Table 1. Photophysical properties of the compounds.

Compounds	λema (nm)	ФFb (%)	ФFc (%)	τe (ns)	τf (ns)
PyCl	486	2.5	0.2	0.14	2.71
PyNO3	467	10.4	0.3	0.26	1.85
PyOTs	448	13.1	0.1	0.16	7.81
PyPh4B	—	<1	—	0.11	0.1

^aEmission wavelength in the solid state.

^bAbsolute fluorescence quantum yields of solids determined by a calibrated integrating sphere.

^cAbsolute fluorescence quantum yields in acetonitrile of compounds determined by a calibrated integrating sphere.

^dFluorescence lifetimes in acetonitrile.

^eFluorescence lifetimes of the solid samples.