Elongation of the molecular probe DDNP with phenylethynylidene or phenyldiazenylidene spacers

- The syntheses and optical properties of two elongated DDNP analogs are described.
- Bromination and subsequent debromination can be a viable protective procedure.
- Solid-state structures of extended DDNP analogs were determined.
- Phenylethynylidene moiety affects the size but not the optical properties.