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Organoselenium ligands have attracted great attention among researchers during the past two decades. Various homogeneous, heterogeneous and nanocatalytic systems have been designed using such ligands. Though reports on selenium ligated...

Two N-pyrene based ligands L1 (1-pyrene-CH=N(CH 2 ) 2 -SPh) and L2 (1-pyrene-CH=N(CH 2 ) 2 -SePh) with an imine functionality and a chalcogen donor have been synthesized and characterized using 1 H as well as 13 C NMR spectral techniques. Palladium(II) complexes (1; PdCl 2 À ĸ 2 À L1 and 2; PdCl 2 À ĸ 2 À L2) of L1 and L2 have been prepared, isolated and characterized using NMR and single crystal X-ray diffraction studies. The geometry around Pd is nearly square planar in these complexes and ligands are coordinated to the metal centre in a bidentate (S/ Se, N) mode. The molecular complexes 1 and 2 have been explored as potential catalysts in O À arylation reaction between substituted aryl halides and phenol. Both the complexes showed excellent efficiency towards this coupling and a TON of 990 (maximum TOF 310) has been achieved using 0.1 mol% of catalyst 2. The effect of the nature of chalcogen donor atom (S/Se) on catalytic efficiency of the complexes has been observed as selenium congener was more efficient than sulphur counterpart.

Rationally designed multiple hydroxyl-group-based chemosensors L1–L4 containing arene-based fluorophores are presented for the selective detection of Al3+ and Ga3+ ions. Changes in the absorption and emission spectra of L1–L4 in ethanol were easily observable upon the addition of Al3+ and Ga3+ ions. Competitive binding studies, detection limits, and binding constants illustrate significant sensing abilities of these chemosensors with L4, showing the best results. The interaction of Al3+/Ga3+ ions with chemosensor L4 was investigated by fluorescence lifetime measurements, whereas Job’s plot, high-resolution mass spectrometry, and 1H NMR spectral titrations substantiated the stoichiometry between L4 and Al3+/Ga3+ ions. The solution-generated [L-M3+] species further detected pyrophosphate ion (PPi) by exhibiting emission enhancement and a visible color change. The binding of Al3+/Ga3+ ions with chemosensor L4 was further supported by density functional theory studies. Reversibility for the detection of Al3+/Ga3+ ions was achieved by utilizing a suitable proton source. The multiionic response, reversibility, and optical visualization of the present chemosensors make them ideal for practical applications for real samples, which have been illustrated by paper-strip as well as polystyrene film-based detection.

First precursor-architecture controlled synthesis of Pd9Te4 and PdTe nanostructures that have potential applications in Suzuki coupling of 4-chlorobenzaldehyde and catalytic reduction of 4-nitrophenol.