Mononuclear Mn(III) and dinuclear Mn(III,III) Schiff base complexes: Influence of π–π stacking on magnetic properties
Abstract Synthesis of a mononuclear Mn(III) (1) and a dinuclear Mn(III, III) (2) complex of a tetradentate N2O2 donor Schiff base ligand with ancillary carboxylate ligands are reported. Complex 1 crystallizes in the monoclinic space group C2/c, complex 2 in the triclinic space group P-1. In both complexes the central Mn(III) ions are hexacoordinated having a distorted octahedral MnN2O4 coordination environment. Intermolecular hydrogen bonding and strong π–π stacking in both 1 and 2 leads to dimerization of 1 and formation of a syn–anti one-dimensional chain for 2. Magnetic properties of 1 and 2 are reported. Both complexes show very weak intermolecular antiferromagnetic interaction. Most in…
Synthesis, structural characterization and electrochemical activity of oxidovanadium(IV/V) complexes of a diprotic ONS chelating ligand
Abstract The present work reports the chemistry of a few oxidovanadium(IV) and (V) complexes of the ONS chelating ligand S-benzyl-β-N-(2-hydroxyphenylethylidine) dithiocarbazate (H2L). Major objective of this work is to arrive at some general conclusions about the influence of binding environment generated by the replacement of an O-donor center by a S-donor point in a ligand (of a similar arrangement of the other O- and N-donor points) on the redox behavior and on the structural features of comparable [VO(OEt)(ONS)] and [VO(OEt)(ONO)] complexes. Synthesis, characterization by various physicochemical techniques (UV–Vis, IR, EPR and elemental analysis), exploration of electrochemical activit…
A novel Cu(II) dimer containing oxime-hydrazone Schiff base ligands with an unusual mode of coordination: Study of magnetic, autoreduction and solution properties
Abstract Synthesis of a new hydrazone based Schiff base ligand, 3-methylpyrazole-5-carbohydrazone of 2,3-butanedione monoxime (HL) is reported. The reaction of Cu(ClO4)2·6H2O with HL in any ratio in ethanol affords the dinuclear complex [CuL(EtOH)]2(ClO4)2·2H2O (1). An unusual coordination mode of the ligand was observed, in which the ligand forms stable six and five membered chelate rings around the metal centres without enolization of the carbonyl group of the hydrazone moiety. The same coordination behavior of the ligand was observed in its cobalt(III) complex. The reaction of CoCl2·6H2O in methanol with the ligand HL affords the mononuclear complex [CoL2]Cl (2). Both 1 and 2 were charac…
2-Amino-2-methyl-1,3-propanediol (ampdH2) as ligand backbone for the synthesis of cobalt complexes: Mononuclear Co(II), binuclear Co(II,III) and hexanuclear Co(II,III)
Abstract Three cobalt complexes have been synthesized using 2-amino-2-methyl-1,3-propanediol (ampdH2) and its Schiff base derivative ligands and structurally characterized. The three complexes 1, 2 and 3 are very different and consist of mononuclear Co(II), mixed-valence binuclear Co(II,III) and mixed-valence hexanuclear Co(II,III) complexes respectively. The properties of the coordinated donor atoms of the ligand play the predominant role in stabilizing the oxidation states of the cobalt centers. The presence of intermolecular hydrogen bonds in 1 via non-coordinating perchlorate ions lead to the formation of a 1D-Chain network while a sheet-like 2D network was observed in 3.
