Fatma Yuksel

Synthesis and solvent effects on the spectroscopic properties of octatosylamido phthalocyanines

Octatosylamido-substituted metal-free, Ni(II) and Zn(II) phthalocyanines (pcs, 3a–c) have been synthesized from 4,5-dicyano-N,N’-ditosyl-o-phenylenediamine (2, tosyl: toluene-p-sulfonyl) in the presence of an anhydrous metal salt and a strong base. The new compounds have been characterized by elemental analysis, IR and UV-vis spectroscopy, different NMR techniques (1H, 13C, 1H–15N HSQC, 1H–13C HSQC and 1H–13C HMBC) and mass spectroscopy. The influence of the solvent on the 1H, 13C NMR and UV-vis spectra has been determined. In chloroform, 3a–c are able to form intramolecular hydrogen bonds between four NH and oxygen atoms from neighbouring tosyl units and two tosyl groups occur in one single molecule: while four tosyl units are in the pc plane, the other four are nearly vertical to it. They have different chemical environments because of the magnetic anisotropy of the pc ring. For this reason, in chloroform, each of the protons and carbon atoms gives two sets of signals in the 1H and 13C NMR spectra of pcs. In tetrahydrofuran, the intramolecular hydrogen bonding of pcs is disrupted and all tosyl units are located in the same environment. In the electronic spectra of 3a–c, all bands change with the solvent. This solvatochromism is caused by solvent basicity. Compounds 3a–c show rapid and reversible colour change upon addition of a base.

4,5-, 3,6-, and 3,4,5,6-tert-Butylsulfanylphthalonitriles: synthesis and comparative structural and spectroscopic analyses

Three tert-butylsulfanylphthalonitriles have been prepared with optimized synthetic procedures. Their comparative structural analyses have been completed, with a focus on IR and NMR spectroscopy and refined X-ray structural data. Miscellaneous parameters such as UV absorption, melting points, and related polarity of the compounds are summarized.

First paraben substituted cyclotetraphosphazene compounds and DNA interaction analysis with a new automated biosensor.

Cancer, as one of the leading causes of death in the world, is caused by malignant cell division and growth that depends on rapid DNA replication. To develop anti-cancer drugs this feature of cancer could be exploited by utilizing DNA-damaging molecules. To achieve this, the paraben substituted cyclotetraphosphazene compounds have been synthesized for the first time and their effect on DNA (genotoxicity) has been investigated. The conventional genotoxicity testing methods are laborious, take time and are expensive. Biosensor based assays provide an alternative to investigate this drug/compound DNA interactions. Here for the first time, a new, easy and rapid screening method has been used to investigate the DNA damage, which is based on an automated biosensor device that relies on the real-time electrochemical profiling (REP™) technology. Using both the biosensor based screening method and the in vitro biological assay, the compounds 9 and 11 (propyl and benzyl substituted cyclotetraphosphazene compounds, respectively), have resulted in higher DNA damage than the others with 65% and 80% activity reduction, respectively.

Synthesis of a new class of fused cyclotetraphosphazene ring systems.

Octachlorocyclotetraphosphazene (1) was reacted with butylamines [n-butyl, i-butyl, sec-butyl, and t-butyl] in a 1:0.8 mol ratio in THF to obtain cyclotetraphosphazenes bearing a P-NH group, N4P4Cl7(NHR) [R = n-butyl (2a), i-butyl (2b), sec-butyl (2c), t-butyl (2d)](2a-d). The cyclotetraphosphazene derivatives 2a, 2b, and 2c were treated with sodium hydride giving rise to a new type of cyclophosphazene compounds (P8N8 ring) consisting of three fused tetramer rings (3a-c). Whereas reaction of sodium hydride with the t-butylaminocyclophosphazene derivative (2d) gave a P-O-P bridged compound (4) presumably as a result of hydrolysis reaction associated with moisture in the solvent. It is likely that the 16-membered cyclooctaphosphazene derivatives (3a-c) are formed by a proton abstraction/chloride ion elimination, intramolecular nucleophilic attack, ring opening and intermolecular condensation processes, respectively.

Conversion of a cyclotriphosphazene to a cyclohexaphosphazene by ring expansion.

Deprotonation of a cyclotriphosphazene with a tert-butylamino group in the side chain results in ring expansion to a very stable, planar cyclohexaphosphazene derivative that still contains eight P-Cl bonds suitable for forming macromolecular structures.

