Photoisomeric molecular tagging velocimetry with CCVJ

The molecular rotor 9-(2-Carboxy-2-cyanovinyl)julolidine (CCVJ) exists in two isomers. While the E isomer, which is present in the absence of light, yields a fluorescent behavior, the Z isomer is a photoproduct with no detectable luminescence. This regenerative behavior is utilized for Molecular Tagging Velocimetry (MTV).