Multi-stimuli-responsive induced chirality of polyoxometalates in natural polysaccharide hydrogels†
Abstract
Induced circular dichroism (ICD) of polyoxomolybdates and polyoxotungstates was realized in three kinds of natural polysaccharide hydrogels possessing hierarchical chirality. Interestingly, the extrinsic chiral factors were dominant in ionic κ/ι-carrageenan hybrids, while the ICD of clusters was dominantly influenced by the intrinsic alternating bond length (ABL) distortions of polyoxometalates in agarose hybrid. The optical activity of the POMs shows sensitive response to multiple stimuli, such as temperature, K+ salts, UV irradiation and redox agents.