Changing to Poly（rod-coil） Polymers： A Promising Way for an Optoelectronic Compound to Improve Its Film Formation

Good film formation is one of basic requirements for organic optoelectronic materials to achieve the capability for fabrication of large area devices. Small molecular optoelectronic compounds have a definite chemical structure and clear device performance, and thus are welcomed in the field. However, they are generally suffering from poor film formation, especially in a large area. For addressing it, this contribution proposes and demonstrates a strategy, that is, changing them into poly（rod-coil） polymers. With one optoelectronic compound [BDT（DTBT）2] and three poly（rod-coil） polymers （P1, P2, and P3） having different non-conjugated coil segments as examples, the work clearly shows that the change to poly（rod-coil） polymers keeps many basic optoelectronic properties of the refer- ence compound, including light absorption in solution, bandgap and frontier orbital energy levels, but suppresses strong intermolecular interactions and crystalline structure in film state. Further comparisons on film formation quality on glass and ITO glass illustrate that all the three polymers have a better film formation property than the reference compound.

Regioregular and Nondestructive Graphene Functionalization for High-Performance Electrochromic and Supercapacitive Devices

To overcome two obstacles in graphene functionalization—the random distribution of functional groups and substantial lattice defects,in this contribution,we rationally bypass the universal yet destructive graphene oxide(GO)-derived methodologies and adopt reductive covalent functionalization of natural graphite.In this strategy,ultrahigh density graphene sheets with evenly distributed negative charges were intermediately yielded by potassium reduction to graphite.Subsequently,they were regioregularly and efficiently brominated by the benchmark electrophile of molecular bromine.The combined characterizations determined the graphene bromide derivative to have a molecular formula of C_(24)-Br,corresponding well with the brominated entity of the inseparable C_(24)-K^(+)graphite intercalation compounds.Due to the regular distribution of Br groups and intact hexagonal lattice of the graphene matrix,the C_(24)-Br_GBr delivers exceptional electrical properties although theπ-conjugation is partially blocked by C(sp^(3))-Br sites and greatly outperforms its counterparts derived from GO bromination.In both model applications of quickly switchable electrochromic devices and all-solid-state supercapacitors,C_(24)-Br_GBr exhibits impressive performance,which highlights the great significance and prospect of regioregular and lattice-nondestructive graphene functionalization.