Now showing items 21-30 of 30
Abstract: | Four oxovanadium and one dioxovanadium complex with 2-hydroxyacetophenone N(4)- phenylthiosemicarbazone (H2L) which are represented as [VOLphen]·2H2O (1), [VOLbipy] (2), [VOLdmbipy] (3), [VOL]2 (4) and [VO2HL]·CH3OH (5) have been synthesized and characterized by elemental analyses, electronic, infrared and EPR spectral techniques. In all the complexes 1–4 the ligand coordinates through phenolic oxygen, azomethine nitrogen and thiolate sulfur. But in complex [VO2HL]·CH3OH, coordination takes place in thione form instead of thiolate sulfur. All the complexes except [VO2HL]·CH3OH are EPR active due to the presence of an unpaired electron. In frozen DMF at 77 K, all the oxovanadium(IV) complexes show axial anisotropy with two sets of eight line patterns |
Description: | Spectrochimica Acta Part A 71 (2009) 2040–2044 |
URI: | http://dyuthi.cusat.ac.in/purl/4010 |
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Synthesis and s ... iosemicarbazone ligand.pdf | (501.2Kb) |
Abstract: | Eight new transition metal complexes of benzaldehyde-N(4)–phenylsemicarbazone have been synthesized and characterized by elemental analyses, molar conductance, electronic and infrared spectral studies. In all the complexes, the semicarbazone is coordinated as neutral bidentate ligand. 1H NMR spectrum of [Zn(HL)2(OAc)2] shows that there is no enolisation of the ligand in the complex. The magnetic susceptibility measurements indicate that Cr(III), Mn(II), Fe(III), Co(II) and Cu(II) complexes are paramagnetic and Ni(II) is diamagnetic. The EPR spectrum of [Mn(HL)2(OAc)2] in DMF solution at 77K shows hyperfine sextet with low intensity forbidden lines lying between each of the two main hyperfine lines. The g values calculated for the [Cu(HL)2SO4] complex in frozen DMF, indicate the presence of unpaired electron in the dx2−y2 orbital. The metal ligand bonding parameters evaluated showed strong in-plane bonding and in-plane bonding. The ligand and complexes were screened for their possible antimicrobial activities. |
Description: | Spectrochimica Acta Part A 76 (2010) 22–28 doi:10.1016/j.saa.2010.02.035 |
URI: | http://dyuthi.cusat.ac.in/purl/4004 |
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Synthesis, char ... orsemicarbazone ligand.pdf | (591.0Kb) |
Abstract: | A new semicarbazone, HL has been synthesized from quinoline-2-carboxaldehyde and N4-phenyl-3- semicarbazide and structurally and spectrochemically characterized. 1H NMR, 13C NMR, IR and electronic spectra of the compound are studied. The existence of keto form in the solid state is supported by the crystal structure and IR data. The compound crystallizes into an orthorhombic space group P212121. Intra and intermolecular hydrogen bonding interactions facilitates unit cell packing in the crystal lattice |
Description: | J Chem Crystallogr (2010) 40:927–932 DOI 10.1007/s10870-010-9765-z |
URI: | http://dyuthi.cusat.ac.in/purl/4000 |
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Synthesis, Spec ... ral Studies of a Novel.pdf | (464.0Kb) |
Abstract: | A novel binuclear Ni(II) complex of salicylaldehyde 3-azacyclothiosemicarbazone (H2L) has been synthesized and characterized by elemental analysis, IR and UV–Vis spectroscopy. The single crystal X-ray structure of the complex shows that bridging occurs through thiolato sulfur and phenolic oxygen atoms. Nickel centers in the complex have square planar and octahedral geometries |
Description: | Inorganica Chimica Acta 362 (2009) 2515–2518 |
URI: | http://dyuthi.cusat.ac.in/purl/4008 |
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Synthesis, spec ... cyclothiosemicarbazone.pdf | (266.4Kb) |
Abstract: | Oxovanadium(IV/V) complexes of 2-hydroxyacetophenone- 3-hydroxy-2-naphthoylhydrazone (H2L) have been synthesized and characterized. The complexes were characterized by elemental analyses, IR, electronic and EPR spectra. The oxovanadium(V) complex [VOL (OCH3)] is crystallized in two polymorphic forms, denoted by 1a and 1b, with space groups Pn21a and P 1, respectively. Both have distorted square pyramidal structures. |
Description: | Struct Chem (2010) 21:599–605 DOI 10.1007/s11224-010-9589-7 |
URI: | http://dyuthi.cusat.ac.in/purl/4003 |
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Synthesis, spec ... (V)complex [VOL(OCH3)].pdf | (421.5Kb) |
