Synthesis and spectral characterization of 1-(aminoformyl- N -phenylform)-4-ethylthiosemicarbazide and its metal complexes

Synthesis of Some Novel Nanosized Chelates of Anchoring Bisazo Dye 5-[5-(4,6-Dioxo-2-thioxo-hexahydro-pyrimidin-5-ylazo)-naphthalen-1-ylazo]-2-mercapto-1H-pyrimidine-4,6-dione and Their Applications as Antioxidant and Antitumor Agents

A novel bisazo 5-[5-(4,6-dioxo-2-thioxo-hexahydro-pyrimidin-5-ylazo)-naphthalen-1-ylazo]-2-mercapto-1H-pyrimidine-4,6-dione (H4L) ligand has been synthesized from diazotization coupling between naphthalene-1,5-diamine and 2-thiobarbituric acid. Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Fe(III) chelates were prepared. All prepared compounds were characterized by different techniques. The azo groups did not participate in chelation according to the infrared spectra, whereas the thioamide group did participate. The azo dye ligand coordinated with all metallic ions in a neutral-keto-thiol structure and behaved as a bi- and tridentate moiety. Zinc, manganese, and iron chelates had an octahedral structure, while nickel and cobalt chelates had a tetrahedral structure, but the copper chelate had a square pyramidal geometry. The thermal behavior of all prepared compounds was investigated and thermokinetic parameters were also discussed. X-ray diffraction (XRD) data reflected that Fe(III) and Zn(II) complexes were crystalline while the Cu(II) complex was amorphous. Calcination of the Fe(III) complex at 600 °C yielded a nanosized Fe2O3 crystalline phase, elucidated by XRD and transmission electron microscope. The novel azo dye and some of its chelates were tested against HepG-2. The Fe2O3 nanooxide showed remarkable activity against the HepG-2 cell line rather than its precursor Fe(III) complex. Co(II) had a higher antioxidant activity than the other investigated complexes. In both activities, the Cu(II) complex did not show any activity. Molecular modeling and some theoretical studies were validated, and the experimental results were interpreted.

Spectral, thermal, molecular modeling and biological studies on mono- and binuclear complexes derived from oxalo bis(2,3-butanedionehydrazone)

Background

Hydrazones and their metal complexes were heavily studied due to their pharmacological applications such as antimicrobial, anticonvulsant analgesic, anti-inflammatory and anti-cancer agents. This work aims to synthesize and characterize novel complexes of VO²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Zr⁴⁺and Pd²⁺ ions with oxalo bis(2,3-butanedione-hydrazone). Single crystals of the ligand have been grown and analyzed.

Results

Oxalo bis(2,3-butanedionehydrazone) [OBH] has a monoclinic crystal with P 1 21/n 1 space group. The VO²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Zr⁴⁺ and Pd²⁺ complexes have the formulas: [VO(OBH–H)₂]·H₂O, [Co(OBH)₂Cl]Cl·½EtOH, [Ni₂(OBH)Cl₄]·H₂O·EtOH, [Cu(OBH)₂Cl₂]·2H₂O, [Zn(OBH–H)₂], [Zr(OBH)Cl₄]·2H₂O, and [Pd₂(OBH)(H₂O)₂Cl₄]·2H₂O. All complexes are nonelectrolytes except [Co(OBH)₂Cl]Cl·½EtOH. OBH ligates as: neutral tetradentate (NNOO) in the Ni²⁺ and Pd²⁺ complexes; neutral bidentate (OO) in [Co(OBH)₂Cl]Cl·½EtOH, [Zr(OBH)Cl₄]·2H₂O and [Cu(OBH)₂Cl₂]·2H₂O and monobasic bidentate (OO) in the Zn²⁺ and VO²⁺ complexes. The NMR (¹H and ¹³C) spectra support these data. The results proved a tetrahedral for the Zn²⁺ complex; square-planar for Pd²⁺; mixed stereochemistry for Ni²⁺; square-pyramid for Co²⁺ and VO²⁺ and octahedral for Cu²⁺ and Zr⁴⁺ complexes. The TGA revealed the outer and inner solvents as well as the residual part. The molecular modeling of [Ni₂(OBH)Cl₄]·H₂O·EtOH and [Co(OBH)₂Cl]Cl·½EtOH are drawn and their molecular parameters proved that the presence of two metals stabilized the complex more than the mono metal. The complexes have variable activities against some bacteria and fungi. [Zr(OBH)Cl₄]·2H₂O has the highest activity. [Co(OBH)₂Cl]Cl·½EtOH has more activity against Fusarium.

