PMID- 17500519
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20070626
LR  - 20070530
IS  - 0002-7863 (Print)
IS  - 0002-7863 (Linking)
VI  - 129
IP  - 22
DP  - 2007 Jun 6
TI  - Phenalenyl-based neutral radical molecular conductors: substituent effects on 
      solid-state structures and properties.
PG  - 7163-74
AB  - We report the preparation, crystallization, and solid-state characterization of 
      cycloheptyl and cyclooctyl-substituted spirobiphenalenyl radicals and the 
      corresponding sigma-dimer of the cyclooctyl derivative. The crystal structure 
      shows that the cycloheptyl radical (9) is monomeric in the solid state, with the 
      molecules packed in an unusual one-dimensional (1-D) fashion that we refer to as 
      a pi-chain structure, whereas the cyclooctyl variant exists both as pi-dimer 10 
      and sigma-dimer 10d. The neutral radical 9 shows the temperature-independent 
      Pauli paramagnetism characteristic of a metal with a magnetic susceptibility, 
      chip approximately 4.5x10(-4) emu/mol and is assigned a resonating valence bond 
      (RVB) ground state. We highlight the relationship between the magnetic properties 
      of the Heisenberg antiferromagnet and the RVB ground state in 1-D and further 
      elucidate the electronic structure of this new class of compounds. Magnetic 
      susceptibility measurements show that 10 is a diamagnetic pi-dimer, whereas 10d 
      is a diamagnetic sigma-dimer. Extended Huckel calculations for 9 indicate that 
      the solid is a one-dimensional organic metal with a bandwidth of about 0.4 eV. 
      Pressed pellet conductivity measurements indicate values of sigmaRT=1.5x10(-3) 
      S/cm for compound 9 and sigmaRT=1.0x10(-6) S/cm for compound 10. The structural 
      results and transport properties are discussed in the light of extended Huckel 
      theory band structure calculations and DFT investigations of the electronic 
      structure of related compounds.
FAU - Pal, Sushanta K
AU  - Pal SK
AD  - Department of Chemistry, University of California, Riverside, California 
      92521-0403, USA.
FAU - Itkis, Mikhail E
AU  - Itkis ME
FAU - Tham, Fook S
AU  - Tham FS
FAU - Reed, Robert W
AU  - Reed RW
FAU - Oakley, Richard T
AU  - Oakley RT
FAU - Donnadieu, Bruno
AU  - Donnadieu B
FAU - Haddon, Robert C
AU  - Haddon RC
LA  - eng
PT  - Journal Article
DEP - 20070515
PL  - United States
TA  - J Am Chem Soc
JT  - Journal of the American Chemical Society
JID - 7503056
EDAT- 2007/05/16 09:00
MHDA- 2007/05/16 09:01
CRDT- 2007/05/16 09:00
PHST- 2007/05/16 09:00 [pubmed]
PHST- 2007/05/16 09:01 [medline]
PHST- 2007/05/16 09:00 [entrez]
AID - 10.1021/ja070103i [doi]
PST - ppublish
SO  - J Am Chem Soc. 2007 Jun 6;129(22):7163-74. doi: 10.1021/ja070103i. Epub 2007 May 
      15.