64174-57-8Relevant articles and documents
A family of Fe3+ based double-stranded helicates showing a magnetocaloric effect, and Rhodamine B dye and DNA binding activities
Adhikary, Amit,Jena, Himanshu Sekhar,Konar, Sanjit
, p. 15531 - 15543 (2015)
Herein, the synthesis, structural characterization, magnetic properties and guest binding activities of four Fe3+ based double-stranded helicates namely; [Fe2(L)2](ClO4)(Cl)·4(CH3OH)·2(H2O) (1), [Fe2(L)2](BF4)2·2(H2O) (2), [Fe2(L)2](NO3)2·3(CH3OH)·2(H2O) (3), and [Fe2(L)2](Cl)2·2(CH3OH)·4(H2O) (4) are reported. Complexes 1-4 have been synthesized using the hydrazide-based ligand H2L (H2L = N′1,N′4-bis(2-hydroxybenzylidene)succinohydrazide) and the corresponding Fe2+ salts. Each of the independent cationic complexes [Fe2(L)2]2+ shows double-stranded helicates from the self-assembly of the ligand and metal ions in a 2 : 2 ratio, where the individual Fe3+ centre is lying on a C2-axis and the ligand strands wrap around it. In 1-4, ligand L adopts pseudo-C conformations and forms a double-stranded dinuclear helicate with a small cage in between them. Moreover, in 1-4, each of the independent cationic complexes [Fe2L2]2+ is inherently chiral and possesses P for right-hand and M for left-hand helicity and as a consequence is a racemic solid. Detailed magnetic studies of all the complexes reveal that the Fe3+ centres are magnetically isolated and isotropic in nature. Estimation of the Magnetocaloric Effect (MCE) from magnetization data unveils a moderate MCE at a temperature of 3 K with magnetic entropy changes (-ΔSm) of 22.9, 27.7, 24.1, 26.5 J kg-1 K-1 at a magnetic field of 7 T for complexes 1-4, respectively. Also, the variation of the -ΔSm values was justified by considering the parameter of magnetization per unit mass. Stability of all the complexes in solution phase was confirmed by ESI-mass spectrometric analysis and liquid phase FT-IR spectroscopy. Further, the interaction of the complexes 1-4 with Rhodamine B dye was examined by UV-vis and fluorescence spectroscopic study. The observed blue-shift in the fluorescence study and hyperchromicity and hypochromicity with the appearance of two isosbestic points in the UV-vis study ascertain the interactions of the dye with the complexes. A DNA binding study by absorption spectral titration suggests the weak external intercalation of complex 1 within the nucleotide of calf thymus DNA. Computational study supports the isotropic nature of the metal centres and the consequent high spin multiplicity, which assists the complexes to show significant magnetic entropy changes.
Synthesis, structure, magnetic and biological activity studies of bis-hydrazone derived Cu(II) and Co(II) coordination compounds
Golla, Upendarrao,Adhikary, Amit,Mondal, Amit Kumar,Tomar, Raghuvir Singh,Konar, Sanjit
, p. 11849 - 11863 (2016)
Four coordination compounds of formulae [CuII2(H2L1)(HL1)](ClO4)3·H2O (1), [CuII2(H2L2)(CH3OH)2](ClO4)2·2CH3OH (2), [CoII2(H2L1)2](ClO4)4 (3) and [CoII2(H2L2)2]·2H2O (4) were synthesized via self-assembly of succinohydrazone derived ligands (H2L1 = N′,N′-4-bis(2-pyridyl)succinohydrazide, H4L2 = N′,N′-4-bis(2-hydroxybenzylidene)succinohydrazide) and Cu2+ and Co2+ ions, respectively. The compounds were characterized by crystal structure determination, magnetic measurements and biological activities. Compounds 1, 3 and 4 have discrete double helicate structures, whereas compound 2 is a one-dimensional chain. Magnetic studies show antiferromagnetic exchange interactions in 2 with a J value of -67.1 cm-1 and antiferromagnetic spin-canting in compound 3 originates through supramolecular H-bonding. For compound 3, a clear bifurcation was observed in zero field cooled (ZFC) and field cooled (FC) measurement at a temperature of 3.5 K and field of 0.1 T, implying long range magnetic ordering below this temperature. Interestingly, all of compounds 1-4 show significant changes in their absorption (hypo- and hyperchromism) in the presence of SS-DNA, inferring interaction between the compounds and DNA. In addition, compounds 1-4 significantly exhibited nuclease activities on both RNA and pUC19 plasmid DNA. Moreover, the nuclease activity was further enhanced in the presence of oxidant (H2O2) and suggests the possible role of reactive oxygen species in DNA nicking ability of compounds 1-4. Furthermore, compounds 1, 2 and 4 exhibited significant cytotoxicity against mammalian cancer cell lines (HeLa, A549 and MDAMB-231). In addition, our results from Annexin/PI staining and DNA fragmentation assays revealed that these compounds are capable of inducing apoptosis and have potential to act as anticancer drugs.
A new dihydrazone based turn on fluorescent sensor for Zn(II) ion in aqueous medium
Borthakur,Thapa,Asthana,Mitra,Ismail,Lal
, p. 6 - 13 (2015)
A new simple dihydrazone based colorimetric and fluorescent turn-on chemosensor (disalicyladehyde succinoyldihydrazone, I) for Zn(II) was designed and synthesized. The photophysical behavior of the ligand and metal coordinated complex was characterized by steady state and time-resolved fluorescence, density functional theory calculation in combination with 1H NMR and mass spectroscopy results. The compound acts as a highly selective and sensitive detector of Zn(II) in aqueous medium with almost six times increase in fluorescence intensity. The optimum condition for sensing ability of I with a detection limit of ca. 2 μM of Zn(II) was found at solution pH 8.6 and at excitation wavelength of 380 nm. The other interfering elements, including Cd(II), show either no or very little change in fluorescence intensity under similar experimental conditions.
Synthesis, characterization, crystal structure, and reactivity of heterobimetallic dioxovanadium(V) complexes containing multidentate hydrazone ligands
Kurbah, Sunshine D.,Kumar, Arvind,Sanentiba Ozukum,Syiemlieh, Ibanphylla,Lal, Ram A.
, p. 2969 - 2985 (2017/10/07)
Two new heterobimetallic complexes of the composition [(VO2)2(μ3-slsch){Na2(μ-H2O)2(H2O)2}]n (1) and [(VO2)2(μ3-npsch){Na2(μ-H2O)2(H2O)2}(DMF)]n (2) were obtained by reaction of the ligand and vanadium pentoxide in a 1:1 molar ratio in methanol in the presence of Na2CO3 (2 equivalents). The complexes obtained were characterized using various spectroscopic studies. The structures of both the complexes were established by single crystal X-ray crystallographic study. We have also explored the catalytic behavior of the complexes in oxidative bromination of phenol red, which is the bio-inspired reaction catalyzed by an enzyme haloperoxidase.
