Publications by authors named "Zeynel Kılıç"

31 Publications

Phosphorus-nitrogen compounds: part 53-synthesis, characterization, cytotoxic and antimicrobial activity, DNA interaction and molecular docking studies of new mono- and dispirocyclotriphosphazenes with pendant arm(s).

Mol Divers 2021 May 14. Epub 2021 May 14.

Department of Physics, Hacettepe University, 06800, Ankara, Turkey.

Mono-/dispirocyclotriphosphazenes with pendant arm(s) are robust, but they are less investigated inorganic ring systems. In this study, a series of mono (3 and 4)- and dispirocyclotriphosphazenes with 4-chloro-benzyl pendant arm(s) (13-16) was obtained from the Cl exchange reactions of hexachlorocyclotriphosphazene with sodium (N-benzyl)aminopropanoxides (1 and 2). When compound (3) reacted with excess pyrrolidine, morpholine, tetra-1,4-dioxa-8-azaspiro[4,5]decane (DASD) and piperidine, the fully substituted monospirocyclotriphosphazenes (7, 9, 10 and 12) occurred. But, the reactions of 4 with excess piperidine and morpholine produced the gem-piperidino (5)- and morpholino (6)-substituted monospirocyclotriphosphazenes, whereas the reactions of 4 with excess pyrrolidine and DASD gave the fully substituted monospirocyclotriphosphazenes (8) and (11). However, it should be indicated that these derivatives were obtained to be used for the investigation of their spectral, stereogenic and biological properties. The structures of 5, 7 and 14 were determined crystallographically. X-ray data of 5 and 14 displayed that both of compounds were chiral in solid state, and their absolute configurations were assigned as R and RR. Additionally, the antimicrobial activities of phosphazenes were investigated. Minimum inhibitory concentrations, minimal bacterial concentrations and minimum fungicidal concentrations of phosphazenes were determined. The interactions of phosphazenes with plasmid DNA were evaluated by agarose gel electrophoresis. The cytotoxic activities of compounds were studied against L929 fibroblast and DLD-1 colon cancer cells. In addition, density functional theory calculations of 5, 7 and 14 were reported, and their molecular docking studies with DNA, E. coli DNA gyrase and topoisomerase IV were presented.
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http://dx.doi.org/10.1007/s11030-021-10231-5DOI Listing
May 2021

Phosphorus-nitrogen compounds (Part 51): the relationship between spectroscopic and crystallographic data of mono- and di- cyclophosphazene derivatives with 4-fluoro/nitrophenylmethyl pendant arm/arms.

Turk J Chem 2020 1;44(3):559-573. Epub 2020 Jun 1.

Department of Chemistry, Faculty of Science, Ankara University, Ankara Turkey.

A great wealth of structural information about phosphazenes can be gleaned from the combined spectroscopic and crystallographic data. When data from P NMR spectroscopy and X-ray crystallography are put together like pieces in a puzzle, a number of correlations can be obtained for phosphazene derivatives. A systematic study concerning the correlations among the structural parameters (e.g., P NMR data, endocyclic/exocyclic NPN bond angles and bond lengths) revealed some characteristics of mono- and di- cyclophosphazene derivatives bearing 4-fluoro/nitrophenylmethyl pendant arm/arms. These correlations include the relationship between the δ P shifts, the values of electron density transfer parameters Δ(P-N), and the endocyclic and exocyclic NPN bond angles of the cyclophosphazenes. The structural parameters were compared with each other for 19 compounds of 5 different architectural types of cyclophosphazenes with 5- to 7-membered -rings.
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http://dx.doi.org/10.3906/kim-1911-43DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7671196PMC
June 2020

Phosphorus-nitrogen compounds- (Part 50): correlations between structural parameters for cylophosphazene derivatives containing ferrocenyl pendant arm(s).

Turk J Chem 2020 1;44(3):543-558. Epub 2020 Jun 1.

Department of Chemistry, Faculty of Science, Ankara University, Ankara Turkey.

The results of a systematic study of -cyclotri/tetraphosphazenes with ferrocenyl pendant arm on the basis of correlation between structural parameters were presented. The main parameters were obtained from Xray crystallography and P NMR results in order to investigate the relationship between the δ P shift values and endocyclic and exocyclic NPN bond angles, and electron density transfer parameters. Structural parameters derived from 11 types of the ferrocenyl cyclophosphazene derivatives with 5- to 7-membered -rings introduced to the literature from our research group were studied and compared with each other.
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http://dx.doi.org/10.3906/kim-1909-83DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7671203PMC
June 2020

Synthesis and spectroscopic properties of (N/O) mono- and dispirocyclotriphosphazene derivatives with benzyl pendant arms: study of biological activity.

Turk J Chem 2020 11;44(1):15-30. Epub 2020 Feb 11.

Department of Physics, Faculty of Science, Hacettepe University, Beytepe, Ankara Turkey.

