Cobalt(II), nickel(II) and copper(II) complexes of some o-hydroxycrotonophenones

1980 ◽  
Vol 33 (4) ◽  
pp. 729 ◽  
Author(s):  
M Palaniandavar ◽  
C Natarajan
Keyword(s):  
High Spin ◽  
Metal Ion ◽  
Magnetic Measurements ◽  
Thermal Studies ◽  
Ligand Field ◽  
Square Planar ◽  
Infrared Studies ◽  
Stabilization Energies ◽  
Back Bonding ◽  
High Ligand

Metal(II) complexes of the type ML2,nB [M = CuII, NiII, CoII; L = 2- hydroxy-5-X-crotonophenone where X = H, CH3, Cl; B = H2O, pyridine; n = 0, 1, 2] have been obtained and investigated. With the help of element analyses, magnetic measurements, ligand field and infrared spectra and thermal studies, the structure and the nature of bonding have been established. The anhydrous copper(II) chelates are monomeric and possess trans-square-planar configuration while the corresponding cobalt(II) and nickel(II) compounds are polymeric and possess high-spin trans-octahedral configuration. All the base adducts possess high-spin trans-octahedral structure with lesser tendency toward dissociation in solution. Infrared studies indicate that v(C=O) and v(M-O) are affected by metal ion and phenyl substitutions and adduct formation. The order of stabilities, namely Cu > Ni > Co, derived from v(M-O) parallels the crystal field stabilization energies. Substitution in the phenyl ring of the complexes produces shifts in v(M-O) which are related to the resonance capacities of the substituents. ��� The relatively high ligand field strength of o-hydroxycrotonophenone compared to salicylaldehyde is attributed to the conjugation of C=O with C=C which lowers the energy of the π3* orbital leading to extensive back-bonding with dπ orbitals of the metal.

Cobalt(II), nickel(II) and copper(II) complexes of some 2'-hydroxychalcones

1980 ◽  
Vol 33 (4) ◽  
pp. 737 ◽  
Author(s):  
M Palaniandavar ◽  
C Natarajan
Keyword(s):  
Infrared Spectra ◽  
Metal Ion ◽  
Magnetic Moments ◽  
Phenyl Group ◽  
Ligand Field ◽  
Square Planar ◽  
Spin Pairing ◽  
Square Configuration ◽  
Electron Sink ◽  
Octahedral Configuration

Metal(II) bis-chelates of the type ML2 [M = CoII, NiII, CuII; L = 2'- hydroxy-5'-X-chalcone where X = H, CH3, Cl] have been prepared and studied. Structures have been assessed by the measurement of magnetic moments, ligand field and infrared spectra and thermal properties. These chelates possess low-spin trans-square-planar configuration and show resistance to adduct formation in contrast to metal(II) chelates of β-diketones, salicylaldehyde, o-hydroxyaryl ketones and esters and o-hydroxy-crotonophenones, which have high-spin octahedral configuration. Extensive conjugation lowers the energy of the π3* orbital which enters into a very strong dπ-π3* interaction leading to spin-pairing. ��� Infrared spectra indicate that the carbonyl group is perturbed only slightly by coordination to metal. A change in metal ion affects v(C=O), v(M-O) and other vibrations and the order of stability, namely, Co ≈ Ni < Cu, inferred from these vibrations is as expected for the low-spin square configuration of the chelates. Introduction of substituents (5'-X) alters only v(M-O) significantly and the order of stability, namely, Cl > CH3 > H, derived from v(M-O) is consistent with Taft's resonance polar parameters of the substituents. All these observations are explained by the electron sink property of the phenyl group.

Fluorinated Alkoxides. Part VIII. Mixed Ligand Complexes of Perfluoropinacol with Ni2+, Pd2+, Pt2+ and Cu2+. Solvation Equilibria between 4- and 5-coordinate Ni2+

1975 ◽  
Vol 53 (6) ◽  
pp. 809-816 ◽  
Author(s):  
W. Stafford Cripps ◽  
Christopher J. Willis
Keyword(s):  
Metal Ion ◽  
Nickel Complexes ◽  
Mixed Ligand ◽  
Ligand Field ◽  
Electronic Effects ◽  
Unusual Behavior ◽  
Planar Structures ◽  
Square Planar ◽  
Phosphorus Containing ◽  
Fluorinated Alkoxides

