Nooraziah Mohd Lair

Bio: Nooraziah Mohd Lair is an academic researcher from University of Malaya. The author has contributed to research in topics: Schiff base & Hydrogen bond. The author has an hindex of 3, co-authored 9 publications receiving 52 citations.

(E)-4-Hydr-oxy-N'-(2-hydr-oxy-4-methoxy-benzyl-idene)benzohydrazide monohydrate

Abstract: The Schiff base mol­ecule of the title compound, C15H14N2O4·H2O, adopts a trans configuration with respect to the C=N double bond; the Schiff base itself is almost planar (r.m.s. deviation for all non-H atoms = 0.040 A). The amido N atom is the hydrogen-bond donor to the water mol­ecule, which is the hydrogen-bond donor to the hydr­oxy groups of two neighboring mol­ecules. One of the hydroxyl groups acts as an intra­molecular and the other as an inter­molecular hydrogen-bond donor.

(E)-4-Hydr-oxy-N'-(2-hydr-oxy-4-methoxy-benzyl-idene)benzohydrazide N,N-dimethyl-formamide solvate.

Abstract: The Schiff base mol­ecule of the title compound, C15H14N2O4·C3H7NO, adopts a trans configuration with respect to the C=N double bond; the Schiff base itself is nearly planar (rms deviation 020 A) The amido N atom is a hydrogen-bond donor to the dimethyl­formamide solvate mol­ecule One of the hydr­oxy groups forms an intra­molecular hydrogen bond to the N atom of the C=N double bond, whereas the other forms an inter­molecular hydrogen bond to the carbonyl group

Bis[μ-4-hydr­oxy-N′-(4-meth­oxy-2-oxido­benzyl­idene)benzohydrazidato]bis­[pyridine­copper(II)]

Abstract: In the title compound, [Cu2(C15H12N2O4)2(C6H5N)2], each CuII atom is chelated by the tridentate doubly deprotonated Schiff base and a pyridine mol­ecule in a nearly planar environment (rms deviation for all non-H atoms = 0107 A) The metal ions are bridged by one O atom from the symmetry-related Schiff base ligands, forming a centrosymmetric dinuclear copper(II) complex The dimeric complex is linked to another dimer via weaker Cu—O inter­actions and also O—H⋯N hydrogen bonds

[N'-(4-Meth-oxy-2-oxidobenzyl-idene)4-nitro-benzohydrazidato-κO,N,O'](pyridine-κN)copper(II).

Abstract: The pyridine-coordinated CuII atom in the title Schiff base complex, [Cu(C15H11N3O5)(C5H5N)], is O,N,O′-chelated by the doubly deprotonated Schiff base ligand. The metal centre is in a square-planar coordination geometry.

5-Meth-oxy-2-[(2-morpholinoeth-yl)-iminio-meth-yl]phenolate.

Abstract: Each of the two independent mol­ecules of the title comound, C14H20N2O3, exists in the zwitterionic form as the imino N atoms are protonated. The =N—H unit forms an intra­molecular hydrogen bond to the negatively charged O atom, and also a weaker intermolecular N—H⋯O bond, the latter resulting in inversion dimers.

Structural Characterization of Organics Using Manual and Automated Electron Diffraction

Abstract: In the last decade the importance of transmission electron microscopic studies has become increasingly important with respect to the characterization of organic materials, ranging from small organic molecules to polymers and biological macromolecules. This review will focus on the use of transmission electron microscope to perform electron crystallography experiments, detailing the approaches in acquiring electron crystallographic data. The traditional selected area approach and the recently developed method of automated diffraction tomography (ADT) will be discussed with special attention paid to the handling of electron beam sensitive organic materials.

