|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2-Bromopyrimidine
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Nitrogen and Bromine |
|
|
|
Nuclear
Quadrupole Coupling Constants |
|
|
|
in 2-Bromopyrimidine |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Chen, Paulse, and
Davis [1] measured the bromine nqcc's
in 2-bromopyrimidine and determined an effective molecular structure. |
|
|
|
|
|
|
|
|
|
|
|
|
Calculation of
both nitrogen and bromine nqcc's were
made here on the B3P86/6-31G(3d,3p) optimized molecular
structure. The nitrogen results are shown in Table
1. In
Table 2, calculated bromine nqcc's are compared with the experimental
values. Structure parameters, effective and
optimized, are
compared in Table 3; rotational constants, in Table 4. In
Table 5, atomic coordinates are given
for
the optimized structure. |
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
Table 1.
Nitrogen
nqcc's in 2-Bromopyrimidine (MHz). |
|
| |
|
|
|
|
|
|
|
|
|
|
|
Calc. |
|
Expt. |
|
| |
|
|
|
|
|
|
|
|
14N(1,3) |
Xaa |
- |
0.049 |
|
|
|
|
|
Xbb |
-
|
2.911 |
|
|
|
|
|
Xcc |
|
2.961 |
|
|
|
|
|
Xab |
± |
2.877 |
|
|
|
| |
|
|
|
|
|
|
|
|
|
RSD |
0.030 (1.3
%) |
|
| |
|
|
|
|
|
|
|
|
|
Xxx |
|
1.733 |
|
|
|
|
|
Xyy |
|
2.961 |
|
|
|
|
|
Xzz |
-
|
4.694 |
|
|
|
|
|
ETA |
|
0.262 |
|
|
|
|
|
Øz,a |
|
58.22 |
|
|
|
|
|
Øa,bi |
|
58.22 |
|
|
|
|
|
Øz,bi* |
|
0.00 |
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
* Angle between
the principal z-axis and the bisector ('bi') of the CNC angle. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
Table 2.
Bromine
nqcc's in 2-Bromopyrimidine (MHz). |
|
| |
|
|
|
|
|
|
|
|
|
|
|
Calc. |
|
Expt. [1] |
|
| |
|
|
|
|
|
|
|
|
79Br |
Xaa |
|
566.99 |
|
567.8(7) |
|
|
|
Xbb |
-
|
334.93 |
-
|
329(5) |
|
|
|
Xcc |
- |
232.07 |
- |
239(5) |
|
|
|
ETA * |
- |
0.181 |
|
|
|
|
|
|
|
|
|
|
|
| |
|
RMS
|
|
5.3 (1.4 %)
|
|
|
|
|
|
RSD |
1.58 (0.39
%) |
|
| |
|
|
|
|
|
|
|
|
81Br |
Xaa |
|
473.71 |
|
475.6(6) |
|
|
|
Xbb |
- |
279.82 |
- |
274(2) |
|
|
|
Xcc |
-
|
193.88 |
-
|
201(2) |
|
|
|
|
|
|
|
|
|
|
|
RMS |
|
5.4 (1.7 %) |
|
|
|
|
|
RSD |
|
1.38 (0.40 %) |
|
|
|
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
* ETA = (Xbb
- Xcc)/Xaa
= (Xxx - Xyy)/Xzz. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Table 3.
Structure parameters ropt
and ro (Å and degrees). |
|
|
|
|
|
|
ropt |
ro [1] |
|
|
|
|
|
C(2)Br(2) |
1.8778 |
1.889 |
|
C(2)N(3) |
1.3227 |
1.3305 |
|
N(3)C(4) |
1.3333 |
1.340 |
|
C(4)C(5) |
1.3868 |
1.391 |
|
C(4)H(4) |
1.0871 |
1.081 |
|
C(5)H(5) |
1.0826 |
1.081 |
|
N(1)C(2)N(3) |
128.28 |
128.51 |
|
C(2)N(3)C(4) |
115.28 |
|
|
N(3)C(4)C(5) |
122.52 |
|
|
C(4)C(5)C(6) |
116.11 |
116.6 |
|
C(5)C(4)H(4) |
121.37 |
121.5 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Table 4.
Rotational Constants (MHz). 79Br
species. |
|
|
|
|
|
|
Calc. ropt |
Expt. [1] |
|
|
|
|
|
A |
6147.4 |
6078.760(66) |
|
B |
1072.3 |
1062.99006(61) |
|
C |
913.0 |
904.71668(45) |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Table 5.
Atomic
coordinates, ropt 79Br
species. |
| (More
figures are shown than are significant.) |
|
|
|
|
|
|
|
|
|
a (Å) |
|
b (Å) |
|
|
|
|
|
|
|
N(1,3) |
- |
0.867367 |
± |
1.190200 |
|
C(2) |
- |
0.290424 |
|
0.0 |
|
C(4,6) |
- |
2.200591 |
± |
1.176793 |
|
C(5) |
- |
2.934377 |
|
0.0 |
|
Br(2) |
|
1.587355 |
|
0.0 |
|
H(4,6) |
- |
2.688798 |
± |
2.148151 |
|
H(5) |
- |
4.016938 |
|
0.0 |
|
|
|
|
|
|
|
|
|
|
|
|
|
[1] J.Chen,
C.D.Paulse, and R.W.Davis,
J.Mol.Spectrosc. 145,18 (1991). |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Pyrimidine |
2-Chloropyrimidine |
|
|
|
|
2-Fluoropyrimidine |
2-Cyanopyrimidine |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Table of Contents |
|
|
|
|
|
Molecules/Nitrogen |
|
|
|
|
|
Molecules/Bromine |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2BrPRM.html |
|
|
|
|
|
|
Last
Modified 27 Feb 2004 |
|
|
|
|
|
|
|
|
|
|