Pyridoxal Based Fluorescent Chemosensor for Detection of Copper(II) in Solution With Moderate Selectivity and Live Cell Imaging.

A pyridoxal-based fluorescent probe HL was synthesized for the detection of Cu(2+) in methanol with moderate selectivity. Upon addition of Cu(2+), to the solution of the probe in methanol exhibited a remarkable change in emission at 500 nm. With the limit of detection of 10 µM, the probe could well meet the recommended (less than 32 µM in drinking water) of the World Health Organization (WHO). The intracellular Cu(2+) imaging behaviour of HL was carried out on HeLa cells.

Bis{2-[(5-hy-droxy-pent-yl)imino-meth-yl]phenolato-κ(2) N,O (1)}copper(II).

In the title compound, [Cu(C12H16NO2)2], the Cu(II) ion, located on a center of inversion, is coordinated by two singly deprotonated Schiff base ligands derived from condensation of salicyldehyde and 1-amino-pentan-5-ol. The imino N and phenol O atoms from both ligands offer a square-planar arrangement around the metal ion. The Cu-N and Cu-O bond lengths are 2.0146 (15) and 1.8870 (12) Å, respectively. Since the Cu-O and Cu-N bond lengths are different, it can be concluded that the resulting geometry of the complex is distorted. The aliphatic -OH group of the ligand is not coordinated and points away from the metal coordination zone and actively participates in hydrogen bonding connecting two other units and thus stabilizing the crystal lattice. This results in a two-dimensional extended array parallel to (201).