Abstract Two series of organic—inorganic composite materials were synthesized through solvothermal imine condensation between diketopyrrolopyrrole dialdehyde DPP-1 and 5,10,15,tetrakis 4-aminophenyl porphyrin TAPP in the presence of varying amounts of either amino- or carboxy-functionalized superparamagnetic iron oxide nanoparticles FeO.
Whereas high FeO loading induced cross-linking of the inorganic nanoparticles by amorphous imine polymers, a lower FeO content resulted in the formation of crystalline covalent organic framework domains.
Crystallinity, chromophore stacking, and visible absorption features are directly correlated to the mass fraction of the components, thus allowing for a fine-tuning of materials properties. Organic—inorganic hybrid materials[ 1 ] can combine highly variable properties of diverse components into multifunctional composites. In nature, the complex hierarchical assembly of brittle minerals and organic molecules results in biomaterials with exceptional fracture resistance,[ 2 ] which also inspired the design of biomimetic materials.
In this regard, we recently succeeded in the combination of magnetic iron oxide nanoparticles and luminescent lanthanoid metal—organic frameworks into nanocomposites for switching isotropic and anisotropic optical properties,[ 5 ] white magnetism,[ 6 ] shear stress detection,[ 7 ] or ratiometric water sensing.
As another class of porous materials, covalent organic frameworks COFs [ 9 ] have emerged as porous crystalline materials with potential applications in gas storage,[ 10 ] heterogeneous catalysis,[ 11 ] or organic electronics. Up to date, only a few examples for the combination of COFs and magnetic particles are reported, which have been used as magnetically recoverable adsorbents[ 19 ] to remove toxins from biological samples,[ 20 ] for solid-phase extraction[ 21 ] or the photothermal conversion of near-IR absorption.