Perfluoropinacol, (CF3)2C(OH)C(OH)(CF3)2, ionizes by loss of two protons, and the resulting dinegative ion (PFP2−) chelates to Ni2+, Pd2+, Pt2+, and Cu2+. A variety of stable neutral complexes may be isolated if the tetracoordination of the metal ion is completed with two monodentate or one bidentate nitrogen- or phosphorus-containing ligands; square-planar structures are invariably found. The structures of these complexes are contrasted with those of analogous halides, and it is concluded that electronic effects are predominant in determining them, although steric influences may sometimes be important. The ligand field strength of the perfluoropinacolato ion is approximately equal to that of the thiocyanate ion.The nickel complexes Ni(PFP)22− and (PFP)Ni(RNHCH2CH2NHR) react with donor solvents (water, methanol, pyridine, etc.) to give equilibria between four- and five-coordinate solvated species; six-coordinate species are not observed. This unusual behavior is attributed to the steric hindrance imposed by the bulk of the PFP2− ligand.

scholarly journals Complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with ligand formed by condensation reaction of isatin with glutamic acid

2020 ◽  
Vol 45 (3) ◽  
pp. 12-27
Author(s):  
Wiesława Ferenc ◽  
Dariusz Osypiuk ◽  
Jan Sarzyński ◽  
Halina Głuchowska
Keyword(s):  
Glutamic Acid ◽  
Metal Ion ◽  
Magnetic Measurements ◽  
Condensation Reaction ◽  
Chemical Properties ◽  
Ligand Field ◽  
Decomposition Products ◽  
Carboxylate Groups ◽  
Physico Chemical ◽  
Crystalline Forms

The complexes of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with ligand (H2L=C13H12N2O5) formed by condensation reaction of isatin and glutamic acid were synthesized. Their physico-chemical properties were characterized using elemental analysis, XRF, XRD, FTIR, TG–DSC and TG–FTIR methods and magnetic measurements (Gouy’s and SQUID-VSM methods). The complexes were obtained in crystalline forms (monoclinic or triclinic) with the formulae: M(LH)2·nH2O for Mn(II), Ni(II) and Zn(II) and ML·nH2O for Co(II) and Cu(II), where LH=C13H11N2O5–, L-=C13H10N2O52–, n = 1 for Mn(II), Cu(II) and Zn(II), n = 2 for Co(II) and n = 3 for Ni(II). In air at 293–1173 K they decompose in three steps forming finally the oxides of the appropriate metals. The gaseous decomposition products were identified as: H2O, CO2, CO, hydrocarbons and N2O. The magnetic moment values for complexes (except Zn(II) complex) show their paramagnetic properties with the ferro- and antiferromagnetic interactions between central ions. The compounds of Mn(II) and Co(II) are high spin complexes with weak ligand field. In Co(II) and Cu(II) complexes two carboxylate groups take part in the metal ion coordination while in those of Mn(II), Ni(II) and Zn(II) only one carboxylate anion coordinates to central ion.

scholarly journals The First Metal Complexes of 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione: Preparation, Physical and Spectroscopic Studies, and Preliminary Antimicrobial Properties

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Sahar I. Mostafa ◽  
Constantina Papatriantafyllopoulou ◽  
Spyros P. Perlepes ◽  
Nick Hadjiliadis
Keyword(s):  
Metal Ion ◽  
Room Temperature ◽  
Free Ligand ◽  
Antimicrobial Properties ◽  
Spectroscopic Studies ◽  
Ligand Field ◽  
Square Planar ◽  
Elemental Analyses ◽  
Bidentate Chelate

The new complexes[M2O5L2(H2O)2]⋅H2O (M=Mo,1;M=W,2),[RuL2(H2O)2]⋅H2O (3),[ML3]⋅xH2O (M=Rh,x=2,4;M=Ir,x=1,5),[RhL2(PPh3)2](ClO4)⋅2H2O (6),[PdL2]⋅2H2O (7),[PdL(phen)]Cl⋅H2O (8),[Re⁡OL2(PPh3)]Cl (9)and[UO2L2] (10)are reported, where LH is 4,6-diamino-1-hydro-5-hydroxy-pyrimidine-2-thione. The complexes were characterized by elemental analyses, physical techniques (molar conductivity, room-temperature magnetic susceptibility), and spectroscopic (IR, Raman, UV/VIS/ligand field, NMR, mass) methods. The ligandL−is in its thione form and behaves as a bidentate chelate with the deprotonated (hydroxyl) oxygen and the nitrogen of one amino group as donor atoms. Oxobridged dinuclear(1, 2)and various mononuclear(3–10)structures are assigned for the complexes in the solid state. The metal ion coordination geometries are octahedral(1–6, 9, 10)or square planar(7, 8). The free ligand LH and complexes1,4,7, and8were assayed in vitro for antimicrobial activity against two bacterial and two fungal cultures.

