Twisted π-electron system chromophore compounds with very large molecular hyperpolarizabilities and related compositions and devices
Unconventional twisted π-electron system electro-optic (EO) chromophores/compounds, compositions and related device structures. Crystallographic analysis of several non-limiting chromophores reveals, for instance, large ring-ring dihedral twist angles and a highly charge-separated zwitterionic structure in the ground state, in both solution phase and solid-state.
1. A chromophore compound of a formula
wherein X is selected from NR′, O, PR′ and S; each of R′, R 1 -R 4 and Z 1 -Z 4 is independently selected from linear alkyl, substituted linear alkyl, branched alkyl, substituted branched alkyl, cycloalkyl, substituted cycloalkyl aryl, heterocyclic, alkylaryl, alkylheterocycle and arylheterocycle moieties; and Y comprises a substituent comprising a moiety selected from anionic carbon and heteroatom moieties; and salts, conjugate acids and charge-transfer isomers thereof
2. The compound of claim 1 wherein each Z 1 -Z 4 and of R 1 -R 4 is independently selected from a C n H 2n+1 moiety, where n is an integer selected from 1 and integers greater than 1, and said moieties comprising at least one electron-withdrawing substituent.
3. The compound of claim 2 wherein Y is a substituent selected from O − and (Ew 1 )(Ew 2 )C − moieties, where Ew 1 and Ew 2 are selected from electron withdrawing substituents.
4. The compound of claim 2 in a composition comprising a polymeric film.
5. The compound of claim 4 incorporated into an electro-optic device.
6. The compound of claim 1 wherein Y comprises a substituent of a formula
wherein z and w are independently selected from S, O, NR″ and CH═CH, and R″ is selected from linear alkyl, substituted linear alkyl, branched alkyl, substituted branched alkyl, cycloalkyl and substituted cycloalkyl moieties; m, n and l are independently selected from 0 and integers greater than 0, provided at least one of said m, n and l is at least 1; and Y′ is selected from anionic carbon and heteroatom moieties.