Search

Reactions of octachlorocyclotetraphosphazene (OCCP), N4P4Cl8 (1), with two equimolar amounts of N-ethyl-N′-(4-fluorobenzyl)-1,2-diaminoethane (L1) gave the trans-monocyclic-(2) and cis-monocyclic-(3) bis(ethyl-4-fluorobenzylspiro)cyclotetraphosphazenes. The obtained trans-monocyclic-bis-(2) reacted separately with excess n-propyl and iso-propylamines to afford the monocyclic (4c and 4d) and bicyclic (5b and 5c) cyclotetraphosphazenes, respectively. The reactions of trans-monocyclic-bis-(2) with n-propylamine in 1 : 1/1 : 2 mole ratios were also investigated to elucidate the formation pathways of bicyclophosphazenes. Trichloro-n-propylamino-(4a), dichloro-bis(n-propylamino)-(4b) and monochloro-2-trans-6-bis(4-fluorobenzylspiro)bicyclo-(5a) tetraphosphazenes were formed. Thus, it was determined how many Cl atoms in the tetramer ring of 2 were replaced by amines and a route to the formation of the bicyclic product was proposed. Moreover, the reaction of cis-monocyclic-bis (3) was carried out only with excess n-propylamine. Monocyclo-(6a) and bicyclo-(7a) cyclotetraphosphazenes were obtained. Spectroscopic, crystallographic (2 and 4c) and thermal characterization of the new phosphazenes was performed. [ABSTRACT FROM AUTHOR]

The aim of this research is to synthesize and characterize new organic–inorganic hybrid multi-heterocyclic dichlorodispiro(N/N)cyclotriphosphazenes and to elucidate their antituberculosis activities. To achieve this aim, primarily, trans (6a–11a) and cis (6b–11b) unsymmetrical dichlorodispiro(N/N)cyclotriphosphazenes were obtained from ferrocenyldiamines (4 and 5) and benzyl-pendant armed tetrachloromonospirophosphazenes as starting materials. Several spectroscopic techniques (mass spectrometry, FTIR, and 1H, 13C, and 31P NMR), as well as elemental analysis, were employed to characterize the new phosphazenes. All unsymmetrically substituted phosphazenes are expected to be racemic mixtures (RR′/SS′ and RS′/SR′) due to two different stereogenic P-centers. In addition, the molecular and crystal structures of cis-6b, cis-10b, and cis-11b isomers were elucidated via single-crystal X-ray crystallography. They belong to centrosymmetric C2/c, P21/c, and P1¯ space groups, respectively; thus, their crystal lattices must contain both the enantiomers, RR′/SS′ or SR′/RS′. Moreover, only one oxidation–reduction wave was observed for the ferrocenyl-dispirophosphazenes in the reversible cyclic voltammograms. The HOMO and LUMO energy values of the phosphazenes were calculated using the oxidation potential (Eox) and the optical band gap values using Tauc plots, respectively. To determine the phototunable charge storage properties of the four dispirophosphazenes, their memory functions were investigated under UV illumination. The antituberculosis activities of the dichlorodispiro(N/N)cyclotriphosphazenes trans-6a, cis-6b, trans-10a, and cis-10b against Mycobacterium tuberculosis H37Rv (ATCC 27294) strain were evaluated. The results showed that among these compounds, trans-6a (MIC value 18 μg mL−1) was much more effective than the other phosphazenes. [ABSTRACT FROM AUTHOR]

The starting reagents tetrachloro-mono- [1; R1=(CH2)3, R2=H] and tetrachloro-bis- [2; R1=(CH2)3, R2=FPhCH2- and 3; R1=(CH2)2, R2=FPhCH2-] (4-fluorobenzyl)monospiro(N/N)cyclotriphosphazenes, were obtained from the condensation reactions of hexachlorocyclotriphosphazatriene (N3P3Cl6; trimer; HCCP) with N-(4-fluorobenzyl)propane-1,3-diamine (L1), N,N'-bis(4-fluorobenzyl)propane-1,3-diamine (L2) and N,N'-bis(4-fluorobenzyl)ethane-1,2-diamine (L3), respectively. Substitution reactions of 1 and 2 with excess sodium(3-amino-1-propanoxide) separately yielded the only monospiro(N/O)amino-propanoxy-(4-fluorobenzyl)spiro(N/N) (1a) and monospiro-(N/O)aminopropanoxy-bis-(4-fluorobenzyl)spiro(N/N) (2a) cyclophosphazenes. Both monospiroaminopropanoxy (3a) and trans-bisspiroaminopropanoxy (3b) cyclotriphosphazenes were synthesized by the reactions of 3 with the excess sodium(3-amino-1-propanoxide). The structural features of all new products were identified using elemental analysis, FTIR, ESI-MS, 1H, 13C and 31P NMR data. DNA-cleavage activities of 1a-3a and 3b were tested with pBR322 plasmid DNA, and the four cyclotriphosphazenes caused changes in DNA intensity and mobility. It was found that compounds 2a and especially 3b were highly active against DNA. Furthermore, antimicrobial activities of the obtained cyclotriphosphazenes on some bacteria and yeast strains were evaluated and minimum inhibitory concentrations of the active compounds were calculated. According to these results, the most effective compound is 3b. It appears that this compound is even more active against yeasts than the standard antibiotic ketoconazole, even at very low concentrations (156 µM for C. albicans and 312.5 µM for C. tropicalis). [ABSTRACT FROM AUTHOR]

In the present investigation, the condensation reaction of octachlorocyclotetraphosphazene, N4P4Cl8 (1) (tetramer, OCCP), with sodium 3-(N-ferrocenylmethylamino)-1-propanoxide (L) resulted in the formation of the starting compound hexachloromonoferrocenylspiro(N/O)cyclotetraphosphazene (2). Thereafter, reactions of spiro (2) with excesses of 1-(2-aminoethyl)pyrrolidine, 1-(2-aminoethyl)piperidine and 4-(2-aminoethyl)morpholine in dry THF gave hexaaminomono-ferrocenylspiro(N/O)cyclotetraphosphazenes, 2a, 2b, and 2c, respectively. These new products were prepared for investigation of spectral and electrochemical properties, tuning of redox features, and examination of antituberculosis activities. The structures of 2a–2c were elucidated using elemental analysis, mass spectrometry (ESI-MS), FTIR, HMBC, HSQC, 1H, 13C {1H}, and 31P {1H} NMR data. The electrochemical behavior of these products containing monoferrocenyl group was investigated. Their use as potential alternative electrolyte redox couples for dye-sensitized solar cells (DSSC) was examined. The findings may inspire solar cell studies to explore the redox mediator behind the working mechanisms of DSSCs. Conversely, the antituberculosis activities of three compounds were examined against Mycobacterium tuberculosis H37Rv. The MIC values of 2a and 2 b were found to be as 30 and 35 µg/mL, respectively, against the H37Rv reference strain. [ABSTRACT FROM AUTHOR]