New iron (III) complexes of S-methyl-βN-(5-methylpyrazole-3-yl) methylenedithiocarbazate, S-benzyl-β-N-β-(5-methylpyrazole-3-yl) methylenedithiocarbazate, 5-methyl-3-formylpyrazole-3- pyrrolidinylthiosemicarbazone, and 5-methyl-3-formylpyrazole- 4N-benzylthiosemicarbazone have been synthesized and physicochemically characterized by elemental analyses, magnetic moment measurements (polycrystalline state), electronic, IR, and EPR spectra, as well as conductance measurements, are used to confirm the coordination geometry. The spectral studies reveal the low-spin distorted octahedral structure of the iron (III) complexes containing two uninegative tridentate ligands with NNS donor sites, where the EPR data confirm the presence of a spin - paired iron (III) with d xz 2 d yz 2 d xy 1 configuration in the ground state. © 2009 Pleiades Publishing, Ltd.

I C BAEK

S I SEOK

N SAHA

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

&nbsp;

The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

&nbsp;

It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Synthesis and spectroscopic characterization of new iron(III) complexes of S-Alkyl/Aryl dithiocarbazates of 5-methyl-3-formylpyrazole and 5-methyl-3-formylpyrazolyl-thiosemicarbazones

Russian Journal of Coordination Chemistry/Koordinatsionnaya Khimiya

Two new pyrimidine based NNS tridentate Schiff base ligands S-methyl-3-((2-S-methyl-6-methyl-4-pyrimidyl)methyl)dithiocarbazate [HL1] and S-benzyl-3-((2-S-methyl-6-methyl-4-pyrimidyl)methyl)dithiocarbazate [HL2] have been synthesised by the 1:1 condensation of 2-S-methylmercapto-6-methylpyrimidine-4-carbaldehyde and S-methyl/S-benzyl dithiocarbazate. A Ni(II) complex of HL1 and Co(III) and Fe(III) complexes of HL2 have been prepared and characterized by elemental analyses, molar conductivities, magnetic susceptibilities and spectroscopic studies. All the bis-chelate complexes have a distorted octahedral arrangement with an N4S2 chromophore around the central metal ion. Each ligand molecule binds the metal ion using the pyrimidyl and azomethine nitrogen and thiolato sulfur atoms (except in the nickel complex, one ligand molecule uses the thione sulfur in lieu of thiolato sulfur atom). In the Ni(II) complex, one of the ligand molecules behaves as a neutral tridentate and the other molecule functions as a uninegative tridentate, whereas in the Co(III) and Fe(III) complexes, the ligand molecules behave as monoanionic tridentate. All the complexes were analyzed by single crystal X-ray diffraction and significant differences concerning the distortion from an octahedral geometry of the coordination environment were observed. © 2007 Elsevier Ltd. All rights reserved.

Polyhedron

Metal complexes of pyrimidine derived ligands - Syntheses, characterization and X-ray crystal structures of Ni(II), Co(III) and Fe(III) complexes of Schiff base ligands derived from S-methyl/S-benzyl dithiocarbazate and 2-S-methylmercapto-6-methylpyrimidi

New iron(III) complexes of 5-methyl-3-formylpyrazole 3- hexamethyleneiminylthiosemicarbazone (HMPz3Hex), [Fe(MPz3Hex)2]X • nH2O (where X = Cl, NO3or ClO4 and n = 1-2) have been synthesized and physico-chemically characterized by magnetic data (polycrystalline state), electronic, i.r. and e.p.r. spectral studies. The reported complexes are all cationic electrolytes (1:1) containing two moles of monodeprotonated title ligand and an anionic counterpart. I.r. spectra (4000-200 cm-1) indicate coordination to the central iron(III) ion via the pyrazolyl (tertiary) ring nitrogen, azomethine nitrogen and thiolato sulphur atoms of the primary ligand molecule. E.p.r. data (r.t. and l.n.t.) show the presence of a low-spin iron(III) cation with d xz 2 d xz 2 d xz 1 configuration. Cyclic voltammograms of iron(III) complexes indicate a reversible Fe +3/Fe+2 couple. X-ray data of [Fe(MPz3Hex) 2]ClO4 • 2H2O (P1, triclinic) authenticate a FeN4S2 distorted octahedral coordination with the two azomethine nitrogens trans to each other; the pyrazolyl nitrogens and thiolato sulphurs are in cis-positions, indicating an unusual rotation about the azomethine (C=N) double bond of the free HMPz3Hex during complexation with iron(III). © Springer 2005.

