Synthesis of homobimetallic molybdenum(VI) complex of bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone and its reaction with electron and proton bases

Substituent effect on the chemical and biological properties of diisatin dihydrazone Schiff bases: DFT and docking studies

According to the considered role of lipophilicity-hydrophobicity on organic Schiff base hydrazones, different substituents of phenyl, ethyl, and methyl groups were inserted in the synthetic strategy of diisatin dihydrazones (L1-4). The biochemical enhancement was evaluated depending on their inhibitive potential of the growth power of three human tumor cells, fungi, and bacteria. The biochemical assays assigned the effected role of different substituents of phenyl, ethyl, and methyl groups on the effectiveness of their diisatin dihydrazone reagents. The interacting modes with calf thymus DNA (i.e. Ct-DNA) were studied via viscometric and spectrophotometric titration. The organo-reagent L1 with the oxalic derivative assigned a performed inhibitive action for the examined microbes and the human tumor cell lines growing up over the terephthalic (L4) > malonic (L2) > succinic (L3) ones. From Kb = binding constant, and ∆Gb≠ = Gibb's free energy values, the binding of interaction within Ct-DNA was evaluated for all compounds (L1-4), in which L1, L3, and L4 assigned the highest reactivity referring to the covalent/non-covalent modes of interaction, as given for (L1-4), 14.32, 13.28, 10.87, and 12.41 × 107 mol-1 dm3, and -45.17, -43.24, -43.75, and -44.05 kJ mol-1, respectively. DFT and docking studies were achieved to support the current work.

Palladium complexes containing NNN pincer type ligands and their activities in Suzuki-Miyaura cross coupling reaction

Five new NNN pincer-type ligands and their palladium complexes were successfully synthesised and characterised by FT-IR, ¹H NMR, ¹³C NMR, and UV-vis analyses. TEM analysis was used to observe the morphological character of the black residues obtained from the fourth cycle of the reusability test. Furthermore, suitable crystals of the N²,N⁶-bis(2-tert-butylphenyl)pyridine-2,6-dicarboxamide and its palladium complex were elucidated with the X-ray single crystal diffraction method. Both the ligand and its palladium complex crystallise in a monoclinic system with space group P2₁/c for the H₂L⁴ and C2/c for the palladium complex. The structure of the pincer ligand and its palladium complex were stabilised by intramolecular and intermolecular C-H⋅⋅⋅O, C-H⋅⋅⋅N, and N-H⋅⋅⋅N contacts. A Suzuki-Miyaura cross-coupling reaction between aryl halides and phenylboronic acid was used to assess the catalytic abilities of the palladium pincer complexes. All of the prepared complexes exhibited considerable catalytic activity. However, complexes 4 (Acetonitrile-N²,N⁶-bis(2-tert-butylphenyl)pyridine-2,6-dicarboxamidopalladium(II)) and 5 (Acetonitrile-N²,N⁶-bis(2-nitrophenyl)pyridine-2,6-dicarboxamidopalladium(II)) provided almost 100% conversion with nearly 100% yield in the reaction between 4-bromotoluene and phenylboronic acid. Furthermore, these active complexes catalysed the reaction of the sterically hindered and deactivated substrates (1-Bromo-4-izobutylbenzene and 2-bromo-6-methoxynaphthalene) with phenylboronic acid, and complete conversion and yields up to 100% were achieved in a short time with the 2-bromo-6-methoxynaphthalene.

Synthesis, characterization and electrochemical studies of some Ni(II)Cu(II) heterobimetallic complexes derived from succinoyldihydrazones

Synthesis, structural characterization and redox properties of three heterobimetallic complexes with formule {[NiCu(L(n))(CH3OH)3]·CH3OH} using [Cu(H2L(n))(H2O)] as metalloligand have been demonstrated in the present paper. Electronic spectroscopy suggests that the copper center has a pseudo square pyramidal stereochemistry in all the complexes while the nickel center has a distorted octahedral stereochemistry. The electron transfer reactions of the complexes have been investigated by cyclic voltammetry.

Assessment of conformational, spectral, antimicrobial activity, chemical reactivity and NLO application of Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone)

An orange colored pyrrole dihydrazone: Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone) (PDBO) has been synthesized by reaction of oxalic acid dihydrazide with 2,5 diformyl-1H-pyrrole and has been characterized by spectroscopic analysis (1H, 13C NMR, UV-visible, FT-IR and DART Mass). The properties of the compound has been evaluated using B3LYP functional and 6-31G(d,p)/6-311+G(d,p) basis set. The symmetric (3319, 3320 cm(-1)) and asymmetric (3389, 3382 cm(-1)) stretching wave number confirm free NH2 groups in PDBO. NBO analysis shows, inter/intra molecular interactions within the molecule. Topological parameters have been analyzed by QTAIM theory and provide the existence of intramolecular hydrogen bonding (N-H⋯O). The local reactivity descriptors analyses determine the reactive sites within molecule. The calculated first hyperpolarizability value (β0=23.83×10(-30) esu) of pyrrole dihydrazone shows its suitability for non-linear optical (NLO) response. The preliminary bioassay suggested that the PDBO exhibits relatively good antibacterial and fungicidal activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, Aspergillus niger. The local reactivity descriptors--Fukui functions (fk+, fk-), local softnesses (sk+, sk-) and electrophilicity indices (ωk+, ωk-) analyses have been used to determine the reactive sites within molecule.

