19.1.11 Cyclophanes

Ohya-Nishigushi, H.; Terahara, A.; Tajima, K.

doi:10.1007/10394223_24

Cited by 1 publication

(1 citation statement)

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“…2. The same spectrum was observed upon electrolytic reduction of 3 in DME (helical Au-Hg cathode, Pt anode in the cell axis, Bu,NPF, as the supporting salt [20]). In sharp contrast to 3t, the spectrum of 3-exhibited a poor resolution which could not be improved by variation of concentration to mol/dm3), temperature (193 to 298 K), solvent (DME, THF, MTHF), and counterion (K+, Bu,N+).…”

Section: Radical Ions Of a Bishomobinaphthylene Containingsupporting

confidence: 64%

Radical Ions of a Bishomobinaphthylene Containing two 1,6‐methano[10]annulene moieties: An ESR and ENDOR study

Bachmann

Gerson

Kusch

et al. 1993

Helvetica Chimica Acta

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The radical cation and the radical anion of 'syn'-cyclobuta[l,2-c :3,4-c']di-1,6-niethano [lO]annulene ('syn'-4a, 12a :6a, 1Oa-bishomobinaphthylene; 3) have been characterized by their hyperfine data. The highly resolved ESR spectrum of 3f is dominated by a triplet splitting from the outer pair of methano p-protons (HJ. In contrast, the ESR spectrum of 3-is poorly resolved with the largest coupling constants arising from perimeter a-protons. The different hyperfine features of 3f and 3' are rationalized by MO models. The SOMO of 3f yIsA(bl), has substantial LCAO coefficients of the same sign at the bridged atoms C(1), C(6), C(l l), and C(16), whereas in the SOMO of 3', yIss(a,), the four atoms lie in the vertical nodal planes. The large width and the reluctance to saturation of the lines in the ESR spectrum of 3' are attributed to the near-degeneracy of the lowest antibonding MO's. Due to their similar nodal properties, the SOMO's of 3' and the radical anions of binaphthylene (4), 1,6-methano [lO]annulene (l), and naphthalene (2) are interrelated. Moreover, because the cyclic n-systems in 3 and 1 deviate in the same way from planarity, the effect of such distortions on the coupling constants, aHp, of the perimeter a-protons in 3' and 1' should be comparable. Indeed, on going from 4' to 3', the laH,I values are reduced exactly by half as much as the corresponding values on passing from 2' to I-, of which the cyclic n-systems are twice contained in 4' and 37, respectively.

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Section: Radical Ions Of a Bishomobinaphthylene Containingsupporting

confidence: 64%