Dioxomolybdenum(VI) and dioxotungsten(VI) complexes chelated with the ONO tridentate hydrazone ligand: synthesis, structure and catalytic epoxidation activity

Abstract: Synthesis of the dioxomolybdenum(VI) complexes [MoO2(L3OMe)(EtOH)] (1), [MoO2(L4OMe)(EtOH)] (2) and [MoO2(LH)(EtOH)] (3) and dioxotungsten(VI) complexes [WO2(L3OMe)(EtOH)] (4), [WO2(L4OMe)(EtOH)] (5) and [WO2(LH)]n (6a) was carried out using [MO2(C5H7O2)2] (M = Mo or W) and the corresponding aroylhydrazone ligand H2LR (3-methoxysalicylaldehyde 4-hydroxybenzhydrazone (H2L3OMe), 4-methoxysalicylaldehyde 4-hydroxybenzhydrazone (H2L4OMe), or salicylaldehyde 4-hydroxybenzhydrazone (H2LH) in ethanol. Compounds obtained upon heating of the mononuclear complexes in acetonitrile or dichloromethane, [MO2(LR)]n (1a–6a) or [MoO2(L3OMe)]2 (1b), respectively, were also investigated. Crystal and molecular structures of the mononuclear 1, 2 and 3, polynuclear 1a·MeCN and dinuclear 1b complexes were determined by the single crystal X-ray diffraction method. Powder X-ray diffraction showed isostructurality of 1 and 4, and 2 and 5. The complexes were further characterized by elemental analysis, IR spectroscopy, TG and DSC analyses, and one- and two-dimensional NMR spectroscopy. The catalytic performances of 1–5 and 6a were investigated for epoxidation of cyclooctene using aqueous tert-butyl hydroperoxide (TBHP) as the oxidant.

Copper(ii) complexes with benzhydrazone-related ligands: synthesis, structural studies and cytotoxicity assay

Abstract: The dinuclear copper(II) complexes [Cu2(LH)2] (1), [Cu2(L3OMe)2] (2), [Cu2(L4OMe)2] (3) as well as the tetranuclear complex [Cu4(L3OMe)4]·4MeOH·2H2O (2a·4MeOH·2H2O), (where LH = 2-oxybenzaldehyde benzhydrazonato, L3OMe = 3-methoxy-2-oxybenzaldehyde benzhydrazonato or L4OMe = 4-methoxy-2-oxybenzaldehyde benzhydrazonato) were synthesized by reacting copper(II) acetate with the corresponding aroylhydrazone. Reactions in the presence of N-donor ligands D (pyridine, 4,4′-bipyridine or 1,10-phenanthroline) afforded complexes with different nuclearities and Cu : L : D ratios. They can be classified as dinuclear, [Cu2(LH)2(py)2] (1py), [Cu2(L3OMe)2(py)2]·3H2O (2py·3H2O), [Cu2(L4OMe)2(py)2] (3py), [{Cu(LH)}2(bpy)] (1bpy), [{Cu(L3OMe)}2(bpy)] (2bpy), and [{Cu(L4OMe)}2(bpy)] (3bpy), mononuclear [Cu(LH)(phen)] (1phen), [Cu(L3OMe)(phen)] (2phen) and [Cu(L4OMe)(phen)] (3phen), and polynuclear [{Cu(LH)}2(bpy)]n·2nMeOH (1bpy*·2MeOH) complexes. Conversion of complexes 1py–3py to complexes 1–3 proceeded via solid state reactions. The crystal and molecular structures of 2a·4MeOH·2H2O, 2py·3H2O, 3py, 1bpy*·2MeOH, 2bpy, 1phen and 3phen were determined by the single crystal X-ray diffraction method. All complexes were characterized by means of elemental and thermogravimetric analysis, FT-IR spectroscopy and the powder X-ray diffraction method. In vitro cytotoxicity of benzhydrazone-related ligands and their copper(II) complexes against THP-1 and HepG2 cells demonstrated that the complexes are significantly more cytotoxic than the corresponding ligands.

