Structure Data of Free Polyatomic Molecules
313
MW
C 2H 8O 2
r0
O...H
Methanol dimer
(weakly bound complex)
Å a)
1.96(2)
θ0
b
φ )
donor(i,a) c)
donor(i,b) c)
donor(i,c) c)
acceptor(i,a) c)
acceptor(i,b) c)
acceptor(i,c) c)
deg a)
77(2)
49.7(3)
110.5(18)
47.4(14)
120.79(2)
37.1(13)
71.4(20)
C1
(large-amplitude motion)
CH3OH · CH3OH
It was shown that the K = 1 states are split into the 16 expected states through the assignment
of the Ka = 1 a-type transitions and ∆Ka = 1 b-type transitions. The effective barrier to internal
rotation for the donor methyl group is V3 = 183.0 cm–1, while the barrier to internal rotation of
the acceptor methyl group is 120 cm–1.
a
) Estimated standard errors.
) Tilt angle of the acceptor methanol defined
by the O – H...O axis and the bisector of the
H–O–C angle of the acceptor methanol. It was
assumed that the donor proton is bonded
symmetrically to the H–O–C angle.
c
) Angle between the CH3 internal rotation axis and the g (=a, b, c) principal inertial axis.
b
Lovas, F.J., Hartwig, H.: J. Mol. Spectrosc. 185 (1997) 98.
Replaces II/25B(3, 942)
Landolt-Börnstein
New Series II/28B