The Cl replacement reactions of hexachlorocyclotriphosphazene (trimer; N P Cl ) with sodium (N-benzyl)- aminopropanoxides (1 and 2) produced monospiro- (3 and 4), cis-, and trans-dispirocyclotriphosphazenes (13-16). The monospiro tetrakis-aminocyclotriphosphazenes (5-12) were obtained by the Cl substitutions of 3 and 4 with different secondary amines. The cis- (13 and 14) and trans-dispirophosphazenes (15 and 16) possessed 2 chiral P centers, and they were able to present meso and racemic forms, respectively. Moreover, the structures of compounds 5 and 14 were designated using X-ray data. The absolute configuration of compound 14 was found as SR in the solid state. Analytical and spectroscopic data of the phosphazenes were consistent with their suggested structures. Antimicrobial activities of the benzyl-pendant-armed cyclotriphosphazenes were scrutinized against G(+) and G(-) bacteria and yeast strains. The bacterium most affected by the synthesized compounds was . Minimum inhibitory concentrations and minimal bacterial concentrations were in the range of 125-500 μM. Interactions between the phosphazenes (3-12 and 15) and plasmid DNA were studied with agarose gel electrophoresis. The phosphazene- DNA interaction studies of the cyclotriphosphazenes revealed that phosphazenes 3, 4, and 15 had a substantial effect on supercoiled DNA by cleavage of the double helix.
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http://dx.doi.org/10.3906/kim-1908-17DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7751824PMC
February 2020

Synthesis and characterization of trimeric phosphazene based ionic liquids with tetrafluoroborate anions and their thermal investigations.

Sci Rep 2020 Jul 16;10(1):11705. Epub 2020 Jul 16.

Department of Biochemistry, University of Dumlupınar, Kütahya, Turkey.

The quaternized compounds (PzIL1-9) reacted with sodium tetrafluoroborate (NaBF) to generate phosphazene based ionic liquids (PzILs), PzIL1a-9a. The newly synthesized ionic compounds (PzIL1a-9a) were verified using elemental CHN analyses and functional and spectroscopic (FTIR and H, C, P-NMR) analyses techniques. The thermal properties of PzIL1a-9a were investigated using thermogravimetric analysis (TGA). According to the initial decomposition temperature values calculated based on the TGA thermograms, PzIL7a (213 °C) was recognized to be more thermally stable than the other PzILs studied. PzIL1a-9a exhibited good solubility in the water and demonstrate a typical dielectric relaxation behavior, conductivity levels for both low and high-frequency regions. AC conductivity mechanisms and dielectric relaxation behavior of each sample are investigated by fabricating parallel plate capacitors.
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http://dx.doi.org/10.1038/s41598-020-68709-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7367273PMC
July 2020

Phosphorus-nitrogen compounds: part 30. Syntheses and structural investigations, antimicrobial and cytotoxic activities and DNA interactions of vanillinato-substituted NN or NO spirocyclic monoferrocenyl cyclotriphosphazenes.

J Biol Inorg Chem 2015 Jan 10;20(1):165-78. Epub 2014 Dec 10.

Department of Chemistry, Karabük University, 78050, Karabük, Turkey.

The gradual Cl replacement reactions of NN (1-3) or NO spirocyclic monoferrocenyl cyclotriphosphazenes (4 and 5) with the potassium salt of 4-hydroxy-3-methoxybenzaldehyde (potassium vanillinate) resulted in the mono (1a-5a), geminal (gem-1b-5b), non-geminal (cis-5b and trans -1b-4b), tri (1c, 3c-5c) and tetra-vanillinato-substituted phosphazenes (1d-5d). All the phosphazene derivatives have stereogenic P-center(s), except tetra-substituted ones. The vanillinatophosphazenes have reversible voltammograms with one-electron anodic and cathodic peaks which are attributed to ferrocenyl redox probe. The structures of the new phosphazene compounds were determined by FTIR, MS, (1)H, (13)C{(1)H} and (31)P{(1)H} NMR spectral data. The solid-state structure of cis -5b was examined by single-crystal X-ray diffraction techniques. In addition, the compounds were tested in HeLa cancer cell lines using MTT assay. The 12 phosphazene derivatives were screened for antimicrobial activity, and 3c was very effective against S. aureus even at 4.88 µM concentration, taking into account the MIC values. Besides, interactions between the phosphazenes and pBR322 plasmid DNA were also investigated.
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http://dx.doi.org/10.1007/s00775-014-1223-5DOI Listing
January 2015

Phosphorus-nitrogen compounds. Part 29. Syntheses, crystal structures, spectroscopic and stereogenic properties, electrochemical investigations, antituberculosis, antimicrobial and cytotoxic activities and DNA interactions of ansa-spiro-ansa cyclotetraphosphazenes.

Eur J Med Chem 2014 Nov 5;87:662-76. Epub 2014 Oct 5.

Department of Clinical Microbiology, Kocaeli University, 41380 Kocaeli, Turkey.

