Locked planarity: a strategy for tailoring ladder-type π-conjugated anilido-pyridine boron difluorides.

A novel series of syn- and anti-ladder-type anilido-pyridine boron difluorides (APBDs) were synthesized by stepwise incorporation of boron into laddered ligands. The boron coordination-locked strategy endows the ladder-type APBDs with a stiff conformation, which results in a substantial bathochromic shift of their absorption spectra and a narrowed HOMO-LUMO energy gap, reinforcing the compounds for potential applications in organic electronics.

Synthesis and photophysical properties of doubly β-to-β bridged cyclic Zn(II) porphyrin arrays.

A series of doubly β-to-β bridged cyclic Zn(II) porphyrin arrays were prepared by a stepwise Suzuki-Miyaura coupling reaction of borylated Zn(II) porphyrin with different bridge groups. The coupling of the building block of β,β'-diboryl Zn(II) porphyrin 1 with different bridges provided the doubly β-to-β carbazole-bridged Zn(II) porphyrin array 3, the fluorene-bridged Zn(II) porphyrin array 5, the fluorenone-bridged Zn(II) porphyrin array 7, and the three-carbazole-bridged Zn(II) porphyrin ring 8. The structural assignment of 3 was confirmed by the X-ray diffraction analysis, which revealed a highly symmetrical and remarkably bent syn-form structure.