Filling the Gaps (IMAGE) Washington University in St. Louis Caption Using what they had learned about the link between structure and absorption of pigment molecules, a small group of chemists was able to synthesize molecules that filled a hole in the absorption spectrum of native pigments (the chlorin-imides) and extended absorption deeper into the infrared (the bacteriochlorin-(bis)imides). Credit Holten et al. Usage Restrictions Please credit License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.