Chromophore Nanohybrids for Sensing and Singlet Oxygen Generation

Abstract

Nanohybrid materials can exhibit the physical properties of their components and be used in various applications. Also, novel chromophores involving synthetically flexible molecules such as pyrazinacenes1 and porphyrins2 can be incorporated into these structures by different means in particular as MOFs or COFs, while other components include simple transition metal salts or oligonuclear metal-oxo clusters. In this work, we discuss nanohybrids materials containing oxoporphyrinogen (OxP), tetrapyrroles or fullerene as the organic component, with hybridization using respectively Ag(I) salt or oxo-Zr(IV) cluster. This yields nanohybrid materials having structures and properties due to their individual components. Highly-colored OxP is a tetrapyrrole macrocycle which can be stimulated to generate reactive singlet oxygen (1O2) under appropriate conditions (1O2 can be used for applications such as photodynamic therapy and environmental remediation). 1O2 generation by OxP undergoes significant enhancement over its unhybridized state when incorporated in nanohybrid structures, either MOFs or COFs, containing respectively oxo-Zr(IV) nodes or electron deficient linkers in porous coordination polymer nanoarchitectures. OxP-oxoZr(IV) nanohybrid can then be applied for oxidation of small molecule substrates to selected products.3 Also, C60 fullerene can be co-crystallized with silver(I) nitrate at the molecular level4 leading to a material that exhibits unique properties during its decomposition so that silver nitrate is released with concurrent deposition of highly nanostructured C60-only crystalline networks. The resulting nanohybrid material has been studied for application as slow-release antibacterial material.4 Other work includes porous materials for sensing applications. The utility of the nanohybrid approaches is demonstrated by using these examples.