Conclusion

Oxalo bis(2,3-butanedionehydrazone) structure was proved by X-ray crystallography. It coordinates with some transition metal ions as neutral bidentate; mononegative bidentate and neutral tetradentate. The complexes have tetrahedral, square-planar and/or octahedral structures. The VO²⁺ and Co²⁺ complexes have square-pyramid structure. [Cu(OBH)₂Cl₂]·2H₂O and [Ni₂(OBH)Cl₄]·H₂O·EtOH decomposed to their oxides while [VO(OBH–H)₂]·H₂O to vanadium. The energies obtained from molecular modeling calculation for [Ni₂(OBH)Cl₄]·H₂O·EtOH are less than those for [Co(OBH)₂Cl]Cl·½EtOH indicating the two metals stabilized the complex more than mono metal. The Co(II) complex is polar molecule while the Ni(II) is non-polar.

Graphical abstract

Electronic supplementary material

The online version of this article (doi:10.1186/s13065-015-0135-y) contains supplementary material, which is available to authorized users.

Crystal structure, complexation, spectroscopic characterization and antimicrobial evaluation of 3,4-dihydroxybenzylidene isonicotinyl-hydrazone

A single crystal of 3,4-dihydroxybenzylidene isonicotinylhydrazone, HBINH, has been grown and solved by X-ray crystallography. The VO(2+), Zr(4+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+) and Pd(2+) complexes of HBINH have been prepared and spectroscopically characterized. The data confirmed the formulae [Co(HBINH)(H2O)Cl]Cl·H2O, [Pd(HBINH)Cl2], [Zn(HBINH)2Cl2], [Cd(HBINH)(H2O)2Cl2]·1½H2O, [(VO)2(HBINH-3H)(OH)(H2O)], [Ni2(HBINH)(H2O)6Cl2]Cl2, [Cu2(HBINH-3H)(H2O)2(OAc)]·3H2O, [Zr2(HBINH-3H)Cl4]Cl, [Hg2(HBINH)Cl4] and the dimer {[Cu(HBINH)Cl]Cl}2. Most of the complexes have intense colors and high melting points and some are electrolytes in DMSO solution. The ligand behaves as a neutral bidentate in the Co(II), Cu(II), Pd(II), Zn(II) and Cd(II) complexes; dibasic tetradentate in [Ni2(HBINH)(H2O)6Cl2]Cl2 and tribasic tetradentate in [Cu2(HBINH-3H)(OAc)]·5H2O, [(VO)2(HBINH-3H)(OH)(H2O)] and [Zr2(HBINH-3H)Cl4]Cl by the loss of 3H(+) due to the deprotonation of the two hydroxyl groups and the enolization of the amide (OCNH) group. A tetrahedral geometry was proposed for the Co(II), Cu(II), Zn(II) and Hg(II) complexes; square-planar for the Pd(II) complex; square-pyramid for the VO(2+) complex and octahedral for the Ni(II) and Cd(II) complexes. The complexes [Cd(HBINH)(H2O)2Cl2]·1½H2O, [(VO)2(HBINH-3H)(OH)(H2O)] and [Cu2(HBINH-3H)-(H2O)2(OAc)]·3H2O have activities against Bacillus sp. M3010, Candida albicans, Escherichia coli, Staphylococcus aureus and Slamonella sp. PA393.

