232
A. V. Pomogaeva and A. Y. Timoshkin
groups. Irrespective to the group 13 metal M, the middle M 3 N 3 ring in closed
oligomers is rather “flat” compared with a bent chair shape in the open oligomer.
Middle M 3 N 3 rings of the closed oligomers have larger N-M-N and M-N-M
angles and shorter M-N bonds.
Since both types of oligomers can be simultaneously generated at the experimental conditions, it is of interest if they can be distinguished by IR spectroscopy. Computed gas phase IR spectra of closed [CH 3 MNH] 10 and open
(CH 3 ) 3 [CH 3 MNH] 9 H 3 (M=Al, Ga, In) oligomers are shown in Fig. 6.16. The
spectra are qualitatively similar for compounds with different metal atoms, but there
are some specific features that are helpful to distinguish between closed and open
structures. The open oligomer has two neighboring fingerprint bands associated with
Fig. 6.16 Computed IR spectra of [CH 3 MNH] 10 (dashed line) and (CH 3 ) 3 [CH 3 MNH] 9 H 3 (solid
line)
A. V. Pomogaeva and A. Y. Timoshkin
groups. Irrespective to the group 13 metal M, the middle M 3 N 3 ring in closed
oligomers is rather “flat” compared with a bent chair shape in the open oligomer.
Middle M 3 N 3 rings of the closed oligomers have larger N-M-N and M-N-M
angles and shorter M-N bonds.
Since both types of oligomers can be simultaneously generated at the experimental conditions, it is of interest if they can be distinguished by IR spectroscopy. Computed gas phase IR spectra of closed [CH 3 MNH] 10 and open
(CH 3 ) 3 [CH 3 MNH] 9 H 3 (M=Al, Ga, In) oligomers are shown in Fig. 6.16. The
spectra are qualitatively similar for compounds with different metal atoms, but there
are some specific features that are helpful to distinguish between closed and open
structures. The open oligomer has two neighboring fingerprint bands associated with
Fig. 6.16 Computed IR spectra of [CH 3 MNH] 10 (dashed line) and (CH 3 ) 3 [CH 3 MNH] 9 H 3 (solid
line)