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41.
Ni(II) complexes (1–5) of di-2-pyridyl ketone N(4)-phenylthiosemicarbazone (HL) have been synthesized and spectrochemically characterized. Elemental analyses revealed a NiL2 · 2H2O stoichiometry for compound 1. However, the single crystals isolated revealed a composition NiL2 · 0.5(H2O)0.5(DMF). The compound crystallizes into a monoclinic lattice with the space group P21/n. Complexes 2, 3 and 4 are observed to show a 1:1:1 ratio of metal:thiosemicarbazone:gegenion, with the general formula NiLX · yH2O [X = NCS, y = 2 for 2; X = Cl, y = 3 for 3 and X = N3, y = 4.5 for 4]. Compound 5 is a dimer with a metal:thiosemicarbazone:gegenion ratio of 2:2:1, with the formula [Ni2L2(SO4)] · 4H2O. 相似文献
42.
Four molybdenum(VI) thiosemicarbazonato complexes have been synthesized and characterized. The dinuclear complexes [(MoO2L1)2] (1) and [(MoO2L2)2] (3) have been prepared by the reaction of [MoO2(acac)2] with 2-hydroxyacetophenone N(4)-cyclohexyl (H2L1) and N(4)-phenyl (H2L2) thiosemicarbazones in alcoholic medium. Mononuclear dioxomolybdenum(VI) complexes of the type [MoO2L1py] (2) and [MoO2L2py] (4) have been prepared by the reaction of 1 or 3 with pyridine (py) in alcoholic medium. In all the complexes, molybdenum is coordinated by two terminal oxo-oxygen atoms, (Ot), oxygen, nitrogen and sulfur atoms from the principal ligand and by an oxygen atom from the second unit in 1, and by a nitrogen atom from pyridine in complexes 2 and 4. All complexes have been spectroscopically characterized. The molecular structures of complexes 1, 2 and 4 have been determined by the single crystal X-ray diffraction method. 相似文献
43.
A new ligand N′-(pyridin-2-ylmethylene)nicotinohydrazide (HL2) and two Ni(II) complexes of stoichiometry NiL1·H2O [L1-2-benzoylpyridine nicotinoylhydrazone] and NiL2·H2O have been synthesized and characterized by elemental analyses, IR and UV–Vis spectral studies. Structures of HL2 and Ni(II) compounds have been determined by single crystal X-ray diffraction studies which reveal a distorted octahedral
geometry around the two Ni(II) centers.
Graphical abstract A new ligand N¢-(pyridin-2-ylmethylene)nicotinohydrazide (HL2) and two Ni(II) complexes of stoichiometry NiL1·H2O [L1-2-benzoylpyridine nicotinoylhydrazone] and NiL2·H2O have been synthesized and characterized by elemental analyses, IR, UV–Vis spectral studies and single crystal X-ray analysis.相似文献
44.
Varughese Philip V. Suni M. R. Prathapachandra Kurup 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(12):o856-o858
The molecule of the title compound, C19H17N5S, adopts a Z configuration about the azomethine bond and exists as the thione tautomer. The overall structure of the molecule is distributed in four different planes. An intramolecular hydrogen bond involving the pyridyl N atom and the H atom attached to the hydrazine N atom leads to the formation of a six‐membered ring. 相似文献
45.
B N Raja Sekhar S Padmanabhan Aparna Shastri P Meenakshi Raja Rao M B Kurup K G Prasad 《Pramana》1998,50(3):231-237
Beam-foil spectrum of fluorine was recorded in the wavelength region of 2000–4500 Å using F+ ion beams of energies ranging from 216 to 296 KeV. Some of the spectral lines of fluorine observed during the present investigation are hitherto unknown. Mean lifetimes of a few of the excited levels of F II and F III are reported for the first time. 相似文献
46.
Heterocyclic base adducts of salicylaldehyde N(4)- cyclohexylthiosemicarbazone(H2L) copper(II) complexes have been synthesized
and characterized. I.r., electronic and e.s.r. spectra of the complexes, as well as i.r., electronic and 1H- and 13C-n.m.r.
spectra of the thiosemicarbazone have been obtained. Based on e.s.r. studies, all possible parameters have been calculated.
The g values, calculated for all the complexes in frozen solution, indicate the presence of the unpaired electron in the dx2−y2
orbital. The metal–ligand bonding parameters evaluated showed strong in-plane σ- and in-plane π-bonding. The magnetic and
spectroscopic data indicate a square-planar geometry for the four-coordinate and a distorted square-pyramidal structure for
the five-coordinate complexes. From cyclic voltammetric data quasireversible copper(II)/copper(I) couples are observed for
the complexes.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
47.