A Discrete μ 4 ‐Oxido Tetranuclear Iron(III) Cluster
Reaction of a Schiff base ligand derived from salicyloyl hydrazide and diacetyl monooxime (H2L) with a triangular μ3-oxido-centered [Fe3(μ3-O)]7+ core yields a new tetranuclear iron(III) complex. FeIII4(μ4-O) crystallizes in the triclinic space group P. Structural studies reveal that this tetranuclear iron(III) complex is a new structure type of an uncharged (alkoxido)(oxido)iron(III) cluster in which the four iron(III) ions are located at the corners of a distorted tetrahedron. A study of the magnetic properties supports the presence of antiferromagnetic interactions through the central μ4-oxido ion as well as the μ2-methoxy groups present, giving an an S = 0 ground state. Mossbauer spectr…
Mononuclear and tetranuclear Fe(III) complexes with two different types of N, O donor Schiff base ligands
Abstract A mononuclear Fe(III) complex of a tetradentate N 2 O 2 donor Schiff base ligand derived from 3-ethoxysalicaldehyde and ethylenediamine has been reported. In addition two tetranuclear Fe(III) complexes with discrete Fe 4 III (μ 4 -O) cores have been synthesized and characterized using two Schiff base ligands (H 2 L 1–2 ) derived from two different aromatic acid hydrazides and diacetyl monoxime. The mononuclear Fe(III) and one of the tetranuclear Fe(III) complexes have been structurally characterized by single-crystal X-ray crystallography. The mononuclear complex has a highly distorted octahedral geometry. The tetranuclear Fe(III) complexes are found to be rare examples with discre…
Malonato complexes of oxidovanadium(IV): Synthesis, structural characterization and exploration of their insulin mimetic properties
Abstract Several bis-malonatooxidovanadium(IV) complexes of the general type [M2(H2O)n][VO(mal)2(H2O)] (where M = Li(1), Na(2), K(3), Cs(4) and NH4(5); n = 3.5, 1, 3, 1 and 1, respectively) were isolated in good yield and high purity. These complexes were fully characterized by various physicochemical techniques (elemental analysis, UV–Vis, IR, EPR, CV, etc.) complexes 1, 2 and 3 were structurally characterized by single crystal X-ray diffraction technique. In vivo antidiabetic properties of bis-malonato complexes 1, 2, 3 and 5 have been studied using Streptozotocin induced diabetic rats. Significant lowering of blood sugar level has been noticed. At the same time these complexes were found…
Coordination versatility of 1,5-bis(salicylidene)carbohydrazide in Ni(II) complexes
Abstract Versatile coordination behavior of a polydentate Schiff base ligand 1,5-bis(salicylidene)carbohydrazide (H3bsc) has been explored in Ni(II) complexes. [Ni(H3bsc)2](ClO4)2 (1)·H2O·3CH3CN is a bis chelate mononuclear complex of H3bsc in keto form, and [Ni4(H0.5bsc)2(O2CCMe3)3(CH3OH)4](2)·2H2O·2CH3OH is a tetranuclear complex of H3bsc with an unusual coordination. In 2, one phenolate group of the ligand coordinates in a monodentate way and the other coordinates in a μ2-bridging mode to the Ni(II) center. This unusual coordination mode of the ligand stabilizes the Ni(II) complex in a tetranuclear form where the carbonyl oxygen of the ligand exists in between keto and enol form of bond …
CCDC 766437: Experimental Crystal Structure Determination
Related Article: Manas Sutradhar, Tannistha Roy Barman, Gurunath Mukherjee, Manoj Kar, Sourya Sekhar Saha, Michael G.B. Drew, Saktiprosad Ghosh|2011|Inorg.Chim.Acta|368|13|doi:10.1016/j.ica.2010.12.018
CCDC 766438: Experimental Crystal Structure Determination
Related Article: Manas Sutradhar, Tannistha Roy Barman, Gurunath Mukherjee, Manoj Kar, Sourya Sekhar Saha, Michael G.B. Drew, Saktiprosad Ghosh|2011|Inorg.Chim.Acta|368|13|doi:10.1016/j.ica.2010.12.018
CCDC 816865: Experimental Crystal Structure Determination
Related Article: Manas Sutradhar, Tannistha Roy Barman, Eva Rentschler|2014|Inorg.Chem.Commun.|39|140|doi:10.1016/j.inoche.2013.11.018
CCDC 766436: Experimental Crystal Structure Determination
Related Article: Manas Sutradhar, Tannistha Roy Barman, Gurunath Mukherjee, Manoj Kar, Sourya Sekhar Saha, Michael G.B. Drew, Saktiprosad Ghosh|2011|Inorg.Chim.Acta|368|13|doi:10.1016/j.ica.2010.12.018
CCDC 816864: Experimental Crystal Structure Determination
Related Article: Manas Sutradhar, Tannistha Roy Barman, Eva Rentschler|2014|Inorg.Chem.Commun.|39|140|doi:10.1016/j.inoche.2013.11.018
CCDC 919439: Experimental Crystal Structure Determination
Related Article: Manas Sutradhar, Tannistha Roy Barman, Michael G.B. Drew, Eva Rentschler|2013|J.Mol.Struct.|1041|44|doi:10.1016/j.molstruc.2013.02.035
CCDC 919440: Experimental Crystal Structure Determination
Related Article: Manas Sutradhar, Tannistha Roy Barman, Michael G.B. Drew, Eva Rentschler|2013|J.Mol.Struct.|1041|44|doi:10.1016/j.molstruc.2013.02.035