On the Colour of Fountain Pen Inks

Kaitlin Krivak, Carlos Romero-Mejia Mentor: Dr. Álvaro Castillo-Aguilar, Department of Chemistry & Biochemistry

The ability for Time Dependent Density Functional Theory (TD-DFT) methods to predict the colour of the dye eosin Y were studied to determine if the method is precise and accurate. Our aim is to develop a better understanding of eosin dyes and promote the development of new colours in the ink industry. Four different DFT functionals were investigated (APFD, PBE, PBE0, and CAM-B3LYP) with eight basis sets (STO-3G, 3-21G, 6-31G(d), 6-31+G(d), 6-311+G(d,p), 6-311+G(2d,p), cc-pVDZ, and cc-pVTZ). Acrolein, aniline and nitrobenzene were used as model compounds to find an accurate and cost-effective computation protocol. The most accurate method for acrolein with an average error of 4.4% for λmax is PBE/6-31+G(d,p). This method was then applied to the other compounds. Additional calculations were conducted on acrolein using the Polarizable Continuum Model (PCM) to study the effects of water as a solvent. The same analysis was also carried out for aniline and nitrobenzene; our results indicate that the most accurate method is PBE/cc-pVTZ with an average error of 2.5%. All attempts to study eosin Y resulted in a colourless, closed structure of the molecule. Modifications of the eosin structure were studied in order to understand how these variations affect the overall colour of the compound. Tetrachloro-eosin Y, tetratrichloromethyl-eosin Y, and nitro-eosin Y derivatives were studied; our calculations predict their colours to be orange-yellow, red, and dark red respectively. Our preliminary results indicate that the PBE0/6-311+G(2d,p) combination including a Frank-Condon analysis is a good compromise between accuracy and cost for the prediction of the UV-VIS spectra of the model molecules.

Additional Abstract Information

Presenters: Kaitlin Krivak, Carlos Romero -

Institution: Elmhurst University

Type: Poster

Subject: Chemistry

Status: Approved

Time and Location

Session: Poster 4
Date/Time: Tue 11:00am-12:00pm
Session Number: 3516