Structure of the complexes of ethylenediphosphinetetraacetic acid in solution

1985 ◽  
Vol 50 (2) ◽  
pp. 445-453 ◽  
Author(s):  
Jana Podlahová ◽  
Josef Šilha ◽  
Jaroslav Podlaha
Keyword(s):  
Metal Ion ◽  
Carboxyl Groups ◽  
Complex Solution ◽  
Square Planar ◽  
Weak Complexes ◽  
Carboxylic Groups ◽  
Uv Visible ◽  
The Stability ◽  
Tetrahedral Complexes ◽  
Free Carboxyl

Ethylenediphosphinetetraacetic acid is bonded to metal ions in aqueous solutions in four ways, depending on the type of metal ion: 1) through an ionic bond of the carboxylic groups to form weak complexes with a metal:ligand ratio of 1 : 1 (Ca(II), Mn(II), Zn(II), Pb(II), La(III)); 2) through type 1) bond with contributions from weak interaction with the phosphorus (Cd(II)); 3) through coordination of the ligand as a monodentate P-donor with the free carboxyl groups with formation of 2 : 1 and 1 : 1 complexes (Cu(I), Ag(I)); 4) through formation of square planar or, for Hg(II), tetrahedral complexes with a ratio of 1 : 2 with the ligand as a bidentate PP-donor with the free carboxyl groups (Fe(II), Co(II), Ni(II), Pd(II), Pt(II)). On acidification of the complex solution, the first two protons are bonded to the carboxyl groups. The behaviour during further protonation depends on the type of complex: in complexes of types 1) and 2) phosphorus is protonated and the complex dissociates; in complexes of types 3) and 4) the free carboxyl groups are protonated and the phosphorus-metal bond remains intact. The results are based on correlation of the stability constants, UV-visible, infrared, 1H and 31P NMR spectra and magnetic susceptibilities of the complexes in aqueous solution.

Interaction of ditertiary phosphines with phenyl- and 1-naphthyldithiocarbamatonickel(II)

1985 ◽  
Vol 50 (6) ◽  
pp. 1383-1390
Author(s):  
Aref A. M. Aly ◽  
Ahmed A. Mohamed ◽  
Mahmoud A. Mousa ◽  
Mohamed El-Shabasy
Keyword(s):  
Thermal Analysis ◽  
Powder Diffraction ◽  
Spin Structure ◽  
Magnetic Measurements ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
X Ray ◽  
Square Planar

The synthesis of the following mixed ligand complexes is reported: [Ni(phdtc)2(dpm)2], [Ni(phdtc)2(dpe)2], [Ni(phdtc)2(dpp)3], [Ni(1-naphdtc)2(dpm)2], [Ni(1-naphdtc)2], and [Ni(1-naphdtc)2(dpp)2], where phdtc = PhNHCSS-, 1-naphdtc = 1-NaPhNHCSS-, dpm = Ph2PCH2PPh2, dpe = Ph2P(CH2)2PPh2, and dpp = Ph2P(CH2)3PPh2. The complexes are characterised by microanalysis, IR and UV-Vis spectra, magnetic measurements, conductivity, X-ray powder diffraction, and thermal analysis. All the mixed ligand complexes are diamagnetic, and thus a square-planar or square-pyramidal (low-spin) structure was proposed for the present complexes.

scholarly journals Crystal structures of [Mn(bdc)(Hspar)2(H2O)0.25]·2H2O containing MnO6+1capped trigonal prisms and [Cu(Hspar)2](bdc)·2H2O containing CuO4squares (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate)

2016 ◽  
Vol 72 (1) ◽  
pp. 96-101
Author(s):  
Zhe An ◽  
Jing Gao ◽  
William T. A. Harrison
Keyword(s):  
Hydrogen Bonds ◽  
Water Molecule ◽  
Crystal Structures ◽  
Metal Ion ◽  
Three Dimensional ◽  
Trigonal Prism ◽  
Planar Geometry ◽  
Cationic Complex ◽  
Counter Ion ◽  
Square Planar

The syntheses and crystal structures of 0.25-aqua(benzene-1,4-dicarboxylato-κ2O,O′)bis(sparfloxacin-κ2O,O′)manganese(II) dihydrate, [Mn(C8H4O4)(C19H22F2N4O3)2(H2O)0.25]·2H2O or [Mn(bdc)(Hspar)2(H2O)0.25]·2H2O, (I), and bis(sparfloxacin-κ2O,O′)copper(II) benzene-1,4-dicarboxylate dihydrate, [Cu(C19H22F2N4O3)2](C8H4O4)·2H2O or [Cu(Hspar)2](bdc)·2H2O, (II), are reported (Hspar = sparfloxacin and bdc = benzene-1,4-dicarboxylate). The Mn2+ion in (I) is coordinated by twoO,O′-bidentate Hspar neutral molecules (which exist as zwitterions) and anO,O′-bidentate bdc dianion to generate a distorted MnO6trigonal prism. A very long bond [2.580 (12) Å] from the Mn2+ion to a 0.25-occupied water molecule projects through a square face of the prism. In (II), the Cu2+ion lies on a crystallographic inversion centre and a CuO4square-planar geometry arises from its coordination by twoO,O′-bidentate Hspar molecules. The bdc dianion acts as a counter-ion to the cationic complex and does not bond to the metal ion. The Hspar ligands in both (I) and (II) feature intramolecular N—H...O hydrogen bonds, which closeS(6) rings. In the crystals of both (I) and (II), the components are linked by N—H...O, O—H...O and C—H...O hydrogen bonds, generating three-dimensional networks.

