HF2SiN=C=O
























 





 








Nitrogen

Nuclear Quadrupole Coupling Constants


in Difluoroisocyanato Silane


 








 








 








Calculation of the nitrogen nqcc's in difluoroisocyanato silane was made on molecular structures given by HF/6-31G(3d,3p), HF/6-311G(3d,3p), and CCSD(T)/6-311++G(3df,3pd) optimization, the latter derived by Guirgis et al. [1].  These are compared with the experimental nqcc's [1] in Table 1.  Structure parameters in Z-matrix format are given in Table 2, rotational constants in Table 3.

 








In Table 1, RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percentage of average experimental nqcc).  RSD is the residual stand deviation of calibration of the B3PW91/6-311+G(df,pd) model for calculation of the efg's/nqcc's.

 








 








   









Table 1. 14N nqcc's in HF2SiN=C=O (MHz).  Calculation was made on the (1) HF/6-31G(3d,3p), (2) HF/6-311G(3d,3p), and (3) CCSD(T)/6-311++G(3df,3pd) optimized structures.
   











Calc (1)
Calc (2)
Calc (3)
Expt. [1]
   









Xaa
1.906
1.878
2.003
1.8833(27)

Xbb -
 0.980
 -
 0.982
 -
 1.053 - 0.9524(32) *

Xcc -
 0.926
 -
 0.896
 -
 0.950 - 0.9309(32) *

|Xac|
0.263
0.152
0.048



 









RMS
0.021 (1.7 %)
 0.027 (2.1 %)
 0.091 (7.3 %)


RSD
0.030 (1.3 %) 0.030 (1.3 %) 0.030 (1.3 %)


 









Xxx -
 0.950
 -
 0.904
 -
 0.950



Xyy -
 0.980 -
 0.982 -
 1.053



Xzz
1.930
1.886
2.004



ETA
0.0155
0.0414
0.0514



Øz,a
5.27
3.13
0.94



Øa,N=C
0.23
4.86
6.28



Øz,N=C
5.04
7.99
7.22














   








* Derived here from experimental Xaa and Xbb - Xcc = -0.0214(58) MHz.

 








 








Table 2.  HF2SiN=C=O structure parameters (Å and degrees):  HF/6-31G(3d.3p), HF/6-311G(3d.3p), and CCSD(T)/6-311++G(3df,3pd).

 








 H
 Si,1,R1
 N,2,R2,1,A1
 C,3,R3,2,A2,1,D1
 O,4,R4,3,A3,1,D2
 F,2,R5,3,A4,1,D3
 F,2,R6,3,A5,1,D4











  HF/6-31G(3d.3p)
 HF/6-311G(3d.3p)  CCSD(T)





 



 R1=1.44842021
 R2=1.67292676
 R3=1.18313768
 R4=1.14113117
 R5=1.56377129
 R6=1.56377129
 A1=112.56785585
 A2=166.13574368
 A3=178.90494955
 A4=108.63362561
 A5=108.63362561
 D1=0.
 D2=180.
 D3=121.88389266
 D4=-121.88389266
  R1=1.44986651
 R2=1.67706189
 R3=1.18267873
 R4=1.13673596
 R5=1.56332
 R6=1.56332
 A1=112.93244485
 A2=157.018334
 A3=178.17530274
 A4=108.59591867
 A5=108.59591867
 D1=0.
 D2=180.
 D3=121.78671115
 D4=-121.78671115
  R1=1.456
 R2=1.687
 R3=1.206
 R4=1.165
 R5=1.579
 R6=1.579
 A1=112.6
 A2=154.6
 A3=-177.4
 A4=108.6
 A5=108.6
 D1=0.
 D2=0.
 D3=121.6
 D4=-121.6












 













Table 3.  HF2SiN=C=O.  Rotational Constants (MHz).







HF/6-31G(3d,3p) HF/6-311G(3d,3p)   Expt [1]






A
       7210.2
       7266.9
 7111.28104(179)

B
       1544.1
       1553.7 1565.77581(49)

C
       1338.7
       1343.1
 1347.52275(77)


 








 








[1] G.A.Guirgis, Z.Wang, J.Lirjoni, M.H.Palmer, D.Obeenchain, R.A.Peebles, S.A.Peebles, J.Mol.Struct. 983,5(2010).

 








 








HNCO
 CH3CH2NCO CH3SiF2NCO CH3-SiHF-NCO

 








 








Table of Contents




Molecules/Nitrogen




 








 













HF2SiNCO.html






Last Modified 10 Nov 2016