Synthesis, characterization, molecular modeling and antioxidant activity of Girard's T thiosemicarbazide and its complexes with some transition metal ions

The chelation behavior of N-{[(allylamino) thiomethyl] hydrazinocarbonylmethyl} trimethylammonium chloride (H3ATHC) towards VO(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+) and UO2(2+) ions have been studied. The structures of the complexes were elucidated using elemental analyses, spectral (IR, UV-visible, (1)H NMR and ESR and mass) as well as magnetic and thermal measurements. The ligand acted as ON bidentate, ONS tridentate donor forming mononuclear complexes. A tetrahedral geometry for Co(2+), square-planar for Ni(2+) and Cu(2+), an octahedral for Zn(2+) and a square-pyramidal arrangement for VO(2+) complexes were proposed, respectively. The EPR spectra of Cu(2+) and VO(2+) complexes confirmed the suggested geometries with values of α(2) and β(2) indicating that the in-plane σ-bonding and in-plane π-bonding are appreciably covalent, and were consistent with very strong in-plane σ bonding in the complexes. Also, the bond length, bond angle, HOMO, LUMO, dipole moment and charges on the atoms have been calculated. Also, the thermal behavior and kinetic parameters were determined using Coats-Redfern and Horowitz-Metzger methods. Furthermore, the synthesized compounds were screened for their superoxide-scavenging activity in the PMS/NADH-NBT system as well as their scavenging effect on ABTS (2,2'-azino-bis(3-ethyl benzthiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl(DPPH) radicals. Among these compounds, the ligand and Zn(2+) complex, exhibited the potent ABTS (2,2'-azino-bis(3-ethyl benzthiazoline-6-sulfonic acid) radical scavenging activity, comparable to that of vitamin C.

Ligational, analytical and biological applications on oxalyl bis(3,4-dihydroxybenzylidene) hydrazone

The molecular modeling and parameters have been calculated to confirm the geometry of oxalyl bis(3,4-dihydroxybenzylidene) hydrazone, H(6)L. The metal complexes of Cr(3+), VO(2+), ZrO(2+), HfO(2+), UO(2)(2+) and MoO(2)(2+) with H(6)L have been prepared and characterized by partial elemental analysis, spectral studies (electronic; IR), thermal analysis and magnetic measurements. The data suggest the formation of polymer complexes with a unit [Cr(H(4)L)(H(2)O)(3)Cl].H(2)O, [VO(H(4)L)(H(2)O)(2)], [Hf(H(4)L)(H(2)O)].H(2)O [UO(2)(H(4)L)(H(2)O)(2)].2H(2)O [MoO(2)(H(4)L)] and [(ZrO)(2)(H(2)L)-(C(2)H(5)OH)(2)]. The ligand behaves as a dibasic bidentate in all complexes except ZrO(2+) which acts as a tetrabasic tetradentate with the two ZrO(2+) ions. An octahedral geometry was proposed for the Cr(3+), HfO(2+), MoO(2)(2+)and UO(2)(2+) complexes and square pyramid for VO(2+). The Cr(3+) is necessary to degrade the DNA of eukaryotic subject completely; the other complexes have little effect. H(6)L was found suitable as a new reagent for the separation and preconcentration of ZrO(2+) ions from different water samples using flotation technique with satisfactory results.

