Improved Dynamic Properties of Charge-Transfer-Type Supramolecular Rotor Composed of Coronene and F₄TCNQ

Abstract

A charge-transfer (CT)-type supramolecular rotor, (coronene) 2 F 4 TCNQ, was obtained by vacuum cosublimation. The CT complex has an unprecedented crystal structure consisting only of DDA-type alternating π-columns of coronene (D) and electron acceptor (A), and coronene molecules with a pronounced undulating structure form no C−H···F hydrogen bonds with adjacent F 4 TCNQ molecules in the side-by-side direction. These structural features are in contrast with those reported for (coronene)F 4 TCNQ that has DA-type alternating π-columns, which was obtained by diffusion in dichloromethane/pentane. Coronene molecules in the present complex undergo an in-plane rotation in the gigahertz region at 233 K, which is 3 orders of magnitude faster than that in (coronene)F 4 TCNQ. Furthermore, the activation energy for the rotation was found to be about half of the value reported for (coronene)F 4 TCNQ. These results clearly demonstrate that dynamic properties of the assemblies (CT complexes) can be varied by changing the assembly method (crystallization method), even when the parts (molecules) used as rotator and stator components are the same.

Crystal growth of new charge-transfer salts based on π-conjugated donor molecules

“…= 228 • C meaning both compounds were intact and TCNQ was not decomposed in this temperature regime. The melting point for the complex phenanthrene/TCNQ lies in between the melting points for the single compounds, which looks reasonable and is in good agreement to the different crystal growth areas for acceptor, CT complex and donor [11,22,18] and is also apparent in Figure 2. Sublimation points could not be detected by DTA but are stronger depending on pressure than melting points.…”

“…All charge transfer crystals grow in a 1:1 stoichiometry with the applied starting conditions. There is no other stoichiometry detected as for example 2:1 in Coronene 2 /TCNQ-F 4 [18]. Besides the growth of CT salts in a closed system, the oven can be used also for crystal growth or purification of organic semiconductors (molecular crystals with one type of molecule).…”

Organic Cocrystals: Beyond Electrical Conductivities and Field‐Effect Transistors (FETs)

“…[2] Other packing ratios (except for 1:1) are unusual in cocrystals,cocrystal formation with such ratios needs appropriate donors,a cceptors and preparation conditions. [52] Moreover,the degree of charge transfer, afeature of charge-transfer cocrystals,i sd efined as q (0 q 1), which can be related to many physical properties. [52] Moreover,the degree of charge transfer, afeature of charge-transfer cocrystals,i sd efined as q (0 q 1), which can be related to many physical properties.…”

“…[38a] In these cocrystals,t he extra donor or acceptor compounds can either exist within the co-stack or form anew stack. [52] Moreover,the degree of charge transfer, afeature of charge-transfer cocrystals,i sd efined as q (0 q 1), which can be related to many physical properties. [34] Specifically,the cocrystals dominated by charge-transfer interactions (larger q value) normally possess high conductivity,while the ones with weak charge-transfer interactions (smaller q value) show potentially smaller conductivity.…”

PAH/PAH(CF3)n Donor/Acceptor Charge‐Transfer Complexes in Solution and in Solid‐State Co‐Crystals

“…Comparison of the structure of (CORO) 2 /ANTH-6-1 with (CORO) 2 /F 4 TCNQ The different CORO/CORO p-p overlaps in the crystal structures of (CORO) 2 /ANTH-6-1, (CORO) 2 /F 4 TCNQ), [68,73] and pure CORO at 100 Ka re shown in FigureS47, andt he differentm olecular stackings and packings in these three structures are shown in Figure S48. The(CORO) 2 pair in (CORO) 2 /ANTH-6-1 exhibitsb oth major (11%)a nd minor (21 %) axis slippage and a greater number of p-overlapped Ca toms (15) than the (CORO) 2 pair in (CORO) 2 /F 4 TCNQ (12), which exhibits almost no major axis slippage and 30 %m inor axis slippage, although the areas of overlap are approximately the same.…”