Synthesis and characterization of perchlorato bridged Cu2(II)Zn(II) heterotrinuclear complexes derived from succinoyldihydrazones

In the present paper three new heterotrimetallic Cu(II)-Zn(II)-Cu(II) complexes have been synthesized and characterized by analytical and spectroscopic studies. The molar conductance values for the complexes fall in the region 1.2-1.7Ω(-1)cm(2)mol(-1) in DMSO solution indicating that all of the complexes are non-electrolyte. The dihydrazone ligand is present in enol form in all of the complexes. Both the copper centres have distorted square pyramidal stereochemistry in all of the complexes while the zinc centre in all hetero metal complexes has octahedral stereochemistry. The EPR parameters of the complexes indicate that the copper centre has [Formula: see text] orbital as the ground state. The electron transfer reactions of the complexes have been investigated by cyclic voltammetry.

Synthesis, characterization and reactivity of trinuclear Cu(II) complexes derived from disalicylaldehyde malonoyldihydrazone

Three new homotrinuclear copper(II) complexes [Cu3(slmh)(μ-Cl)2(CH3OH)3]⋅0.5CH3OH (1), [Cu3(slmh)(NO3)2(CH3OH)5]⋅1.5CH3OH (2) and [Cu3(slmh)(μ-ClO4)2(CH3OH)3]⋅2CH3OH (3) from disalicylaldehyde malonoyldihydrazone have been synthesized and characterized. The composition of the complexes has been established on the basis of data obtained from analytical and thermoanalytical data. The structure of the complexes has been discussed in the light of molar conductance, electronic, FT-IR and far-IR spectral data, magnetic moment and EPR spectral studies. The molar conductance values for the complexes in DMSO solution indicate that all of them are non-electrolyte. The magnetic moment values for the complexes suggest considerable metal-metal intramolecular interaction between metal ions in the structural unit of the complexes. The EPR spectral features reveal that at RT, the ground state for the complexes is a mixture of the quartet state (S=3/2) and doublet state (S=1/2). At lower temperature, the ground state for the complexes is dx(2)-y(2) with considerable contribution from dz(2) orbital. Dihydrazone ligand is present in enol form in all of the complexes. The complexes have distorted square pyramidal stereochemistry. The electron transfer reactions of the complexes have been investigated by cyclic voltammetry. Hydrogen peroxide mediated oxidation of benzyl alcohol catalyzed by complex 1 has been studied.

Synthesis and characterization of heterotrinuclear bis(μ2-chlorido)dicopper (II) mono zinc(II) complexes derived from succinoyldihydrazones

Three new zinc (II)-copper (II) heterometallic trinuclear complexes of the composition [ZnCu2(L(n))(μ2-Cl)2(H2O)6]⋅2H2O (H4L(n)=H4L(1), H4L(2), H4L(3)) have been synthesized from substituted succinoyldihydrazones (H4L(n)) in methanol medium. The composition of the complexes has been established on the basis of data obtained from analytical, mass spectral studies and molecular weight determinations in DMSO. The structure of the ligand H4L(2) has been established by X-ray crystallography. The structure of the complexes has been discussed in the light of molar conductance, magnetic moment, electronic, EPR, IR and FT-IR spectral studies. The molar conductance values for the complexes fall in the region 1.2-1.7 ohm(-1) cm(2) mol(-1) in DMSO solution indicating that all of these are non-electrolyte. The magnetic moment values suggest weak M-M interaction in the structural unit of the complexes. The dihydrazone ligand is present in enol form in all of the complexes. Copper centre has tetragonally distorted octahedral stereochemistry. The EPR parameters of the complexes indicate that the copper centre has doublet state as the ground state. The electron transfer reactions of the complexes have been investigated by cyclic voltammetry.

Synthesis and characterization of homotrimetallic copper complexes derived from bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone

Copper (II) complexes [Cu(3)(nph)(μ(2)-X)(2)(H(2)O)(6)]·2H(2)O [X=Cl (1), (ClO(4)) (3)] and [Cu(3)(nph)(NO(3))(2)(H(2)O)(6)] (2) have been synthesized from bis(2-hydroxy-1-naphthaldehyde)oxaloyldihydrazone in methanol medium and characterized. The structures of the complexes have been discussed in the light of data obtained from analytical, thermoanalytical, mass spectral studies, molar conductance, magnetic moment, electronic, EPR, IR, FT-IR spectroscopic studies. The molar conductance values for the complexes fall in the region 0.5-0.9 Sm(2) mol(-1) in DMSO solution indicating that all of them are non-electrolyte. The magnetic moment values for the complexes suggest weak M-M interaction in the structural unit of the complexes. The dihydrazone ligand is present in enol form in all of the complexes. Copper centre has tetragonally distorted octahedral stereochemistry in chlorido and perchlorato complexes while in nitrato complex, copper has mixed square-pyramidal and distorted-octahedral stereochemistry. The EPR parameters of the complexes indicate that the copper centre has the doublet state as the ground state.