A number of novel ansa-spiro-ansa (asa) cyclotetraphosphazenes (1a-5b) was prepared in the range of 63-90 % yields. The structures of the compounds were verified by MS, FTIR, (1)H, (13)C{(1)H} and (31)P{(1)H} NMR, heteronuclear single quantum coherence (HSQC), and heteronuclear multiple-bond correlation (HMBC) techniques. The crystal structures of 1b, 2c and 5a were determined by X-ray crystallography. The compound 2c was analyzed by the changes in the (31)P{(1)H}NMR spectrum in addition of the chiral solvating agent; (R)-(+)-2,2,2-trifluoro-1-(9'-anthryl)-ethanol (CSA), to investigate its stereogenic properties. The result supports that compound 2c was found to be in the racemic mixture. Cyclic voltammetric and chronoamperometric data of the mono-ferrocenyl-spiro-asa-cyclotetraphosphazenes exhibited electrochemically reversible one-electron oxidation of Fe redox centres. The mono-ferrocenyl-spiro-asa compounds (3a-5b) were evaluated for antituberculosis activity against reference strain Mycobacterium tuberculosis H37Rv and M. tuberculosis clinical strain, which is resistant to rifampicin and isoniazid. These compounds appear not to be good candidates for being antituberculosis agents to clinical strains. All of the compounds were screened for antibacterial activities against G(+) and G(-) bacteria, and for antifungal activities against yeast strains. They seem to be more active against Gram positive bacteria than Gram negative. The interactions of the phosphazenes with plasmid DNA and the evaluations for cytotoxic activity against MCF-7 breast cancer cell lines were investigated. The compounds 1b, 2b, 3a and 4a were found to be more effective than Cisplatin against MCF-7 breast cancer cell lines at lower concentrations.
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http://dx.doi.org/10.1016/j.ejmech.2014.10.005DOI Listing
November 2014

Phosphorus-nitrogen compounds part 27. Syntheses, structural characterizations, antimicrobial and cytotoxic activities, and DNA interactions of new phosphazenes bearing secondary amino and pendant (4-fluorobenzyl)spiro groups.

Eur J Med Chem 2013 8;70:294-307. Epub 2013 Oct 8.

Department of Chemistry, Gaziosmanpaşa University, 60150 Taşlıçiftlik Kampüsü, Tokat, Turkey.

A number of partly (7-9) and fully (10a-12d, Scheme 1) substituted mono(4-fluorobenzyl)spiro cyclotriphosphazenes was prepared. The structures of the compounds were determined by MS, FTIR, 1D and 2D NMR techniques. The crystal structures of 9, 11b and 12b were verified by X-ray diffraction analysis. In vitro cytotoxic activity of the phosphazenes (10a-12d) against HeLa cervical cancer cell lines was evaluated. Compound 12c was found to be the most effective, as it is a cytotoxic reagent that might activate apoptosis by altering mitochondrial membrane potential. Compounds 10b, 11b and 12b showed very good activity against yeast strains Candida tropicalis and Candida albicans. BamHI and HindIII digestion results demonstrate that the compounds (10a-12a, 10b-12b, 10d-12d), and (9, 10c-12c) bind with G/G and A/A nucleotides, respectively.
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http://dx.doi.org/10.1016/j.ejmech.2013.09.046DOI Listing
September 2014

Phosphorus-nitrogen compounds. Part 24. Syntheses, crystal structures, spectroscopic and stereogenic properties, biological activities, and DNA interactions of novel spiro-ansa-spiro- and ansa-spiro-ansa-cyclotetraphosphazenes.

Inorg Chem 2012 Dec 19;51(23):12841-56. Epub 2012 Nov 19.

Department of Chemistry, Ankara University, 06100 Ankara, Turkey.

The reactions of octachlorocyclotetraphosphazene, N(4)P(4)Cl(8), with N(2)O(2) donor-type aminopodands (1a, 1b, 1g, and 1h) afforded two kinds of derivatives, namely, spiro-ansa-spiro (sas) (2a, 2b, 2g, and 2h) and ansa-spiro-ansa (asa) (3a and 3b) phosphazenes. The partly substituted sas phosphazenes (2a and 2b) reacted with excess pyrrolidine and morpholine in tetrahydrofuran to produce the tetrapyrrolidino (2c and 2d) and morpholino (2e and 2f) derivatives. The reactions of the asa phosphazenes (3a and 3b) with excess pyrrolidine and morpholine produced gem-2-trans-6-dichloropyrrolidinophosphazenes (3c and 3d) and -morpholinophosphazenes (3e and 3f). However, the fully substituted products were not obtained in these solvents. In addition, the expected fully substituted compound was not obtained from the reaction of 3a with excess pyrrolidine by standard or microwave-assisted methods. The reaction of the long-chain starting compound (1g) with N(4)P(4)Cl(8) gave sas (2g) and the interesting 2,6-ansa-spiro-bicyclo product (bicyclo-2,6-as; 4g), while the reaction of 1h with N(4)P(4)Cl(8) yielded only sas (2h). The structural investigations of the compounds were verified by elemental analyses, mass spectrometry, Fourier transform infrared, and DEPT, HSQC, HMBC, (1)H, (13)C, and (31)P NMR techniques. The crystal structures of 2b, 3a, 3b, 3e, and 4g were determined by X-ray crystallography. Compounds 2a-2h, 3a-3f, and 4g had two stereogenic P atoms. Compound 3b had one enantiomer according to the Flack parameter, and 3f was a racemic mixture, as shown by chiral high-performance liquid chromatography and chiral-solvating-agent, (R)-(+)-2,2,2-trifluoro-1-(9'-anthryl)ethanol, experiments. Furthermore, compounds 2a, 2c, and 2d exhibited weak antibacterial activity against (G+) bacterium, and 3c and 3d displayed moderate antifungal activity against Candida tropicalis. Gel electrophoresis data demonstrated that 2e, 3c, and 3e promoted the formation of DNA cleavage. The prevention of BamHI digestion by 2a-2f and 3a-3f, except 2b and 2e, disclosed binding with GG nucleotides in DNA.
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http://dx.doi.org/10.1021/ic3017134DOI Listing
December 2012

