1. VIBRATIONAL SATELLITES IN THE ROTATIONAL SPECTRA OF
e-CAPROLACTAM AND CYCLOHEXANONE OXIME
NOBUHIKO KUZE, EMI SATO, NORIKO INOUE,
TAKESHI SAKAIZUMI AND OSAMU OHASHI
Department of Chemistry
Sophia University
Tokyo , Japan

2. e-CAPROLACTAM AND CYCLOHEXANONE OXIME
BECKMANN REARRANGEMENT
e-CAPROLACTAM
CYCLOHEXANONE OXIME
Chemical Week, Sep. 15, 2005
(Yamabe et al., 2005)

3. THIS WORK
The rotational spectra of the normal and deuterated species of
e -caprolactam and cyclohexanone oxime have been studied
e -caprolactam
e -caprolactam-d
cyclohexanone oxime
cyclohexanone oxime-d
cyclohexanone oxime-2,2,6,6-d4
The rotational spectra were observed in the range of GHz
by using a 100 kHz square-wave Stark modulation spectrometer.
Determination of the molecular conformation
Analyses of the excited vibrational satellites

4. THREE POSSIBLE CONFORMERS OF e-CAPROLACTAM
chair
boat
twist
Crystal structure
(Winkler and Dunitz, 1975)
e-caprolactam adopts a
chair conformation

5. e-CAPROLACTAM IN THE GAS PHASE: chair CONFORMER ONLYb
H(D)

6. VIBRATIONAL SATELLITES FOR e-CAPROLACTAM:
THREE VIBRATIONAL STATES WERE FOUND ν1
v=0
J= ← ν2
v=1
v=1 I0
v=2
Estimation of the
vibrational wavenumbers ν3 Iv
v=1
35050
35100
35150
35200
35250 MHz

7. SIX POSSIBLE CONFORMERS OF CYCLOHEXANONE OXIME
cis-isomer
NOH
NOH
NOH N O H
trans-isomer
chair
boat
twist-boat
Crystal structure
(Olivato et al., 2001)
(Lutz et al., 2004)
cis-isomer
chair conformation

8. CYCLOHEXANONE OXIME : chair CONFORMER ONLY
normal species
80, 73 and 39 spectral lines were fitted in the least-square analyses for normal, d1 and d4 species, respectively.
d1 species
d4-species
chair
twist-boat

9. r0 STRUCTURE OF CYCLOHEXANONE OXIME
C(ipso)
C(para)
Torsion angles for cyclohexyl ring
Deviations (Å) of C(ipso) and
C(para) atoms from the central
plane

10. VIBRATIONAL SATELLITES FOR CYCLOHEXANONE OXIME:
TWO VIBRATIONAL STATES WERE FOUND
v = 0
J= ←
vt = 1
vb = 1
vb = 2
vb = 3
31050 MHz
31100 MHz
31150 MHz
31200 MHz
31050 MHz
31100 MHz
31150 MHz
31200 MHz
a) Ohara (1983).
c) κ=(2B-A-C)/(A-C)
d) ΔI=Ic-Ia-Ib
e) MP2/6-31G(d, p)
b) ( ):1σ

11. ASSIGNMENT OF THE VIBRATIONAL MODESz
ASSIGNMENT OF THE VIBRATIONAL MODES
e-CAPROLACTAM
Ring-bending
Ring-twisting
Ring-twisting
58(15) cm-1 (observed)
70 cm-1 (B3LYP/6-31G(d,p))
78 cm-1 (B3LYP/6-31++G(d,p))
105(25) cm-1
166 cm-1
237(29) cm-1
237 cm-1
238 cm-1
CYCLOHEXANONE OXIME
Out-of-plane-bending
Ring-twisting
97(28) cm-1
78 cm-1 (MP2/6-31G(d,p))
81 cm-1 (B3LYP/6-31G(d,p))
198(35) cm-1
182 cm-1
178 cm-1