A Selective Fluorescence Sensor for Fe (III) Based on Phenanthroimidazole Imine Compound.

Experimental studies in the aqueous solution are crucial for the detection of metal cations in environmental and biological media. Polymer materials allow to work in aqueous media for fluorescent substances which are insoluble in water. Fluorescence sensor studies of the phenanthroimidazole imine compound (PI) synthesized previously by our group were performed in the polymer medium and the selective response to Fe (III) cation was obtained. The resulting sensor exhibited a selective fluorescence quenching effect to Fe (III). A logarithmic calibration graph was obtained in the range of 5.0 × 10- 5 and 1.0 × 10- 2 M. The interference effects of other ions besides Fe (III) have been examined and it has been observed that PI compound behaves selectively to Fe (III) ion in aqueous media. In addition, regeneration and reproducibility studies were carried out to determine the long-term usage of PI doped polymer film and reproducible results have been obtained for Fe (III) cation.

Synthesis and Spectroscopic Studies of Phenanthroimidazole-Imine Derivatives and Evaluation of Their Antioxidant Activity.

The phenanthroimidazole derivatives are used in the drug industry in large scale. In this study four new phenanthroimidazole-imine derivatives were synthesized and their spectroscopic studies as well as their antioxidant behaviors were examined. Structural analyses were made by FT-IR, 1H-NMR, 13C-NMR, LC-MS spectroscopy techniques. UV-vis absorption and emission spectroscopy techniques have been used to determine the photophysical characteristics of four newly synthesized phenanthroimidazoles. The maximum absorption and emission wavelengths, molar extinction coefficients (ε), singlet energy levels (Es), Stokes' shift values (Δλ) of phenanthroimidazole-imine derivatives are given. Additionally, the antioxidant behavior of all compounds were investigated which the ascorbic acid used as standard molecule in present study.

3,9-Dimethyl-2,3-dihydro-spiro-[carb-az-ole-1,2'-[1,3]dithio-lan]-4(9H)-one.

The title compound, C16H17NOS2, consists of a carbazole skeleton with methyl and dithiol-ane groups as substituents. In the indole ring system, the benzene and pyrrole rings are nearly coplanar, forming a dihedral angle of 1.02 (11)°. The cyclo-hexenone ring has a twisted conformation, while the dithiol-ane ring adopts an envelope conformation with one of the CH2 C atoms at the flap. In the crystal, weak C-H⋯O hydrogen bonds link the mol-ecules into supra-molecular chains nearly parallel to the c axis. These hydrogen bonds together with weak C-H⋯π inter-actions link the molecules into a three-dimensional supramolecular network.

Ethyl 4-hydr-oxy-9-tosyl-9H-carbazole-3-carboxyl-ate.

In the title compound, C(22)H(19)NO(5)S, the carbazole skeleton is nearly planar [maximum deviation = 0.043 (1) Å] with the pyrrole ring oriented at dihedral angles of 2.32 (6) and 1.77 (6)° with respect to the adjacent benzene rings. The dihedral angle between the benzene ring of the tosyl group and the carbazole skeleton is 82.25 (5)°. Intra-molecular O-H⋯O hydrogen bonding results in the formation of a planar six-membered ring, which is oriented at a dihedral angle of 3.06 (4)° with respect to the adjacent carbazole skeleton. In the crystal structure, weak inter-molecular C-H⋯O inter-actions link the mol-ecules into infinite chains and π-π contacts between the benzene rings and between the pyrrole and benzene rings [centroid-centroid distances = 3.374 (1) and 3.730 (1) Å, respectively] may further stabilize the structure. A weak C-H⋯π inter-action is also present.