Phosphorus-nitrogen compounds. Part 23: syntheses, structural investigations, biological activities, and DNA interactions of new N/O spirocyclotriphosphazenes.

Spectrochim Acta A Mol Biomol Spectrosc 2012 Feb 31;86:214-23. Epub 2011 Oct 31.

Department of Chemistry, Ankara University, 06100 Ankara, Turkey.

The Schiff base compounds (1 and 2) are synthesized by the condensation reactions of 2-furan-2-yl-methylamine with 2-hydroxy-3-methoxy- and 2-hydroxy-5-methoxy-benzaldehydes and reduced with NaBH(4) to give the new N/O-donor-type ligands (3 and 4). The monospirocyclotriphosphazenes containing 1,3,2-oxazaphosphorine rings (5 and 6) are prepared from the reactions of N(3)P(3)Cl(6) with 3 and 4, respectively. The reactions of 5 and 6 with excess pyrrolidine, morpholine, and 1,4-dioxa-8-azaspiro [4,5] decane (DASD) produce tetrapyrrolidino (5a and 6a), morpholino (5b and 6b), and 1,4-dioxa-8-azaspiro [4,5] deca (5c and 6c) spirocyclotriphosphazenes. The structural investigations of the compounds are examined by (1)H, (13)C, (31)P NMR, DEPT, HSQC, and HMBC techniques. The solid-state structures of 5, 5a, and 6 are determined using X-ray crystallography. The compounds 5a, 5b, 5c, 6a, 6b, and 6c are subjected to antimicrobial activity against six patojen bacteria and two yeast strains. In addition, interactions between these compounds and pBR322 plasmid DNA are presented by agarose gel electrophoresis.
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http://dx.doi.org/10.1016/j.saa.2011.10.027DOI Listing
February 2012

Syntheses, spectroscopic properties and stereochemistry of bis-C-pivot macrocycles with two dialkyl phosphonate groups.

Spectrochim Acta A Mol Biomol Spectrosc 2011 Oct 23;81(1):441-8. Epub 2011 Jun 23.

Department of Chemistry, Ankara University, 06100 Tandoğan-Ankara, Turkey.

Bis-C-pivot macrocycles containing dimethyl (1a, 2a) or diethyl phosphonate (1b, 2b) groups have been prepared by adding dimethyl or diethyl phosphite to two -CH=N bonds in corresponding dibenzo-bis-imino crown ethers (1 and 2). Bis-C-pivot macrocycles possess two equivalent stereogenic centres giving rise to diastereoisomers (meso and racemate). The structures were characterized by elemental analysis, FTIR, MS, TGA, DSC and NMR measurements. (1)H, (13)C and (31)P NMR assignments were made for the isolated meso form of compounds 2a and 2b and for the meso and racemic forms of compounds 1a and 1b by analysis of chemical shifts, signal intensities and splitting patterns and the DEPT and 2D HETCOR NMR techniques. Thermal analysis and (1)H NMR showed that the crystallised form of compound 1a contained an equimolar amount of water of crystallisation.
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http://dx.doi.org/10.1016/j.saa.2011.06.034DOI Listing
October 2011

Phosphorus-nitrogen compounds. 21. Syntheses, structural investigations, biological activities, and DNA interactions of new N/O spirocyclic phosphazene derivatives. The NMR behaviors of chiral phosphazenes with stereogenic centers upon the addition of chiral solvating agents.

Inorg Chem 2010 Aug;49(15):7057-71

Department of Chemistry, Kirikkale University, Kirikkale, Turkey.

