Synthesis,structure and infrared spectral studies of some new metal (II) complexes of 3-phenyl-4-acetyl-5-isoxazolone (HPAI)

The divalent metal complexes of Mn, Co, Ni, Cu, Zn, Mg, Cd and Pb with 3-phenyl-4-acetyl-5-isoxazolone (HPAI) have been prepared for the first time. The complexes were characterized by utilising elemental analysis, conductivity measurements, i.r. and proton NMR spectroscopy. It has been shown that HPAI behaves as a bidentate ligand forming neutral metal chelates through the carbonyl and hydroxyl groups of the enolic form. The MO stretching frequencies for the transition metals show good agreement with the Irwing—Williams stability order Cu ⪢ Ni ⪢ Co ⪢ Zn ⪢ Mn.     

Extraction of ternary complexes of thorium(IV) with 3-phenyl-4-benzoyl-5-isoxazolone and neutral donors from nitric acid medium

The extraction behaviour of thorium(IV) from aqueous nitric acid employing 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) in the presence of tri-n-octyl phosphine oxide (TOPO) as well as tri-n-butyl phosphate (TBP) in xylene medium was investigated. The extraction constant (log k(ex)) for the binary organic phase species Th(PBI)(4) was determined to be 8.26 which is by far the largest amongst the corresponding values known for other beta-diketones. The overall extraction constant (log K) for the ternary species Th(PBI)(4) TBP and Th(PBI)(4).2TOPO were estimated to be 14.96 and 20.96 respectively. An inverse correlation of the adduct formation constant (log K(s)) with the pK(a) of the beta-diketones, 2-thenoyltrifluoroacetone, 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone and HPBI, was observed. The steric as well as the electronic effects of adduct formation have been discussed. Analytical application of HPBI for the separation of (234)Th radiotracer from natural uranium (99.3% (238)U) has been suggested.     

Studies on the liquid-liquid extraction of iron(III) and titanium(IV) with 3-phenyl-4-benzoyl-5-isoxazolone

The extraction behaviour of iron(III) and titanium(IV) from acidic chloride solutions has been investigated using 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) in xylene as an extractant. The results demonstrate that these metal ions are extracted into xylene as Fe(PBI)(3) and TiO(PBI)(2). The equilibrium constants of the extracted complexes have been deduced by non-linear regression analysis by taking into account complexation of metal ion with inorganic ligands in the aqueous phase and all plausible complexes extracted into the organic phase. IR and proton NMR ((1)H NMR) spectra were used to further clarify the nature of complexes extracted into organic phase. The effect of the nature of the diluent on the extraction of iron(III) and titanium(IV) has been studied and correlated with dielectric constants. The extraction behaviour of titanium(IV) has also been compared with that of other metal ions, viz. magnesium(II), vanadium(V), chromium(VI), iron(III), manganese(II), zinc(II) and zirconium(IV), which are associated with the titanium in waste chloride liquors of the titanium-mineral-processing industry.     

Synthesis, spectral, and biological studies of some metal(II) complexes with benzil salicylaldehyde acyldihydrazones

Complexes of the general formula [M(Bsodh)]Cl and [M(Bsmdh)]Cl, where M = Co(II), Ni(II), Cu(II), Zn(II,) and Cd(II) (HBsodh = benzil salicylaldehyde oxalic acid dihydrazone and HBsmdh = benzil salicylaldehyde malonic acid dihydrazone) were synthesized and characterized by elemental analyses, molar conductance, magnetic moments, electronic, ESR, infrared spectra, and X-ray diffraction studies. The complexes are stable solids insoluble in common organic solvents and 1: 1 electrolytes. The magnetic moments and electronic spectra reveal a square-planar geometry for [M(Bsodh)]Cl and a six-coordinate octahedral geometry for [M(Bsmdh)]Cl. The HBsodh ligand bonds to the metal ion via one >C=O, two >C=N−, and one deprotonated phenolate group, whereas HBsmdh bonds through three >C=O, two >C=N−, and one phenolate group. The lattice parameters for [Co(Bsodh)]Cl and [Ni(Bsmdh)]Cl correspond to tetragonal and orthorhombic crystal lattices, respectively. ESR spectral data indicate the presence of an unpaired electron in of the Cu²⁺ ion. The ligands, as well as their metal complexes, show significant antibacterial activity against Bacillus subtilis and Pseudomonas fluorescens. The text was submitted by the authors in English.     

