Search

A series of triorganotin(IV) compounds {Me3SnL (1), Bu3SnL (2), Ph3SnL (3)} and di-organotin(IV) complexes {Me2SnL2 (4), Bu2SnL2 (5) and Ph2SnL2 (6)}, where Me = methyl, Bu = butyl, Ph = phenyl and L = 2-(1H-indole-3-yl)acetate) have been synthesized and characterized by FT-IR and multinuclear NMR (1H-, 13C- and 119Sn-NMR) spectroscopy. Tri- and diorganotin(IV) derivatives exhibited five- and six-coordinate geometries, respectively, in solid state as evident from the Δν value. Five-coordinate trigonal bipyramidal and six-coordinate octahedral geometry was assigned to 1 and 4 in solution state based on NMR data as evident from 2J(119Sn,1H) and 1J(119Sn-13C) coupling constant values, which was further attested by 119Sn NMR. Single crystal XRD analysis on 1 revealed that it exhibited polymeric crystal structure with distorted trigonal bipyramidal geometry around the tin center with two unequal Sn–O bonds. The screening of the synthesized compounds for cytotoxicity showed good activity in comparison to cis-platin. They have also displayed moderate to good antimicrobial activities. [ABSTRACT FROM AUTHOR]

Di- and triorganotin(IV) derivatives of 3-(4-nitrophenyl)-2-methylacrylic acid (HL), i.e., [n-Bu2SnL2] (1), [Me2SnL2] (2), [n-Bu3SnL]n (3) [Me3SnL]n (4) and [Ph3SnL]n (5) were synthesized and characterized by the elemental analysis, FT-IR and multinuclear (1H and 13C) NMR. The IR analysis showed a chelating/bridging bidentate coordination of the ligand in diorganotin(IV)/triorganotin(IV) derivatives resulting in the formation of 6/5 coordinated tin centers, respectively, in the solid state. The NMR study indicated a decrease in the coordination number of tin in the complexes in solution form. The triorganotin(IV) complexes (3, 5) showed promising in vitro antifungal and antitumor properties comparable to standard drugs used and were found more cytotoxic than the diorganotin(IV) derivatives (1, 2). Molecular docking studies carried out on tubulin as receptor showed a similar mode of antitumor action for complex 5 and standard drug vincristine. The docking analysis for antifungal activity of complex 3 as model compound showed hydrogen bonding, polar and hydrophobic interactions with the target proteins of the fungal strains. [ABSTRACT FROM AUTHOR]

Two new binuclear Cu(II) complexes Cu2L4(DMS)2 (1) and Cu2L4(3BrPy)2 (2) where L = para-chlorophenyl acetate, DMS = dimethylsulfoxide and 3BrPy = 3-bromopyridine have been synthesised and characterised using FT-IR, single crystal XRD analysis, absorption and conductance studies. In both the complexes copper(II) ion lies in distorted square pyramidal geometry where the apical position is occupied by pyridine in monodentate fashion while the equatorial positions are occupied by four carboxylate ligands in bidentate coordination mode. The supramolecular structures of the complexes arise primarily as a result of C–H...O and H–C...H types of interactions and are different owing to the different apical ligands. The DNA-binding activity of the complexes has been studied through absorption spectroscopy, viscometry and competitive ethidium bromide displacement techniques. These techniques indicated a mixed electrostatic and intercalative mode of interaction with DNA-binding constant values Kb of 1.98 × 104 M−1 and 2.86 × 104 M−1 for complexes 1 and 2, respectively. These activities represent the preliminary biological relevance of the synthesised complexes. [ABSTRACT FROM AUTHOR]

Copper(II) complexes with a general formula [Cu2(3,4-F2C6H3CH2COO)4(L)2], where L = 2-methylpyridine (1) and 3-methylpyridine (2), are reported here. The FTIR spectra of the complexes confirmed the bridging bidentate coordination mode of the carboxylate ligand. The low (475 and 449 cm−1) and strong (727 & 725 cm−1) intensity bands in the FTIR spectra, due to Cu-N stretches and pyridyl ring vibrations, confirmed coordination of the 2-/3-methyl pyridine co-ligands in complexes 1 and 2, respectively. A binuclear paddlewheel structural arrangement with a square pyramidal geometry was confirmed for copper atoms in the complexes via single-crystal X-ray analysis. The DPPH, •OH radical, and α-amylase enzyme inhibition assays showed higher activities for the complexes than for the free ligand acid. The binding constant (Kb = 1.32 × 105 for 1 and 5.33 × 105 for 2) calculated via UV-VIS absorption measurements and docking scores (−6.59 for 1 and −7.43 for 2) calculated via molecular docking showed higher SS-DNA binding potential for 2 compared to 1. Viscosity measurement also reflected higher DNA binding ability for 2 than 1. Both complexes 1 and 2 (docking scores of −7.43 and −6.95, respectively) were found to be more active inhibitors than the free ligand acid (docking score of −5.5159) against the target α-amylase protein. This in silico study has shown that the herein reported compounds follow the rules of drug-likeness and exhibit good potential for bioavailability. [ABSTRACT FROM AUTHOR]

