73818-26-5Relevant academic research and scientific papers
Nickel(II) 2,6-diacetylpyridine bis(isonicotinoylhydrazonate) and bis(benzoylydrazonate) complexes: Structure and antimycobacterial evaluation. Part XI
Bottari,Maccari,Monforte,Ottana,Vigorita,Bruno,Nicolo,Rotondo,Rotondo
, p. 2203 - 2211 (2001)
The reaction of 2,6-diacetylpyridine (dap) and isonicotinoyl- or benzoylhydrazide leads to bishydrazones H2dapin (1a) and H2dapb (1b), respectively. The condensation can either take place as a bimolecular kinetic process between the two reactants or as a monomolecular metal-templated synthesis in the presence of nickel(II) ions. In the latter case the reaction products are charged 2,6-diacetylpyridine bis(hydrazone) nickel(II) complexes, which can be easily deprotonated to neutral hydrazonates. Diffractometric analysis of one of these [Ni(dapb)]2 (8b) has shown a binuclear structure with two octahedral nickel(II) ions bridged by two helicoidal dap (bishydrazonates) in a spheroidal structure of C2V symmetry. The synthesized complexes 8 are promising as antimycobacterial agents against M. tuberculosis H37Rv. In particular, 8b displays significant activity (MIC = 0.025 μg/mL) 10-fold higher than rifampin and equal to isoniazid, while its ligand is ineffective. Compound 8b is also capable of reducing HIV-induced cytopathogenic effect in human T4lymphocytes.
Pb ? N interactions and π-stacking in lead(II) bis(hydrazone) compounds
Schwade, Vania Denise,Bessega, Tiago,Lang, Ernesto Schulz,Abram, Ulrich
, p. 96 - 103 (2016)
2,6-Diacetylpyridine-bis(benzoylhydrazone), H2LPh, reacts with Pb(OAc)2·3H2O and NEt3 as a supporting base forming a polymeric solid of the composition [Pb(LPh)]n. A reaction wit
The first pentagonal-bipyramidal vanadium(iii) complexes with a Schiff-base N3O2pentadentate ligand: Synthesis, structure and magnetic properties
Bazhenova, Tamara A.,Klingeler, Rüdiger,Koo, Changhyun,Manakin, Yuriy V.,Maximova, Olga V.,Mironov, Vladimir S.,Simonov, Sergey V.,Spillecke, Lena,Vasiliev, Alexander N.,Yagubskii, Eduard B.,Zorina, Leokadiya V.
, p. 15287 - 15298 (2020)
A series of three mononuclear pentagonal-bipyramidal V(iii) complexes with the equatorial pentadentate N3O2 ligand (2,6-diacethylpyridinebis(benzoylhydrazone), H2DAPBH) in the different charge states (H2DAPBH0, HDAPBH1-, DAPBH2-) and various apical ligands (Cl-, CH3OH, SCN-) were synthesized and characterized structurally and magnetically: [V(H2DAPBH)Cl2]Cl·C2H5OH (1), [V(HDAPBH)(NCS)2]·0.5CH3CN·0.5CH3OH (2) and [V(DAPBH)(CH3OH)2]Cl·CH3OH (3). All three complexes reveal paramagnetic behavior, resulting from isolated S = 1 spins with positive zero-field splitting energy expected for the high-spin ground state of the V3+ (3d2) ion in a PBP coordination. Detailed high-field EPR measurements for compound 3 show that its magnetic properties are best described by using the spin Hamiltonian with the positive ZFS energy (D = +4.1 cm-1) and pronounced dimer-like antiferromagnetic spin coupling (J = -1.1 cm-1). Theoretical analysis based on superexchange calculations reveals that the long-range spin coupling between distant V3+ ions (8.65 ?) is mediated through π-stacking contacts between the planar DAPBH2- ligands of two neighboring [V(DAPBH)(CH3OH)2]+ complexes.
