|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CH3-O-CH2CN |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Nitrogen |
|
|
|
Nuclear
Quadrupole Coupling Constants |
|
|
in
Cyanomethyl-Methyl Ether
|
|
|
|
(aka
Methoxyacetonitrile)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Calculation was made here of
the Nitrogen nqcc tensors in both gauche
and trans conformers of
CH3-O-CH2CN on approximate
equilibrium (~re) molecular structures given by
(1) MP2/aug-cc-pVTZ
optimization with empirically corrected CC and CN bond
lengths,
and (2) MP2/6-311+G(3df,3pd)
optimization also with empirically corrected CC and CN bond
lengths.
These calculated nqcc tensors are given in
Tables 1 and 2. Structure parameters are given in
Table 3, rotational constants and dipole moments in
Table 4. |
|
|
|
|
|
|
|
|
|
|
|
|
gauche |
|
|
trans |
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Note: Egauche < Etrans by 6.7 kJ/mol for calculation
at the MP2/aug-cc-pVTZ level on the optimized molecular structures, and
by 6.6 kJ/mole for calculation at the MP2/6-311+G(3df,3pd) level on the
optimized structures. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Below, in Tables 1 and 2,
subscripts a,b,c refer to
principal axes of the inertia tensor; x,y,z to principal axes
of the nqcc tensor.
Ø (degrees) is the angle between its subscripted
parameters. ETA = (Xxx - Xyy)/Xzz. |
|
|
RSD is the calibration residual
standard deviation of
the B3PW91/6-311+G(df,pd) model for calculation of the nqcc's. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
Table 1. 14N
nqcc's in gauche CH3-O-CH2CN
(MHz). Calculation was made on (1) MP2/aug-cc-pVTZ and (2)
MP2/6-311+G(3df,3pd), each with ~re CC and CN bond lengths. |
|
| |
|
|
|
|
|
|
|
|
|
|
|
Calc (1) |
|
Calc (2) |
|
Expt |
|
| |
|
|
|
|
|
|
|
|
|
Xaa |
- |
2.071 |
- |
2.078 |
|
|
|
|
Xbb |
|
0.208 |
|
0.214 |
|
|
|
|
Xcc |
|
1.863 |
|
1.864 |
|
|
|
|
|Xab| |
|
3.131 * |
|
3.132 * |
|
|
|
|
|Xac| |
|
0.888 |
|
0.882 |
|
|
|
|
|Xbc| |
|
0.258 |
|
0.255 |
|
|
|
|
|
|
|
|
|
|
|
|
|
RSD |
|
0.030 (1.3 %) |
|
0.030 (1.3 %) |
|
|
|
|
|
|
|
|
|
|
|
|
|
Xxx |
|
2.554 |
|
2.555 |
|
|
|
|
Xyy |
|
1.833 |
|
1.834 |
|
|
|
|
Xzz |
- |
4.387 |
- |
4.389 |
|
|
|
|
ETA |
- |
0.164 |
- |
0.164 |
|
|
|
|
Øz,CN |
|
0.41 |
|
0.41 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
* The algebraic sign of the
product XabXacXbc is negative. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
Table 2. 14N
nqcc's in trans CH3-O-CH2CN
(MHz). Calculation was made on (1) MP2/aug-cc-pVTZ and (2)
MP2/6-311+G(3df,3pd), each with ~re CC and CN bond lengths. |
|
| |
|
|
|
|
|
|
|
|
|
|
|
Calc (1) |
|
Calc (2) |
|
Expt |
|
| |
|
|
|
|
|
|
|
|
|
Xaa |
- |
3.660 |
- |
3.654 |
|
|
|
|
Xbb |
|
1.828 |
|
1.822 |
|
|
|
|
Xcc |
|
1.832 |
|
1.832 |
|
|
|
|
|Xab| |
|
2.107 |
|
2.113 |
|
|
|
|
|
|
|
|
|
|
|
|
|
RSD |
|
0.030 (1.3 %) |
|
0.030 (1.3 %) |
|
|
|
|
|
|
|
|
|
|
|
|
|
Xxx |
|
2.544 |
|
2.542 |
|
|
|
|
Xyy |
|
1.832 |
|
1.832 |
|
|
|
|
Xzz |
- |
4.375 |
- |
4.375 |
|
|
|
|
ETA |
- |
0.163 |
- |
0.162 |
|
|
|
|
Øz,a |
|
18.76 |
|
18.31 |
|
|
|
|
Øa,CN |
|
18.50 |
|
18.57 |
|
|
|
|
Øz,CN |
|
0.26 |
|
0.26 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
| Table 3.