This study highlights the utility of new pyridinium based cationic surfactants, N-(n-heptyl)-3-methylpyridinium bromide (Py7) and N-(n-nonyl)-3-methylpyridinium bromide (Py9), formed via a single step substitution reaction, for their application towards drugs delivery. Fourier-transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopic methods have been employed for the characterization of these amphiphiles. Aggregation behavior of the surfactants in solution i.e. the critical micelle concentration (CMC), has been investigated by conductometric and spectrophotometric analyses. The results reveal that the amphiphiles can act as excellent surface active agents due to their low critical micelle concentration (CMC). Furthermore, the interaction of these surfactants with two anionic drugs i.e., Ketoprofen (KP, 2-(3-Benzoylphenyl)propanoic acid) and Diclofenac sodium (DF, Sodium 2-(2,6-dichloranilino) phenylacetate), has been explored below and above the CMC value using UV-visible spectroscopy. The enhanced absorption intensities of both the drugs in the presence of synthesized surfactants indicated stronger interactions between surfactants and drugs molecules. [ABSTRACT FROM AUTHOR]

The synthesis of new cationic surfactants i.e., n‐hexyl‐3‐methylpyridium bromide (a) and n‐octyl‐3‐methylpyridium bromide (b), and their characterization using multinuclear nuclear magnetic resonance spectroscopy (NMR) (1H, 13C) and Fourier‐transform infrared spectroscopy (FT‐IR) spectroscopic techniques were reported. The micellization behavior of the synthesized surfactants was studied using conductometry and ultraviolet–Visible spectroscopy. The critical micelle concentration (CMC) of compounds a and b was found to be 0.41 and 0.35 m mol L−1, respectively. The effect of temperature on the CMC of these compounds was examined in the range of 298–318 K and thermodynamic parameters (ΔG, ΔH, and ΔS) of the micellization process were calculated. The antibacterial study of the synthesized surfactants revealed their strong activity against different bacterial strains. Moreover, the interaction of drugs i.e., flurbiprofen and ketoprofen, with the synthesized surfactants was investigated for gaining insights into the role of micelles as drug‐delivery devices. Drug–surfactant interactions were also confirmed via a conductometric method. [ABSTRACT FROM AUTHOR]

A dinuclear centrosymmetric copper(II) complex has been prepared and characterized via FT-IR, UV-Visible and electron spin resonance spectroscopy, electrochemical method, and powder and single crystal XRD techniques. The two copper(II) ions are connected by two μ-1,1-O atoms belonging to para-fluorophenyl acetate ligands. Each copper(II) ion is coordinated by two other carboxylate ligands in monodentate and a 2,2'-bipyridine molecule in bidentate manner. Thus the geometry around each penta-coordinated copper(II) ion is square pyramidal with distortion factor τ = 0.04. Purity and uniform crystalline nature of the complex was assessed from powder XRD spectrum. ESR signal consisted of partially resolved hyperfine splitting pattern while electrochemical studies revealed diffusion controlled electron transfer processes with diffusion co-efficient of 1.628 × 10-;7 cm2 s-;1. The results of all spectroscopic experiments support each other. The complex afforded mixed binding mode with DNA yielding DNA-binding constant values of 3.667 × 104 and 1.438 × 104 M-;1 using cyclic voltammetry and absorption spectroscopy, respectively. The preliminary studies heralded good structural and biological importance of the synthesized complex. [ABSTRACT FROM AUTHOR]

Four new diorganotin(IV) carboxylates, [n-Bu2SnL2] (1), [Et2SnL2] (2), [Me2SnL2] (3) and [n-Oct2SnL2] (4), where L = 3-(4-chlorophenyl)-2-methylacrylate, were synthesized and characterized by elemental analysis, FT-IR, multinuclear NMR (1H, 13C, and 119Sn) and X-ray single crystal analysis for 1. A chelating bidentate ligand and six-coordinate tin centers were confirmed in the solid state by IR for all complexes and for 1 by X-ray single crystal analysis. The NMR study has shown a decrease in the coordination number of tin in solution. The complexes were screened for their in vitro antibacterial and antifungal activities. A compromised lipo/hydrophilicity and a diffusion controlled antimicrobial activity was shown by the complexes in the order 1 > 2>3 > 4. Molecular docking studies have shown hydrogen bonding and hydrophobic interactions for 1 with the target proteins of the antimicrobial strains. [ABSTRACT FROM AUTHOR]

This review emphasized on the antituberculosis activity of organotin complexes. The astonishing antituberculosis activity of organotin complexes of mefenamic acid, 2-[(2,6-dimethylphenyl)amino]benzoic acid (HDMPA), and [bis(2,6-dimethylphenyl)amino]benzoic acid, NSAIDs from the carboxylic acid, oxicams family, meclofenamic acid or (N-(2,6-dichloro-m-tolylanthranilic acid), cinnamic acid, (Z)-2-acetamido-3-phenylacrylic acid, 3-methyl-but-2-enoic acid, and 2,2-diphenylacetic acid is scrutinized usingMycobacterium tuberculosisH37Rv. It showed that there exists a beguiling, range of structural diversity for organotin moiety in all these complexes. Biologically active compounds should have available coordination positions at tin. Antituberculosis activity of organotin complexes is influenced by the nature of the ligand environment, organic groups attached to the tin, compound structure, toxicity, and potential mechanism of action; though generally, an MIC ≤ 1 μg ml−1in a new compound class is considered a good lead. The results of complexes exhibited that triorganotin(IV) complexes have superior antituberculosis activity as compared to diorganotin(IV) complexes. It may be due to the fact that generally toxicity of the organotin compounds is associated with the organic ligand and the toxicity decreases with the order of tri > di > mono-organotins. [ABSTRACT FROM AUTHOR]

Four heterobimetallic derivatives of the type, [R2(Cl)SnL]PdCl2(R = n-Bu:1)/[R3SnL]PdCl2(R = Me:2;n-Bu:3; Ph:4) where L = 4-(2-hydroxyethyl)piperazine-1-carbodithioic acid, have been synthesized by refluxing 4-(2-hydroxyethyl)piperazine-1-carbodithioic acid with R2SnCl2/R3SnCl in 1:1 M/L ratio and then stirring with PdCl2at room temperature. The complexes have been characterized by various spectroscopic (IR,1H and13C NMR, and EI-MS) techniques and thermogravimetric analysis. FTIR data demonstrated the bidentate binding of dithiocarbamate group. The NMR data demonstrated 4-coordinated geometry in solution. The complex4exhibits the interaction with salmon sperm DNA (SS-DNA) with significant hypochromic effect and suggests intercalating mode of binding. The complex2was found most active for inhibition of alkaline phosphates enzyme (ALPs). The complexes1–4showed significant antimicrobial activities as compared to the inactive free ligand precursor. Thein vitrohemolytic activity showed that average lysis of human red blood cells was significantly lower as compared to Triton-X 100 (positive control, 100% lysis). [ABSTRACT FROM AUTHOR]

The mol­ecule of the title compound, [Sn(C2H5)2(C11H12N3O2S2)Cl], features an asymmetrically chelating thio­carboxyl­ate ligand. The Sn atom is five-coordinate within a C2ClS2 donor set that is best described as trigonal bipyramidal with S and Cl atoms in axial positions, defining a bond angle of 156.58 (2)°. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, [Sn(CH3)3-(C3H4N3S)]n, consists of a linear chain in which adjacent trimethyltin groups are bridged by the 4-methyl-4H-1,2,4-triazole-3-thiolate anion through its N and S atoms. [ABSTRACT FROM AUTHOR]

Six heteroleptic Cu(II) carboxylates (1–6) were prepared by reacting 2-chlorophenyl acetic acid (L1), 3-chlorophenyl acetic acid (L2), and substituted pyridine (2-cyanopyridine and 2-chlorocyanopyridine). The solid-state behavior of the complexes was described via vibrational spectroscopy (FT-IR), which revealed that the carboxylate moieties adopted different coordination modes around the Cu(II) center. A paddlewheel dinuclear structure with distorted square pyramidal geometry was elucidated from the crystal data for complexes 2 and 5 with substituted pyridine moieties at the axial positions. The presence of irreversible metal-centered oxidation reduction peaks confirms the electroactive nature of the complexes. A relatively higher binding affinity was observed for the interaction of SS-DNA with complexes 2–6 compared to L1 and L2. The findings of the DNA interaction study indicate an intercalative mode of interaction. The maximum inhibition against acetylcholinesterase enzyme was caused for complex 2 (IC50 = 2 µg/mL) compared to the standard drug Glutamine (IC50 = 2.10 µg/mL) while the maximum inhibition was found for butyrylcholinesterase enzyme by complex 4 (IC50 = 3 µg/mL) compared to the standard drug Glutamine (IC50 = 3.40 µg/mL). The findings of the enzymatic activity suggest that the under study compounds have potential for curing of Alzheimer's disease. Similarly, complexes 2 and 4 possess the maximum inhibition as revealed from the free radical scavenging activity performed against DPPH and H2O2. [ABSTRACT FROM AUTHOR]

A series of organotin(IV) derivatives R 3 SnL ( 1–3 ), R 2 SnLCl ( 4–6 ) and R 2 SnL 2 ( 7–9 ) (where R = Me, Bu, Ph and L = 4-(benzo[d][1,3]dioxol-5-ylmethyl)piperazine-1-carbodithioate) were prepared from the reaction of 4-(benzo[d][1,3]dioxol-5-ylmethyl)piperazine-1-carbodithioate (L-salt) with the corresponding triorganotin(IV) chlorides and diorganotin(IV) dichlorides. All compounds were characterized by FT-IR, 1 H, 13 C and 119 Sn NMR spectroscopy. Dimethylstannyl bis(4-(benzo[d][1,3]dioxol-5-ylmethyl)piperazine-1-carbodithioate) ( 7 ) was also characterized in the solid state by single crystal x-ray diffraction, showing a distorted octahedral geometry. The diorganotin(IV) derivatives have shown significant antibacterial and antifungal activity and good cytotoxic activity against ovarian cancer cells with IC 50 values greater or comparable to that of cisplatin . [ABSTRACT FROM AUTHOR]

Review: 81 refs. [ABSTRACT FROM AUTHOR]

A series of tri- and diorganotin(IV) derivatives of 4-(2-thienyl)butyric acid have been synthesized by the reaction of ligand acid with tri- and diorganotin salts in 1:1 and 2:1 molar ratios, respectively. The synthesized compounds have been confirmed by CHNS elemental analyses, FTIR, multinuclear NMR (H and C) spectroscopy and X-ray diffraction studies. NMR data reveal a 5-coordinate geometry for the triorganotin(IV) derivatives, while 6-coordinate for the diorganotin(IV) derivatives, respectively. The X-ray crystallographic analysis of the compound 2 showed polymeric 5-coordinate trigonal bipyramidal geometry. Antimicrobial studies were also evaluated against different strains of bacteria ( Escherichia coli, Klebsiella pneumoniae, Bacillus subtilis and Staphylococcus aureus) and fungi ( Mucor species, Aspergillus solani, Helminthosporium oryzae, Aspergillus flavus, Aspergillus niger) to establish the biological significance of these compounds. The synthesized compounds probably work by interfering with the ability of bacteria to form cell walls by keeping unwanted substances from entering their cells and stop the contents of their cells from leaking out due which the bacteria get die. The antifungal activity of some of the tested compound is comparable to that of the standard drug, terbinafine. From their antimicrobial results, it was concluded that they might be used as potential candidate for the generation of new antimicrobial drugs. [ABSTRACT FROM AUTHOR]

Objective: The current study was conducted to determine whether people will keep practicing physical distancing behavior as part of their daily lives after the end of the COVID-19 pandemic. Materials and Methods: A structured questionnaire was prepared online using "Question Pro" software for surveys, and the study was conducted electronically. The questionnaire for the study had two components, the first was related to the participant's demographics, and the other was about physical distancing questions. There were 16 questions in total. Results: Women were more fearful/careful and would want to limit socializing than men. The religious aspect is one primary reason people will be willing to avoid physical distancing. Physical distancing was more acceptable to people with higher education levels. This physical distancing trend might affect the public transportation and tourism industry. Conclusion: This study showed that the female gender and population with higher education are willing to follow better adherence to SOPs of the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

Denture base fracture is one of the most annoying problems for both prosthodontists and patients. Denture repair is considered to be an appropriate solution rather than fabricating a new denture. Digital denture fabrication is widely spreading nowadays. However, the repair strength of CAD-CAM milled and 3D-printed resins is lacking. This study aimed to evaluate the effect of surface treatment on the shear bond strength (SBS) of conventionally and digitally fabricated denture base resins. One l heat-polymerized (Major base20), two milled (IvoCad, AvaDent), and three 3D-printed (ASIGA, NextDent, FormLabs) denture base resins were used to fabricate 10 × 10 × 3.3 acrylic specimens (N = 180, 30/resin, n = 10). Specimens were divided into three groups according to surface treatment; no treatment (control), monomer application (MMA), or sandblasting (SB) surface treatments were performed. Repair resin was bonded to the resin surface followed by thermocycling (5000 cycles). SBS was tested using a universal testing machine where a load was applied at the resin interface (0.5 mm/min). Data were collected and analyzed using ANOVA and a post hoc Tukey test (α = 0.05). SEM was used for failure type and topography of fractured surfaces analysis. The heat-polymerized and CAD-CAM milled groups showed close SBS values without significance (p > 0.05), while the 3D-printed resin groups showed a significant decrease in SBS (p < 0.0001). SBS increased significantly with monomer application (p < 0.0001) except for the ASIGA and NextDent groups, which showed no significant difference compared to the control groups (p > 0.05). All materials with SB surface treatment showed a significant increase in SBS when compared with the controls and MMA application (p < 0.0001). Adhesive failure type was observed in the control groups, which dramatically changed to cohesive or mixed in groups with surface treatment. The SBS of 3D-printed resin was decreased when compared with the conventional and CAD-CAM milled resin. Regardless of the material type, SB and MMA applications increased the SBS of the repaired resin and SB showed high performance. [ABSTRACT FROM AUTHOR]

This article reports the synthesis, characterization, geometrical optimization, and biological studies of new MBH-based organometallic compounds of medicinal significance. The ligand (MNHA) was prepared via the Morita–Baylis–Hillman (MBH) synthetic route, from aromatic aldehyde containing multiple functional groups. Metal complexes were prepared in an alkaline medium and under other suitable reaction conditions. Spectral and elemental analyses were used to identify the structural and molecular formulas of each compound. Optimized geometry was determined through density functional theory (DFT) B3LYP and 6-311++ G (d,p) basis set for the MBH adduct, whereas structures of novel complexes were optimized with the semi-empirical PM6 method. Powder XRD analysis furnished the crystal class of complexes, with Co3+, Cr3+, and Mn2+ being cubic, while Ni2+ was hexagonal, and Cu2+ was orthorhombic. Moreover, the ligand, along with Ni2+ and Co3+ complexes, showed profound antibacterial action against S. aureus, E. coli, B. pumilis, and S. typhi. Additionally, all of the complexes were shown to persist in the positive antioxidant potential of the ligand. Contrarily, not a single metal complex conserved the antifungal potentials of the ligand. [ABSTRACT FROM AUTHOR]

In the solid state, the title compound, C14H13NO2, crystallizes as a zwitterion. Two molecules comprise the asymmetric unit. The molecules exhibit two types of hydrogen bonds: N—H...O hydrogen bonds involving hydroxy and imine groups generate an S(6) ring motif, and O—H...O hydrogen bonds linking two symmetry-related molecules form a centrosymmetric dimer. [ABSTRACT FROM AUTHOR]

The title compound, [Sn(C6H5)2(C8H6N2O2)], features a five-coordinate C2NO2 coordination geometry for Sn that is inter­mediate between trigonal-bipyramidal and square-pyramidal. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title compound, C13H10O3, contains two mol­ecules with small conformational differences. Both mol­ecules form hydrogen-bonded inversion dimers through their carboxyl groups. [ABSTRACT FROM AUTHOR]

The crystal packing of the essentially planar molecules of the title compound, C14H10F3NO2, is stabilized by O—H⋯O hydrogen bonds and possible C—H⋯O and C—H⋯F inter­actions. [ABSTRACT FROM AUTHOR]

In the zigzag polymeric title compound, [Sn(CH3)3(C16H20NO3)] n, the Sn atom adopts a distorted trigonal–bipyramidal geometry. [ABSTRACT FROM AUTHOR]

The structure of the title compound, [Sn(C6H5)3(C7H5ClNO2)], contains dimeric units that are stabilized by inter- and intra­molecular hydrogen bonds involving amino H atoms and carbonyl O and Cl atoms. The geometry around Sn is slightly distorted tetra­hedral and the Sn—C distances are essentially identical. [ABSTRACT FROM AUTHOR]

The Sn atom in the title compound, [Sn(CH3)2(C13H16NS2)2], has a highly distorted octa­hedral geometry that may be best described as skew-trapezoidal planar for thio­carboxyl­ates. The ligands are asymmetrically coordinated to the Sn atom, with shorter Sn—S bond lengths that are very close to the sum of the covalent radii of Sn and S, while the longer Sn—S distances are significantly less than the sum of their van der Waals radii. [ABSTRACT FROM AUTHOR]

The title mol­ecule, C15H18BrNO3, contains a cyclo­hexyl ring in a chair conformation linked to an aromatic ring through an HC=N—CH2 group. The mol­ecular conformation may be partially controlled by an intra­molecular O—H⋯N hydrogen bond, while the crystal structure is stabilized by inter­molecular O—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

In the paper by Hanif, Ali, Hussain, Bhatti, Karmazin Brelot & Stoeckli-Evans [ ], the name and address of the fourth author are given incorrectly. The correct author list is shown opposite. [ABSTRACT FROM AUTHOR]

The structure of the title compound, C17H20N2S, exhibits hydrogen bonding of the type N—H⋯S, resulting in chains of mol­ecules running along the b axis. [ABSTRACT FROM AUTHOR]

The title complex, [Sn(C4H9)2(C11H12N3O2S2)Cl], features an asymmetrically chelating thio­carboxyl­ate ligand. There are two molecules in the asymmetric unit. The Sn atom is five-coordinated within a C2ClS2 donor set that is best described as trigonal–bipyramidal with one S atom and the Cl atom in axial positions, subtending bond angles of 155.67 (2) and 155.11 (2)°, respectively. [ABSTRACT FROM AUTHOR]

In the title complex, [Sn(C6H5)2(C10H16NS2)Cl], the Sn atom has a distorted trigonal–bipyramidal geometry, with an axial S—Sn—Cl bond angle of 156.87 (3)°. Intra­molecular hydrogen bonding is present between an S atom and the H atom of the amine group. The mol­ecules are linked by an inter­molecular C—H⋯Cl hydrogen bond to form chains extending in the c direction. [ABSTRACT FROM AUTHOR]

In the solid-state structure of the title compound, C16H11NO4, the double bond is E, and the mean planes through the two aromatic rings are inclined to one another by 64.81 (12)°. In the crystal structure, symmetry-related mol­ecules are linked by O—H⋯O hydrogen bonds, forming centrosymmetric carboxylic acid dimers. The crystal structure is further stabilized by C—H⋯O and C—H⋯F inter­molecular hydrogen bonds, leading to the formation of a slab-like structure, two mol­ecules thick, extending in the ab plane. [ABSTRACT FROM AUTHOR]

In the title compound, [Sn(CH3)3(C7H5ClNO2)], the Sn atom is bonded to three methyl groups and one O atom in a distorted tetra­hedral geometry, with Sn—C bond lengths of 2.118 (2)–2.119 (2) Å and an Sn—O bond length of 2.0804 (12) Å. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, C15H11NO4·H2O, there are hydrogen-bonded clusters involving conventional and unconventional hydrogen bonds of the types O—H⋯O and C—H⋯O. Pairs of mol­ecules lie parallel to each other in a head-to-tail fashion, exhibiting strong π–π overlapping. [ABSTRACT FROM AUTHOR]

The title compound, C8H6O4, consists of a cyclic diether fused to benzoic acid and crystallizes as a hydrogen-bonded carboxylic acid dimer. [ABSTRACT FROM AUTHOR]

The title compound, [Sn(CH3)2(C7H12NS2)2], comprises SnIV coordinated by two 4-methyl­piperidine­dithio­carboxyl­ate ligands and two methyl groups. The coordination geometry around Sn is distorted octa­hedral, with the methyl groups adopting an arrangement inter­mediate between a cis and trans configuration. There are two independent complexes in the asymmetric unit, with closely comparable geometries. [ABSTRACT FROM AUTHOR]

The mol­ecule of the title compound, [Sn(C4H9)2(C15H9ClFO2)2], has a skewed-trapezoidal planar geometry, defined by four O donors from the carboxyl­ate ligands and two C atoms from the n-butyl groups. The C—Sn—C bond angle is 133.95 (12)°. The O atoms of the carboxyl­ate ligands are bonded asymmetrically to Sn, with significantly different Sn—O distances; the values for the shorter are 2.0914 (18) and 2.1134 (19) Å, while the longer Sn—O distances are 2.513 (2) and 2.650 (2) Å. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, [Sn(CH3)3(C15H15O2)], is composed of polymeric chains of monomers, linked by secondary coordinating bonds from the O atoms of the hydroxyl group to the Sn atoms, with an Sn⋯O distance of 2.646 (2) Å. This additional bond leads to a distorted trigonal–bipyramidal geometry around the Sn atom, with three methyl C atoms in equatorial and two O atoms in axial positions. [ABSTRACT FROM AUTHOR]

Developing a cost-effective, efficient, and stable oxygen evolution reaction (OER) catalyst is of great importance for sustainable energy conversion and storage. In this study, we report a facile one-step fabrication of cationic surfactant-assisted Prussian blue analogues (PBAs) Mx[Fe(CN)5CH3C6H4NH2]∙yC19H34NBr abbreviated as SF[Fe-Tol-M] (where SF = N-tridecyl-3-methylpyridinium bromide and M = Mn, Co and Ni) as efficient heterogeneous OER electrocatalysts. The electrocatalysts have been characterized by Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) analysis, and X-ray photoelectron spectroscopy (XPS). In the presence of cationic surfactant (SF), PBAs-based electrodes showed enhanced redox current, high surface area and robust stability compared to the recently reported PBAs. SF[Fe-Tol-Co] hybrid catalyst shows superior electrochemical OER activity with a much lower over-potential (610 mV) to attain the current density of 10 mA cm−2 with the Tafel slope value of 103 mV·dec−1 than that for SF[Fe-Tol-Ni] and SF[Fe-Tol-Mn]. Moreover, the electrochemical impedance spectroscopy (EIS) unveiled that SF[Fe-Tol-Co] exhibits smaller charge transfer resistance, which results in a faster kinetics towards OER. Furthermore, SF[Fe-Tol-Co] offered excellent stability for continues oxygen production over extended reaction time. This work provides a surface assisted facile electrode fabrication approach for developing binder-free OER electrocatalysts for efficient water oxidation. [ABSTRACT FROM AUTHOR]

A series of organotin(IV) carboxylate complexes: [Me 2 SnL 2 ] ( 1 ), [ n -Bu 2 SnL 2 ] ( 2 ), [ n -Oct 2 SnL 2 ] ( 3 ), [Me 3 SnL] ( 4 ), [ n -Bu 3 SnL] ( 5 ) and [Ph 3 SnL] ( 6 ), where L = 3-(4-fluorophenyl)acrylic acid, have been successfully synthesized and characterized by FT-IR, NMR ( 1 H, 13 C) and single crystal analysis. The ligand coordinates to tin atom via carboxylate group. Compound 4 was also analyzed by single crystal XRD analysis. Crystallographic data for trimethyltin(IV) complex showed that the tin has approximate trigonal bipyramidal geometry with the CH 3 groups in the trigonal plane. The carboxylate groups bridge the adjacent tin atoms, resulting in polymeric chains. FT-IR and NMR data also support the 5-coordination geometry for the triorganotin(IV) derivatives. In the case of the diorganotin(IV) derivatives a six-coordinate geometry at the tin atom is proposed from spectroscopic data. The Me–Sn–Me bond angle in complexes 1 and 4 was determined from the 2 J [ 119 Sn– 1 H] value as 138.4° and 111° that falls in the range of 5-coordinated trigonal bipyramidal and 6-coordinated octahedral geometries, respectively. The synthesized compounds were screened for their biological activities including antibacterial, antifungal and cytotoxicity. The compounds 4 – 6 exhibit excellent antibacterial, antifungal and cytotoxic activities. The cytotoxicity data reveals that the HL and 1 – 3 are almost non-toxic and exhibited LD 50 values in the range 73.45–675.1 μg/mL while 4 – 6 are found to be cytotoxic to mildly cytotoxic with LD 50 values in the range 6.43–13.49 μg/mL. The compound interacts with DNA via intercalation of aromatic ring into the base pairs of DNA resulting in hypochromism and minor red shift. [ABSTRACT FROM AUTHOR]

Dinuclear copper(II) complexes ACu(B) 4 CuA ( 1 and 2 ), where A is N-donor ligand such as 2,2′-bipyridine ( 1 ) and 3-bromopyridine ( 2 ) and B is O-donor carboxylate ligand such as 4-methylphenyl acetate, have been synthesized and characterized by FT-IR and single crystal X-ray crystallography. Crystallographic data of complex 1 revealed a square pyramidal geometry for each Cu center with bridging oxygen atoms at the elongated axial sites. For complex 2 a paddlewheel structure with bidentate coordination mode of the carboxylate moieties was observed. The mode of coordination of the carboxylate moiety was also determined from FT-IR data indicating a monodentate coordination mode in complex 1 and a bridging bidentate mode in complex 2 . A close agreement for Δ ν value was also observed between the FT-IR and single crystal X-ray data for both the complexes. Electrochemical studies of the complexes showed two redox peaks corresponding to Cu(III)/Cu(II) and Cu(II)/Cu(I) processes. The values of diffusion coefficient ( D o ), heterogeneous rate constant ( k °), formal potential ( E °) and charge transfer coefficient ( α ) have been calculated for the electron transfer processes and correlated to the structural parameters of the complexes. The complexes bind to DNA via intercalative interactions resulting in significant hypochromism and bathochromic shift as confirmed by UV–Vis spectroscopy. The synthesized complexes have a negative value of miLog P (−0.97 for complex 1 and −4.22 for complex 2 ) evaluated by Petra/Osiris/Molinspiration (POM) analyses which indicate their ability to penetrate through bio-membranes. [ABSTRACT FROM AUTHOR]

A series of organotin(IV) complexes have been synthesized by reacting potassium o -isobutyl carbonodithioate with di- and triorganotin halides in methanol under stirring conditions. The newly synthesized complexes have been characterized by elemental analysis, FT-IR, NMR ( 1 H and 13 C) and X-ray crystallography. The FT-IR results show that the ligand acts as bidentate in complexes 1 – 3 and monodentate in complexes 4 and 5 , which were also confirmed by theoretical calculations. The NMR data reveal four and six coordinated geometries in solution. A HOMO–LUMO study shows that all the complexes are stable. Biological screenings demonstrate that, with a few exceptions, all the complexes show significant activity against various bacterial and fungal strains. The synthesized complexes were also found to be effective antioxidants of the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). All the complexes have been assayed for antileishmanial activity in vitro and found some promising results. The UV–Vis studies confirmed that the ligand and its complexes bind to DNA via intercalative interactions, resulting in hypochromism and minor red shifts. [ABSTRACT FROM AUTHOR]

A series of new tri- and diorganotin(IV) derivatives of an S-donor ligand with the formulae Me 3 SnL ( 1 ), n -Bu 3 SnL ( 2 ), Ph 3 SnL ( 3 ), Me 2 SnClL ( 4 ), Bu 2 SnClL ( 5 ), Ph 2 SnClL ( 6 ) and Me 2 SnL 2 ( 7 ) were prepared by the reaction of organotin(IV) chlorides with the ligand L = 4-[bis(4-flourophenyl)methyl]piperazinium 4-[bis(4-flourophenyl)methyl]piperazine-1-carbodithioate, refluxing for 6–7 h, using dry toluene as a solvent. The synthesized compounds were characterized by elemental analysis (CHN), FT-IR, multinuclear NMR ( 1 H and 13 C) and single crystal X-ray crystallography. The NMR study reveals a four coordinated geometry in the solution state for complexes 1 – 7 . It was also concluded from the crystallographic data that the synthesized complexes exhibit four coordinated monodentate structures in the solid state. A DNA binding study was performed by UV–Visible spectroscopy, viscometric measurements and cyclic voltammetry. These techniques showed an intercalative mode of interaction for the compounds with SS-DNA. A new and efficient strategy to identify pharmacophores and anti-pharmacophores sites in dithiocarbamates derivatives for antibacterial/antifungal activity using Petra, Osiris and Molinspiration (POM) analyses was also carried out. The synthesized complexes have negative values of miLog P which indicate their ability to penetrate through bio-membranes. Parameters like miLog P and TPSA for the studied complexes fall in a range that is to be expected for compounds predicting oral absorption of a drug, which means they have good bioavailability. Based on the four precise criteria (GPCR ligand, ion channel modulator, Kinase inhibitor and nuclear receptor ligand) the synthesized compounds are expected to have drug properties. [ABSTRACT FROM AUTHOR]

Four new zinc(II) complexes formulated as [Zn(L)2] (1), [Zn(L)2(phen)] (2), [Zn(L)2(bipy)H2O] (3), and [Zn(en)2(H2O)2](L)2(H2O)2(4), where HL = 4-methyltrans-cinnamic acid, bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline, and en = ethylenediamine, have been synthesized and characterized by FT-IR and NMR spectroscopy. Single-crystal XRD revealed distorted square-pyramidal structure for3and octahedral for4. The complexes were screened for DNA interaction via viscommetry and UV–visible spectroscopy. The apparent binding constants were calculated to be 1.18 × 104, 1.26 × 105, 4.64 × 104,and 1.89 × 104for1–4, respectively. The binding propensity to salmon sperm DNA was in the order: K2 > K3 > K4 > K1. Furthermore, these complexes demonstrated efficient inhibition of alkaline phosphatase, which was attributed to the binding of zinc(II) to the enzyme’s active site. [ABSTRACT FROM AUTHOR]