Abstract: | An interesting series of nine new copper(II) complexes [Cu2L2(OAc)2] H2O (1), [CuLNCS] ½H2O (2), [CuLNO3] ½H2O (3), [Cu(HL)Cl2] H2O (4), [Cu2(HL)2(SO4)2] 4H2O (5), [CuLClO4] ½H2O (6), [CuLBr] 2H2O (7), [CuL2] H2O (8) and [CuLN3] CH3OH (9) of 2-benzoylpyridine-N(4)-phenyl semicarbazone (HL) have been synthesized and physico-chemically characterized. The tridentate character of the semicarbazone is inferred from IR spectra. Based on the EPR studies, spin Hamiltonian and bonding parameters have been calculated. The g values, calculated for all the complexes in frozen DMF, indicate the presence of the unpaired electron in the dx2 y2 orbital. The structure of the compound, [Cu2L2(OAc)2] (1a) has been resolved using single crystal X-ray diffraction studies. The crystal structure revealed monoclinic space group P21/n. The coordination geometry about the copper(II) in 1a is distorted square pyramidal with one pyridine nitrogen atom, the imino nitrogen, enolate oxygen and acetate oxygen in the basal plane, an acetate oxygen form adjacent moiety occupies the apical position, serving as a bridge to form a centrosymmetric dimeric structure |
Description: | Polyhedron 30 (2011) 70–78 |
URI: | http://dyuthi.cusat.ac.in/purl/4705 |
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Synthesis, spec ... 4)-phenylsemicarbazone.pdf | (631.8Kb) |
Abstract: | This study concentrates the chemical properties of hydrazones due to its chelating capability and their pharmacological applications. Studies cover the preparation of different acid hydrazones and their structural studies and studies on their antimicrobial activity, synthesis and spectral characterization of different complexes of copper oxovanadium, manganese, nickel etc. Effect of incorporation of heterocyclic bases to the coordination sphere, change in the biological activity of acid hydrazones upon coordination, development of X-ray quality single crystals and its X-ray diffraction studies, studies on the redox behavior of the coordinated metal ions and correlation between the stereochemistry and biological activities. |
URI: | http://dyuthi.cusat.ac.in/purl/18 |
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Dyuthi-T0290.pdf | (2.715Mb) |
Abstract: | Six new copper complexes of di-2-pyridyl ketone nicotinoylhydrazone (HDKN) have been synthesized. The complexes have been characterized by a variety of spectroscopic techniques and the structure of [Cu(DKN)2]·H2O has been determined by single crystal X-ray diffraction. The compound [Cu(DKN)2]·H2O crystallized in the monoclinic space group P21 and has a distorted octahedral geometry. The IR spectra revealed the presence of variable modes of chelation for the investigated ligand. The EPR spectra of compounds [Cu2(DKN)2( -N3)2] and [Cu2(DKN)2( -NCS)2] in polycrystalline state suggest a dimeric structure as they exhibited a half field signal, which indicate the presence of a weak interaction between two Cu(II) ions in these complexes |
Description: | Spectrochimica Acta Part A 78 (2011) 926–934 |
URI: | http://dyuthi.cusat.ac.in/purl/4704 |
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Versatile bindi ... re of a Cu(II) complex.pdf | (1.013Mb) |
Abstract: | FT-IR spectrum of quinoline-2-carbaldehyde benzoyl hydrazone (HQb H2O) was recorded and analyzed. The synthesis and crystal structure data are also described. The vibrational wavenumbers were examined theoretically using the Gaussian03 package of programs using HF/6-31G(d) and B3LYP/6-31G(d) levels of theory. The data obtained from vibrational wavenumber calculations are used to assign vibrational bands obtained in infrared spectroscopy of the studied molecule. The first hyperpolarizability, infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar derivatives and is an attractive object for future studies of non-linear optics. The geometrical parameters of the title compound obtained from XRD studies are in agreement with the calculated values. The changes in the CAN bond lengths suggest an extended p-electron delocalization over quinoline and hydrazone moieties which is responsible for the non-linearity of the molecule |
Description: | Journal of Molecular Structure 973 (2010) 36–46 http://dx.doi.org/10.1016/j.molstruc.2010.03.016 |
URI: | http://dyuthi.cusat.ac.in/purl/4002 |
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Vibrational spe ... computational study of.pdf | (593.3Kb) |
Abstract: | The title compound, C15H16N4S, exists in the Z conformation with the thionyl S atom lying cis to the azomethine N atom. The shortening of the N—N distance [1.3697 (17) A ° ] is due to extensive delocalization with the pyridine ring. The hydrazine– carbothioamide unit is almost planar, with a maximum deviation of 0.013 (2) A ° for the amide N atom. The stability of this conformation is favoured by the formation of an intramolecular N—H N hydrogen bond. The packing of the molecules involves no classical intermolecular hydrogenbonding interactions; however, a C—H interaction occurs |
Description: | Acta Cryst. (2011). E67, o3195 |
URI: | http://dyuthi.cusat.ac.in/purl/4702 |
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(Z)-N,N-Dimethy ... ydrazinecarbothioamide.pdf | (705.9Kb) |
Now showing items 21-30 of 30
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