Crystal Study of Salicylaldehyde N(4)-Phenylthiosemicarbazone

Abstract The crystal structure of salicylaldehyde N(4)-phenyl thiosemicarbazone is described. The compound crystallizes in the triclinic crystal system, space group P Z = 6, V = 2002.1(5) ?³ with unit cell parameters a = 10.6733(15) ?, b = 13.8856(19) ?, c = 14.052(2) ?, α = 81.851(2)°, β = 77.061(2)° and γ = 83.482(2)°. There are three independent molecules in the asymmetric unit. The crystal structure reveals that the compound exists in the thione form and S1 and N3 are at E configuration to each other with respect to N2–C7 bond. Similarly, S2 and N6 are trans to each other with respect to N5–C21 bond in the second molecule of the asymmetric unit and S3 and N9 are trans to each other with respect to N8–C35 bond in the third molecule of the asymmetric unit. The packing of the molecules in the crystal lattice is stabilized by intermolecular hydrogen bonds. Index Abstract The compound salicylaldehyde N(4)-phenyl thiosemicarbazone crystallizes in the triclinic crystal system, space group P Z = 6, V=2002.1(5) ?³ with unit cell parameters a = 10.6733(15) ?, b = 13.8856(19) ?, c = 14.052(2) ?, α = 81.851(2)°, β = 77.061(2)° and γ = 83.482(2)°. The structure of the compound salicylaldehyde N(4)-phenylthiosemicarbazone     

A study of structural effects on linear and nonlinear response of bicompartmental Ni (II) Schiff base complexes

Herein we investigate imaginary third order NLO activity, optical limiting capability and first hyperpolarizabilities of five Ni (II) salen complexes using experimental and theoretical methods. The complexes are tuned to have different NLO response by changing mainly the diimine spacer group. Out of the compounds reported, the one with o‐phenylene spacer group exhibits the highest NLO activity comparable with that of polymers and semiconductors which is followed by the compound with ethylene spacer unit. The order of activity is a direct function of the degree of π‐delocalization. Further all the tested compounds returned outstanding optical limiting capabilities making them excellent materials for fabrication of such devices. The experimental results were substantiated with frontier orbital calculations carried out using DFT at M06/6‐31G* level of theory and complex with aromatic spacer group exhibits least energy gap and highest activity. The total dipole moment, polarizability and first hyperpolarizability were also calculated at the same level of theory which are also in line with the experimentally observed results.     

A Schiff base colorimetric chemosensor for CN- ion and its dioxidomolybdenum (VI) complexes: Evaluation of structural aspects and optoelectronic properties

Six new cis-dioxidomolybdenum(VI) complexes featured with a tridentate ONO donor Schiff base derived from salicylidene-2-aminophenolato backbone have been synthesised and characterised by elemental analysis, spectroscopic techniques (like IR, UV-vis and ¹H-NMR) and cyclic voltammetry. Suitable single crystals of the parent complex [MoO₂L(MeOH)]₂·H₂O ( 1 ) was obtained by the slow evaporation of the mother liquor, whereas the crystals of the complexes 2 - 6 were grown in coordinating solvents like ethanol, DMF, DMSO etc. and were characterised by single crystal X-ray diffraction as monomers stabilised by the solvent molecules used for the recrystallization purpose. The structures of the complexes were further quantified using Hirshfeld surface analysis. The Schiff base acts as a colorimetric chemosensor for CN^- ions in DMSO solution. The receptor-CN^- ion interaction and the sensing mechanism of the chemosensor were verified by colorimetric, UV-vis, ¹H-NMR and FT-IR spectroscopic studies. Hydroxyl moiety present in the receptor function as the binding site for cyanide ion thereby leading to its optical discrimination in presence of other anions by producing a visible colour change from colourless to yellow. Therefore the Schiff base sensor portrays estimable selectivity and sensitivity towards CN^- ion. Additionally the Schiff base as well as the molybdenum complexes exhibit good third order non-linear optical properties and optical power limiting when analysed by the Z-scan technique.     

