The low molecular weight gelator, disodium L-(3,5-di-tert-butyl-2-hydroxy-benzyl)amino aspartic acid (Na 2 HL), has been used to prepare three metal-organic hydrogels (metallogel) with the metal ions Ni 2 + (MOG 1), Co 2 + (MOG 2), and VO 2 + (MOG 3). The gels have been prepared by mixing the aqueous solutions (0.5 mL) of the Na 2 HL(0.01 to 0.05 mmol) and M(CH 3 COO) 2 ⋅4H 2 O {M=Ni or Co} or VO(SO) 4 ⋅H 2 O (0.01 to 0.05 mmol). The gels have been characterized by IR spectroscopic studies, MALDI TOF spectrometry and various microscopic studies. All the gels are multi-responsive in nature to different external stimuli, and among them, MOG 1 and MOG-2 show the self-healable property indicating a strong metal-ligand interaction and hydrogen bonding interactions in the gel network. The thixotropic behavior and viscoelastic nature of the self-healable metallogels have been confirmed by time dependent stepstrain experiment at room temperature. It was observed that MOG 1 shows rapid and more efficient selective dye adsorption of cationic dyes, rhodamine B (RhB) {61.7 mg g À 1 }, and malachite green (MG) {15.3 mg g À 1 } from mixtures of cationic, anionic dyes, and neutral dyes. MOG 2 also selectively adsorb cationic dyes from the mixture of dyes. The gel, MOG 3, selectively degrades fluorescein (FL) dye.

A self-healable metallohydrogel of Mn(ii) has been prepared using a low molecular weight gelator, Na2HL, which is capable of encapsulation and delivery of the anti-cancer drug, gemcitabine and the NSAID, indomethacin.