Leyla Tatar

Synthesis, crystal structure and electrochemical behaviour of water soluble Schiff bases

Abstract Four water soluble Schiff bases were prepared from the reaction of salicylaldehyde and 2-hydroxy-1-naphtaldehyde with 2-amino-2-methyl-1,3-dihydroxy propane and 2-amino-2-methoxy-1,3-dihydroxy propane. Two of the Schiff bases were characterized using elemental analysis, IR spectroscopy and single crystal X-ray diffraction. In addition cyclic voltammetric studies were performed. The Schiff bases C11H5NO4 (II) and C15H17NO3 (III) crystalize in monoclinic space group P21/c with unit cell dimensions a = 10.499(2), b = 8.725(2), c = 12.635(10) Å, β = 101.649(11); a = 14.579(8), b = 9.834(13), c = 9.542(5) Å, β = 107.559(5) respectively.

Computer‐simulation analysis of the ESR spectra of mechanoradicals in PMMA

In this study, initially, we tried to obtain the mechanoradicals of PMMA (poly(methyl methacrylate)). For this purpose, we designed a simple drilling appara- tus. Using this apparatus, we prepared some PMMA samples at 77 K in vacuum. Later, by using an ESR (electron spin resonance spectrometer), we observed ESR signals for these samples at 77 K. This means that mechanoradicals have been successfully pro- duced by mechanical fracture in PMMA using our drilling apparatus. Secondly, we tried to identify the radicals from these spectra through using theoretical analyses and, some computer simulations have been done by suggesting two different theoretical models for these ESR signals. Finally, by using experimental and theoretical data, we showed that our simple apparatus could be used to obtain mechanoradicals from poly- mers. Results were seen to be in very good agreement with the literature. q 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 2195-2200, 1997

Zinc(II) complexes of bidentate Schiff base ligands containing methoxyphenyl and nitrophenyl groups

In the title compounds, bis[2-(3-nitrophenylnitrilomethylidyne)phenolato-N,O]zinc(II), [Zn(C 13 H 9 N 2 O 3 ) 2 ], and bis[2-(3-methoxyphenylnitrilomethylidyne)phenolato-N,O]zinc(II), [Zn(C 14 H 12 NO 2 ) 2 ], the triclinic unit cell contains two inversion-related molecules. In both compounds, the Zn atom is in a slightly distorted tetrahedral coordination involving O and N atoms of two bidentate ligands. The dihedral angle defined by the two chelate rings is 98.09 (4)° for the methoxyphenyl complex and 98.05 (7)° for the nitrophenyl complex. The molecules are cross-linked via intermolecular hydrogen bonds.

Two new mononuclear Ni(II) complexes with reduced ONNO type Schiff base

Abstract N,N′-bis(salicylidene)-1,3-propanediamine (LH2) and N,N′-bis(salicylidene)-2,2′-dimethyl-1,3-propanediamine (DMLH2) were reduced to phenolic amines by using NaBH4. Mononuclear complexes were obtained with Ni (II) in a N3O6 coordination sphere with these amines and N3– ions, in DMF media. It was established with the XRD studies that the coordination spheres were distorted octahedral and the complex obtained with LH2 formed dimeric structures via phenolic OH bonds. The other complex was seen to have monomeric structure. The complexes were characterized by X-ray diffraction, elemental analysis, termogravimetry, IR spectroscopy and simple magnetic susceptibility (Gouy method). In addition, cyclic voltammetric studies have been performed.