Iron(III) complexes of 2-acetylpyridine-4-phenyl-3-thiosemicarbazones: Magnetic,E.s.r. and spectral studies

Summary Iron(III) complexes of 2-acetylpyridine-4-phenyl-3-thiosemicarbazone (LH) with the general formulae FeLX₂ (X = Cl, Br, NO₃ or SCN) and FeLSO₄ have been prepared and characterised by elemental analysis and by magnetic measurements in the polycrystalline state in the 77–298 K range and by electronic, i.r. and e.s.r. spectra. The FeLX₂ species (X = Cl, NCS or NO₃) are square pyramidal of intermediate spin-state (S=3/2) with an⁴ A ₂ ground state. The magnetic behaviour of FeLSO₄ is commensurate with high order effects coupled with antiferromagnetic exchange interactions. FeLBr₂ is a spin-free dimer involving bromine bridging between two FeLBr₂ square pyramids. However, the low-spin species [FeL(DMF)₃]²⁺ exists in dimethylformamide solution.     

两亲性四（3－苯基－4－苯甲酰基－5－异噁唑酮）合稀土酸十六烷基吡啶的合成、荧光及成膜性能

合成了４种两亲性的３－苯基－４－苯甲酰基－５－异唑酮（ＨＰＢＩ）合稀土酸十六烷基吡啶配合物：Ｌｎ（ＰＢＩ）４·ＨＤＰ（Ｌｎ＝Ｓｍ，Ｅｕ，Ｔｂ，Ｄｙ）．用元素分析、红外光谱、差热－热重谱、紫外－可见光谱对其进行了表征。研究了这４种配合物在固态下的荧光光谱并用频域法（Ｆｒｅｑｕｅｎｃｙ－ｄｏｍａｉｎ）测定了它们的荧光寿命，另外，还对这４种配合物在空气／水界面上单分子膜的（Ｌａｎｇｍｕｉｒ膜）行为进行了研究，表明它们均能形成稳定的单分子膜。     

Synthesis,characterization, and antimicrobial studies of some Schiff-base metal(II) complexes

Neutral complexes of Co(II), Ni(II), Cu(II), and Zn(II) have been synthesized from the Schiff bases derived from 3-nitrobenzylidene-4-aminoantipyrine and aniline (L¹)/p-nitro aniline (L²)/p-methoxy aniline (L³) in the molar ratio 1 : 1. The structural features have been determined from microanalytical, IR, UV-Vis, ¹H-NMR, mass, and ESR spectral data. The Cu(II) complexes are square planar, while Co(II), Ni(II), and Zn(II) complexes are tetrahedral. Magnetic susceptibility measurements and molar conductance data provide evidence for the monomeric and neutral nature of the complexes. The X-band ESR spectrum of Cu(II) complexes at 300 and 77 K were recorded. The electrochemical behavior of the complexes in MeCN at 298 K was studied. The in vitro biological screening effects of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola, and Candida albicans by the well-diffusion method. Comparison of the inhibition values of the Schiff bases and their complexes indicate that the complexes exhibit higher antimicrobial activity.     

The synergistic extraction of thorium(IV) and uranium(VI) with mixtures of 3-phenyl-4-benzoyl-5-isoxazolone and crown ethers

The extraction of thorium(IV) and uranium(VI) from nitric acid solutions has been studied using mixtures of 3-phenyl-4-benzoyl-5-isoxazolone (HPBI) and dicyclohexano-18-crown-6, benzo-18-crown-6, dibenzo-18-crown-6 or benzo-15-crown-5. The results demonstrate that these metal ions are extracted into chloroform as Th(PBI)(4) and UO(2)(PBI)(2) with HPBI alone and as Th(PBI)(4) . CE and UO(2)(PBI)(2) . CE in the presence of crown ethers (CE). The equilibrium constants of the above species have been deduced by non-linear regression analysis. The addition of a CE to the metal chelate system enhances the extraction efficiency and also improves the selectivities between thorium and uranium. IR spectral data of the extracted complexes were used to further clarify the nature of the complexes. The binding to the CEs by Th(PBI)(4) and UO(2)(PBI)(2) follows the CE basicity sequence but with DC18C6 and DB18C6, steric effects become more important.     

