Search results for "HIF"
showing 10 items of 1515 documents
A ferromagnetic methoxido-bridged Mn(III) dimer and a spin-canted metamagnetic μ(1,3)-azido-bridged chain.
2012
Two new Mn(III) complexes of formulas [MnL(1)(N(3))(OMe)](2) (1) and [MnL(2)(N(3))(2)](n) (2) have been synthesized by using two tridentate NNO-donor Schiff base ligands HL(1){(2-[(3-methylaminoethylimino)-methyl]-phenol)} and HL(2) {(2-[1-(2-dimethylaminoethylimino)methyl]phenol)}, respectively. Substitution of the H atom on the secondary amine group of the N-methyldiamine fragment of the Schiff base by a methyl group leads to a drastic structural change from a methoxido-bridged dimer (1) to a single μ(1,3)-azido-bridged 1D helical polymer (2). Both complexes were characterized by single-crystal X-ray structural analyses and variable-temperature magnetic susceptibility measurements. The ma…
Synthesis, X-ray crystal structure and magnetic study of a novel μ2-1,1-azido bridged dimeric copper(II) complex
2007
Abstract A new azido derivative of tridentate Schiff base copper(II) complex has been synthesized and characterized. X-ray single crystal structure analysis reveals that the complex [Cu2L2(N3)2(NO3)2] (1), containing 1-(N-pyridylimino)-3-aminopropane (L) as co-ligand, is a dimer in which copper(II) ions are bridged by two azido groups in end-on fashion. The coordination environment around copper(II) is distorted octahedral which is rarely observed among these types of azido bridged copper(II) dimers. Three among the four coordination sites of the basal plane of the octahedron are occupied by the nitrogen atoms of the Schiff base and the fourth site is occupied by a nitrogen atom of a μ2-1,1…
Synthesis, X-ray structure and magnetic properties of the azido adducts of quadridentate Schiff base manganese(III) complexes
2004
Abstract Two new azido derivatives of quadridentate Schiff base manganese(III) complexes have been synthesized and characterized structurally and magnetically. X-ray structure analysis revealed that both complexes viz. [Mn2(L1)2(N3)2] (1) and [Mn2(L2)2(N3)2] (2), where H2L1=N,N′-(1,1-dimethylethylene)-bis-(salicylaldiimine) and H2L2=bis(o-hydroxyacetophenone)-ethylenediimine exist as phenoxo-bridged dimer. The magnetic susceptibility of the complexes has been measured in the 5–300 K range. At room temperature the MnIII ions in complexes 1 and 2 possess an S=4 ground state. The global magnetic interaction in complex 1 is found to be ferromagnetic, while for complex 2 it is anti-ferromagnetic.
Asymmetric bis-(μ1,1-azido) bridged dinuclear copper(II) complex with N2O donor Schiff base: synthesis, structure and magnetic study
2015
A copper(II) complex, [Cu2(L)2(N3)2] [where HL = 2-((3-(methylamino)propylimino)methyl)-6-methoxyphenol] has been synthesized and characterized by elemental analysis, IR, UV–vis and fluorescence spectroscopy, and single-crystal X-ray diffraction studies. The complex crystallizes in the trigonal space group R. The deprotonated tridentate Schiff base occupies three coordination sites of copper(II). The fourth coordination site is occupied by an azide. A symmetry-related azide from a different molecule coordinates with the fifth site of copper(II), thereby forming a double end-on azide-bridged centrosymmetric dimer. Variable temperature solid–state magnetic studies between 2 and 300 K were car…
Unexplored analytics of some novel 3d–4f heterometallic Schiff base complexes
2014
Three heterometallic Schiff-base complexes of Cu having Pr, Nd and Sm as the heteroatoms have been synthesized. The compounds have also been characterized by their IR spectra and CHN analysis. The single crystal structures of these compounds have been studied from the X-ray crystallographic data. To the best of our knowledge the article describes the possibility of application of these compounds in the field of species dependent anion sensing for the first time. Amongst a number of anionic species, certain sulphur species were found to have greater reactivity towards a Schiff-base complex as they can incur probable changes in the molecular complexity. The S2O82−and S2O32− species could modi…