Transition Metal Chemistry

Synthesis, spectroscopy and cyclic voltammetry of new iron(III) complexes with 5-methyl-3-formyl pyrazole 3-hexamethyleneiminyl thiosemicarbazone (HMPz3Hex): X-ray crystallographic identification of [Fe(MPz3Hex) 2]ClO4 Â· 2H2O with an indication for unusu

Two new cobalt(III) complexes with S-benzyl-β-N-(5-methylpyrazole-3-yl)methylenedithiocarbazate (H2L), [Co(HL)2]NO3·EtOH (1) and [Co(HL)(L)]·H2O (2), have been synthesised and characterised using single-crystal X-ray diffraction and spectroscopic (electronic, IR and NMR) techniques. The structure of 1 consists of [Co(HL)2]+ cation and NO3-anion linked by an ethanol solvent molecule, that of 2 consists of neutral monomeric species [Co(HL)(L)] with one mole water of crystallisation where the two ligand molecules are uniquely non-equivalent. In both the complexes the coordination geometry about cobalt is distorted octahedral and the two ligands are in the mer configuration (S and tertiary N atom cis to each other and the iminic N atoms trans). © 2002 Elsevier Science Ltd. All rights reserved.

Synthesis and spectroscopic characterisation of cobalt(III) complexes with S-benzyl-Î²-N-(5-methylpyrazole-3-yl)methylenedithiocarbazate (H 2 L): X-ray structures of [Co(HL) 2 ]NO 3 Â·EtOH (1) and [Co(HL)(L)]Â·H 2 O (2)

New iron(III) complexes of 5-methyl-3-formylpyrazole-N(4)-dipropylthiosemicarbazone (HMPzNPr2) and 5-methyl-3-formylpyrazole-N(4)-dibutylthiosemicarbazone (HMPzNBut2), [Fe(MPzNPr2)2]NO3·H 2O (I) and [Fe(MPzNBut2)2]ClO4·H 2O (II), respectively, have been synthesised for the first time and physico-chemically characterised by magnetic measurements (polycrystalline state), electronic, IR and EPR spectra. Both are cationic complexes containing two monodeprotonated tridentate ligands with NNS donor sites and an anionic counterpart; the complex species behave as 1:1 electrolytes in MeOH. IR spectra (4000-200 cm-1) indicate the co-ordination to central iron(III) via the pyrazolyl (tertiary) ring nitrogen, azomethine nitrogen and thiolato sulphur atom. EPR data (RT and LNT) reveal the presence of a spin-paired iron(III) cation with d2xz d2yz d1xy configuration. X-ray crystallographic data of I and II (both P1̄, triclinic) have authenticated a FeN4S2 octahedral co-ordination in both the complex ions, as envisaged from spectral data. In both species, the two azomethine nitrogen atoms are trans to each other, while the pyrazolyl ring nitrogen atoms and the thiolato sulphurs are in cis positions. © 2002 Elsevier Science B.V. All rights reserved.

Inorganica Chimica Acta

Synthesis and structural characterisation of new iron(III) complexes with biologically relevant pyrazolyl thiosemicarbazones

New iron(III) complexes of 5-methyl-3-formylpyrazole thiosemicarbazone (HMPzTS) and 5-methyl-3-formylpyrazole-4-phenylthiosemicarbazone (HMPzPTS), namely [Fe(MPzTS)2]X and [Fe(MPzPTS)2]X respectively, where X = Cl, NO3, SCN and ClO4, have been synthesised and physico-chemically characterised by magnetic measurements (polycrystalline state), electronic, i.r., e.s.r. and Mössbauer spectra. All are cationic complexes containing two monoprotonic tridentate ligands with NNS donor sites and an anionic counterpart; they behave as 1:1 electrolytes in MeOH/DMF. Coordination to central iron(III) via the pyrazolyl nitrogen (2N), the azomethine nitrogen and the thiolato sulphur atom is confirmed in the complexes from i.r. data. E.s.r. data (RT &amp; LNT) reveal the presence of a spin-paired iron(III) cation with d2xyd2yzd1xy configuration. The 57Fe Mössbauer spectral data (RT) are commensurate with the presence of two iron(III) spin states, the percentage of each being dependent upon the counterion of the species.

Journal	Russian Journal of Coordination Chemistry/Koordinatsionnaya Khimiya
Publisher	PLEIADES PUBLISHING INC
ISSN	1070-3284