Utilizing the π‑Acidity of Boron Subphthalocyanine To Achieve Novel Solid-State Arrangements

The ability to control the solid-state
structure of organic electronic
materials can have a large effect on the quality of the devices to
which they are applied. In this paper, we describe the use of π–π
interactions to direct the crystal structure/solid-state arrangement
of boron subphthalocyanine (BsubPc) derivatives by taking advantage
of the π-electron-deficiency (π-acidity) of the BsubPc
molecular fragment. First, we outline why BsubPc is a π-acid
by looking at its chemical characteristics and the structure of crystals
formed with other π-acidic moieties. Then we show how the solid-state
arrangement of BsubPc can be purposefully altered by adding π-basic
substituents. We found that adding a naphthoxy substituent provides
an interaction that is strong enough to direct BsubPc into a novel
solid-state arrangement made up of ribbons (or catemers) of molecules
linked through π-stacking interactions between the naphthoxy
and neighboring BsubPc molecular fragments. A similar effect was also
seen when the naphthoxy fragment was added to the stronger π-acid
perfluoro-BsubPc (F12BsubPc).