Synthesis and spectral investigations of Mn(II) complexes of pentadentate bis(thiosemicarbazones)

Five Mn(II) complexes of bis(thiosemicarbazones) which are represented as [Mn(H₂Ac4Ph)Cl₂] (1), [Mn(Ac4Ph)H₂O] (2), [Mn(H₂Ac4Cy)Cl₂]·H₂O (3), [Mn(H₂Ac4Et)Cl₂]·3H₂O (4) and [Mn(H₂Ac4Et)(OAc)₂]·3H₂O (5) have been synthesized and characterized by elemental analyses, electronic, infrared and EPR spectral techniques. In all the complexes except [Mn(Ac4Ph)H₂O], the ligands act as pentadentate neutral molecules and coordinate to Mn(II) ion through two thione sulfur atoms, two azomethine nitrogens and the pyridine nitrogen, suggesting a heptacoordination. While in compound [Mn(Ac4Ph)H₂O], the dianionic ligand is coordinated to the metal suggesting six coordination in this case. Magnetic studies indicate the high spin state of Mn(II). Conductivity measurements reveal their non-electrolyte nature. EPR studies indicate five g values for [Mn(Ac4Ph)H₂O] showing zero field splitting.     

Electrochemical investigation of magnetite-carbon nanocomposite in situ grown on nickel foam as a high-performance binderless pseudocapacitor

Journal of Solid State Electrochemistry - Magnetite-carbon nanocomposite was grown in situ on nickel foam by a novel auto-combustion method, and it was investigated for application as a...     

Semileptonic (Λ b → Λcev) decay in a field theoretic quark model

The semileptonic decay width of heavy baryons such as (Λ _b → Λcev) has been estimated in the framework of a nonrelativistic field theoretic quark model where four component quark field operators along with a harmonic oscillator wave function are used to describe translationally invariant hadronic states. The present estimation does not make an explicit use of heavy quark symmetry and has a reasonable agreement with the experimentally measured decay width, polarisation ratio and form factors with the harmonic oscillator radii and quark momentum distribution inside the hadron as free parameters.     

A Base-Mediated Approach Towards Dihydrofuro[2,3-b]Benzofurans from 2-Nitrobenzofurans and 1,3-Dicarbonyls

A straight-forward approach for the synthesis of a dihydrofuro[2,3-b]benzofuran derivatives has been achieved through a base-mediated Michael addition of 1,3-dicarbonyls to 2-nitrobenzofurans followed by intramolecular cyclization. A variety of 1,3-dicarbonyls, including cyclic as well as trifluoromethylated ones, have been subjected to react with 2-nitrobenzofurans under optimal conditions, and the respective dihydrofuro[2,3-b]benzofurans could be accessed in moderate to excellent yields.     

Studies on Co(II) and Co(III) complexes of di-2-pyridyl ketone N(4)-cyclohexyl and N(4)-phenyl thiosemicarbazones

Six new Co(II) and Co(III) complexes (1–6) of di-2-pyridyl ketone N(4)-cyclohexyl thiosemicarbazone (HL¹) and di-2-pyridyl ketoneN(4)-phenyl thiosemicarbazone (HL²) have been synthesized and spectrochemically characterized. HL¹ is newly synthesized and has been structurally characterized by single crystal X-ray diffraction studies, while HL² has been previously reported. HL¹ crystallizes into a monoclinic lattice with the space group P2₁. The complexes are characterized by magnetic, EPR, NMR and other spectroscopic studies. The EPR spectra of the paramagnetic complexes reveal axial features with eight hyperfine lines clearly resolved in the perpendicular region.     

Synthesis, Spectral and Thermal Studies of o-vanillin Oxime Complexes of Zinc(II), Cadmium(II) and Mercury(II)

Zinc(II), cadmium(II) and mercury(II) complexes of o-vanillin oxime have been synthesized and characterized by different physicochemical techniques. All the complexes have been subjected to non-isothermal decomposition studies in nitrogen atmosphere using thermogravimetry. The kinetic parameters for the decomposition of these complexes were evaluated using different methods and comparatively better results were obtained by these different methods. It has also been found that the decomposition processes of all these complexes follow first order kinetics. This revised version was published online in July 2006 with corrections to the Cover Date.