Synthesis, Crystal Structure, Fluorescence and Theoretical Calculations of Three Zn(II)/Cd(II) Complexes with Bis-dentate N,N-Quinoline Schiff Base

Three d10 metal complexes, ZnL(OAc)2 (1), CdL(OAc)2 (2) and [CdL2(NO3)2]·CH3CN (3) were synthesized using the ligand (E)-N-(3-methoxy-4-methylphenyl)-1-(quinolin-2-yl)methanimine (L) and characterized by FT-IR spectra, NMR spectra, and CHN elemental analysis. Single-crystal X-ray diffraction analysis revealed that complexes 1 and 2 are isostructural, with the central metal adopting a hexacoordinate octahedral geometry, while complex 3 adopts a triangular dodecahedron geometry. Thermal gravimetric analysis showed that these complexes exhibit good thermal stability. Solid-state fluorescence spectroscopy measurements demonstrated that complexes 1-3 exhibit bright yellow-green fluorescence (λem = 564 nm for 1; 524 nm for 2; 542 nm for 3), suggesting their potential as photoluminescent materials. Furthermore, DFT calculations, including frontier molecular orbitals, energy levels, and surface electrostatic potential, provided insights into the structural and electronic spectral properties of complexes 1-3.

A pyridine based Schiff base as a selective and sensitive fluorescent probe for cadmium ions with “turn-on” fluorescence responses

A pyridine based Schiff base probe (PMPA) showed high selectivity and sensitivity towards Cd2+ ions with intense bluish green fluorescence. The sensing mechanism of probe PMPA for detecting Cd2+ was based on the inhibited PET and CHEF processes.

Photo- and electro-luminescent properties of 2,7-disubstituted spiro[fluorene-9,9′-xanthene] derivatives containing imidazole-derived moieties

Two spiro[fluorene-9,9′-xanthene]/imidazole-derived moiety hybrid compounds were synthesized for OLED applications.

A novel hot exciton blue fluorophores and white organic light-emitting diodes with simplified configuration

The two efficient non-doped blue emitters with hybridized local and charge transfer state namely, NDBNPIN and DBTPIN have been synthesised and characterised. These materials are employed as a host for green and red phosphorescent OLEDs. The white device based on DBTPIN:Ir(MDQ)2(acac) (4%) exhibit maximum external quantum efficiency (ηex) -24.8%; current efficiency (ηc) -57.1 cdA-1; power efficiency (ηp) -64.8 lmW-1 with Commission Internationale de l'Eclairage (CIE:0.49, 0.40) than NDBNPIN:Ir(MDQ)2acac (4%) device [ηex - 23.1%; ηc -54.6 cd A-1; ηp- 60.0 lm W-1 with CIE (0.47, 0.42)].

A simple quinolone Schiff-base containing CHEF based fluorescence 'turn-on' chemosensor for distinguishing Zn2+ and Hg2+ with high sensitivity, selectivity and reversibility

A new simple 'dual' chemosensor MQA ((E)-2-methoxy-N-((quinolin-2-yl)methylene)aniline) for distinguishing Zn²⁺ and Hg²⁺ has been designed, synthesized and characterized. The sensor showed excellent selectivity and sensitivity with a fluorescence enhancement to Zn²⁺/Hg²⁺ over other commonly coexisting cations (such as Na⁺, Mg²⁺, Al³⁺, K⁺, Mn²⁺, Fe²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, Ga³⁺, Cd²⁺, In³⁺ and Pb²⁺) in DMSO-H₂O solution (1/99 v/v), which was reversible with the addition of ethylenediaminetetraacetic acid (EDTA). The detection limit for Zn²⁺/Hg²⁺ by MQA both reached the 10^-8 M level. The 1 : 1 ligand-to-metal coordination patterns of the MQA-Zn2+ and MQA-Hg2+ were calculated through a Job's plot and ESI-MS spectra, and were further confirmed by X-ray crystal structures of complexes MQA-Zn2+ and MQA-Hg2+. This chemosensor can recognize similar metal ions by coherently utilizing intramolecular charge transfer (ICT) and different electronic affinities of various metal ions. DFT calculations have revealed that the energy gap between the HOMO and LUMO of MQA has decreased upon coordination with Zn(ii)/Hg(ii).

Structure–property relationship of blue solid state emissive phenanthroimidazole derivatives

A series of phenanthro[9,10-d]imidazole derivatives featuring multifunctional properties of ambipolar transport have been synthesized, a deep blue emission with high fluorescence quantum yield is observed, and the formation of thermally stable molecular glass is described.

An ambipolar 3,3′-dimethyl-9,9′-bianthracene derivative as a blue host material for high-performance OLEDs

A new ambipolar 3,3′-dimethyl-9,9′-bianthracene derivative (MBAn-(4)-tBu) was designed as a deep blue fluorophore and blue host material for high-performance OLEDs.

Different conjugated system Zn(ii) Schiff base complexes: supramolecular structure, luminescent properties, and applications in the PMMA-doped hybrid materials

Five Zn(ii) complexes with different conjugated systems were synthesized. Zn3 was incorporated into PMMA, creating a high performance material.

Thermally-induced single-crystal-to-single-crystal transformations from a 2D two-fold interpenetrating square lattice layer to a 3D four-fold interpenetrating diamond framework and its application in dye-sensitized solar cells

In this work, a rare 2D → 3D single-crystal-to-single-crystal transformation (SCSC) is observed in metal-organic coordination complexes, which is triggered by thermal treatment. The 2D two-fold interpenetrating square lattice layer [Cd(IBA)2]n (1) is irreversibly converted into a 3D four-fold interpenetrating diamond framework {[Cd(IBA)2(H2O)]·2.5H2O}n (2) (HIBA = 4-(1H-imidazol-1-yl)benzoic acid). Consideration is given to these two complexes with different interpenetrating structures and dimensionality, and their influence on photovoltaic properties are studied. Encouraged by the UV-visible absorption and HOMO-LUMO energy states matched for sensitizing TiO2, the two complexes are employed in combination with N719 in dye-sensitized solar cells (DSSCs) to compensate absorption in the ultraviolet and blue-violet region, offset competitive visible light absorption of I3(-) and reducing charge the recombination of injected electrons. After co-sensitization with 1 and 2, the device co-sensitized by 1/N719 and 2/N719 to yield overall efficiencies of 7.82% and 8.39%, which are 19.94% and 28.68% higher than that of the device sensitized only by N719 (6.52%). Consequently, high dimensional interpenetrating complexes could serve as excellent co-sensitizers and have application in DSSCs.