Beulen MW Bugler J de Jong MR Lammerink B Huskens J Schonherr H Vancso GJ Boukamp BA Wieder H Offenhauser A Knoll W van Veggel FC Reinhoudt DN 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(7):1176-1183
We have developed synthesis routes for the introduction of short and long dialkylsulfides onto the primary side of alpha-, beta-, and gamma-cyclodextrins. Monolayers of these cyclodextrin adsorbates were characterized by electrochemistry, wettability studies, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and atomic force microscopy (AFM). The differences in thickness and polarity of the outerface of the monolayers were measured by electro-chemistry and wettability studies. On average about 70% of the sulfide moieties were used for binding to the gold, as measured by XPS. Tof-SIMS measurements showed that the cyclodextrin adsorbates adsorb without any bond breakage. AFM measurements revealed for beta-cyclodextrin monolayers a quasi-hexagonal lattice with a lattice constant of 20.6 A, which matches the geometrical size of the adsorbate. The alpha-cyclodextrin and gamma-cyclodextrin monolayers are less ordered. Interactions of the anionic guests 1-anilinonaphthalene-8-sulfonic acid (1,8-ANS) and 2-(p-toluidinyl)naphthalene-6-sulfonic acid (2,6-TNS) and the highly ordered monolayers of heptapodant beta-cyclodextrin adsorbates were studied by surface plasmon resonance (SPR) and electrochemical impedance spectroscopy. The SPR measurements clearly showed interactions between a beta-cyclodextrin monolayer and 1,8-ANS. Electrochemical impedance spectroscopy measurements gave high responses even at low guest concentrations (< or = 5 microM). The association constant for the binding of 1,8-ANS (K = 289,000 +/- 13,000M-1) is considerably higher than the corresponding value in solution. (Partial) methylation of the secondary side of the beta-cyclodextrin strongly decreases the binding. 相似文献
48.
Anwar Usman Ibrahim Abdul Razak Suchada Chantrapromma Hoong‐Kun Fun A. Sreekanth S. Sivakumar M. R. Prathapachandra Kurup 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):m461-m463
One half of the molecule of the title complex, [Mn(C14H13N4S)2], is related to the other half by a twofold axis passing through the Mn atom. This high‐spin Mn atom is six‐coordinated, in an octahedral geometry, by the azomethine N, the pyridyl N and the thiolate S atom of two planar 1‐(pyridin‐2‐yl)ethanone N(4)‐phenylthiosemicarbazone ligands. In the crystal, the molecules are interconnected by N—H?S and C—H?N interactions, forming a three‐dimensional network. 相似文献
49.
Bhagwan S. Garg M. R. Prathapachandra Kurup Satendra K. Jain Yudhvir K. Bhoon 《Transition Metal Chemistry》1988,13(2):92-95
Summary Manganese(II) bis(ligand) complexes of substituted thiosemicarbazones and selenosemicarbazones derived from 2-acetylpyridine of general formula [MnL2] (where L=deprotonated ligand) have been synthesized and characterised by elemental analyses, electronic spectra in solution, i.r. spectra, magnetic measurements and e.s.r. spectra recorded in polycrystalline state and in solution at room temperature and 77K. The terdentate character of the ligands in all the complexes is inferred from i.r. spectra. The electronic spectra along with e.s.r. spectra suggest an octahedral environment around the manganese(II). The metal-ligand bonds are moderately covalent. Thus all the complexes reported here are six-coordinated and high-spin octahedral. 相似文献
50.
Bessy Raj BN Prathapachandra Kurup MR Suresh E 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(4):1253-1260
A new aroyl hydrazone, N-2-hydroxy-4-methoxybenzaldehyde-N'-4-nitrobenzoyl hydrazone (H2L) and its mixed ligand Cu(II) complex [CuLpy] [py, pyridine] have been prepared. The ligand is characterized by elemental analysis, electronic, infrared and NMR spectral studies and the complex by electronic, infrared, EPR spectral studies and the magnetic susceptibility data. The structures of the compounds were determined by single crystal X-ray diffraction studies. Both the ligand and the Cu complex crystallize into a triclinic lattice with a space group of PI. From the crystal studies, it is concluded that the ligand molecule exits in the keto form in the solid state, while at the time of complexation, it tautomerises into the enol form. The complex is formed by the double deprotonation of the ligand molecule--both the phenolic and the enolic protons. 相似文献