HOLE TRANSPORTING CYCLOBUTENE COMPOUND

摘要

A material substituted with a group of formula (I): wherein: Ar1 is an aryl or heteroaryl group; Sp1 represents a first spacer group; nl is 0 or 1; m1 is 1 if nl is 0 and m1 is at least 1 if nl is 1; R1 independently in each occurrence is H or a substituent, with the proviso that at least one R1 is a group R11 selected from: alkyl comprising a tertiary carbon atom directly bound to a carbon atom of the cyclobutene ring of formula (I); branched alkyl wherein a secondary or tertiary carbon atom of the branched alkyl is spaced from a carbon atom of the cyclobutene ring of formula (I) by at least one -CH2- group; and alkyl comprising a cyclic alkyl group; or with the proviso that at least two R1 groups are linked to form a ring.