Yangs Biradikal / Yang's biradical

Yang biradical 2d Yang biradical 3d
3D coordinates from crystal structure analysis: H. Bock et al., Angew. Chem., 1993, 105, 416.

Monoradical from Yang's biradical and ...-d54

...-d54: perdeuteriated tert-butyl groups (prepared by Jörg von Gersdorff, Diplomarbeit, FU Berlin, 1985)

Yang mono EPR 296 K
EPR spectrum: Yang monoradical-d54, toluene, 296 K (JCAMP-DX)
URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-d54-mono.jdx
EPR simulation: Yang monoradical-d54, toluene, 296 K (JCAMP-DX) URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-d54-mono_sim.jdx

SIMULATION PARAMETERS
units: MHz
no. of sets of nuclei: 3
  HFC       Spin  Number var.:
    3.6820  0.5   4      0.0100
    0.5588  0.5   2      0.0100
    0.0276  1.0  36      0.0000
Lineshape: 2 (Gaussian)
  Linewidth   var.:
    0.3504      0.0100
Spectrum width: 55.658
  Offset      var.:
  -27.6086      0.0100
  Fit range (points):
    1   4096
sigma=     57.037

Yang mono ENDOR 200 K
ENDOR spectrum: Yang monoradical, toluene, 200 K (JCAMP-DX)
URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-mono_endor.jdx
Yang-d54 mono ENDOR 200 K
ENDOR spectrum: Yang monoradical-d54, toluene, 200 K (JCAMP-DX)
URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-d54-mono_endor.jdx
ENDOR spectrum: Yang monoradical-d54, toluene, 296 K (JCAMP-DX) URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-d54-mono_endor_296k.jdx

ENDOR data (toluene, 200 K and 296 K; νH = 14.48 MHz):

  200 K                 296 K
  HFC, MHz   Number     HFC, MHz
    3.60     4H           3.70
    0.65     2H           0.55
    0.12    36H           0.18

Yang's biradical

ENDOR, toluene, 260 K: 2.39 MHz (6H);
B. Kirste, Dissertation, FU Berlin, 1977

Labeled Yang's biradical: glass spectra

labeling: -d54: perdeuteriated tert-butyl groups, -d6: deuteriated ring positions, -C13: C-13 labeled at the central position

Yang-d6 bi EPR 160 K
EPR spectrum: Yang's biradical-d6, toluene, 160 K, glass spectrum (JCAMP-DX)
URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-d6-bi_160k.jdx
Yang-c13 bi EPR 160 K
EPR spectrum: Yang's biradical-C13, toluene, 160 K, glass spectrum (JCAMP-DX)
URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-c13-bi_160k.jdx
Yang-c13 bi EPR 160 K sim
EPR simulation: Yang's biradical-C13, toluene, 160 K, glass spectrum (JCAMP-DX)
URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-c13-bi_160k_sim.jdx

SIMULATION PARAMETERS of 13C-labeled biradical
                 units: MHz      C-13
 gxx = 2.00542   |D| =  94.453   Axx = -17.283
 gyy = 2.00526   |E| =   3.063   Ayy = -17.326
 gzz = 2.00263                   Azz = -35.854
Lineshape: 1 (Lorentzian)
 linewidth = 12.46

Note: The sign of D has been determined experimentally as negative, although a simple theoretical model suggests a positive sign for a biradical with almost threefold symmetry (see ref. below).

ENDOR glass spectra of Yang's biradical-d54

Yang-d54 bi ENDOR hf-xy
ENDOR spectrum: Yang's biradical-d54, toluene, 107 K, glass spectrum, high-field xy setting (3422 G) (JCAMP-DX)

URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-d54-bi_endor_hf-xy.jdx
Yang-d54 bi ENDOR lf-xy
ENDOR spectrum: Yang's biradical-d54, toluene, 107 K, glass spectrum, low-field xy setting (3392 G) (JCAMP-DX)

URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-d54-bi_endor_lf-xy.jdx
Yang-d54 bi ENDOR hf-z
ENDOR spectrum: Yang's biradical-d54, toluene, 107 K, glass spectrum, high-field z setting (3439 G) (JCAMP-DX)

URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-d54-bi_endor_hf-z.jdx
Yang-d54 bi ENDOR lf-z
ENDOR spectrum: Yang's biradical-d54, toluene, 107 K, glass spectrum, low-field z setting (3373 G) (JCAMP-DX)

URL: http://kirste.userpage.fu-berlin.de/chemistry/jdx/yang-d54-bi_endor_lf-z.jdx

Ref.: H. van Willigen et al., Tetrahedron 1982, 38, 759


Copyright © Burkhard Kirste, Freie Universität Berlin, 2014.