The syntheses and photochem. properties of the novel aminoaryldiarylboranes which are isoelectronic with triarylmethane dyes, and also pyrrolyl- and indolyldiarylboranes, are described. The fluorescence spectra are strongly dependent on the solvent. The use of o-disubstituted arenes as stabilizing substituents at the boron atom leads to highly colored solids which are stable to air and moisture. The structures of two of the triarylboranes were confirmed by X-ray analyses.