10.1021/ja908768a.s009 Pradip Bag Pradip Bag Mikhail E. Itkis Mikhail E. Itkis Sushanta K. Pal Sushanta K. Pal Bruno Donnadieu Bruno Donnadieu Fook S. Tham Fook S. Tham Hyunsoo Park Hyunsoo Park John A. Schlueter John A. Schlueter Theo Siegrist Theo Siegrist Robert C. Haddon Robert C. Haddon Resonating Valence Bond and σ-Charge Density Wave Phases in a Benzannulated Phenalenyl Radical American Chemical Society 2010 RVB phase carbon atoms benzannulated phenalenyls CDW phases conductivity interchain overlap 150 K interchain interaction benzannulated phenalenyl room temperature structure compound displays resonating valence bond σ RT occupancy state behavior 293 K phenalenyl radicals unit cell Benzannulated Phenalenyl RadicalWe report Resonating Valence Bond C 4 carbon atoms 2010-03-03 00:00:00 Dataset https://acs.figshare.com/articles/dataset/Resonating_Valence_Bond_and_Charge_Density_Wave_Phases_in_a_Benzannulated_Phenalenyl_Radical/2787880 We report the preparation of the first benzannulated phenalenyl neutral radical conductor (<b>18</b>), and we show that the compound displays unprecedented solid state behavior: the structure is dominated by two sets of intermolecular interactions: (1) a π-chain structure with superimposed π-overlap of the benzannulated phenalenyls along [0 0 1], and (2) an interchain overlap involving a pair of carbon atoms (C4) along [0 1 0]. The π-chain-type stacking motif is reminiscent of previously reported phenalenyl radicals and the room temperature structure (space group <i>P</i>2/<i>c</i>) together with the conductivity of σ<sub>RT</sub> = 0.03 S/cm and the Pauli-like magnetic susceptibility are best described by the resonating valence bond (RVB) model. The interchain interaction is unstable with respect to the formation of a σ-charge density wave (σ-CDW) involving pairs of C4 carbon atoms between adjacent radicals and this phase is characterized by the <i>P</i>2<sub>1</sub>/<i>c</i> space group which involves a doubling of the unit cell along the [0 1 0] direction. The RVB and CDW phases compete for structural occupancy throughout the whole temperature range (15−293 K) with the RVB phase predominating at 15 and 293 K and the σ-CDW phase achieving a maximum structural occupancy of about 60% at 150 K where it produces clearly discernible effects on the magnetism and conductivity.