The reactions of hexachlorocyclotriphosphazatriene, N(3)P(3)Cl(6), with N/O-donor-type N-alkyl (or aryl)-o-hydroxybenzylamines (1a-1e) produce mono- (2a-2e), di- (3a-3d), and tri- (4a and 4b) spirocyclic phosphazenes. The tetrapyrrolidino monospirocyclic phosphazenes (2f-2i) are prepared from the reactions of partly substituted compounds (2a-2d) with excess pyrrolidine. The dispirodipyrrolidinophosphazenes (3e-3h) and trispirophosphazenes (3i-3k) are obtained from the reactions of trans-dispirophosphazenes with excess pyrrolidine and sodium (3-amino-1-propanoxide), respectively. Compounds 3a-3d have cis and trans geometric isomers. Only the trans isomers of these compounds are isolated. Compounds 3a-3h have two stereogenic P atoms. They are expected to be in cis (meso) and trans (racemic) geometric isomers. In the trans trispiro compounds (3i-3k), there are three stereogenic P atoms. They are expected to be in racemic mixtures. The stereogenic properties of 3a-3k are confirmed by (31)P NMR spectroscopy upon the addition of the chiral solvating agent; (S)-(+)-2,2,2-trifluoro-1-(9'-anthryl)ethanol. The molecular structures of 3i-3k, 4a, and 4b look similar to a propeller, where the chemical environment of one P atom is different from that of others. Additionally, 4a and 4b are also expected to exist as cis-trans-trans and cis-cis-cis geometric isomers, but both of them are found to be in cis-trans-trans geometries. The solid-state structures of 2a, 2e, 2f, 3e, and 3f are determined by X-ray crystallography. The compounds 2f-2i, 3e-3i, and 3k are screened for antibacterial activity against gram-positive and gram-negative bacteria and for antifungal activity against yeast strains. These compounds (except 3f) have shown a strong affinity against most of the bacteria. Minimum inhibitory concentrations (MIC) are determined for 2f-2i, 3e-3i, and 3k. DNA binding and the nature of interaction with pUC18 plasmid DNA are studied. The compounds 2f-2i, 3e-3i, and 3k induce changes on the DNA mobility. The prevention of BamHI and HindIII digestion (except 2g) with compounds indicates that the compounds bind with nucleotides in DNA.
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http://dx.doi.org/10.1021/ic100781vDOI Listing
August 2010

Phosphorus-nitrogen compounds. Part 20: Fully substituted spiro-cyclotriphosphazenic lariat (PNP-pivot) ether derivatives.

Spectrochim Acta A Mol Biomol Spectrosc 2010 Aug 4;76(3-4):401-9. Epub 2010 May 4.

Department of Chemistry, Ankara University, Tandoğan 06100, Ankara, Turkey.

The condensation reactions of partly substituted spiro-cyclotriphosphazenic lariat (PNP-pivot) ethers, N(3)P(3)[(o-NHPhO)(2)R]Cl(4) [where R=-CH(2)CH(2)- (1) and -CH(2)CH(2)OCH(2)CH(2)- (2)] with morpholine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD) produce fully substituted morpholino (3 and 4) and 1,4-dioxa-8-azaspiro[4,5]deca (5 and 6) phosphazenes. These are the new examples of the spiro-cyclophosphazenic lariat ether derivatives with N(2)O(x) (x=2 and 3) donor type containing 11- and 14-membered macrocycles. The solid state structures of 3, 5 and 6 have been determined by X-ray diffraction techniques. Compound 3 has intermolecular N-H...O hydrogen bond, compound 5 has intra- and intermolecular N-H...O hydrogen bonds, while compound 6 has intramolecular N-H...O and O-H...N and intermolecular N-H...O and O-H...O hydrogen bonds. The correlations of the endocyclic (alpha) and exocyclic (alpha') NPN bond angles with deltaP(spiro) values are investigated. The structural investigations of 3-6 have been verified by elemental analyses, MS, FTIR, (1)H, (13)C and (31)P NMR, DEPT and HETCOR techniques.
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http://dx.doi.org/10.1016/j.saa.2010.04.007DOI Listing
August 2010

Phosphorus-nitrogen compounds. 18. Syntheses, stereogenic properties, structural and electrochemical investigations, biological activities, and DNA interactions of new spirocyclic mono- and bisferrocenylphosphazene derivatives.

Inorg Chem 2009 Nov;48(21):10102-16

Department of Chemistry, Ankara University, 06100 Ankara, Turkey.

