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 102-8554, Japan

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

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 26-40 GHz by using a 100 kHz square-wave Stark modulation spectrometer. Determination of the molecular conformation Analyses of the excited vibrational satellites

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

e-CAPROLACTAM IN THE GAS PHASE: chair CONFORMER ONLY b H(D)

VIBRATIONAL SATELLITES FOR e-CAPROLACTAM: THREE VIBRATIONAL STATES WERE FOUND ν1 v=0 J=13 0 13←12 0 12 ν2 v=1 v=1 I0 v=2 Estimation of the vibrational wavenumbers ν3 Iv v=1 35050 35100 35150 35200 35250 MHz

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

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

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

VIBRATIONAL SATELLITES FOR CYCLOHEXANONE OXIME: TWO VIBRATIONAL STATES WERE FOUND v = 0 J=13 0 13←12 0 12 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

ASSIGNMENT OF THE VIBRATIONAL MODES z 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