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     

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.     

Raman and resonance-Raman spectra of CsI/I−3

Raman and resonance-Raman spectra of the I^?₃ ion isolated within CsI crystals have been studied using 647 nm and 488 nm exciting radiation. Sample temperatures between 300 and 20 K have been used. Eleven overtones of the symmetric stretching mode (nν₁) have been observed in the resonance-Raman spectrum excited by the 488 nm Ar⁺ laser line. Bands centred at 153, 170, 264 and 304 cm^?1 have been assigned as ν₃, 2ν₂, ν₁+ν₃ and 2ν₃(Σ⁺) respectively. The remaining structure between the nν₁ lines has been assigned as due to combinations of these lines with the lattice vibrations of the CsI crystal.     

Spectral studies of iron(III) complexes of substituted thiosemicarbazones of 2-acetylpyridine

Summary Iron(III) complexes of four substituted thiosemicarbazones of 2-acetylpyridine of general. formula [FeL₂]ClO₄ (where L is a deprotonated ligand) have been synthesised and characterised by elemental analyses, magnetic susceptibility measurements in the polycrystalline state at room temperature, i.r. spectra, electronic spectra and e.s.r. spectra recorded in polycrystalline state, in methanol solution at room temperature and at 77 K. All the complexes are 1:1 electrolytes. The ligands coordinate via the pyridine nitrogen, imine nitrogen and thione sulphur. E.s.r. spectra and with magnetic studies suggest a spin-paired configuration for the iron(III) complexes.Author to whom all correspondence should be directed     

Copper(II) complexes of N(4)-substituted thiosemicarbazones derived from pyridine-2-carbaldehyde: Crystal structure of a binuclear complex

Ten copper(II) complexes {[CuL¹Cl] (1), [CuL¹NO₃]₂ (2), [CuL¹N₃]₂ · 2/3H₂O (3), [CuL¹]₂(ClO₄)₂ · 2H₂O (4), [CuL²Cl]₂ (5), [CuL²N₃] (6), [Cu(HL²)SO₄]₂ · 4H₂O (7), [Cu(HL²)₂] (ClO₄)₂ · 1/2EtOH (8), [CuL³Cl]₂ (9), [CuL³NCS] · 1/2H₂O (10)} of three NNS donor thiosemicarbazone ligands {pyridine-2-carbaldehyde-N(4)-p-methoxyphenyl thiosemicarbazone [HL¹], pyridine-2-carbaldehyde-N(4)-2-phenethyl thiosemicarbazone [HL²] and pyridine-2-carbaldehyde N(4)-(methyl), N(4)-(phenyl) thiosemicarbazone [HL³]} were synthesized and physico-chemically characterized. The crystal structure of compound 9 has been determined by X-ray diffraction studies and is found that the dimer consists of two square pyramidal Cu(II) centers linked by two chlorine atoms.     

Structural and spectral studies of nickel(II) complexes with N(4),N(4)-(butane-1,4-diyl) thiosemicarbazones

Nickel(II) complexes of quinoline-2-carbaldehyde N(4),N(4)-(butane-1,4-diyl) thiosemicarbazone (HL¹) and 2-benzoylpyridine N(4),N(4)-(butane-1,4-diyl) thiosemicarbazone (HL²) have been synthesized and physico-chemically characterized by means of partial elemental analyses, molar conductance measurements, magnetic measurements, electronic and infrared spectral studies. Three complexes were given the formulae [Ni(HL¹)₂]Cl₂ (1), [Ni(HL²)L²]ClO₄ · 7H₂O (2) and [NiL²Cl] · 0.5H₂O (3). The structure of compound 1 has been solved by single crystal X-ray crystallography and is found to be distorted octahedral. Compound 2, when crystallized in DMSO solution, got deprotonated to form a new compound [Ni(L²)₂] (2a), with a distorted octahedral Ni(II) center. In compound 1, HL¹ coordinates to the metal in the thione form, while in compounds 2a and 3, HL² coordinates in its deprotonated thiolate form.     

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.     

Structural and spectral studies on manganese(II) complexes of di-2-pyridyl ketone N(4)-methyl and N(4)-ethyl thiosemicarbazones

Four manganese(II) complexes of di-2-pyridyl ketone N(4)-methyl (HDpyMeTsc) and N(4)-ethyl thiosemicarbazones (HDpyETsc) were synthesized and physico-chemically characterized by means of partial elemental analyses, molar conductance measurements, electronic, infrared and EPR spectral studies. The complexes are represented as [Mn(DpyMeTsc)₂] (1), [Mn(HDpyMeTsc)Cl₂] (2), [Mn(HDpyMeTsc)₂](ClO₄)₂ · H₂O (3) and [Mn(DpyETsc)₂] · 2H₂O (4). The crystal structure of [Mn(DpyMeTsc)₂] was established by single crystal X-ray diffraction studies. The compound crystallizes into a monoclinic lattice with P2₁/n space group. Manganese(II) exists in a distorted octahedral geometry in the complex.     

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.