Novel Inorganic Hydrogels Based on The Polymerization of Cyanometalate Transition Metal Complexes With [PdCl4]2-: A New Approach To Ceramic And Alloy Precursors

1994 ◽  
Vol 346 ◽  
Author(s):  
Andrew B. Bocarsly ◽  
Gireesh Kumar ◽  
Marija Heibel
Keyword(s):  
Transition Metal ◽  
Metal Ion ◽  
Sol Gel ◽  
Metallic Matrix ◽  
Linear Polymers ◽  
New Approach ◽  
Square Planar ◽  
Delafossite Structure ◽  
Cyanide Ligand ◽  
Sol Gel Transition

ABSTRACTThe reaction of a wide variety of cyanometalate complexes of the general form [M(CN)x]n- (where M= a transition metal ion) with square planar [PdCl4]2- in aqueous solution leads to the formation of linear polymers. Polymerization occurs via substitution of chloride ligands on the Pd(II) centers, by the nitrogen end of the cyanide ligand to generate extended bridging cyanide structures. Upon generation at room temperature polymer solutions of this type under go a sol-gel transition to generate robust hydrogels having water content in excess of 95%. In the case of the cyanocobaltate/tetrachloropalladate gel, pyrolysis at 900°C produces ferromagnetic Pd/Co metallic alloys having novel morphological character. Materials formed with a hydrogel having a 2:1 Pd to Co stoichiometry are found to be “sponge-like”. When placed in water, the metallic matrix swells becoming pliable and holding up to seven equivalents of water per metal site. The conductivity and magnetic properties of this material are maintained in the swollen state. Sintering of the Pd/Co hydrogel in air generates the layered oxide, PbCoO2 having a delafossite structure.

scholarly journals Ni(II) Dimers of NNO Donor Tridentate Reduced Schiff Base Ligands as Alkali Metal Ion Capturing Agents: Syntheses, Crystal Structures and Magnetic Properties

2018 ◽  
Vol 4 (4) ◽  
pp. 51 ◽  
Author(s):  
Monotosh Mondal ◽  
Maharudra Chakraborty ◽  
Michael G. B. Drew ◽  
Ashutosh Ghosh
Keyword(s):  
Schiff Base ◽  
Metal Ion ◽  
Magnetic Measurements ◽  
Dft Method ◽  
Distorted Octahedral Geometry ◽  
Schiff Base Ligands ◽  
Reduced Schiff Base ◽  
Ferromagnetic Interactions ◽  
Experimental Values ◽  
Reduced Schiff Base Ligands

Three trinuclear Ni(II)-Na(I) complexes,[Ni2(L1)2NaCl3(H2O)]·H2O (1), [Ni2(L2)2NaCl3(H2O)] (2), and [Ni2(L3)2NaCl3(OC4H10)] (3) have been synthesized using three different NNO donor tridentate reduced Schiff base ligands, HL1= 2-[(3-methylamino-propylamino)-methyl]-phenol, HL2= 2-[(3-methylamino-propylamino)-methyl]-4-chloro-phenol, and HL3= 2-[(3-methylamino-propylamino)-methyl]-6-methoxy-phenol that had been structurally characterized. Among these complexes, 1 and 2 are isostructural in which dinuclearNi(II) units act as metalloligands to bind Na(I) ions via phenoxido and chlorido bridges. The Na(I) atom is five-coordinated, and the Ni(II) atom possesses hexacordinated distorted octahedral geometry. In contrast, in complex 3, two -OMe groups from the dinuclear Ni(II) unit also coordinate to Na(I) to make its geometry heptacordinated pentagonal bipyramidal. The magnetic measurements of complexes 1–3 indicate ferromagnetic interactions between dimeric Ni(II) units with J = 3.97 cm−1, 4.66 cm−1, and 5.50 cm−1for 1–3, respectively, as is expected from their low phenoxido bridging angles (89.32°, 89.39°, and 87.32° for 1–3, respectively). The J values have been calculated by broken symmetry DFT method and found to be in good agreement with the experimental values.

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