Bandar A. Babgi

Organometallic Complexes for Non-Linear Optics. 51. Second- and Third-Order Non-Linear Optical Properties of Alkynylgold Complexes*

The alkynes HC≡CC6H2-2,6-Et2-4-C≡CC6H4-4-NO2 (4) and HC≡CC6H4-4-C≡CC6H2-2,6-Et2-4-C≡CC6H4-4-NO2 (6) and gold alkynyl complexes Au{C≡CC6H2-2,5-(OEt)2-4-C≡CC6H4-4-NO2}(PPh3) (7), Au(C≡CC6H2-2,6-Et2-4-C≡CC6H4-4-NO2)(PPh3) (8), and Au(C≡CC6H4-4-C≡CC6H2-2,6-Et2-4-C≡CC6H4-4-NO2)(PPh3) (9) have been synthesized. The linear optical properties and quadratic optical non-linearities of 7–9 have been measured, the latter by hyper-Rayleigh scattering at 1064 nm, and compared with data for the previously reported complexes Au(C≡CC6H4-4-NO2)(PPh3) (10) and Au(C≡CC6H4-4-C≡CC6H4-4-NO2)(PPh3) (11). The optical absorption maximum red-shifts and the first hyperpolarizabilities increase on π-system lengthening and on introduction of electron-releasing substituents on the π-bridge ring adjacent to the metal centre. The cubic non-linear optical properties of 1,4-{(PCy3)Au(C≡C)}2C6H4 (12) and {(PCy3)Au(C≡C-4-C6H4C≡C)}6C6 (13) have been assessed by wide spectroscopic range femtosecond Z-scan studies; the maximal values of the imaginary component and the effective two-photon absorption cross-section increase markedly on proceeding from linear complex 12 to 6-fold-symmetric complex 13, an increase that is maintained when data are scaled by relative molecular weight.

Optical Sensing Properties of Pyrene-Schiff Bases toward Different Acids

A set of (4-substituted-phenyl)-pyren-1-ylmethylene-amine (PMA) was prepared by the reaction of pyrene-1-carboxaldehyde and the corresponding 4-substituted aniline. The structure of the PMA compounds were confirmed by spectroscopic data (IR, 1HNMR, 13CNMR, ISI-MS and elemental analysis. The structure of (4-bromo-phenyl)-pyren-1-ylmethylene-amine (BrPMA) was further confirmed by the single X-ray crystallography. The absorption and emission spectroscopic behaviors were investigated in variant acids. The compounds showed dramatic spectroscopic changes upon acidifying with strong acids and negligible effects when weak acids are used in the acidifications. Hence, the PMA compounds can be used as sensors to distinguish between weak and strong acids.

Synthesis of Ni(II), Cu(II) and Co(II) complexes with new macrocyclic Schiff-base ligand containing dihydrazide moiety: Spectroscopic, structural, antimicrobial and antioxidant properties

In this study, the macrocyclic Schiff base ligand (L) derived from 1, 4-dicarbonyl-phenyl-dihydrazide and glyoxal (2:2) and its Ni (II), Cu (II) and Co(II) complexes were synthesised and were characterised by elemental analyses, FTIR, UV-Vis., mass and 1H NMR. The ligand (L) behaves as a tetradentate ligand and coordinates to the metal ions via the nitrogen atoms and the complexes have the mononuclear structures. The synthesised compounds were evaluated for their inhibition potential against bacterial and fungal strains and the assay indicated that the metal complexes exhibited a remarkable antibacterial and antifungal activity against these tested strains. In addition, the antioxidant activity of the compounds was also studied through scavenging effect on DPPH radicals with the copper complex showing enhanced antioxidant activity than other metal complexes.

Synthesis, structural, electrochemical, and spectroscopic studies of some (diimine)ruthenium nitrile complexes

The syntheses of cationic ruthenium(II) complexes [Ru(Me2-bpy)(PPh3)2RRʹ][PF6]x {Me2-bpy = 4,4ʹ-dimethyl-2,2ʹ-bipyridine, (3) R = Cl, Rʹ = N≡CMe, x = 1, (4) R = Cl, Rʹ = N≡CPh, x = 1, (5) R = Rʹ = N≡CMe, x = 2} and [Ru(Me2-bpy)(κ2-dppf)RRʹ][PF6]x {dppf = 1,1ʹ-bis(diphenylphosphino)ferrocene, (6) R = Cl, Rʹ = N≡CMe, x = 1, (7) R = Cl, Rʹ = N≡CPh, x = 1, (8) R = Rʹ = N≡CMe, x = 2} are reported, together with their structural confirmation by NMR (31P, 1H) and IR spectroscopy and elemental analysis, and, in the case of trans-[Ru(Me2-bpy)(PPh3)2(N≡CCH3)Cl][PF6] (3), by X-ray crystallography. Electronic absorption and emission spectra of the complexes reveal that all complexes except 4 and 6 are emissive in the range 370–400 nm with 8 exhibiting an emission in the blue. Cyclic voltammetry studies of 3–8 show reversible or quasi-reversible redox processes at ca. 1 V, assigned to the Ru(II/III) couple.

Crystal structure of trans-di­chloridobis­[N-(5,5-di­methyl-4,5-di­hydro-3H-pyrrol-2-yl-κN)acetamide]palladium(II) dihydrate

The synthesis and crystal structure of the complex trans-[dichlorido-bis(N-(4,5-dihydro-5,5-dimethyl-3H-pyrrol-2-yl)acetamide)]palladium(II) dihydrate is described.