Abstract: A compound of formula (I) wherein X is O or S; each A is a LUMO-deepening substituent; R5 and R6 are independently in each occurrence a substituent; x independently in each occurrence is 0, 1, 2, 3 or 4; y independently in each occurrence is 0, 1 or 2, and each z is independently 0 or 1 with the proviso that at least one z is 1. The compound may be used as a host for a phosphorescent light-emitting material in an organic light-emitting device.

Abstract: A polymer comprising a fluorescent light-emitting repeating unit comprising a group of formula ED-EA wherein ED is an electron-donating unit; EA is an electron-accepting unit; and a band gap EgCT of a charge-transfer state formed from the electron-donating unit and the electron-accepting unit is smaller than the bandgap of either the electron-accepting unit EgEA or that of the electron-donating unit EgED.

Abstract: A method of forming a layer of an electronic device, for example an organic light-emitting device, the method comprising the step of depositing a precursor layer comprising a compound of formula (I) and reacting the compound of formula (I) in a ring-opening addition reaction: Core-(Reactive Group)n??(I) wherein Core is a non-polymeric core group; and each Reactive Group, which may be the same or different in each occurrence, is a group of formula (II): wherein Sp1 independently in each occurrence represents a spacer group; w independently in each occurrence is 0 or 1; Ar in each occurrence independently represents an aryl or heteroaryl group; R1 in each occurrence independently represents H or a substituent, with the proviso that at least one R1 is a substituent; n is at least 1; and * is a point of attachment of the group of formula (II) to the Core; and wherein the compound of formula (I) reacts with itself or with a non-polymeric co-reactant.

Abstract: Methods of metal-catalysed polymerisation are described using a metal catalyst of formula (III): wherein R3 in each occurrence is independently selected from C1-10alkyl and aryl that may be unsubstituted or substituted with one or more substituents; y is 0 or 2; and Z? is an anion. Methods described include Buchwald-type and Suzuki-type polymerisation.

Abstract: A compound of formula (I) wherein: Ar1 represents an aryl or heteroaryl group that may be unsubstituted or substituted with one or more substituents; n is 0 or 1; and Xan independently in each occurrence represents a group selected from formula (IIa) or (IIb): wherein X is O or S; R1 independently in each occurrence is H or a substituent; R2 independently in each occurrence is H or a substituent; p independently in each occurrence is 0, 1, 2, 3 or 4; q is 0, 1, 2 or 3; and * represents a bond to Ar1. Use of compounds of formula (I) as a host for phosphorescent emitters is disclosed.

Abstract: A method of forming a crosslinked polymer comprising the step of reacting a crosslinkable group in the presence of a polymer, wherein: the crosslinkable group comprises a core unit substituted with at least one crosslinkable unit of formula (I): the crosslinkable group is bound to the polymer or is a crosslinkable compound mixed with the polymer; Ar is aryl or heteroaryl which may be unsubstituted or substituted with one or more substituents independently selected from monovalent substituents and a divalent linking group linking the unit of formula (I) to the core unit; and R is independently in each occurrence H, a monovalent substituent or a divalent linking group linking the unit of formula (I) to the core unit, with the proviso that at least one R is not H.

Abstract: A method of forming a layer of an electronic device, for example an organic light-emitting device, the method comprising the step of depositing a precursor layer comprising a compound of formula (I) and reacting the compound of formula (I) in a ring-opening addition reaction: Core-(Reactive Group)n??(I) wherein Core is a non-polymeric core group; and each Reactive Group, which may be the same or different in each occurrence, is a group of formula (II): wherein Sp1 independently in each occurrence represents a spacer group; w independently in each occurrence is 0 or 1; Ar in each occurrence independently represents an aryl or heteroaryl group; R1 in each occurrence independently represents H or a substituent, with the proviso that at least one R1 is a substituent; n is at least 1; and * is a point of attachment of the group of formula (II) to the Core; and wherein the compound of formula (I) reacts with itself or with a non-polymeric co-reactant.

Abstract: A composition comprising a polymer and a phosphorescent material wherein the polymer comprises repeat units of formula (I): wherein A is a heteroaryl group containing a nitrogen atom, and A may be unusubstituted or substituted with one or more substituents; R1 in each occurrence is independently a substituent; and n is 0, 1, 2, 3 or 4.