Synthesis, spectral characterization and biological activities of Mn(II) and Co(II) complexes with benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone

Mn(II) and Co(II) complexes of benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone have been synthesized and characterized by the investigations of electronic and EPR spectra and X-ray diffraction. Based on the spectral studies, an octahedral geometry is assigned for the Mn(II) and Co(II) complexes. X-ray powder diffraction studies reveal that Mn(II) and Co(II) complexes have triclinic crystal lattices. The unit cell parameters of the Mn(II) complex are a=11.0469 ?, b=6.2096 ?, c=7.4145 ?, α=90.646°, β=95.127°, γ=104.776°, V=489.7 ?(3) and those of Co(II) complex are a=9.3236 ?, b=10.2410 ?, c=7.8326 ?, α=90.694°, β=99.694°, γ=100.476°, V=724.2 ?(3). When the free ligand and its metal complexes are subjected to antibacterial activity, the metal complexes are proved to be more active than the ligand. However with regard to in vitro antioxidant activity, the ligand exhibits greater antioxidant activity than its metal(II) complexes.     

Synthesis,crystal structure,Hirshfeld surfaces,and spectral properties of Cu(II) and Co(II) complexes with 3-phenoxymethyl-4-phenyl-5-(2-pyridyl)-1,2,4-triazole

A new asymmetrical substituted triazole, 3-phenoxymethyl-4-phenyl-5-(2-pyridyl)-1,2,4-triazole (L) and its complexes, cis-[Cu₂ L ₂Cl₄]·2CH₃CN (1) and trans-[CoL ₂Cl₂]·2H₂O·2CH₃CN (2), have been synthesized and characterized by IR, single-crystal X-ray diffraction, thermogravimetric analyses and Hirshfeld surfaces. In the structure, two L are mainly stabilized by an intermolecular C–H?N hydrogen bond. In 1 (or 2), each L involves a doubly-bidentate (or chelating bidentate) coordination mode through one pyridine and two nitrogens (or one) of triazole, respectively. Complex 1 has a distorted trigonal bipyramidal [CuN₃Cl₂] core with two cis Cl^? while 2 shows a distorted octahedron [CoN₄Cl₂] with two trans Cl^?. We also prepared molecular Hirshfeld surface and fingerprint plot for L, 1 and 2, which revealed the influence of different metals on coordinate of L.     

Spectroscopic studies of manganese(II) and zinc(II) complexes of 1-phenyl-3-methyl-4-acylpyrazolone-5

Mn(II) and Zn(II) complexes of a series of 4-acyl derivatives of 1-phenyl-3-methylpyrazolone-5 have been synthesized. Characterization was by elemental analyses, UV, IR and ¹H NMR analyses. The chelates were found to conform to a general molecular formula ML₂·xCH₃CH₂OH·yH₂O where M = Mn, Zn; L is the acylpyrazolone-5 anion; x = 0, 1 or 2; and y = 0, 1 or 2. Spectral analyses showed that the adducts associated with the complexes have no effect on the bathochromic shifts observed in the UV and IR spectral properties of the complexes. The stability of the C

O and COM bonds does not follow any regular pattern with respect to the carbon chain of the 4-acyl substituent. The Mn(II) complexes have μ_eff values within the range of 5.3–5.6 B.M.     

Synthesis and spectral studies of new Co(II), Cu(II), and Ni(II) metal complexes with aromatic diamine

1,2-bis(p-aminophenoxy)ethane was obtained with reduction of 1,2-bis(p-nitrophenoxy)ethane and Pd/C as catalyst in hydrazine hydrate. Co(II), Cu(II), and Ni(II) complexes of aromatic bidentate diamine were prepared. The structure of the ligand and its complexes were characterized by IR, elemental analysis, magnetic susceptibility, conductivimetry, UV-Vis and ¹H NMR spectroscopy. The metal/ligand mole ratios were found to be 1:1. The general compositions of these complexes are found to be [CoLCl₂], [CuLCl₂], and [CoLCl₂]. The text was submitted by the authors in English.     

