Conformational Control and Photophysical Properties of Methylene‐Tethered Bis[(naphthalene‐2‐yl)vinyl]benzenes

We have synthesized and isolated three planar dibenzo‐fused oligo(phenylenevinylene) isomers (l‐DBCOPV2, u‐DBCOPV2, and b‐DBCOPV2), which serve as model compounds for rotational conformers of bis[(naphthalene‐2‐yl)vinyl]benzene. Their photophysical properties were examined by UV/Vis absorption and emission spectroscopy, revealing that their emission colors changed from sky‐blue to green depending on the conformation. We have also measured their fluorescence lifetimes and carried out DFT calculations. These investigations revealed a more detailed conformation‐dependent character for l‐DBCOPV2, u‐DBCOPV2, and b‐DBCOPV2: The UV/Vis absorption and emission bands showed bathochromic shifts that increased in the order l‐DBCOPV2