The design of coordination compounds with solvent-responsive optical properties remains a central challenge in molecular photonics. Here, we describe the synthesis and full characterisation of a symmetrical tetradentate diamine ligand, 3,3′-((1,2-phenylenebis(azanediyl))- bis(methanylylidene))bis(pentane-2,4-dione) (H₂L), and its neutral square-planar complexes [M(L)] (M(II) = Co, Ni, Cu). The Cu(II) complex crystallised as [Cu(L)]⋅0.5 (pyrazine), adopting a nearly square-planar geometry (τ₄ = 0.06) in the solid state, as confirmed by single-crystal X-ray diffraction. In DMSO solution, UV–Vis spectra revealed reversible axial coordination of two solvent molecules, driving a transformation to a distorted octahedral geometry. Structural assignments were supported by FT-IR, UV–Vis, NMR, ESI-MS, conductivity, and magnetic susceptibility measurements. Density functional theory (DFT) calculations (B3LYP/6-311 + G(d,p) for H₂L; LANL2DZ for the complexes) reproduced the experimental geometries, mapped frontier orbital distributions, and yielded global reactivity descriptors. Among the complexes, [Cu(L)] displayed the narrowest HOMO–LUMO gap (ΔE = 3.911 eV), the highest polarisability (α = 305.3 a.u.), and an exceptionally large second-order hyperpolarisability (β = 2.20 × 104 a.u.), surpassing benchmark compounds such as urea, p-nitroaniline (pNA), and 2-methyl-4-nitroaniline (MNA) by more than 50 %. These results highlight diamine-derived N₂O₂ frameworks as promising candidates for solvent-responsive nonlinear optical (NLO) materials, combining hydrolytic stability with geometry switching and enhanced second-order optical performance. Importantly, X-ray data reveal that coordination to Cu(II) induces electron redistribution, imparting imine-like character to the nitrogen donors despite the diamine nature of the free ligand. This interplay highlights both the novelty and the performance advantage of the present system within the second-order NLO domain of Cu(II) complexes.
Flat-plate collector considers most common types of collectors, for ease of manufacturing and low price compared with other collectors. The main aim of the present work is to increase the efficiency of the collector, which can be achieved by improving the heat transfer and minimize heat loss experimentally. Five types of solar air collectors have been tested, which conventional channel with a smooth absorber plate (model I), dual channel with a smooth absorber plate (model II), dual channel with perforating “V” corrugated absorber plate (model III), dual channel with internal attached wire mesh (model Ⅳ), and dual channel with absorber sheet of transparent honeycomb, (model Ⅴ). The dual channel collector used for
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Complexes ofCo(ll),Cu(||),Ni(||),pt(|| ),and pd(||) with N3O-chelating Ligand Incorporating Azo and Shiff Base Moieties ;synthesis, spectroscopic ,Thermal Decomposition Theoretical
Background: The synthesis and characterization of novel liquid crystalline compounds have garnered signi|cant attention due to their potential applications in biomedical sciences, including drug delivery systems, biosensing, and diagnostic tools. This study focuses on synthesizing and characterizing new thiazolothiadiazole-based liquid crystals and evaluating their mesophase properties. Methods: A series of novel compounds containing 5H-thiazolo[4,3−b][1,3,4] thiadiazole units were synthesized via multi-step chemical reactions. The synthesis involved the reaction of chloroethyl acetate with 4−hydroxybenzaldehyde to yield an aldehyde intermediate, followed by subsequent transformations using hydrazine hydrate, ethylacetoacetate, and 1,2
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Two series of bent and liner core mesogen containing 1,2,4-traizole ring [VI]a,g and series were synthesized by many steps starting from esterification of isophthalic acid and terephathalic acid with methanol to yield diester compound [I]a,b which was converted to their acid hydrazide [II]a,b and the acid hydrazide reacted with ammonium thiocyanate or diester reacted with thiosemicarbazide to yield compounds [III]a,b. Then cyclization by 4% NaOH to yielded 1,2,4 traizole-3- thiol compounds [IV]a,b , afterword adding hydrazine hydrate to yield compounds [V]a,b. These compounds condensated with different substituted aldehyde to give new Schiff bases[VI]a,b ,[VII]a,b . Also , reaction acid hydrazide [II]a,b with aldehyde [VII] to yielded Schif
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The Ligand 6,6--(1,2-benzenediazo) bis (3-aminobenzoicacid) derived from o-phenylenediamine and 3-aminobenzoicacid was synthesized. The prepared ligand was identified by Microelemental Analysis, 1HNMR, FT-IR and UV-Vis spectroscopic techniques. Treatment of the ligand with the following metal ions (CoII, NiII, CuII and ZnII ) in aqueous ethanol with a 1:1 M:L ratio and at optimum pH. Characterization of these compounds has been done on the basis of elemental analysis, electronic data, FT-IR and UV-Vis, as well as magnetic susceptibility and conductivity measurements. The nature of the complexes formed were studied following the mole ratio and continuous variation methods, Beer's law obeyed over a concentration range (1×10-4 - 3×10-4 M). H
... Show MoreThe free Schiff base ligand (HL1) is prepared by being mixed with the co-ligand 1, 10-phenanthroline (L2). The product then is reacted with metal ions: (Cr+3, Fe+3, Co+2, Ni+2, Cu+2 and Cd+2) to get new metal ion complexes. The ligand is prepared and its metal ion complexes are characterized by physic-chemical spectroscopic techniques such as: FT-IR, UV-Vis, spectra, mass spectrometer, molar conductivity, magnetic moment, metal content, chloride content and microanalysis (C.H.N) techniques. The results show the formation of the free Schiff base ligand (HL1). The fragments of the prepared free Schiff base ligand are identified by the mass spectrometer technique. All the analysis of ligand and its metal complexes are in good agreement with th
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The preparation, spectroscopic characterisation of complexes derived from the mixed ligands with CdII, ZnII and CoII metal ions with Schiff base, Dithiocarbamates (DTCs) and 8-Hydroxyquinoline are reported. The compounds that prepared have been defined via; chloride content, F.T-IR, UV-Vis 1H-NMR spectroscopy and C.H.N.S, as well as conductance and magnetic susceptibility.All data which collected from such methods specified complexes with 6 coordinates in solution and solid states. The biologicalactivity that is related to all the prepared compounds which were screened for their antimicrobial activitiesagainst (G+ and (G-)). The data that collected from biological activity indicate that complexes will have extra activity against such tested
... Show MoreBidentate Schiff base ligand 3-(3,4-Dihydroxy-phenyl)-2-[(4-dimethylamino-benzylidene)-amino]-2-methyl-propionic acid was prepared and characterized by spectroscopic techniques studies and elemental analysis. The Cd(II), Ni(II), Cu(II), Co(II), Cr(III),and Fe(III) of mixed-ligand complexes were structural explicate through Moler conductance , [FT-IR, UV-Vis & AAS], chloride contents, , and magnetic susceptibility measurements. Octahedral geometries have been suggested for all complexes. The Schiff base and its complexes were tested against various bacterial species, two of {gram(G+) and gram(G-)} were shown weak to good activity against all bacteria.