Solvent-Assisted Formation of Vesicles by a Self-Assembling Ni₃−Schiff Base Complex

A linear trinuclear Ni−Schiff base complex [Ni3(salpen)2(PhCH2COO)2(EtOH)] has been synthesized by combining Ni(ClO4)2·6H2O, phenyl acetic acid (C6H5CH2COOH), and the Schiff base ligand, N,N′-bis(salicylidene)-1,3-pentanediamine (H2salpen). This complex is self-assembled through hydrogen bonding and C−H−π interaction in the solid state to generate a sheet-like architecture, while in organic solvent (CH2Cl2), it forms vesicles with a mean diameter of 290 nm and fused vesicles, depending upon the concentration of the solution. These vesicles act as an excellent carrier of dye molecules in CH2Cl2. The morphology of the complex has been determined by scanning electron microscopy and transmission electron microscopy experiments, and the encapsulation of dye has been examined by confocal microscopic image and electronic absorption spectra.