메뉴 건너뛰기




Volumn 108, Issue 20, 2004, Pages 6144-6151

An ideal one-dimensional antiferromagnetic spin system observed in hydrogen-bonded naphth[2,3-d]imidazol-2-yl nitronyl nitroxide crystal: The role of the hydrogen bond

Author keywords

[No Author keywords available]

Indexed keywords

ANTIFERROMAGNETISM; AROMATIC COMPOUNDS; CRYSTAL STRUCTURE; DEUTERIUM; HYDROGEN BONDS; INFRARED SPECTROSCOPY; PARAMAGNETIC RESONANCE; PROTONS; X RAY ANALYSIS;

EID: 2642529616     PISSN: 15206106     EISSN: None     Source Type: Journal    
DOI: 10.1021/jp035849r     Document Type: Article
Times cited : (23)

References (45)
  • 25
    • 0000189651 scopus 로고
    • (c) Becke, A. D. J. Chem. Phys. 1993, 98, 5648.
    • (1993) J. Chem. Phys. , vol.98 , pp. 5648
  • 31
    • 2642560201 scopus 로고    scopus 로고
    • EPR spectrum simulation was performed using PEST WinSIM (authored by D. Duling, National Institute of Environmental Health Sciences, 1996)
    • EPR spectrum simulation was performed using PEST WinSIM (authored by D. Duling, National Institute of Environmental Health Sciences, 1996).
  • 36
    • 85048340734 scopus 로고
    • Hellwege, K.-H.; Hellwege, A. M., Eds.; Springer - Verlag: Berlin
    • Gupta, R. R. In Landolt - Bömstein, Neue Series 11/16; Hellwege, K.-H.; Hellwege, A. M., Eds.; Springer - Verlag: Berlin, 1986; p 4.
    • (1986) Landolt - Bömstein, Neue Series 11/16 , pp. 4
    • Gupta, R.R.1
  • 43
    • 2642572448 scopus 로고    scopus 로고
    • note
    • We calculated spin densities and Fermi contact terms of 2 and phenyl nitronyl nitroxide at the UB3LYP/6-31G*//AM1 level, by changing the dihedral angle between the aryl rings and the ONCNO moieties from 0° to 90°. Calculations for 2 show that the sign of the spin densities at the NH proton changes while changing the angle, although that of Fermi contacts is always positive. On the other hand, the sign of both the spin densities and Fermi contact terms of the ortho-proton of phenyl nitronyl nitroxide is always positive. In the case of 2, the magnitude of spin density induced through a covalent bond seems smaller than that induced through an intramolecular hydrogen bond. Therefore, we consider that the explanation is reasonable for imidazol-2-yl nitronyl nitroxide derivatives. See Supporting Information (Figure IS) for more details.
  • 44
    • 2642562687 scopus 로고    scopus 로고
    • note
    • We investigated the angular dependence of the calculated J values for a hydrogen-bonded dimeric coordinate of 4 by rotating the naphthimidazole ring or NN unit around the C-C bond, from -30° to +30° (0° corresponds to the experimental geometry). The rotation of the naphthimidazole ring does not affect the J values very much, whereas rotation of the NN unit does affect the J values significantly, showing that the close contact between the nitroxide O atoms induced by the intermolecular hydrogen bond, rather than the intermolecular NH...ON hydrogen bond, is responsible for the antiferromagnetic character. In Figure 2S in the Supporting Information, the maximum J value appears at 0°, which implies that the NH...ON hydrogen bond is a ferromagnetic interaction pathway. See Supporting Information (Figures 2S and 3S) for more details.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.