Abstract: A compound of formula (I), D1 and D2 are electron-donating groups; A2 and A3 are electron-accepting groups; B1 and B2 are bridging groups; x1 and x2 are 0, 1, 2 or 3; y1 and y2 are at least 1; z1 and z2 are 0, 1, 2 or 3; and A1 is a group of formula (II) wherein Ar1 is an aromatic or heteroaromatic group; and Y is O, S, NR4 or R1-C?C—R1 wherein R1 in each occurrence is independently H or a substituent wherein two substituents R1 may be linked to form a monocyclic or polycyclic ring and R4 is H or a substituent. The compound may be used as an electron-accepting material with an electron-donating material in an organic photodetector.

Abstract: A compound of formula (I), A1 is a divalent heteroaromatic electron-accepting group comprising at least 3 fused aromatic rings, or has a modelled LUMO of more than 2.70 eV from vacuum level. A2 and A3 are each independently a monovalent electron-accepting group. D1 and D2 independently in each occurrence is an electron-donating group, wherein at least one occurrence of at least one of D1 and D2 is a fused heteroaromatic group comprising at least 4 fused rings. B1 and B2 independently in each occurrence is a bridging group. x1, x2, z1 and z2 are each independently 0, 1, 2 or 3. y1 and y2 are each independently at least 1. The compound of formula (I) may be used as an acceptor in an organic photodetector.

Abstract: A compound of formula (I), A1 is an electron-accepting group; D1 and D2 independently in each occurrence is an N electron-donating group; A1, A2 and A3 are each independently an electron-accepting group; B1 and B2 in each occurrence are independently a bridging group; x1 and x2 are each independently 0, 1, 2 or 3; y1 and y2 are each independently at least 1; z1 and z2 are each independently 0, 1, 2 or 3; and at least one of (i)-(iv) applies: (i) (D1)y1 and (D2)y2 are different; (ii) A2 and A3 are different; (iii) (B1)x1 and (B1)x2 are different; and (iv) (B2)z1 and (B2)z2 are different. The compound of formula (I) may be used as an electron acceptor in an organic photodetector.

Abstract: A compound of formula (I). A1 is a divalent heteroaromatic electron-accepting group; A2 and A3 are each independently a monovalent electron-accepting group; D1 and D2 independently in each occurrence is an electron-donating group; B1 and B2 independently in each occurrence is a bridging group; x1 and x2 are each independently 0, 1, 2 or 3; y1 and y2 are each independently at least 1; and z1 and z2 are each independently 0, 1, 2 or 3, with the proviso that at least one of z1 and z2 is at least 1. The compound of formula (I) may be used as an electron-accepting material in an organic photodetector.

Abstract: A material comprising an electron-accepting unit of formula (I).

Abstract: A polymer comprising a donor repeat unit and an acceptor repeat unit wherein the acceptor repeat unit comprise a repeat unit of formula (I): A1 is selected from formula (IIa): formula (lib); O; S; and NR1 wherein R1 is H or a substituent: (Ha) (lib) Ar3 is a monocyclic or polycyclic aromatic group; X1 and X2 are each independently selected from N and CR2 wherein R2 in each occurrence is H or a substituent with the proviso that at least one of X1 and X2 is selected from N and CR2 wherein R2 is an electron withdrawing group; Ar1 is selected from pyrrole, benzene, pyridine and 1,4-diazine; A2 is O, S, SO2, NR1, PR1, C(R3)2 and Si(R3)2 wherein R3 in each occurrence is independently H or a substituent; and Ar2 is a monocyclic or polycyclic aromatic group.

Abstract: A compound of formula (I) or (II): A1-(B1)x1-(D1)y1-(B1)x2-A1 ??(I) A1-(B2)x5-(D2)y2-(B3)x3-A2-(B3)x4-(D3)y3-(B2)x6-A1 ??(II) wherein: A1 in each occurrence is independently a monovalent electron-accepting group; A2 is a divalent electron-accepting group; D1, D2 and D3 independently in each occurrence is an electron-donating group; y1, y2 and y3 are each independently at least 1; B1, B2, and B3 independently in each occurrence is a bridging group; x1-x6 are each independently 0, 1, 2 or 3 with the provisos that: in the case of the compound of formula (I) at least one of x1 and x2 is at least 1 and at least one B1 is substituted with a fluorinated group; and in the case of the compound of formula (II) at least one of x3, x4, x5 and x6 is at least 1 and at least one occurrence of at least one of B2 and B3 is substituted with a fluorinated group. The compound of formula (I) or (II) may be used as an electron-accepting material in a photoresponsive device.

Abstract: A compound of formula (I): wherein: each X is independently O or S; R1 in each occurrence is independently H a substituent; R2 in each occurrence is independently a substituent; B in each occurrence is independently a bridging unit; n in each occurrence is independently 0 or 1; A1 in each occurrence is independently an electron-accepting group; Z is a direct bond or, together with R1, forms a monocyclic or fused ring; and the compound of formula (I) is substituted with at least one substituent of formula (II): -(L)p-[(OCH2CH2)r-R3]q ??(II) wherein: L is a linking group; p in each occurrence is independently is 0 or 1; r in each occurrence is independently an integer from 1 to 10; R3 is H or a substituent; and q is 1 if p is 0 and q is at least 1 if p is 1.

Abstract: A compound formula (I): wherein: Ar1 is a monocyclic or fused polycyclic group which, together with the rings it is fused to, forms a fused heteroaromatic group; Y is O, S or NR55, wherein R55 is H or a C1-30 hydrocarbyl group; X is O or S; R1 in each occurrence is independently H or a substituent with the proviso that at least one R1 is an electron-withdrawing group; R2 in each occurrence is independently H or a substituent; L is a direct bond or, together with R2, forms an unsubstituted or substituted 5- or 6-membered aromatic or heteroaromatic ring; and A1 in each occurrence is an electron-accepting group.

Abstract: A material comprising an electron-accepting unit of formula (I): Ar is an aromatic ring; Ar1 is a substituted or unsubstituted 5- or 6-membered heteroaromatic ring containing N and C ring atoms; when Ar1 is a substituted or unsubstituted 6-membered heteroaromatic ring, Ar2 is a substituted or unsubstituted 6-membered heteroaromatic ring wherein the ring atoms are selected from N and C; when Ar1 is a 5-membered heteroaromatic ring, Ar2 is a substituted or unsubstituted 5- or 6-membered heteroaromatic ring; Ar3 is a 5-membered ring or a substituted or unsubstituted 6-membered ring; Ar4 is a 5-membered ring or a substituted or unsubstituted 6-membered ring or is absent; Ar5 is a substituted or unsubstituted monocyclic or polycyclic group containing at least one aromatic or heteroaromatic ring; Ar6 is a substituted or unsubstituted monocyclic or polycyclic group containing at least one aromatic or heteroaromatic ring or is absent; and each X is independently a substituent bound to a C atom of Ar3, and where prese