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; n1 is 0 or 1; m1 is 1 if n1 is 0 and m1 is at least 1 if n1 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. The material can be used in an organic electronic device e.g. organic light-emitting device and a method of using the material in the device is also shown.