A compound of formula [I]: X--R[I] wherein X represents the group: ##STR00001## and R is either (i) represented by the formula [II] ##STR00002## wherein n is 1 or 2, and the or each R.sub.7 group is independently selected from the group consisting of hydrogen and halogen atoms, cyano, nitro, mercapto, carbonyl and sulfone groups, and optionally substituted alkyl, haloalkyl, hydroxyalkyl, aryl, alkoxy, aryloxy, alkylamino, arylamino, alkylthio, arylthio, ester, siloxy, cyclic hydrocarbon and heterocyclic groups; or (ii) is selected from the group consisting of optionally substituted alkyl, hydroxyalkyl, aryl, cyclic hydrocarbon and heterocyclic groups; wherein in each case R.sub.1 R.sub.6 are each independently selected from the group consisting of hydrogen and halogen atoms, cyano, nitro, mercapto, carbonyl and sulfone groups, and optionally substituted alkyl, haloalkyl, hydroxyalkyl, aryl, alkoxy, aryloxy, alkylamino, arylamino, alkylthio, arylthio, ester, siloxy, cyclic hydrocarbon and heterocyclic groups. The compounds are useful as hole-transporting materials in electroluminescence devices.