The reactions of hexachlorocyclotriphosphazatriene, N(3)P(3)Cl(6), with mono- (1 and 2) and bisferrocenyldiamines (3-5), FcCH(2)NH(CH(2))(n)NHR(1) (R(1) = H or FcCH(2)-), produce mono- (6 and 7) and spirocyclic bisferrocenylphosphazenes (8-10). The fully substituted phosphazenes (11-15 and 18-21) are obtained from the reactions of corresponding partly substituted phosphazenes (6-10) with excess pyrrolidine and NH(2)(CH(2))(3)ONa, respectively. The reactions of 6 with 1-aza-12-crown-4 afford geminal (16) and tris (17) crown ether-substituted phosphazenes. The structural investigations of the compounds have been verified by elemental analyses, mass spectrometry, Fourier transform IR, (1)H, (13)C, and (31)P NMR, and DEPT, COSY, HETCOR, and HMBC techniques. The crystal structures of 7, 10, 11, and 15 have been determined by X-ray crystallography. In 16 and 17, there are one and two stereogenic P atoms, respectively, and they are expected to be in enantiomeric mixtures. The structures of 18-21 look similar to a propeller. In 20 and 21, there are two stereogenic P atoms, and they exist as cis (meso; 20a and 21a) and trans (racemic; 20b and 21b) geometric isomers, according to the chiral solvating agent (S)-(+)-2,2,2-trifluoro-1-(9'-anthryl)ethanol experiments. Moreover, the compounds 18 and 19 have three stereogenic P atoms, and they exist as enantiomeric mixtures. Cyclic voltammetric investigations of compounds 6-21a reveal that ferrocene redox centers undergo oxidation concurrently at the same potential with basically reversible peaks, and these compounds appear to be quite robust electrochemically. The compounds 11-15 have been screened for antibacterial activity against gram positive and gram negative bacteria and for antifungal activity against yeast strains.The compounds 11, 12, 14, and 15 are evaluated for antituberculosis activity against reference strain Mycobacterium tuberculosis H37Rv (ATCC 27294). Interactions between compounds 11-15 and pBR322 plasmid DNA are studied by agarose gel electrophoresis. These compounds induce conformational changes in the DNA helix.
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http://dx.doi.org/10.1021/ic901039kDOI Listing
November 2009

Phosphorus-nitrogen compounds. 14. Synthesis, stereogenism, and structural investigations of novel n/o spirocyclic phosphazene derivatives.

Inorg Chem 2007 Nov 17;46(23):9931-44. Epub 2007 Oct 17.

Department of Chemistry, Ankara University, 06100 Tandogan-Ankara, Turkey.

The reactions of hexachlorocyclotriphosphazatriene, N3P3Cl6, with N/O donor-type N-alkyl-o-hydroxybenzyl- and o-hydroxynaphthylamines result in novel mono- (3a, 4a and 4b), di- (5a and 5b), and tri- (3b, 6a, and 6b) spirocyclic phosphazene derivatives. The tetrakis-pyrrolidinophosphazene, 3b, has been obtained from the reaction of partly substituted compound 3a with the excess pyrrolidine in tetrahydrofuran. The relationship between the endocyclic NPN (alpha) and exocyclic NPO (alpha') bond angles of the analogous spirocyclic phosphazenes with the deltaP shifts of NPO phosphorus atoms have been presented. It was observed that there is a linearity between alpha angles and deltaP shifts, while no linear relationship has been observed for alpha' angles. In addition, we have found the correlation between Delta(P-N) and deltaNPO shifts, which implies a linear relationship. Delta(P-N)=(a-b), where a and b are the average lengths of two adjacent P-N bonds. The structural investigations of all of the compounds have been made by elemental analyses; mass spectrometry; Fourier transform infrared spectroscopy; one-dimensional 1H, 13C, and 31P NMR; distortionless enhancement by polarization transfer; and two-dimensional correlation spectroscopy, heteronuclear shift correlation, and heteronuclear multiple-bond correlation homo- and heteronuclear correlation techniques. The solid-state structures of 3a, 4a, 4b, and 5a have been determined by X-ray crystallographic techniques. The asymmetric units of compounds 3a and 4a contain two independent molecules, and 3a has strong intermolecular N-H...N hydrogen bonds linking three phosphazene rings. The molecular structure of 6a looks like a propeller where the chemical environment of P1 is different from that of P2 and P3. On the other hand, compounds 5a and 5b are expected to exist as cis- or trans-geometric isomers and to be in cis (meso) or trans (racemic) configurations. The crystallographic and preliminary chiral solvating agents results show that both of them are trans (racemic). In addition, 6a and 6b are also expected to exist as cis-trans-trans- and cis-cis-cis-geometric isomers; both of them are found to be in cis-trans-trans geometries. According to the two-dimensional spectroscopic data, the possible conformations of 3a and 4a in CDCl3 are the same with the solid-state structures.
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http://dx.doi.org/10.1021/ic701216fDOI Listing
November 2007

C-bis-pivot lariat ethers: synthesis and spectral investigations on new 15- and 17-membered coronands containing dimethoxyphosphoryl groups.

Spectrochim Acta A Mol Biomol Spectrosc 2008 Aug 6;70(3):542-9. Epub 2007 Aug 6.

Department of Chemistry, Faculty of Science, Ankara University, 06100 Tandoğan, Ankara, Turkey.

