against breast cancer, Colon Carcinoma, and human heptacellular Carcinoma cells. The platinum complex (6) displays cytotoxicity (IC50 =12.4μM) against breast cancer compared with that reported for cis-platin 9.91μM. [Copyright &y& Elsevier]

Abstract: (1H-benzimidazol-2-ylmethyl)-(4-nitro-phenyl)-amine (L) and its Pd(II) and Pt(II) complexes have been synthesized as potential anticancer compounds and their structures were elucidated using a variety of physico-chemical techniques. The activation thermodynamic parameters were calculated using non-isothermal methods. Theoretical calculations invoking geometry optimization, charge distribution and molecular orbital description HOMO and LUMO were done using density functional theory. Natural bond orbital analysis (NBO) was performed for the investigation of major stabilizing orbital interactions. The experimental results, and the calculated molecular parameters, bond distances and angles, revealed a square-planar geometry around the metallic center through the pyridine-type nitrogen of the benzimidazole ring (Npy) and secondary amino group (NHsec) and two chlorine atoms. Electrochemical investigation of the complexes showed some irreversible, reversible, and quasi-reversible redox reactions. The synthesized ligand, in comparison to its metal complexes was screened for its antibacterial activity. The cytotoxicity assay of the complexes against three-cell lines breast cancer (MCF7), colon Carcinoma (HCT) and human heptacellular Carcinoma (Hep-G2) was studied. [Copyright &y& Elsevier]

The presence of expired and unused Sulfacetamide (SA) drug in water led to a global need for the development of effective advanced method for the quantitative analysis and for minimizing its occurrence in the nature. To find new effective photochemical decomposition method close to that obtained by the well-known Fenton reaction, the photodegradation of SA was investigated in presence of dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and/or other common additives at two different wavelengths (365 and 256 nm). The role of DDQ in the degradation process of SA was evaluated in comparison to the other investigated π-acceptor systems (Chloranilic acid (CHL) and Picric acid (PA)). While the photodegradation process of SA was hardly to proceed in the absence of a catalyst and/or additive, addition of DDQ and NaNO 2 to the solution of SA induced decomposition of about 94% of SA within 25 min upon the exposure to light source at 256 nm. On the other hand, SA was quantitatively analyzed by recording the absorbance of its charge transfer (CT) products with DDQ, CHL and PA at a certain wavelength. CHL is preferred with concentrated samples of SA, while PA is recommended for diluted samples of SA. SA → DDQ has a widely range of stability over the pH range of 4.5–12.0. While SA → CHL is stable only in the acidic medium (pH = 4.8–5.6), SA → PA is steady in the basic medium (pH = 7.5–11.0). The nature of the DDQ CT complex was investigated in the solid state. The electronic structures of the complexes were studied by calculating the time dependent density functional theory (TDDFT) spectra. Unlabelled Image • Investigation of DDQ in the photodegardation of Hazardous materials. • Sodium nitrite accelerates the photodegradation process, while Fe 2 O 3 resists. • Proton transfer process from -NH 2 of SA to C N of DDQ was reported. • DDQ and PA are favored to determine the low concentration of Sulfacetamide, while CHL can be used for the high concentration. • H-bond interactions stabilize the charge transfer process. [ABSTRACT FROM AUTHOR]