Complete charge separation provoked by full cation encapsulation in the radical mono- and di-anions of 5,6:11,12-di-o-phenylene-tetracene

Abstract

Herein, we report the synthesis and molecular structure of the mono- and dianionic aromatic molecules [(B15C5-κ5O)2K+](LDOPT˙-) (1) and [(B15C5-κ5O)2K+]2(LDOPT2-)THFsolv (2) derived from the parent aromatic polyhydrocarbon 5,6:11,12-di-o-phenylenetetracene (DOPT, LDOPT) by a controlled stepwise one and two electron chemical reduction. The effect of single and double electron charge transfer to a polycondensed aromatic hydrocarbon (PAH) without any disturbing influence of an associated metal cation has been demonstrated. This was achieved by fully sandwiching the cationic K+ counterions between two benzo-15-crown-5-ether (B15C5) ligands resulting in a fully encapsulating (κ10O) geometry which ensures a complete separation of the K+ counterions and the bare anionic PAH species [LDOPT˙-] and [LDOPT2-]. The structural changes accompanied by the stepwise reduction from LDOPT to [LDOPT˙-] to [LDOPT2-] are discussed and compared to earlier predictions based on density functional theory (DFT) as well as the results of previous studies of alkaline metal cationic PAH anion interactions of DOPT in which only a partial metal cation encapsulation has been achieved so far.

Two-Fold Reduction of Dibenzo[a,e]cyclooctatetraene with Group 1 Metals: From Lithium to Cesium

“…In the solid-state structure of 6 , a 2D layer is formed through weak C–H···π interactions between the 1 2– anions and the adjacent [2.2.2]­cryptand molecules, with the shortest contacts ranging from 2.350(5) to 2.722(5) Å. All of the above K···C, K···O, and K···N distances are close to those previously reported. ,,, Notably, the series of potassium salts of 1 2– crystallographically characterized in this work ( 4 – 6 ) illustrates how metal binding and overall crystal packing can be effectively modulated with the help of secondary ligands used during crystallization (THF vs 18-crown-6 ether and [2.2.2]­cryptand).…”

Back Cover: Site‐Specific Reduction‐Induced Hydrogenation of a Helical Bilayer Nanographene with K and Rb Metals: Electron Multiaddition and Selective Rb+ Complexation (Angew. Chem. Int. Ed. 10/2022)

“…Furthermore, the coordination observed for Rb + cations opens a new scenario for the preparation, in a selective manner, of new organometallic species from less-explored molecular nanographenes. [28] Finally, since molecular nanographenes exhibit a variety of amazing chemical, photophysical, electrochemical, imaging, sensing and/or chiroptical properties, the data now reported open new opportunities for these chemically…”

Structural deformation and host–guest properties of doubly-reduced cycloparaphenylenes, [n]CPPs2− (n = 6, 8, 10, and 12)

“…The K/ O crown distances of 2.788(2)-2.832(2) A are comparable to those previously reported. [51][52][53][54][55] Two interstitial THF molecules were found in the crystal structure of 2$2THF, lling the structural voids with no close contacts.…”

“…51 The coordination of K + ion is completed by an axially bound 18-crown-6 ether molecule (K/ O crown : 2.751(2)-2.867(2) A) and a capping THF molecule (K/ O THF : 2.728(2) A), with all K/O crown and K/O THF distances being close to those previously reported. [51][52][53][54][55] Scheme 2 Chemical reduction of [8]CPP, [10]CPP, and [12]CPP.…”