Synthesis and characterizations of peripheral octa-amino and octa-amidophthalocyanines

Novel 2,3,9,10,16,17,23,24-octaamino substituted Ni(II) phthalocyanine (2) was synthesized from tosylamido (tosyl: toluene-p-sulphonyl) derivative by the cleavage of tosyl groups in the presence of 90% sulfuric acid. Octa-hexanoylamido Ni(II) phthalocyanine (3a) and octa-lauroylamido Ni(II) phthalocyanine (3b) were obtained by reacting of octa-amino Ni(II) phthalocyanine (2) with hexanoyl chloride and lauroyl chloride, respectively. The new compounds have been characterized by elemental analysis, FT-IR, NMR and UV-vis spectroscopy and mass spectrometry. The aggregation behaviors of new compounds were investigated by UV-vis spectroscopy.

Nucleophilic substitution reactions of 10- and 11-membered fluorodioxy ansa cyclotriphosphazene derivatives.

The reactions of cyclophosphazenes with 10-membered ansa-{N3P3Cl4[OCH2(CF2)3CH2O] (1a)} and 11-membered ansa-{N3P3Cl4[OCH2(CF2)4CH2O] (1b)} rings with the sodium salts of methanol in a THF solution at different molar ratios were used to investigate the reaction pathways and mechanism of nucleophilic substitution at the PCl2 and PCl(OR) phosphorus atoms. The reactions afforded eleven products, whose structures have been characterized by elemental analysis, mass spectrometry, (1)H, (19)F and (31)P NMR spectroscopy and X-ray crystallography; mono-methoxy derivatives (2a, 3a, 3b), di-methoxy derivatives (5a-7a, 5b), tri-methoxy derivatives (8a, 8b) and the tetra-methoxy derivatives (9a, 9b). The X-ray crystallographic studies of four compounds (6a-8a and 8b) demonstrated unambiguously that nucleophilic substitution reactions at the ansa-ring PCl(OR) phosphorus atoms of the cyclotriphosphazene compounds N3P3Cl4[OCH2(CF2)nCH2O] n = 3 (1a) and 4 (1b) occurred with a retention of configuration for both the 10- and 11-membered fluorodioxy ansa rings, respectively. The results confirmed that the reactions with 1a containing the 10-membered ansa-ring occurred competitively at both the PCl2 and P(OR)Cl moieties with an approximate 8 : 1 preference at the PCl2 group, whereas reactions with 1b containing the 11-membered ansa-ring occurred exclusively at the PCl2 group before the P(OR)Cl moiety. The results were mainly rationalized in terms of the P-Cl bond lengths of the reactants and the cation-assisted mechanism of reaction.

Unexpected Ring Expansion of a Four-Membered Cyclophosphazane

Nucleophilic substitution reactions of the N(R),N(R)-spiro-bridged octachlorobis(cyclotriphosphazene), N3P3Cl4[N(CH2)5CH3]2N3P3Cl4 (1), with sodium salts of alcohols (1,3-propanediol, 2,2,3,3,4,4-hexafluoro-1,5-pentanediol, and phenol) give ansa products (2-4) via an unexpected rearrangement. These products were characterized by elemental analysis, mass spectrometry, and (1)H and (31)P NMR spectroscopy. The molecular structures of compounds 3 and 4 were also established by X-ray crystallography. This new class of phosphazene structures consists of three fused P3N3 rings that arise from expansion of the four-membered phosphazane ring in 1 to a six-membered N3P3 ring during alcoholysis reactions.

Structural and Optical Properties of New Naphthalene and Perylene Imide Imidazoles

ABSTRACT New unsymmetrically substituted naphthalene and perylene imide imidazoles, N-(2-ethylhexyl)-naphthalene-3,4-(4,5-dicyano-1,2-benzimidazole)-9,10-dicarboxyimide and N-(1-heptyloctyl)-perilene-3,4-(4,5-dicyano-1,2-benzimid-azole)-9,10-dicarboxyimide, were synthesized via condensation reactions of diaminophthalonitrile and aromatic monoimide monoanhydride derivatives. Their structural analyses have been conducted by using general spectroscopic methods including FT-IR, 1H- and 13C-NMR, mass and elemental analysis. The molecular structure of naphthalene derivative was also determined by single crystal x-ray diffraction. Electronic absorption and emission properties were investigated on comparison. For studied compounds, both DFT and TDDFT calculations were carried out with the 6-311G(d,p) basis set, taking into account solvation effects by means of polarizable continuum model as implemented in the Gaussian 09 package.

6,6-[Ethyl-enebis(sulfanediyl)]-2-(2-methoxy-ethyl)-1,2,3,4,5,6-hexa-hydro-1,5-methano-1H-azocino[4,3-b]indol-3-one.

The title compound, C19H22N2O2S2, consists of a tetracyclic ring system containing an azocine skeleton with methoxyethyl and dithiolane groups as substituents. The benzene and five-membered N-heterocyclic rings are nearly coplanar, making a dihedral angle of 0.81 (12)°. The dithiolane ring adopts an envelope conformation. Intermolecular N—H⋯O hydrogen-bonding and weak C—H⋯π interactions are present in the crystal structure.