Structure Data of Free Polyatomic Molecules
245
C 2H 3N
MW, ab initio calculations
(MP2/cc-pCVQZ,
CCSD(T)/cc-pCVQZ)
Methyl isocyanide
Isocyanomethane
r0
N=C
C–N
C–H
Å
1.1720(16)
1.4223(14)
1.0923(5)
θ0
deg
109.35(3)
rs a)
N=C
C–N
C–H
Å
1.1699(21)
1.4209(16)
1.0937(17)
θs a )
H–C–N
deg
109.37(8)
rm(1) b)
N=C
C–N
C–H
Å
1.1683(22)
1.4186(19)
1.0951(19)
θm(1) b)
H–C–N
deg
109.27(9)
rm(2) c)
N=C
C–N
C–H
Å
1.1708(13)
1.4181(8)
1.0988(8)
θm(2) c)
H–C–N
deg
108.91(12)
r e d)
N=C
C–N
C–H
Å
1.1666(6)
1.4259(3)
1.0902(20)
θ e d)
H–C–N
deg
109.47(15)
H–C–N
C3v
H3C–N=C
The best equilibrium structure, which was derived from high-level ab initio calculations, is
re(C–H) = 1.086 Å, re(C–N) = 1.422 Å, re(N=C) = 1.169 Å, and θe(H–C–N) = 109.47°. The
original paper also reports the results for which r(C–H) – r(C–D) was taken into account.
a
) ca = –0.008(14), cb = cc = 0.115(72), in u½ Å, included in the fit.
) ca = –0.012(9), cb = cc = 0.037(17), in u½ Å, included in the fit.
c
) ca = –0.177(20), cb = cc = 0.008(17), in u½ Å, da = 0.179(21), db = dc = 0.120(78), in u½ Å2,
included in the fit.
d
) Extrapolated from the rz structure
b
Margulés, L., Demaison, J., Rudolph, H.D.: J. Mol. Struct. 599 (2001) 23.
Replaces II/25B(3, 690), MW (first part)
Landolt-Börnstein
New Series II/28B