Fine tuning of the photochromic absorption band of heteromolecular Langmuir–Blodgett films of zwitterionic donor-π-acceptor molecules
Abstract
Mixed Langmuir–Blodgett films of Z-β-(1-hexadecyl-4-pyridinium)-α-cyano-4-styryldicyanomethanide (C16H33-P3CNQ) and Z-β-(1-hexadecyl-4-quinolinium)-α-cyano-4-styryldicyanomethanide (C16H33-Q3CNQ) exhibit a single charge-transfer band that may be tuned within the range 495 to 565 nm; the films are photochromic and exhibit second-harmonic generation.