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     

On the role of polarizability in chemical-biological interactions

This report considers the importance of electronic effects in their role in the QSAR of chemical-biological interactions. The problem of accounting for polarizability effects in ligand-substrate interactions is discussed in terms of molecular polarizability (MR) and NVE (number of valence electrons) using additive values for valence electrons. The two approaches give essentially the same result in examples of frog nerve toxicity and examples of nerve toxicity with rabbits and cockroaches. The point is made that no matter how one approaches QSAR, electronic interactions must be considered if we are to begin to develop a science of chemical-biological interactions.     

Salicylaldehyde 4,4′‐(hexane‐1,6‐di­yl)­thio­semicarbazone

The title compound, C₁₄H₁₉N₃OS, is in the thio­keto form, with the thione S and hydrazine N atoms cis with respect to each other so that the S atom is involved in inter‐ and intra­molecular hydrogen bonds simultaneously. Inter­molecular C—H⋯S and C—H⋯O hydrogen bonds result in one‐dimensional polymeric chains of mol­ecules along the a axis. A weak C—H⋯π ring inter­action binds the polymeric chains together.     

Spectroscopic studies on copper(II) complexes derived from a substituted 2-acetylpyridine thiosemicarbazone

Summary Copper(II) complexes of general formula [Cu(L4A)X] (where L4A is the deprotonated ligand, 1 H-hexahydroazepine-1-thiocarboxylic acid-2-[1-(2-pyridinyl)ethylidene]hydrazide and X=Cl, Br, I, NCS, NO₃ and OAc) and [Cu(HL4A)(L4A)]ClO₄ have been prepared and characterized by elemental analyses, magnetic susceptibility measurements, i.r. spectra, electronic spectra, conductivity measurements and e.s.r. spectra in the polycrystalline state and in chloroform solution. For all complexes, except the perchlorate salt, coordination occurs via imine nitrogen, pyridine nitrogen and thione sulphur. For the perchlorate salt, L4A is tridentate, while HL4A is monodentate via imine nitrogen. Electronic spectra suggest planar geometry for all the complexes. The calculated e.s.r parameters suggest coordination through sulphur in agreement with the i.r. results.     

Structural and spectral studies of an iron(III) complex [Fe(Pranthas)2][FeCl4] derived from 2-acetylpyridine-N(4), N(4)-(butane-1, 4-diyl) thiosemicarbazone (HPranthas)

A novel iron(III) complex of 2-acetylpyridine N(4), N(4)-(butyl-1, 4-diyl) thiosemicarbazone (HPranthas), [Fe(Pranthas)₂]FeCl₄ was synthesized and physico-chemically characterized by means of partial elemental analysis, magnetic measurements (polycrystalline state), UV-Vis and IR spectroscopies. The presence of spin-paired iron(III) cation with ground state is revealed by the EPR and Mössbauer spectral data. Structure of the free ligand HPranthas and the complex [Fe(Pranthas)₂]FeCl₄ were solved by single crystal X-ray diffraction. The framework of iron(III) complex consists of a discrete monomeric cationic entity containing low spin iron(III) in a slightly distorted octahedral environment. The metal ion is bonded to one sulfur and two nitrogens of each thiosemicarbazone molecule. The tetrachloroferrate(III) ion acts as counterion.     

Transition metal complexes of 2-formylthiophene S-methyldithiocarbazate

Transition metal complexes of 2-formylthiophene S-methyldithiocarbazate have been synthesized and characterized. Analytical data show that the complexes are of the type [ML3], where M = Fe3+, and [ML2], where M=Ni2+, Cu2+ or Zn2+. The i.r. spectra suggest coordination to the metal through the azomethine nitrogen and thiolate sulfur. The magnetic and spectroscopic data indicate a square planar geometry for the complexes, except for the Fe3+ complex, which is octahedral. The e.s.r. parameters are indicative of a square planar N2S2 system for the Cu2+ complex.     

2‐Hydroxy­acetophenone 4‐phenyl­thio­semicarbazone

The title compound, C₁₅H₁₅N₃OS, exists in the thione form and adopts an E configuration about the hydrazine bond, which is in the Z form with respect to the thiocarbonyl bond. An O—H⋯N intra­molecular hydrogen bond promotes planarity in part of the mol­ecule.