One stone kills four birds: a novel diazaperinone 12H-pyrazino[2′,3′:3,4]pyrrolo[1,2-a]perimidin-12-one recognizes four different metal ions

Crystal structure, Hirshfeld surface analysis and inter-action energy and DFT studies of 2-(2,3-di-hydro-1H-perimidin-2-yl)-6-meth-oxy-phenol

The title compound, C18H16N2O2, consists of perimidine and meth-oxy-phenol units, where the tricyclic perimidine unit contains a naphthalene ring system and a non-planar C4N2 ring adopting an envelope conformation with the NCN group hinged by 47.44 (7)° with respect to the best plane of the other five atoms. In the crystal, O-HPhnl⋯NPrmdn and N-HPrmdn⋯OPhnl (Phnl = phenol and Prmdn = perimidine) hydrogen bonds link the mol-ecules into infinite chains along the b-axis direction. Weak C-H⋯π inter-actions may further stabilize the crystal structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (49.0%), H⋯C/C⋯H (35.8%) and H⋯O/O⋯H (12.0%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, the O-HPhnl⋯NPrmdn and N-HPrmdn⋯OPhnl hydrogen-bond energies are 58.4 and 38.0 kJ mol-1, respectively. Density functional theory (DFT) optimized structures at the B3LYP/ 6-311 G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.

Phenazine-based colorimetric and fluorescent sensor for the selective detection of cyanides based on supramolecular self-assembly in aqueous solution

Taking advantages of both the well-known phenazine structure and the mechanism of the supramolecular self-assembly and deprotonation process, the fluorescent and colorimetric sensor (ZL) was designed and synthesized, behaving as a circulation utilization (above 10 times) receptor for selective detection of cyanide anion (CN^-) in aqueous media. Upon the addition of CN^-, the sensor displayed obvious color changes from yellow to jacinth by naked eyes and the fluorescence immediately quenched (<10s). With respect to other common anions, the sensor possessed high selectivity and sensitivity (0.05μM) for cyanide anions. In addition, the test strips of ZL were fabricated, which could serve as practical colorimetric and fluorescent sensor for "in-the-field" measurements.

Mercaptooxazole–phenazine based blue fluorescent sensor for the ultra-sensitive detection of mercury(ii) ions in aqueous solution

Herein, a fluorescent sensor based on the mechanism of the deprotonation process was designed and synthesized, which could detect Hg²⁺ in aqueous solution with remarkable fluorescence color changed (from yellow to light blue).

Azaacenes as active elements for sensing and bio applications

Recent progress in the application of azaacenes in sensing and bio-fields has been summarized.