Synthesis,electrochemical and e.p.r. spectral studies of binuclear copper(II) complexes with new pentadentate L-proline-based binucleating ligands

The synthesis, reduction, optical and e.p.r. spectral properties of a series of new binuclear copper(II) complexes, containing bridging moieties (OH^–, MeCO₂ ^–, NO₂ ^–, and N₃ ^–), with new proline-based binuclear pentadentate Mannich base ligands is described. The ligands are: 2,6-bis[(prolin-1-yl)methyl]4-bromophenol [H₃L¹], 2,6-bis[(prolin-1-yl)methyl]4-t-butylphenol [H₃L²] and 2,6-bis[(prolin-1-yl)methyl]4-methoxyphenol [H₃L³]. The exogenous bridging complexes thus prepared were hydroxo: [Cu₂L¹(OH)(H₂O)₂] · H₂O (1a), [Cu₂L²(OH)(H₂O)₂] · H₂O (1b), [Cu₂L³(OH)(H₂O)₂] · H₂O (1c), acetato [Cu₂L¹(OAc)] · H₂O (2a), [Cu₂L²(OAc)] · H₂O (2b), [Cu₂L³(OAc)] · H₂O (2c), nitrito [Cu₂L¹(NO₂)(H₂O)₂] · H₂O (3a), [Cu₂L²(NO₂)(H₂O)₂] · H₂O (3b), [Cu₂L³(NO₂)(H₂O)₂] · H₂O (3c) and azido [Cu₂L¹(N₃)(H₂O)₂] · H₂O (4a), [Cu₂L²(N₃)(H₂O)₂] · H₂O (4b) and [Cu₂L³(N₃)(H₂O)₂] · H₂O (4c). The complexes were characterized by elemental analysis and by spectroscopy. They exhibit resolved copper hyperfine e.p.r. spectra at room temperature, indicating the presence of weak antiferromagnetic coupling between the copper atoms. The strength of the antiferromagnetic coupling lies in the order: NO₂ N₃ OH OAc. Cyclic voltammetry revealed the presence of two redox couples Cu^IICu^II Cu^IICu^I Cu^ICu^I. The conproportionality constant K _con for the mixed valent Cu^IICu^I species for all the complexes have been determined electrochemically.     

Electronic and vibrational studies of copper(II) complexes of 1-phenyl-3-methyl-4-acylpyrazolones-5

The interaction between Cu(II) and 1-pheny]-3-methyl-4-acylpyrazolones in aqueous medium has been investigated. The complexes were isolated and characterized using electronic and vibrational spectral measurments. Bathochromic shifts were observed for the complexes in the UV and infrared (IR) spectral regions. Analysis of the spectral properties of the complexes reveal that the stability of the

bond of the COCu bonding system decreases while that of the CuO bond in the same system increases as the carbon chain of the 4-acyl substituent increases. The complexes have μ_eff values within the range of 1.75–1.82 B.M.     

Synthesis, characterization and properties of some metal(II) 5-(nicotinamido)isophthalate complexes

Four new complexes, {[M(NAIP)(H₂O)₄]·2H₂O}_n (M = Co (1), M = Mn (2)), {[Zn(NAIP)]·0.5H₂O}_n (3) and {Cd(NAIP)(H₂O)₂]·1.5H₂O}_n (4) [H₂NAIP = 5-(nicotinamido)-isophthalic acid] have been prepared and structurally characterized. The ligand NAIP²⁻ exhibits different coordination modes and leads to the formation of various architectures. Complexes 1 and 2 show a one-dimensional (1D) zigzag chain, where hydrogen-bonding interactions further link these chains to a three dimensional (3D) supramolecular structure. For complex 3, a 3D coordination network with a four-coordinated Zn(II) and NAIP²⁻ as a SBU was observed. Complex 4 presents a three-connected 2-fold interpenetrated 3D network with a (10, 3)-b net topology. Their luminescent and magnetic properties have been investigated in the solid state.     