Synthesis, crystal structures and magnetic properties of dinuclear copper(II) compounds with NNO tridentate Schiff base ligands and bridging aliphatic diamine and aromatic diimine linkers

Abstract: The synthesis and the characterization of new dinuclear copper(II) compounds of general formula [(La–d)2Cu2(μ-N–N)](ClO4)2 (1–6) with either neutral aliphatic diamine (N–N = piperazine, pip) or aromatic diimine (N–N = 4,4′-bipyridine, 4,4′-bipy) linker are reported. The copper ligands L− (La− = (E)-2-((2-aminoethylimino)methyl)phenolate, Lb− = (E)-2-((2-aminopropylimino)methyl)-phenolate, Lc− = (E)-2-((2-aminoethylimino)methyl)4-nitrophenolate, Ld− = (E)-2-((2-aminoethylimino)methyl)4-methoxyphenolate) are NNO tridentate Schiff bases derived from the monocondensation of a substituted salicylaldehyde 5-G-salH (G = NO2, H, OMe) with ethylenediamine, en, or 1,3-propylenediamine, tn. The crystal structures of compounds [(La)2Cu2(MeOH)2(μ-4,4′-bipy)](ClO4)2 (1·2MeOH), [(Lb)2Cu2(MeOH)2(μ-4,4′-bipy)](ClO4)2 (2·2MeOH), [(Ld)2Cu2(μ-4,4′-bipy)](ClO4)2 (4), [(La)2Cu2(μ-pip)](ClO4)2 (5) and [(Lb)2Cu2(μ-pip)](ClO4)2 (6) have been determined, revealing the preferred (e-e)-chair conformation of the bridging piperazine in compounds 5 and 6. The presence of hydrogen-bond-mediated intermolecular interactions, that involve the methanol molecules, yields dimers of dinuclear units for 1·2MeOH, and infinite zig-zag chains for 2·2MeOH. The temperature dependences of the magnetic susceptibilities χM(T) for all compounds were measured, indicating the presence of antiferromagnetic Cu–Cu exchange. For the compounds 2–4 with 4,4′-bipy, the coupling constants J are around −1 cm−1, while in compound 1 no interaction could be detected. The compounds 5 and 6 with piperazine display higher Cu–Cu magnetic interactions through the σ-bonding backbone of the bridging molecule, with J around −8 cm−1, and the coupling is favoured by the (e-e)-chair conformation of the diamine ring. The non-aromatic, but shorter, linker piperazine gives rise to stronger Cu–Cu antiferromagnetic couplings than the aromatic, but longer, 4,4′-bipyridine. In the latter case, the rotation along the C–C bond between the two pyridyl rings and the consequent non co-planarity of the two copper coordination planes play an important role in determining the magnetic communication. EPR studies reveal that the dinuclear species are not stable in solution, yielding the solvated [(L)Cu(MeOH)]+ and the mononuclear [(L)Cu(N–N)]+ species; it appears that the limited solubility of the dinuclear compounds is responsible for their isolation in the solid state.

Copper(II) hydrazone complexes with different nuclearities and geometries: synthetic methods and ligand substituent effects

Abstract: A series of copper(II) complexes with 4- hydroxybenzhydrazone-related ligands was synthesized by using various methods, including conventional solution-based method, solvothermal route and electrochemical synthesis. The complexes can be classified as mononuclear [Cu(L3OMe)(py)] (2py), dinuclear [Cu2(LH)2(py)2] (1py), [Cu2(LH)2] (1 and 1β), [Cu2(LH)2(py)2] (1py), [Cu2(L4OMe)2(py)2] (3py), [Cu2(L4OMe )2] (3), [Cu2(L4OMe )2(MeOH)2] (3MeOH), [Cu2(L4OMe)2(EtOH)2] (3EtOH), cubane tetranuclear [Cu4(L3OMe)4]∙xsolv (2MeOH and 2EtOH), or polynuclear [Cu(LH)(py)]n (1py*), where LH = 2- oxybenzaldehyde 4- hydroxybenzhydrazonato, L3OMe = 3-methoxy-2- oxybenzaldehyde 4- hydroxybenzhydrazonato, and L4OMe = 4-methoxy-2- oxybenzaldehyde 4- hydroxybenzhydrazonato ligands. The presented study indicates that complexes having different nuclearities or/and geometries can be achieved by changing synthetic conditions and methods. Thermally induced structural transformations of the dinuclear complexes under solvent-free conditions were also investigated. Crystal and molecular structures of 1β, 1py*, 2MeOH, 2EtOH, 2py, 3 and 3MeOH were determined by the single crystal X-ray diffraction method. All complexes were characterized by microanalysis, FT- IR and CW-EPR spectroscopy, thermogravimetric analysis and powder X-ray diffraction method.