Anion Dependent Self-Assembly of Polynuclear Cd-Ln Schiff Base Nanoclusters: NIR Luminescent Sensing of Nitro Explosives.

Two types of polynuclear Cd-Ln complexes [CdLnL(NO(3))Cl(2)(DMF)(2)] [Ln = La (1) and Nd (2)] and [Ln(2)CdL(2)(NO(3))(2)(DMF)(2)](OH)(2) [Ln = La (3) and Nd (4)] were constructed using a new Schiff base ligand which has a long backbone with two phenyl groups. The Schiff base ligands show a "twist" configuration in 1-4. The crystal structures show that the molecular dimensions of 3 and 4 are about 6 × 10 × 15 à . The Cd-Nd complexes 2 and 4 exhibit the typical NIR luminescence of Nd(3+). Interestingly, 4 shows the luminescent sensing of nitro explosives and exhibits a high sensitivity to 2-nitrophenol at the ppm level.