Mononuclear Mn(III) and dinuclear Mn(III,III) Schiff base complexes: Influence of π–π stacking on magnetic properties
2012
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…
X-ray and DFT-calculated structures of a vanadyl Schiff base complex: (methanol-κO)[2-methoxy-6-({2-[(2-oxido-3-methoxybenzylidene)amino]benzyl}imino…
2012
The central VVatom in the title mononuclear oxovanadium complex, [VO(C23H20N2O4)(CH3OH)]·H2O, has a distorted octahedral coordination. Two N atoms and two O atoms of the Schiff base define the base of the bipyramid and two O atoms are in the apical positions, one from vanadyl and the second from methanol. Density functional theory (DFT) calculations were performed for the title complex and its ligand to compare their geometry in the solid and gas phases. Additional analyses were made of the changes in the geometry of the ligand during complex formation. The HOMA (harmonic oscillator model of aromaticity) descriptor of π-electron delocalization was calculated to estimate the aromaticity of t…
Synthesis and characterization of some diorganotin(IV) complexes of Schiff bases derived from a non-protein amino acid. Crystal structures of {HO2CC6…
2008
Diorganotin(IV) complexes R2Sn(LH)2 (R = Me, nBu) and {[nBu2Sn(LH)]2O}2 (LH = 4-[(2Z)-(3-hydroxy-1-methyl-2-butenylidene)amino]benzoate and 4-[{(E)-1-(2-hydroxyphenyl)methylidene}mino]benzoate) have been reported. The complexes were characterized by elemental analysis, IR, NMR (1H, 13C, 119Sn) and 119mSn Mossbauer spectroscopy. Crystal structures of a ligand {HO2CC6H4[NC(H)}{C(CH3)CH(CH3)-3-OH]-p} and one of its di-n-butyltin(IV) complexes (nBu2Sn{O2CC6H4[NC(H)}{C(CH3)CH(CH3)-3-OH]-p}2) were determined. The spectroscopic data suggest that R2Sn(LH)2 complexes have skew-trapezoidal bipyramidal structure while {[nBu2Sn(LH)]2O}2 complexes adopt a dimeric tetraorganodistannoxane structure in the…
Investigations on organoantimony compounds XI. Triorganoantimony(V) compounds containing potentially tridentate ligands
1974
Triorganoantimony(V) compounds of the types RSbVL, in which R = Me or Ph, and L represents a potentially tridentate dianionic Schiff base ligand of the ONO or SNO type, have been synthesized and investigated by spectroscopic (UV, IR, PMR) methods. Molecular weight determinations in benzene reveal the monomeric nature of these compounds. The free ligands, HL, used in this study are:,′-(methylidynenitrilo)diphenol (HSab), -(o-hydroxyphenyl)benzothiazoline (H-Sat), -(o_hydroxyanilino)crotonophenone (HBah), 4-(o-hydroxyphenylimino)--pentanone (HAah) and -acetonyl--methylbenzothiazoline (HAat). Both the UV and the IR data suggest hexacoordinate molecular structures for the complexes RSbL in whic…
A vanadyl Schiff base complex: {2,2'-[1,1'-(o-phenylenedinitrilo)bis(ethan-1-yl-1-ylidene)]diphenolato}oxovanadium(IV).
2011
The green crystals of the title compound, [V(C(22)H(18)N(2)O(2))O], represent a mononuclear oxovanadium complex. The central V(IV) centre has a distorted square-pyramidal coordination. Two N atoms and two O atoms of the Schiff base ligand define the base of the pyramid, and the oxide O atom is in the apical position. Density functional theory (DFT) calculations were performed to analyse the changes in the geometry of the ligand during the complex formation. The most significant changes are observed in the values of the torsion angles in the vicinity of the donor N atoms. The HOMA index (Harmonic Oscillator Model of Aromaticity) has been calculated to compare the aromaticity of the benzene r…