Structural and optical properties of the p alkylated 2,6 bis benzimidazol phenoles obtained from o phenylenediamine and their sensitive behavior towards zinc II ions

Two compounds, 2 hydroxy 5 methylisophthalaldehyde L1 and 2 hydroxy 5 tert butyl 1,3 benzenedicarboxaldehyde L2 , were obtained in the reaction between o phenylenediamine and aldehydes. The X ray crystal structure determination and DFT calculations aimed at the confirmation of the geometry of L1 and L2 in a solution and in the solid state were performed. The intermolecular interactions in the crystal structure of L1 0.5 CH3COOC2H5, L2 MeOH and L2 0.25 n hexane were analyzed using the 3D Hirshfeld surfaces and related 2D fingerprint plots. The x ray and 3D Hirschfeld analyses show the importance of the presence of the solvent in the crystal lattice. In L2 0.25 n hexane, the solvent is only weakly bound, and only a robust network of Nsingle bondH N and Csingle bondH N hydrogen bonds that stabilise channels was noted. On the other hand, in the L2 MeOH, methanol forms a robust network of hydrogen bonds. The luminescence of L1 and L2 in various solvents and in the solid state was studied. In the solid state, emission was registered at 520 nm and 506 nm for L1 and L2, respectively. DFT calculations of the fluorescence spectra indicate green luminescence of the keto form of the compounds. Thin layers of the obtained compounds were deposited on Si 1 1 1 by the spin coating method and examined with scanning electron microscopy SEM EDS , atomic force microscopy AFM and fluorescence spectroscopy. The fluorescence sensing abilities of the compounds towards Zn2 ions were evaluated. The experimental results showed that L1 and L2 could sensitively and efficiently detect Zn2 ions increase or decrease in the emission band at 443 nm for L1 or 434 nm for L2 amp; 955;ex 290 was observe

New Dinuclear Macrocyclic Copper II Complexes as Potentially Fluorescent and Magnetic Materials

Two dinuclear copper II complexes with macrocyclic Schiff bases K1 and K2 were prepared by the template reaction of R 1,1 amp; 8242; binaphthalene 2,2 amp; 8242; diamine and 2 hydroxy 5 methyl 1,3 benzenedicarboxaldehyde K1, or 4 tert butyl 2,6 diformylphenol K2 with copper II chloride dihydrate. The compounds were characterized by spectroscopic methods. X ray crystal structure determination and DFT calculations confirmed their geometry in solution and in the solid phase. Moreover, intermolecular interactions in the crystal structure of K2 were analyzed using 3D Hirshfeld surfaces and the related 2D fingerprint plots. The magnetic study revealed very strong antiferromagnetic CuII CuII exchange interactions, which were supported by magneto structural correlation and DFT calculations conducted within a broken symmetry BS framework. Complexes K1 and K2 exhibited luminescent properties that may be of great importance in the search for new OLEDs. Both K1 and K2 complexes showed emissions in the range of 392 424 nm in solutions at various polarities. Thin materials of the studied compounds were deposited on Si 111 by the spin coating method or by thermal vapor deposition and studied by scanning electron microscopy SEM EDS , atomic force microscopy AFM , and fluorescence spectroscopy. The thermally deposited K1 and K2 materials showed high fluorescence intensity in the range of 318 531 nm for K1 Si and 326 472 nm for the K2 Si material, indicating that they could be used in optical device

Experimental and Theoretical Studies of the Optical Properties of the Schiff Bases and Their Materials Obtained from o-Phenylenediamine

Two macrocyclic Schiff bases derived from o-phenylenediamine and 2-hydroxy-5-methylisophthalaldehyde L1 or 2-hydroxy-5-tert-butyl-1,3-benzenedicarboxaldehyde L2, respectively, were obtained and characterized by X-ray crystallography and spectroscopy (UV-vis, fluorescence and IR). X-ray crystal structure determination and DFT calculations for compounds confirmed their geometry in solution and in the solid phase. Moreover, intermolecular interactions in the crystal structure of L1 and L2 were analyzed using 3D Hirshfeld surfaces and the related 2D fingerprint plots. The 3D Hirschfeld analyses show that the most numerous interactions were found between hydrogen atoms. A considerable number of such interactions are justified by the presence of bulk tert-butyl groups in L2. The luminescence of L1 and L2 in various solvents and in the solid state was studied. In general, the quantum efficiency between 0.14 and 0.70 was noted. The increase in the quantum efficiency with the solvent polarity in the case of L1 was observed (λex = 350 nm). For L2, this trend is similar, except for the chloroform. In the solid state, emission was registered at 552 nm and 561 nm (λex = 350 nm) for L1 and L2, respectively. Thin layers of the studied compounds were deposited on Si(111) by the spin coating method or by thermal vapor deposition and studied by scanning electron microscopy (SEM/EDS), atomic force microscopy (AFM), spectroscopic ellipsometry and fluorescence spectroscopy. The ellipsometric analysis of thin materials obtained by thermal vapor deposition showed that the band-gap energy was 3.45 ± 0.02 eV (359 ± 2 nm) and 3.29 ± 0.02 eV (377 ± 2 nm) for L1/Si and L2/Si samples, respectively. Furthermore, the materials of the L1/Si and L2/Si exhibited broad emission. This feature can allow for using these compounds in LED diodes

New Dinuclear Macrocyclic Copper(II) Complexes as Potentially Fluorescent and Magnetic Materials

Two dinuclear copper(II) complexes with macrocyclic Schiff bases K1 and K2 were prepared by the template reaction of (R)-(+)-1,1′-binaphthalene-2,2′-diamine and 2-hydroxy-5-methyl-1,3-benzenedicarboxaldehyde K1, or 4-tert-butyl-2,6-diformylphenol K2 with copper(II) chloride dihydrate. The compounds were characterized by spectroscopic methods. X-ray crystal structure determination and DFT calculations confirmed their geometry in solution and in the solid phase. Moreover, intermolecular interactions in the crystal structure of K2 were analyzed using 3D Hirshfeld surfaces and the related 2D fingerprint plots. The magnetic study revealed very strong antiferromagnetic CuII-CuII exchange interactions, which were supported by magneto-structural correlation and DFT calculations conducted within a broken symmetry (BS) framework. Complexes K1 and K2 exhibited luminescent properties that may be of great importance in the search for new OLEDs. Both K1 and K2 complexes showed emissions in the range of 392–424 nm in solutions at various polarities. Thin materials of the studied compounds were deposited on Si(111) by the spin-coating method or by thermal vapor deposition and studied by scanning electron microscopy (SEM/EDS), atomic force microscopy (AFM), and fluorescence spectroscopy. The thermally deposited K1 and K2 materials showed high fluorescence intensity in the range of 318–531 nm for K1/Si and 326–472 nm for the K2/Si material, indicating that they could be used in optical devices