A novel family of hepta-coordinated Cr(III) complexes with a planar pentadentate N3O2 Schiff base ligand: synthesis, structure and magnetism
Bazhenova,Zorina,Simonov,Manakin, Yu.V.,Kornev,Lyssenko,Mironov,Gilmutdinov,Yagubskii
, (2021)
A series of seven-coordinate pentagonal-bipyramidal (PBP) Cr(III) complexes with pentadentate pyridine-based ligands, 2,6-diacetylpyridine bis(4-methoxybenzoylhydrazone), H2DAPMBH (H2LOCH3) or 2,6-diacetylpyridine bis(benzoylhydrazone), H2DAPBH (H2L) and different axial ligands have been prepared. The reaction of the H2LOCH3 with CrCl2·4H2O in methanol or CrCl3·6H2O in CH3CN led to a novel seven-coordinate pentagonal-bipyramidal (PBP) complex [Cr(HLOCH3)Cl2] (1) with the mono-deprotonated chelating ligand in the equatorial plane and two apical Cl atoms. Then, taking advantage of lability of the apical Cl ligands in 1, a number of PBP CrIII complexes with charged (viz. CH3O?, N3?, CN?, NCS?) and neutral (viz. CH3OH, H2O) apical ligands was obtained and characterized: [Cr(HLOCH3)Cl2]·4CHCl3 (1), [Cr(HLOCH3)Cl2]·CH3OH (1a), [Cr(HLOCH3)(H2O)Cl]PF6·CH3OH (2), [Cr(HL)(H2O)Cl]ClO4·0.25H2O (3), [Cr(HLOCH3)(H2O)2](NO3)2·H2O·C2H5OH (4), [Cr(LOCH3)(CH3OH)(OCH3)]·CH3OH (5), [Cr(HLOCH3)(NCS)2]·1.5H2O (6), [Cr(HLOCH3)(N3)2]·xH2O (7, x = 0.2, 8, x = 0, 9, x = 0, three phases in the same synthesis), [Cr(LOCH3)(N3)2][Na(CH3OH)2]·2CH3OH (10), [Cr(LOCH3)(CN)2][Na(H2O)(C2H5OH)] (11). Single crystal X-ray analysis reveals that all the complexes 1–11 have the PBP geometry with a pentadentate ligand in a form of [HLOCH3]? or [LOCH3]2? in the equatorial plane. The PBP complexes are prone to aggregate into dimers or polymers, either due to strong hydrogen bonds or due to the transformation of terminal ligands into bridging between different metallic centers. All complexes 1–11 exhibit considerable in-plane distortion of the CrN3O2 pentagon due to the shift of the CrIII ion from the central position, which is caused by the strong first-order Jahn-Teller (JT) effect for the high-spin 3d3 configuration in the PBP ligand field. The mechanism of JT distortions is rationalized in terms of DFT calculations. DC magnetic measurements indicate a high-spin (S = 3/2) ground state of complex [Cr(HLOCH3)Cl2]·4CHCl3 (1); theoretical analysis of its magnetic properties reveals negative zero-field splitting energy with the anisotropy parameter D = –1.8 cm?1 and weak dimer-like antiferromagnetic spin coupling J = –0.23 cm?1 between neighboring PBP units [CrIII(HLOCH3)Cl2] mediated by π-stacking of planar H2LOCH3 ligands.
Synthesis, anticancer activity and mechanism of iron chelator derived from 2,6-diacetylpyridine bis(acylhydrazones)
Yao, Qian,Qi, Jinxu,Zheng, Yunyun,Qian, Kun,Wei, Lai,Maimaitiyiming, Mukedasi,Cheng, Zhen,Wang, Yihong
, p. 1 - 8 (2019/01/16)
We synthesized five iron chelator derived from 2,6-diacetylpyridine bis(acylhydrazones) and proved their iron complexes structure by X–ray single crystal diffraction. These ligands have a significant anticancer proliferative activity and low cytotoxicity
(Et4N)[MoIII(DAPBH)Cl2], the first pentagonal-bipyramidal Mo(iii) complex with a N3O2-type Schiff-base ligand: manifestation of unquenched orbital momentum and Ising-type magnetic anisotropy
Manakin,Mironov,Bazhenova,Lyssenko,Gilmutdinov,Bikbaev,Masitov,Yagubskii
supporting information, p. 10084 - 10087 (2018/09/18)
The first paramagnetic pentagonal-bipyramidal complex of Mo(iii) with a N3O2-type Schiff-base ligand was synthesized by the comproportionation reaction between Mo(ii) and Mo(iv) congeners. The complex has a low-spin (S = 1/2) ground state of MoIII(4d3) with double orbital degeneracy and unquenched orbital momentum, which result in strong Ising-type magnetic anisotropy.
Versatility of 2,6-diacetylpyridine (dap) hydrazones in stabilizing uncommon coordination geometries of Mn(II): Synthesis, spectroscopic, magnetic and structural characterization
Naskar, Subhendu,Mishra, Dipankar,Chattopadhyay, Shyamal Kumar,Corbella, Montserrat,Blake, Alexander J.
, p. 2428 - 2435 (2007/10/03)
Five seven- or eight-coordinate manganese complexes of hydrazone ligands have been prepared. Three seven-coordinate neutral MnII complexes: [Mn(dapA2)]n (1), [Mn(dapB2)(H 2O)2] (2), [Mn(dap
Investigation into Aroylhydrazones as Chelating Agents. Part 3. Synthesis and Spectroscopic Characterization of Complexes of MnII, CoII, NiII, CuII, and ZnII with 2,6-Diacetylpyridine Bis(benzoylhydrazone) and X-Ray Structure of Aquachloro<2,6-diacetylpyridine bis(benzoylhyd...
Lorenzini, Carlo,Pelizzi, Corrado,Pelizzi, Giancarlo,Predieri, Giovanni
, p. 721 - 728 (2007/10/02)
The chelating behaviour of neutral and deprotonated 2,6-diacetylpyridine bis(benzoylhydrazone) (H2dapb) has been investigated in some new complexes of MnII, CoII, NiII, CuII, and ZnII.An X-ray diffraction analysis was carried out on Cl.The crystals are monoclinic, space group P21/c, with unit-cell dimensions a = 7.065(6), b = 17.096(9), c = 19.446(13) Angstroem, β = 96.89(8) deg, and Z = 4.The structure was solved by the heavy-atom technique from 1545 observed independent reflections recorded at room temperature on an automated diffractometer and refined to a final R value of 0.0329.The structure consists of + cations and Cl- anions.The cation has a pentagonal-bipyramidal geometry, with H2dapb forming the equatorial plane and the H2O and Cl groups occupying the axial positions.The i.r. spectra suggest differences in the interaction of these metals with the hydrazone molecule.
