ja908768a_si_009.cif (20.21 kB)
Resonating Valence Bond and σ-Charge Density Wave Phases in a Benzannulated Phenalenyl Radical
dataset
posted on 2010-03-03, 00:00 authored by Pradip Bag, Mikhail E. Itkis, Sushanta K. Pal, Bruno Donnadieu, Fook S. Tham, Hyunsoo Park, John A. Schlueter, Theo Siegrist, Robert C. HaddonWe report the preparation of the first benzannulated phenalenyl neutral radical conductor (18), 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 P2/c) together with the conductivity of σRT = 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 P21/c 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.
History
Usage metrics
Categories
Keywords
RVB phasecarbon atomsbenzannulated phenalenylsCDW phasesconductivityinterchain overlap150 Kinterchain interactionbenzannulated phenalenylroom temperature structurecompound displaysresonating valence bondσ RToccupancystate behavior293 Kphenalenyl radicalsunit cellBenzannulated Phenalenyl RadicalWe reportResonating Valence BondC 4 carbon atoms
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC