The Experts below are selected from a list of 95715 Experts worldwide ranked by ideXlab platform

Marvadeen A Singhwilmot - One of the best experts on this subject based on the ideXlab platform.

  • synthesis and characterization of a cadmium dichloro compound of n n o di 2 pyridyl ketone thiophene 2 carboxylic Acid hydrazone η 3 dpktch the structure of cdcl2 η 3 dpktch
    Journal of Coordination Chemistry, 2007
    Co-Authors: Mohammed Bakir, Mark A W Lawrence, Marvadeen A Singhwilmot
    Abstract:

    The reaction between dpktch and CdCl2 in refluxing acetonitrile gave [CdCl2(η3-dpktch)] in good yield. Spectroscopic measurements divulge the coordination of dpktch and the elemental analysis confirmed its formulation. Optical measurements in N,N-dimethylformamide (dmf) and dimethylsulfoxide (DMSO) in the absence and presence of a proton donor/acceptor disclosed two highly sensitivity interlocked intra-ligand-charge-transfer transitions (ILCT) that are sensitive to their surroundings. Under basic conditions, a low-energy electronic transition with an extinction coefficient of 17,400 ± 2000 M−1cm−1 appeared at ∼403 nm and a peak minimum appeared at 326 nm. Under Acidic conditions, a high energy electronic transition with extinction coefficient of 13,500 ± 2000 M−1cm−1 appeared at ∼330 nm and a shoulder appeared at ∼400 nm. The addition of an Acid to a dmf solution of [CdCl2(η3-dpktch)] caused the disappearance of the low energy absorption band at 403 nm and a peak maximum appeared at 330 nm. The reverse wa...

Mohammed Bakir - One of the best experts on this subject based on the ideXlab platform.

  • synthesis characterization and structure of the first rhenium compound of di 2 pyridyl ketone thiophene 2 carboxylic Acid hydrazone dpktah fac re co 3 n n κ2 dpktah cl
    Journal of Molecular Structure, 2009
    Co-Authors: Mohammed Bakir, Colin Gyles
    Abstract:

    Abstract fac-[Re(CO)3(κ2-N,N -dpktah)Cl], isolated from the reaction between [Re(CO)5Cl] and di-2-pyridyl ketone Thiophene-2-Carboxylic Acid hydrazone (dpktah) in refluxing toluene, exhibits rich physico-chemical properties. The formulation of fac-[Re(CO)3(κ2-N,N -dpktah)Cl] was established from the results of its elemental analysis and spectroscopic measurements, and confirmed using X-ray crystallography. The 1H NMR spectrum of fac-[Re(CO)3(κ2-N,N-dpktah)Cl] revealed the coordination of dpktah and exchange of the amide proton. Electronic absorption measurements show two intra-ligand charge transfer transitions (ILCT) and established inter-conversion between fac-[Re(CO)3(κ2-N,N-dpktah)Cl] and its conjugate base. Thermo-optical studies confirmed the facile inter-conversion between fac-[Re(CO)3(κ2-N,N-dpktah)Cl] and its conjugate base. Optosensing measurements show [MCl2] (M = Zn, Cd or Hg) in concentrations as low as 1.00 × 10−7 M can be detected and determined using protophilic solutions of fac-[Re(CO)3(κ2-N,N-dpktah)Cl]. X-ray structural analysis done on a single crystal of fac-[Re(CO)3(κ2-N,N-dpktah)Cl] confirmed its identity and divulge two symmetry-independent molecules in the asymmetric unit. The supramolecular structure of fac-[Re(CO)3(κ2-N,N-dpktah)Cl] disclosed anti-parallel chains locked via a network of hydrogen bonds. Non-classic hydrogen bonds of the type C–H…Cl connect molecules in the chain and classic hydrogen bonds of the type N–H…O connect adjacent chains.

  • synthesis and characterization of a cadmium dichloro compound of n n o di 2 pyridyl ketone thiophene 2 carboxylic Acid hydrazone η 3 dpktch the structure of cdcl2 η 3 dpktch
    Journal of Coordination Chemistry, 2007
    Co-Authors: Mohammed Bakir, Mark A W Lawrence, Marvadeen A Singhwilmot
    Abstract:

    The reaction between dpktch and CdCl2 in refluxing acetonitrile gave [CdCl2(η3-dpktch)] in good yield. Spectroscopic measurements divulge the coordination of dpktch and the elemental analysis confirmed its formulation. Optical measurements in N,N-dimethylformamide (dmf) and dimethylsulfoxide (DMSO) in the absence and presence of a proton donor/acceptor disclosed two highly sensitivity interlocked intra-ligand-charge-transfer transitions (ILCT) that are sensitive to their surroundings. Under basic conditions, a low-energy electronic transition with an extinction coefficient of 17,400 ± 2000 M−1cm−1 appeared at ∼403 nm and a peak minimum appeared at 326 nm. Under Acidic conditions, a high energy electronic transition with extinction coefficient of 13,500 ± 2000 M−1cm−1 appeared at ∼330 nm and a shoulder appeared at ∼400 nm. The addition of an Acid to a dmf solution of [CdCl2(η3-dpktch)] caused the disappearance of the low energy absorption band at 403 nm and a peak maximum appeared at 330 nm. The reverse wa...

N Dharmaraj - One of the best experts on this subject based on the ideXlab platform.

