The Relationship between the Steric Hindrance and Absorption Spectrum of Fluoran Dyes. Part I

Abstract

Fluoran compounds used for the thermosensitive data-recording systems usually have substituted amino groups at the 2-position of the fluoran ring. Their absorption spectra are significantly affected by the electron-donative ability of the 2-amino groups. We investigated the relationship between the steric effects around the 2-amino groups and the absorption spectra of fluoran dyes.