Synthesis, characterization and biological study on Cr(3+), ZrO(2+), HfO(2+) and UO(2)(2+) complexes of oxalohydrazide and bis(3-hydroxyimino)butan-2-ylidene)-oxalohydrazide

Cr(3+), ZrO(2+), HfO(2+) and UO(2)(2+) complexes of oxalohydrazide (H(2)L(1)) and oxalyl bis(diacetylmonoxime hydrazone) [its IUPAC name is oxalyl bis(3-hydroxyimino)butan-2-ylidene)oxalohydrazide] (H(4)L(2)) have been synthesized and characterized by partial elemental analysis, spectral (IR; electronic), thermal and magnetic measurements. [Cr(L(1))(H(2)O)(3)(Cl)].H(2)O, [ZrO(HL(1))(2)].C(2)H(5)OH, [UO(2)(L(1))(H(2)O)(2)] [ZrO(H(3)L(2))(Cl)](2).2H(2)O, [HfO(H(3)L(2))(Cl)](2).2H(2)O and [UO(2)(H(2)L(2))].2H(2)O have been suggested. H(2)L(1) behaves as a monobasic or dibasic bidentate ligand while H(4)L(2) acts as a tetrabasic octadentate with the two metal centers. The molecular modeling of the two ligands have been drawn and their molecular parameters were calculated. Examination of the DNA degradation of H(2)L(1) and H(4)L(2) as well as their complexes revealed that direct contact of [ZrO(H(3)L(2))(Cl)](2).2H(2)O or [HfO(H(3)L(2))(Cl)](2).2H(2)O degrading the DNA of Eukaryotic subject. The ligands and their metal complexes were tested against Gram's positive Bacillus thuringiensis (BT) and Gram's negative (Escherichia coli) bacteria. All compounds have small inhibitory effects.

Synthesis, characterization, molecular modeling and antimicrobial activity of 2-(2-(ethylcarbamothioyl)hydrazinyl)-2-oxo-N-phenylacetamide copper complexes

Six Cu(II) complexes of 2-(2-(ethylcarbamothioyl)hydrazinyl)-2-oxo-N-phenylacetamide (H(3)APET) have been prepared and characterized by elemental analyses, spectral (IR, UV-vis, (1)H NMR and ESR) as well as magnetic and thermal measurements. The data revealed that the ligand acts as ON bidentate, ONS tridentate or ONNS tetradentate forming structure in which each copper atom is a tetrahedral or tetragonal environment. The bond length, bond angle, HOMO, LUMO, dipole moment and charges on the atoms have been calculated to confirm the geometry of the ligand and the investigated complexes. Kinetic parameters were determined for each thermal degradation stage of the Cu(II) complexes using Coats-Redfern and Horowitz-Metzger methods. Moreover, the ligand and its complexes were screened against bacteria Staphylococcus aureus, Escherichia coli, Candida and fungi, Albicans and Aspergillus flavus using the inhibitory zone diameter.

Synthesis and characterization of 3-methyl-5-oxo-N,1-diphenyl-4,5-dihydro-1-H-pyrazole-4-carbothioamide and its metal complexes

The molecular parameters have been calculated to confirm the geometry of 3-methyl-5-oxo-N,1-diphenyl-4,5-dihydro-1-H-pyrazole-4-carbothioamide, HL. The compound is introduced as a new chelating agent for complexation with Cr(III), Fe(III), Co(II), Ni(II) and Cu(II) ions. The isolated chelates were characterized by partial elemental analyses, magnetic moments, spectra (IR, UV-vis, ESR; (1)H NMR) and thermal studies. The protonation constant of HL (5.04) and the stepwise stability constants of its Co(II), Cu(II), Cr(III) and Fe(III) complexes were calculated. The ligand coordinates as a monobasic bidentate through hydroxo and thiol groups in all complexes except Cr(III) which acts as a monobasic monodentate through the enolized carbonyl oxygen. Cr(III) and Fe(III) complexes measured normal magnetic moments; Cu(II) and Co(II) measured subnormal while Ni(II) complex is diamagnetic. The data confirm a high spin and low spin octahedral structures for the Fe(III) and Co(II) complexes. The ESR spectrum of the Cu(II) complex support the binuclear structure. The molecular parameters have also been calculated for the Cu(II) and Fe(III) complexes. The thermal decomposition stages of the complexes confirm the MS to be the residual part. Also, the thermodynamic and kinetic parameters were calculated for some decomposition steps.