The reactions of dibenzo-diaza crown ethers (coronands) (1 and 2) with dimethylphosphite led to the formation of the mixture of meso and racemic C-bis-pivot lariat ethers (3 and 4) containing dimethoxyphosphoryl groups. We have failed to make the resolution of the mixture, nevertheless, the detailed characterization and spectral investigations of compounds 3 and 4 have been made by elemental analyses, FTIR, (1)H NMR, (13)C NMR, (31)P NMR, COSY, DEPT, HETCOR and HMBC spectral data. The salient features of the spectral data of these compounds have been presented.
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http://dx.doi.org/10.1016/j.saa.2007.07.049DOI Listing
August 2008

Preparation and characterization of diethylene glycol bis(2-aminophenyl) ether-modified glassy carbon electrode.

Anal Chim Acta 2006 Jul 22;573-574:26-33. Epub 2006 Mar 22.

Ankara University, Faculty of Science, Department of Chemistry, 06100 Tandoğan, Ankara, Turkey.

Diethylene glycol bis(2-aminophenyl) ether (DGAE) diazonium salt was covalently electrografted on a glassy carbon (GC) surface and behavior of this novel surface was investigated. Synthesis of DGAE diazonium salt (DGAE-DAS) and in situ modification of GC electrode were performed in aqueous media containing NaNO2, keeping the temperature below +4 degrees C. For the characterization of the modified electrode surface by cyclic voltammetry, dopamine (DA) was used to prove the attachment of the DGAE-DAS on the GC surface. Raman spectroscopy and electrochemical impedance spectroscopy (EIS) were used to observe the molecular bound properties of the adsorbates at the DGAE-modified GC surface (GC-DGAE). The EIS results were analyzed using the Randles equivalent circuit. The charge transfer resistance on bare GC and the modified surface were calculated using the model equivalent circuit for the ferrocene redox system. Surface coverage was found as 0.4 showing the presence of high pinhole and defects in the modified electrode. The rate constant of electron transfer through the monolayer was calculated for ferrocene. Working potential range and the stability of the DGAE-modified GC electrode was also determined.
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http://dx.doi.org/10.1016/j.aca.2006.03.056DOI Listing
July 2006

Phosphorus-nitrogen compounds. Part 13. Syntheses, crystal structures, spectroscopic, stereogenic, and anisochronic properties of novel spiro-ansa-spiro-, spiro-bino-spiro-, and spiro-crypta phosphazene derivatives.

Inorg Chem 2006 Oct;45(21):8755-67

Department of Chemistry, Ankara University, 06100 Tandogan-Ankara, Turkey.

The condensation reactions of N2Ox (x = 2, 3) donor-type aminopodand (4) and dibenzo-diaza-crown ethers (5, 6, and 9) with hexachlorocyclotriphosphazatriene, N3P3Cl6, produce two kinds of partially substituted novel phosphazene derivatives, namely, spiro-bino-spiro- (19) and spiro-crypta (21, 22, and 25) phosphazenes. The partially substituted spiro-ansa-spiro-phosphazene (11) reacted with pyrrolidine and 1,4-dioxa-8-azaspiro[4,5]decane (DASD) give the corresponding new fully substituted phosphazenes (14 and 16). Unexpectedly, the reactions of 23 and 24 with pyrrolidine result in only geminal crypta phosphazenes (26 and 27). The solid-state structures of 16 and 22 have been determined by X-ray diffraction techniques. The relative inner hole-size of the macrocycle in the radii of 22 is 1.27 A. The relationship between the exocyclic NPN (alpha') and endocyclic (alpha) bond angles for spiro-crypta phosphazenes and exocyclic OPN (alpha') bond angles for spiro-ansa-spiro- and spiro-bino-spiro-phosphazenes with 31P NMR chemical shifts of NPN and OPN phosphorus atoms, respectively, have been investigated. The structures of 10, 14, 16, 19, 21, 22, and 25-27 have also been examined by FTIR, 1H, 13C, and 31P NMR, HETCOR, MS, and elemental analyses. The 31P NMR spectra of 10, 21, 22, and 25 indicate that the compounds have anisochrony. In compounds 16 and 22, the spirocyclic nitrogen atoms have pyramidal geometries resulting in stereogenic properties.
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http://dx.doi.org/10.1021/ic060630nDOI Listing
October 2006

1,3-Bis[2-(2-hydroxybenzylideneamino)phenoxy]propane.

Acta Crystallogr C 2004 Nov 22;60(Pt 11):o803-5. Epub 2004 Oct 22.

Department of Physics, Hacettepe University, 06800 Beytepe, Ankara, Turkey.

The title compound [systematic name: 2,2'-[1,3-propanediyldioxydi-o-phenylenebis(nitrilomethylidyne)]diphenol], C(29)H(26)N(2)O(4), exists as the phenol-imine form in the crystal, and there are strong intramolecular O-H...N hydrogen bonds, with O...N distances of 2.545 (2) and 2.579 (2) A. The C=N imine bond distances are in the range 1.276 (2)-1.279 (2) A and the C=N-C bond angles are in the range 123.05 (16)-124.64 (17) degrees . The configurations about the C=N bonds are anti (1E).
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http://dx.doi.org/10.1107/S0108270104022565DOI Listing
November 2004

4',4',6',6'-Tetrachloro-3,4-dihydro-3-(6-methylpyridin-2-yl)spiro[1,3,2-benzoxazaphosphinine-2,2'-(2lambda5,4lambda5,6lambda5-cyclotriphosphazene)].

