N-substituted triarylmethane sulfonamides and method of preparation

Abstract

A novel class of N-substituted triarylmethane sulfonamides is provided which undergo reversible oxidation into colored form and reversible reduction of the oxidized form into colorless form. The N-substituted triarylmethane sulfonamides can be represented by the formulae: ##STR1## wherein B is a carbocyclic ring or rings; T is a 5- or 6-membered ring; Y is a moiety selected from ##STR2## wherein E, positioned ortho or para to said --OH group, is selected from --OH, --NH.sub.2, --NHR', --NR'R' and --NHSO.sub.2 R' wherein R' and R' each are lower alkyl groups having 1 to 6 carbon atoms or aralkyl wherein the aryl portion may be substituted with alkyl groups having 1 to 24 carbon atoms, and E' is hydrogen or a monovalent group that is substituted on one of the remaining carbon atoms; G and G' each are hydroxy or methoxy, provided one is hydroxy and the other is methoxy; and Z and Z' taken individually represent the moieties to complete the chromophoric system of a triarylmethane dye when said N-containing ring, T, is open and Z and Z' taken together represent the bridged moieties to complete the chromophoric system of a bridged triarylmethane dye when said N-containing ring, T, is open; and Y' represents the quinoid form of Y. Preferred embodiments comprise xanthene sulfonamides having N-aryl substituents, e.g., hydroquinone substituents. These compounds possess redox potentials ranging between about +200 to -500 millivolts and thus are useful as dyes for producing photographic, photothermographic, thermal, and pressure-induced images, as well as being useful as redox indicators in a wide variety of biological and chemical reactions.