New Charge Transfer Cocrystals of F2 TCNQ with Polycyclic Aromatic Hydrocarbons: Acceptor-Acceptor Interactions and Their Contribution to Supramolecular Arrangement and Charge Transfer
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
A series of new charge-transfer cocrystals of F2TCNQ with anthracene, tetracene, and chrysene was prepared and characterized. The donor and acceptor molecules are arranged in alternating D-A-D-A stacks. The linear acenes in combination with F2TCNQ form layered structures due to in-plane lateral donor-acceptor and acceptor-acceptor interactions via multiple C-H···N and C-H···F hydrogen bonds, which govern the crystal structure and significantly alter face-to-face π-πinteractions. In the cocrystal of F2TCNQ with chrysene no interactions between acceptor molecules are observed, and the π-πinteractions prevail. Thus, the donor-acceptor interplanar distance is the smallest in the chrysene complex despite its lower energy level of the HOMO and weaker donor ability, as determined through electrochemical oxidation potentials in this series of PAHs. The charge-transfer values estimated through empirical correlations and QTAIM analysis also do not manifest a direct dependence on the donor ability of PAHs. Thus, though face-to-face π-πinteractions dictate the formation of cocrystals, the lateral noncovalent interactions are as important for the supramolecular arrangement and charge transfer. UV/vis spectroscopy and electronic structure quantum chemical calculations show that these cocrystals may be classified as small-gap semiconductors with energy gaps of 0.7-1.3 eV.
Details
Original language | English |
---|---|
Pages (from-to) | 751-762 |
Number of pages | 12 |
Journal | Crystal Growth and Design |
Volume | 22 |
Issue number | 1 |
Publication status | Published - 5 Jan 2022 |
Peer-reviewed | Yes |