Acta Crystallogr C 2004 Sep 11;60(Pt 9):o639-41. Epub 2004 Aug 11.

Department of Physics, Hacettepe University, 06800 Beytepe, Ankara, Turkey.

The title compound, C13H12Cl4N5OP3, is a phosphazene derivative with a bulky substituted spirocyclic ring. The C3NPO spirocyclic ring has a twist-boat conformation, while the phosphazene ring has a very flattened boat conformation.
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http://dx.doi.org/10.1107/S0108270104016518DOI Listing
September 2004

4,4,6,6-Tetrachloro-2,2-(ethylenedioxydi-o-phenylenediimino)-2lambda5,4lambda5,6lambda5-cyclotriphosphazene.

Acta Crystallogr C 2004 Jul 12;60(Pt 7):o461-3. Epub 2004 Jun 12.

Hacettepe University, Department of Physics, 06800 Beytepe, Ankara, Turkey.

The title ligand, C14H14Cl4N5O2P3, is a cyclophosphazene lariat (PNP pivot) ether with a spiro-cyclic 11-membered macrocyclic ring containing two ether O and two N atoms; the phosphazene ring is nearly planar. The macrocyclic ring contains a four-centred (trifurcate) N-H...O/N-H...N hydrogen bond, and the relative inner-hole size of the macrocycle is approximately 1.14 A in radius. The molecules are linked about inversion centres by N-H...N hydrogen bonds into centrosymmetric dimers.
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http://dx.doi.org/10.1107/S0108270104010169DOI Listing
July 2004

4,4,6,6-Tetrachloro-2,2-(propylenedioxydi-o-phenylenediimino)-2lambda5,4lambda5,6lambda5-cyclotriphosphazene.

Acta Crystallogr C 2004 Jun 11;60(Pt 6):o381-3. Epub 2004 May 11.

Hacettepe University, Department of Physics, 06800 Beytepe, Ankara, Turkey.

The title compound, C(15)H(16)Cl(4)N(5)O(2)P(3), is a cyclophosphazenic lariat (PNP-pivot) ether with a spiro-cyclic 12-membered macrocyclic ligand containing two ether O and two N atoms; the phosphazene ring is nearly planar. In the macrocyclic ring, there is a four-center (trifurcate) N-H.O/N-H.N hydrogen bond. The relative inner-hole size of the macrocycle is estimated as approximately 0.95 A.
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http://dx.doi.org/10.1107/S0108270104006894DOI Listing
June 2004

1,14-dioxa-5,10-diaza-2,3:12,13-dibenzocyclooctadeca-2,12-diene monohydrate.

Acta Crystallogr C 2004 Apr 31;60(Pt 4):o278-80. Epub 2004 Mar 31.

Hacettepe University, Department of Physics, 06800 Beytepe, Ankara, Turkey.

The title compound, C(22)H(30)N(2)O(2).H(2)O, is an 18-membered diaza-crown ether ligand containing two ether O and two aza N atoms. In the macrocyclic ring, the mean N.O distance is 4.526 (4) A. The macrocyclic inner-hole size, estimated as twice the mean distance of the donor atoms from their centroid, is approximately 2.29 A.
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http://dx.doi.org/10.1107/S0108270104004949DOI Listing
April 2004

Crystal structure of N,N,N',N'-tetrakis(methyldiphenylphosphino)-bis(2'-phenoxy)-3,6-dioxaoctane.

Anal Sci 2003 Mar;19(3):465-6

Hacettepe University, Department of Physics, 06532 Beytepe-Ankara, Turkey.

The title molecule, [C70H68N2O4P4], is a polydentate podand consisting of four etheral oxygens, two tertiary amine nitrogens and four diphenylphosphin groups. It crystallizes in the triclinic space group P1, and there is only one half a molecule in the asymmetric unit. The coordinations around the N and P atoms are pyramidal. The conformations about C20-C21, O2-C21 and O2-C22 are gauche, anti and anti, respectively.
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http://dx.doi.org/10.2116/analsci.19.465DOI Listing
March 2003

Crystal structure of 2,5-dioxa-13,17-diazatricyclo[17.4.0.0(6,11)]-tricosa-6,8,10,12,17,19,21,23(1)-octaene.

Anal Sci 2002 Sep;18(9):1065-6

Hacettepe University, Department of Physics, Beytepe-Ankara, Turkey.

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http://dx.doi.org/10.2116/analsci.18.1065DOI Listing
September 2002

Crystal structure of 1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one-4-[(1E)-(aminomethylidenyl)]-5'-hydroxy-benzo-15-crown-5.

Anal Sci 2002 Apr;18(4):495-6

Hacettepe University, Department of Physics, Beytepe-Ankara, Turkey.

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http://dx.doi.org/10.2116/analsci.18.495DOI Listing
April 2002