  • potentially cytotoxic new copper ii hydrazone complexes synthesis crystal structure and biological properties
    Dalton Transactions, 2013
    Co-Authors: Mani Alagesan, Nattamai Bhuvanesh, N Dharmaraj
    Abstract:

    A new set of penta-coordinated copper(II) hydrazone complexes containing solvated methanol were synthesized by reacting the hydrazone ligands, 2-acetylpyridine benzoyl hydrazone (HL1) and 2-acetylpyridine Thiophene-2-Carboxylic Acid hydrazone (HL2), with [CuCl2(DMSO)2] and characterized by different spectral methods. Single crystal X-ray diffraction studies of the complexes revealed that both of them, [CuCl(L1)(MeOH)] (1) and [CuCl(L2)(MeOH)] (2), have square pyramidal geometry around the cupric ion, in which the hydrazone is coordinated through NNO atoms along with a molecule of methanol in the apical position. Interaction of the ligands HL1 and HL2 along with the corresponding copper complexes 1 and 2 with calf thymus DNA (CT-DNA) has been estimated by absorption and emission titration methods which revealed that the compounds interacted with CT-DNA through intercalation. Binding of the compounds, i.e., free ligands and complexes (1) and (2) with bovine serum albumin (BSA) protein investigated using UV-visible, fluorescence and synchronous fluorescence spectroscopic methods indicated that there occurred strong binding of copper complexes to BSA over the ligands. Further, the cytotoxicity of the compounds examined in vitro on a panel of cancerous cell lines such as a human cervical cancer cell line (HeLa), a pancreatic cancer cell line (PANC-1), an Ehrlich ascites cancer cell line (EAC) and Dalton's lymphoma ascitic cancer cells (DLA) and a normal mouse embryonic fibroblasts cell line (NIH3) demonstrated that the complexes 1 and 2 possessed superior cytotoxicity than that of well-known commercial anticancer drug cisplatin to the tumor cells but are less toxic to the normal cell line and have emerged as potential candidates for further studies.

  • synthesis crystal structure electrochemistry and studies on protein binding antioxidant and biocidal activities of ni ii and co ii hydrazone complexes
    Polyhedron, 2012
    Co-Authors: Palanisamy Sathyadevi, Paramasivam Krishnamoorthy, M Alagesan, Kaliyaperumal Thanigaimani, Thomas P Muthiah, N Dharmaraj
    Abstract:

    Abstract Bivalent transition metal hydrazone complexes of the composition [Ni(L1)2] (1), [Co(L1)2] (2), [Ni(L2)2] (3) and [Co(L2)2] (4) have been synthesised from the reactions of [MCl2(PPh3)2] (where M = Ni or Co) with hydrazones derived from 2-acetyl pyridine and carboxylic Acid hydrazides of benzhydrazide (HL1) or Thiophene-2-Carboxylic Acid hydrazide (HL2), respectively. Structure of the ligands HL1 and HL2 and their corresponding complexes with Ni(II) and Co(II) ions were proposed based on the elemental analysis, infrared and 1H NMR spectral methods. Single crystal X-ray diffraction study of complex 1 revealed a distorted octahedral geometry around the metal ion provided by two units of the ligand. To explore the potential medicinal value of the new complexes, binding interaction of all the complexes with bovine serum albumin (BSA) was studied at normal physiological conditions using fluorescence and UV–Vis spectral techniques. The number of binding sites (n) and binding constant (Ka) were calculated according to the double logarithm regression equation. The results of synchronous fluorescence spectrum showed that binding of metal hydrazones with BSA induced conformational changes in BSA. The in vitro antioxidant and antimicrobial potentials of the new chelates were also carried out.

Jim-min Fang - One of the best experts on this subject based on the ideXlab platform.

Maria Alice Da Silva Telles - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of a rapid differentiation test for the mycobacterium tuberculosis complex by selective inhibition with rho nitrobenzoic Acid and thiophene 2 carboxylic Acid hydrazide
    International Journal of Tuberculosis and Lung Disease, 2005
    Co-Authors: Carmen Maria Saraiva Giampaglia, Maria Conceicao Martins, V T G Inumaru, I V Butuem, Maria Alice Da Silva Telles
    Abstract:

    SETTING: Mycobacterial growth in media to which inhibitory substances are added has been used in species identification. Growth of the Mycobacterium tuberculosis complex (MTC) is inhibited by � -nitrobenzoic Acid (PNB), whereas non-tuberculous mycobacteria (NTM) are resistant. Thiophene-2-Carboxylic Acid hydrazide (TCH) is useful in the differentiation of MTC when performed together with other tests. OBJECTIVE: To develop a test using PNB or TCH added to culture medium, and to evaluate its usefulness in the screening of mycobacteria isolates. DESIGN: In 2001, PNB testing was performed in 109 M. tuberculosis strains identified by Instituto Adolfo Lutz (IAL) and 52 NTM strains from the institute’s culture collection. The drugs were added to LowensteinJensen (LJ) medium and to BBL-MGIT. RESULTS: Species differentiation of MTC with the MGIT/TCH method was similar to that observed using the conventional LJ/TCH method. The accuracy of the MGIT/PNB method to differentiate NTM and MTC strains was 99.4%. The BBL-MGIT system allowed presumptive identification in 3‐11 days, compared to � 12 days with LJ medium. CONCLUSION: A simple, low-cost test using growth inhibitors may be incorporated into a modern, safe and quick methodology enabling differentiation of MTC and NTM.