An important feature of biological systems to achieve complexity and precision is the involvement of multiple components where each component plays its own role and collaborates with other components. Mimicking this, we report living supramolecular polymerization achieved by collaborative assembly of two structurally dissimilar components, that is, platinum(II) complexes and poly(ethylene glycol)-b-poly(acrylic acid) (PEG-b-PAA). The PAA blocks neutralize the charges of the platinum(II) complexes, with the noncovalent metal–metal and π–π interactions directing the longitudinal growth of the platinum(II) complexes into 1D crystalline nanostructures, and the PEG blocks inhibiting the transverse growth of the platinum(II) complexes and providing the whole system with excellent solubility. The ends of the 1D crystalline nanostructures have been found to be active during the assembly and remain active after the assembly. One-dimensional segmented nanostructures with heterojunctions have been produced by sequential growth of two types of platinum(II) complexes. The PAA blocks act as adapters at the heterojunctions for lattice matching between chemically and crystallographically different platinum(II) complexes, achieving heterojunctions with a lattice mismatch as large as 21%.
It is common sense that emission maxima of phosphorescence spectra (λP) are longer than those of fluorescence spectra (λF). Here we report a serendipitous finding of up-converted room-temperature phosphorescence (RTP) withλP < λFand phosphorescence lifetime > 0.1 s upon doping benzophenone-containing difluoroboron β-diketonate (BPBF2) into phenyl benzoate matrices. The up-converted RTP is originated from BPBF2’s Tn(n ≥ 2) states which show typical3n-π* characters from benzophenone moieties. Detailed studies reveal that, upon intersystem crossing from BPBF2’s S1states of charge transfer characters, the resultant T1and Tnstates build T1-to-Tnequilibrium. Because of their3n-π* characters, the Tnstates possess large phosphorescence rates that can strongly compete RTP(T1) to directly emit RTP(Tn) which violates Kasha’s rule. The direct observation of up-converted RTP provides deep understanding of triplet excited state dynamics and opens an intriguing pathway to devise visible-light-excitable deep-blue afterglow emitters, as well as stimuli-responsive afterglow materials.