Synthesis, photophysical characterisation and metal ion binding properties of new ligands containing anthracene chromophores

A novel benzothiadiazole-based and NIR-emissive fluorescent sensor for detection of Hg2+ and its application in living cell and zebrafish imaging

The probe TBBA exhibited excellent analytical properties with a remarkably large Stokes shift (195 nm), rapid response, high selectivity and sensitivity, good binding constant (2.37 × 10⁴ M⁻¹) and low LOD (13.10 nM).

New anthracene-based Schiff bases: Theoretical and experimental investigations of photophysical and electrochemical properties

The new Schiff bases bearing anthracene unit were synthesized from 2-aminoanthracene and various aldehydes such as: benzaldehyde, 4-(diphenylamino)benzaldehyde, 9-phenanthrenecarboxaldehyde, 9-anthracenecarboxaldehyde, and biphenyl-4-carboxaldehyde, 2-naphthaldehyde. Resulted azomethines were characterized by IR, NMR (¹H and ¹³C), elemental analysis and UV-vis spectroscopy. The imine consists of anthracene and biphenyl moieties exhibited liquid crystal properties and their nematic phase showed Schlieren texture. The photoluminescence measurements carried out in solution and in solid state as blend with PMMA revealed the ability of the imines to emission of the blue light with quantum yield efficiency in the range of 2.18-6.03% in blend. Based on the electrochemical experiment they showed value of energy gap (E_g) in the range of 2.5-2.7eV. Additionally, density functional theory (DFT) was applied for calculations of both electronic structure and spectroscopic properties of synthesized Schiff bases. Moreover, the results obtained from preliminary tests of application of the azomethines in organic photovoltaic (OPV) devices confirmed their electron acceptor character.

Synthesis, photophysical and electrochemical properties of a new class of fluorescent amidoanthracenophanes

The synthesized amidoanthracenophanes1–4exhibit intense fluorescence emission and electrochemical oxidation reduction characteristic of a flourophoric unit.

Synthesis, Characterization, and Photoluminescent Properties of ZnII, CdII, and HgII Complexes with N,O Hybrid Pyrazole Ligand

The synthesis and characterization by elemental analysis, mass spectrometry, conductance measurements, IR, 1H, and 13C NMR spectroscopies of compounds with the general formula [MCl2(L)2], where M = Zn (1), Cd (2), or Hg (3) and L = 1-(2-hydroxyethyl)-3,5-dimethylpyrazole have been described. The 113Cd{1H} and 199Hg{1H} NMR spectra were also measured to investigate the coordination environment of the metal in solution. The structure of complex [ZnCl2(L)2] was determined by single-crystal structure analysis. The extended structure revealed a 1D chain caused by several O–H···CH3 intermolecular interactions. Moreover, we have determined the fluorescent properties of complexes 1–3; it was found that L demonstrates the higher sensibility to HgII ion, one of the most toxic agent in the environment. The preliminary results indicate that L could have a promising future for the detection of mercury in real environmental samples.

Luminescently Tagged 2,2‘-Bipyridine Complex of FeII: Synthesis and Photophysical Studies of 4-[N-(2-Anthryl)carbamoyl]-4‘-methyl-2,2‘-bipyridine

The anthracene lumiphore was linked to the chelating ligand 2,2'-bipyridine, forming 4-[N-(2-anthryl)carbamoyl]-4'-methyl-2,2'-bipyridine (bpyAnth). Coupling through an amide linkage provides some electronic isolation of the anthracene lumiphore. Electrochemistry suggested little change of the anthracene oxidation whether free (1.35 V) linked to 2,2'-bipyridine as bpyAnth (1.30 V) or appended to Fe(II) (1.29 V). The bpyAnth ligand retained the structured luminescence characteristic of anthracene at 375, 400, 419, and 441 nm. This anthracene emission persists even when bpyAnth is complexed to an Fe(II) center. The complex [Fe(bpyAnth)3]2+ is emissive, in marked contrast to typical polyazine iron(II) complexes. This bpyAnth ligand serves as a luminescently tagged analogue of 2,2'-bipyridine, useful for coordination to a variety of metals.

New Fluorescence PET Systems Based on N2S2 Pyridine-Anthracene-Containing Macrocyclic Ligands. Spectrophotometric, Spectrofluorimetric, and Metal Ion Binding Studies

Three new fluorescent devices for protons and metal ions have been synthesized and characterized, and their photophysical properties have been explored; these are the macrocycles 7-(9-anthracenylmethyl)-3,11-dithia-7,17-diazabicyclo[11.3.1]heptadeca-1(17),13,15-triene (L1) and 7-(10-methyl-9-anthracenylmethyl)-3,11-dithia-7,17-diazabicyclo[11.3.1]heptadeca-1(17),13,15-triene (L2) and the bis macrocycle 7,7'-[9,10-anthracenediylbis(methylene)]bis-3,11-dithia-7,17-diazabicyclo[11.3.1]heptadeca-1(17),13,15-triene (L3). All these systems have a pyridil-thioether-containing macrocycles as a binding site and an anthracene moiety as a signaling agent. The coordination properties of these ligands toward Cu(II), Co(II), Ni(II), Zn(II), and Pd(II) have been studied in solution and in the solid state. The addition of these metal ions to dichloromethane solutions of L1, L2, and L3 produce strong changes in the absorption and emission spectra of these ligands. The stoichiometry of the species, formed at 298 K, have been determined from absorption and fluorescence titrations. The Co(II) and Cu(II) complexes of L1 have been studied by EPR spectroscopy. This last complex and its free ligand have also been characterized by X-ray crystallography.