1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮稀土配合物的合成、晶体结构、发光性能与密度泛函理论计算

以1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮(Hpmbp)和4,4′-二甲基-2,2′-联吡啶(dmbipy)为配体合成了一类单核稀土配合物[Ln(pmbp)₃(dmbipy)]·C₂H₅OH,其中 Ln=Tb (1-Tb)、Ho (1-Ho)、Er (1-Er)、Tm (1-Tm)。结构表征显示该类配合物由稀土金属离子与3个pmbp^-配体、1个dmbipy配体配位而成,同时存在一分子非配位的乙醇。Ln³⁺离子的配位环境均接近于三角十二面体构型。荧光测试表明,1-Tb、1-Ho、1-Er和1-Tm均表现出了相应稀土离子的特征发射峰。此外,利用密度泛函理论计算分析了Hpmbp配体、dmbipy配体及稀土配合物的HOMO-LUMO信息。     

Synthesis,spectral and magnetic studies of some mixed ligand complexes of spin-free cobalt(II)

The reactions of acetylacetone, methyl acetoacetate and ethyl acetoacetate derivatives of cobalt(II) with diamines and hydroxyquinoline have resulted in the isolation of hexacoordinated complexes of the stoichiometry Co(L)₂(L′); where L = acetylacetone (AA), methyl acetoacetate (MeAA) or ethyl acetoacetate (EtAA) and L′ = ethylenediamine (En), propylenediamine (Pn) or 8-hydroxyquinoline. Their magnetic, IR and electronic spectral properties have been used to establish the stereochemistry. The values of the Racah interelectronic repulsion parameter (B) and crystal field splitting energy (10Dq) have been calculated using numerical as well as graphical procedures.     

Synthesis, spectral characterization and catalytic studies of new ruthenium(II) chalcone thiosemicarbazone complexes

A series of new hexa-coordinated ruthenium(II) complexes of the type [Ru(CO)(EPh₃)(B)(L)] (E = P or As; B = PPh₃, AsPh₃ or Py; L = chalcone thiosemicarbazone) have been prepared by reacting [RuHCl(CO)(EPh₃)₂(B)] (E = P or As; B = PPh₃, AsPh₃ or Py) with chalcone thiosemicarbazones in benzene under reflux. The new complexes have been characterized by analytical and spectroscopic (IR, UV-vis, ¹H, ³¹P and ¹³C NMR) methods. On the basis of data obtained, an octahedral structure was assigned for all of the complexes. The chalcone thiosemicarbazones behave as dianionic tridentate O, N, S donors and coordinate to ruthenium via the phenolic oxygen of chalcone, the imine nitrogen of thiosemicarbazone and thienol sulfur. The new complexes exhibit catalytic activity for the oxidation of primary and secondary alcohols to their corresponding aldehydes and ketones and they were also found to be efficient catalysts for the transfer hydrogenation of carbonyl compounds.     

1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮稀土配合物的合成、晶体结构、发光性能与密度泛函理论计算

以1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮(Hpmbp)和4,4′-二甲基-2,2′-联吡啶(dmbipy)为配体合成了一类单核稀土配合物[Ln(pmbp)₃(dmbipy)]·C₂H₅OH,其中Ln=Tb (1-Tb)、Ho (1-Ho)、Er (1-Er)、Tm (1-Tm)。结构表征显示该类配合物由稀土金属离子与3个pmbp-配体、1个dmbipy配体配位而成,同时存在一分子非配位的乙醇。Ln³⁺离子的配位环境均接近于三角十二面体构型。荧光测试表明,1-Tb、1-Ho、1-Er和1-Tm均表现出了相应稀土离子的特征发射峰。此外,利用密度泛函理论计算分析了Hpmbp配体、dmbipy配体及稀土配合物的HOMO-LUMO信息。     

Study of some reactions of ethyl 4-phenyl-3-benzoyl-2-pyrazoline-5-carboxylate

Several reactions of the pyrazoline 1a were investigated. With bromine water, potassium permanganate, hydrogen peroxide, or potassium hydroxide, different pyrazole derivatives were formed. While the reaction with hydroxylamine or some hydrazines gave the corresponding pyrazoline Schiff bases, with aroylhydrazines, pyrazole Schiff bases were formed.