Carborane-substituted triphenylamines were prepared to demonstrate the effective fluorescent enhancement of triphenylamine as a typical non-fluorescent pi-conjugated compound on the basis of molecular design to suppress the non-radiative decay by reduced vibronic coupling. Non-fluorescent carborane substituents work to reduce only the HOMO distribution in the non-fluorescent parent pi-conjugated core, thereby leading to increase in fluorescence quantum yield by suppressing internal conversion. (C) 2015 Elsevier B.V. All rights reserved.