Synthesis, characterization and structural relevance of four new copper carboxylate complexes (1–4) has been presented here. The complexes have been synthesized by direct treatment of the substituted phenyl acetate and pyridine ligands in aqueous medium. The complexes were stable indefinitely with excellent yields and were characterized using spectroscopic and single crystal XRD techniques. FTIR spectroscopy revealed the bridging bidentate coordination mode for the carboxylate moiety in accordance to the actual structure revealed by XRD. Moreover, UV-Visible spectroscopic and cyclic voltammetric studies helped in their characterization and yielded signals which were typical of the copper(II) complexes. Successfully solved single crystal XRD data showed binuclear paddlewheel structures for all the complexes with both copper ions linked through four OCO bridges of ortho-methoxy phenyl acetate (1–3) and ortho-methyl-meta-nitrophenyl acetate (4). The geometry around each copper was distorted square pyramidal where the apical positions are occupied by meta-bromopyridine (1), meta-methylpyridine (2) and DMSO (3 and 4) molecules. The complexes exhibited excellent DNA-binding activity majorly via intercalation as revealed by four experimental techniques. This preliminary study showed that the synthesized complexes add to the existing treasury on the paddlewheel complexes.Air stable newly synthesized and purified crystalline complexes with their preliminary structural relevance.The Index Abstract: Synthesis, characterization and structural relevance of four new copper carboxylate complexes (1–4) has been presented here. The complexes have been synthesized by direct treatment of the substituted phenyl acetate and pyridine ligands in aqueous medium. The complexes were stable indefinitely with excellent yields and were characterized using spectroscopic and single crystal XRD techniques. FTIR spectroscopy revealed the bridging bidentate coordination mode for the carboxylate moiety in accordance to the actual structure revealed by XRD. Moreover, UV-Visible spectroscopic and cyclic voltammetric studies helped in their characterization and yielded signals which were typical of the copper(II) complexes. Successfully solved single crystal XRD data showed binuclear paddlewheel structures for all the complexes with both copper ions linked through four OCO bridges of ortho-methoxy phenyl acetate (1–3) and ortho-methyl-meta-nitrophenyl acetate (4). The geometry around each copper was distorted square pyramidal where the apical positions are occupied by meta-bromopyridine (1), meta-methylpyridine (2) and DMSO (3 and 4) molecules. The complexes exhibited excellent DNA-binding activity majorly via intercalation as revealed by four experimental techniques. This preliminary study showed that the synthesized complexes add to the existing treasury on the paddlewheel complexes.Air stable newly synthesized and purified crystalline complexes with their preliminary structural relevance. [ABSTRACT FROM AUTHOR]

Six new Schiff based diorganotin(IV) complexes have been synthesized and structurally characterized through multitude analytical techniques. The compound-DNA interaction study has been performed through UV–Visible spectroscopy that revealed high binding potential through a spontaneous process. The complexes have further been investigated for in vitro antimicrobial and anticancer studies. [Display omitted] • Synthesis of six diorganotin(IV) complexes based on two new Schiff base ligands derived by the condensation reaction of aldehydes with acid hydrazides. • Spectroscopic characterization and structural elucidation of all complexes were performed. • Compound-DNA interaction study was performed through UV–Visible spectroscopy. • The compounds were investigated for in vitro antimicrobial studies. • The compounds were evaluated for their anticancer activities. Herein, two Schiff base ligands Ń-(4-diethylamino-2-hydroxybenzylidene) isonicotinohydrazide (L1) and Ń-(2,3-dihydroxybenzylidene) isonicotinohydrazide (L2) and their six di-organotin(IV) complexes (R = C 4 H 9 (1 , 4), C 6 H 5 (2 , 5) and CH 3 (3 , 6)) were synthesized. The solid state and solution chemistry of the ligands and their organotin(IV) complexes was explored through single crystal XRD, FTIR and NMR (1H, 13C and 119Sn) spectroscopy. The single crystal XRD analysis was carried out for complexes 1 , 2 and 5 , reveals the presence square pyramidal, trigonal bipyramidal and pentagonal bipyramidal geometries, respectively. All structures showed distorted geometries because of the constraint offered by five and six membered chelate rings. The results obtained from the interaction study of ligands and complexes with SS-DNA were indicative of high binding potential through a spontaneous process. The results of in vitro antimicrobial studies validated the well-known theory of chelation and overtone concept. Anticancer activities conducted for the ligands and complexes revealed evident anti-proliferative activity of 1 , 2 , 4 and 5 complexes. Complex 2 being the most active one, exhibited pro-apoptotic, cytotoxic effect after PI and DAPI stains. Moreover, after H2DCF-DA staining the treated cancerous cells, an induced oxidative stress was detected. Complexes 2 and 4 also revealed the activation of mitochondrial pathway of apoptosis in treated cancer cells. [ABSTRACT FROM AUTHOR]

Presents a method to design a lid for vacuum line cooling trap.

Describes the design of an apparatus used to make disposable potassium bromide (KBr) pellets for infrared (IR) studies.