Abstract: A hole transport layer in an organic electroluminescent device is made of a material containing at least a ditriphenylaminestyryl derivative expressed by the general formula: ##STR1## where A is selected from the group consisting of substituted and non-substituted alkylidene groups, cycloalkylidene groups, oxygen atom, sulfur atom, amino groups; where Ar.sup.1, Ar.sup.3, Ar.sup.4 and Ar.sup.5 are selected from the group consisting of substituted and non-substituted arylene groups; where Ar.sup.2 and Ar.sup.6 are one selected from the group consisting of substituted aryl groups and non-substituted aryl groups; and where X and Y are substituted groups expressed by the formula: ##STR2## where Ar.sup.7 and Ar.sup.8 are selected from the group consisting of substituted aryl groups and non-substituted aryl groups; and where R.sup.

Abstract: An electrophotographic photosensitive product comprises on a photoconductive substrate a photosensitive layer containing as a main component thereof a compound: ##STR1## wherein X is one of --Ar.sup.7 --CH.dbd.CH--Ar.sup.8 -- and a naphthylene group represented by the following formula: ##STR2## and wherein each of Ar.sup.1, Ar.sup.4, Ar.sup.7, and Ar.sup.8 represents an arylene group, each of Ar.sup.2, Ar.sup.3, Ar.sup.5, and Ar.sup.6 represents an aryl group, and each of R.sup.1 -R.sup.6 represents one of H, a lower alkyl group and an aryl group.

Abstract: An electrophotographic photosensitive element is here disclosed which comprises a conductive substrate and at least a photosensitive layer formed on the conductive substrate, the electrophotographic photosensitive element being characterized in that the photosensitive layer contains, as a charge transport material, a compound represented by the formula (1), (2) or (3) ##STR1##