CH3-O-CH2CN. Heavy atom structure
parameters
(Å
and degrees). (1) MP2/aug-cc-pVTZ optimized
structure with ~re CC with CN bond lengths, and
(2)
MP2/6-311+G(3df,3pd) optimized
structure with ~re CC and CN bond lengths.
Complete structures are given here
in Z-matrix format. |
| |
|
|
|
|
gauche |
~re(1) |
~re(2) |
| |
|
|
| C(1)N |
1.1561 |
1.1560 |
| C(1)C(2) |
1.4753 |
1.4758 |
| C(2)O |
1.4040 |
1.3998 |
| OC(4) |
1.4221 |
1.4180 |
| C(2)C(1)N |
178.57 |
178.55 |
| OC(2)C(1) |
112.24 |
112.30 |
| C(4)OC(2) |
111.84 |
112.24 |
| C(4)OC(2)C(1) |
64.98 |
65.11 |
| OC(2)C(1)N |
- 23.78 |
- 21.14 |
| |
|
|
|
| |
|
|
|
 |
trans |
~re(1) |
~re(2) |
| |
|
|
| C(1)N |
1.1553 |
1.1553 |
| C(1)C(2) |
1.4638 |
1.4642 |
| C(2)O |
1.4074 |
1.4036 |
| OC(4) |
1.4190 |
1.4145 |
| C(2)C(1)N |
178.41 |
178.41 |
| OC(2)C(1) |
108.78 |
108.78 |
| C(4)OC(2) |
110.18 |
110.58 |
| C(4)OC(2)C(1) |
180. |
180. |
| OC(2)C(1)N |
- 180. |
- 180. |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Table 4. CH3-O-CH2CN.
Rotational Constants (MHz) and Dipole Moments (D). (1)
MP2/aug-cc-pVTZ optimized
structure with ~re CC and CN bond lengths, and
(2)
MP2/6-311+G(3df,3pd) optimized
structure with ~re CC and CN bond lengths. |
| |
|
|
|
|
|
|
~re(1) |
~re(2) |
Expt [1] |
|
|
|
|
|
| gauche |
A |
11778.9 |
11840.2 |
11893.73683(123) |
|
B |
3483.2 |
3478.4 |
3423.36198(41) |
|
C |
2911.8 |
2910.4 |
2871.47309(42) |
|
|
|
|
|
| trans |
A |
29562.6 |
29646.6 |
29621.28(139) |
|
B |
2483.3 |
2486.4 |
2470.96295(105) |
|
C |
2359.0 |
2362.2 |
2348.09188(116) |
|
|
|
|
|
|
|
|
|
Expt. [2] |
|
|
|
|
|
| gauche |
|µa| |
2.57 |
2.59 |
2.40(3) |
|
|µb| |
1.10 |
1.11 |
1.37(10) |
|
|µc| |
1.57 |
1.56 |
1.11(11) |
|
|
|
|
|
| trans |
|µa| |
4.26 |
4.26 |
|
|
|µb| |
2.51 |
2.50 |
|
|
|µc| |
zero |
zero |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
[1] R.Braakman and G.A.Blake,
J.Mol.Spectrosc. 262,93(2010). |
|
|
[2] R.Kewley, Can.J.Chem.
52,509(1974). |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
g-CH3-O-CH2Cl |
g-CH3-O-CH2I |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Table of Contents |
|
|
|
|
|
Molecules/Nitrogen |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
CH3OCH2CN.html |
|
|
|
|
|
|
Last
Modified 10 June 2010 |
|
|
|
|
|
|
|
|
|
|