HNCO





 








Deuterium, Nitrogen, and Oxygen

Nuclear Quadrupole Coupling Constants


in Isocyanic Acid


 







 
 
2H, 14N, and 17O nqcc's have been measured in isocyanic acid [1-4].
 
Calculations of the nqcc's were made here on the "modified substitution" molecular structure of Yamada [5], and on the ab initio equilibrium structure of Demaison et al. [6].  These calculated nqcc's are compared with the experimental values in Tables 1-6.  Structure parameters are given in Table 7.

 

 




In Tables 1-6, RMS is the root mean square difference between calculated and experimental diagonal nqcc's (percentage of the average of the magnitudes of the experimental nqcc's).  RSD is the calibration residual standard deviation of the model for calculation of the nqcc's:  B3LYP/6-31G(df,3p) for deuterium, B3PW91/6-311+G(df,pd) for nitrogen, and B1LYP/6-311++G(3df,3p) and MP4(SDQ)/6-311++G(3df,3pd) for oxygen.
 
Subscripts a,b,c refer to the principal axes of the inertia tensor, subscripts x,y,z to the principal axes of the nqcc tensor.  The nqcc y-axis is chosen coincident with the inertia c-axis, these are perpendicular to the plane of the molecule.  Ø (degrees) is the angle between its subscripted parameters. ETA = (Xxx - Xyy)/Xzz.
 

 








   






Table 1.  Deuterium nqcc's in DNCO (kHz).  Calculation was made on the substitution [5] and equilibrium [6] structures.  PDF
   






Calc. [5]
Calc. [6]
Expt. [1]
   





Xaa   53.2   48.7   57.6(54)
Xbb   92.6   88.9   84.9(38)
Xcc - 145.8 - 137.7 - 142.5(38)
|Xab| 207.0 194.7
 
RMS 5.5 (5.7 %) 6.3 (6.6 %)
RSD 1.1 (0.9 %) 1.1 (0.9 %)
 
Xxx - 135.0 - 126.9 - 136.2 *
Xyy - 145.8 - 137.7 - 142.5
Xzz 280.8 264.5 278.7
ETA 0.038 0.041 0.023
Øz,a 47.7 47.95 46.9
Øa,ND 49.2 49.46 49.2
Øz,ND   1.5   1.51   2.3
 


 







* Calculated here from the experimental diagonal nqcc's and the calculated off-diagonal nqcc of 207.0 kHz.
 
 
   






Table 2.  14N nqcc's in DNCO (MHz).  Calculation was made on the substitution [5] and equilibrium [6] structures.    PDF
   







Calc. [5]
Calc. [6]
Expt. [1]
   





Xaa 2.138 2.136 2.1237(15)
Xbb - 0.569 - 0.530 - 0.5528(18)
Xcc - 1.569 - 1.606 - 1.5709(18)
|Xab| 1.008 1.031
 
 RMS 0.012 (0.9 %) 0.025 (1.8 %)
RSD 0.030 (1.3 %) 0.030 (1.3 %)
 
Xxx - 0.903 - 0.882 - 0.890 *
Xyy - 1.569 - 1.606 - 1.5709
Xzz 2.472 2.488 2.461
ETA 0.269 0.291 0.277
Øz,a 18.3 18.86 18.5
Øa,ND 49.2 49.46 49.2
Øz,ND 30.8 30.60 30.7
 
   
* Calculated here from the experimental diagonal nqcc's and the calculated off-diagonal nqcc of 1.008 kHz.
 
 

   






Table 3.  14N nqcc's in HNCO (MHz).   Calculation was made on the substitution [5] and equilibrium [6] structures.
   







Calc. [5]
Calc. [6]
Expt. [2]
   





Xaa 2.083 2.080 2.056(11)
Xbb - 0.514 - 0.473 - 0.473
Xcc - 1.569 - 1.606 - 1.583
|Xab| 1.078 1.100
 
 RMS 0.030 (2.2 %) 0.019 (1.4 %)
RSD 0.030 (1.3 %) 0.030 (1.3 %)
 


 





 
   






Table 4.  14N nqcc's in HNC17O (MHz).  Calculation was made on the substitution [5] and equilibrium [6] structures.
   







Calc. [5]
Calc. [6]
Expt. [3]
   





Xaa 2.084 2.080 2.051(13)
Xbb - 0.515 - 0.474 - 0.4725(68)
Xcc - 1.569 - 1.606 - 1.578
|Xab| 1.077 1.100
 
 RMS 0.031 (2.3 %) 0.023 (1.7 %)
RSD 0.030 (1.3 %) 0.030 (1.3 %)
 
 
 
   






Table 5.  17O nqcc's in HNCO (MHz).  Calculation was made on the substitution [5] and equilibrium [6] structures.    PDF
 
Calc = B1LYP/6-311++G(3df,3p)
   







Calc. [5]
Calc. [6]
Expt. [3]
   





Xaa - 3.284 - 3.191 - 3.276(24)
Xbb - 0.131 - 0.197 - 0.176(13)
Xcc 3.415 3.388 3.452
|Xab| 0.378 0.399
 
RMS 0.034 (1.5 %) 0.063 (2.7 %)
RSD 0.041 (1.4 %) 0.041 (1.4 %)
 
Xxx - 0.086 - 0.145 - 0.133 *
Xyy 3.415 3.388 3.452
Xzz - 3.328 - 3.243 - 3.319
ETA 1.052 1.089
Øz,a 6.7 7.47 6.8
Øa,CO 1.9 2.02 1.9
Øz,CO 4.8 5.44 4.9
 
 
* Calculated here from the experimental diagonal nqcc's and the calculated off-diagonal nqcc of 0.378 MHz.
 
 
   






Table 6.  17O nqcc's in HNCO (MHz).  Calculation was made on the substitution [5] and equilibrium [6] structures.   PDF
 
Calc = MP4(SDQ)/6-311++G(3df,3pd)
   







Calc. [5]
Calc. [6]
Expt. [3]
   





Xaa - 3.318 - 3.228 - 3.276(24)
Xbb - 0.175 - 0.243 - 0.176(13)
Xcc 3.493 3.471 3.452
|Xab| 0.316 0.340
 
 RMS 0.034 (1.5 %) 0.049 (2.1 %)
RSD 0.027 (0.93 %) 0.027 (0.93 %)
 
Xxx - 0.144 - 0.205 - 0.144 *
Xyy 3.493 3.471 3.452
Xzz - 3.349 - 3.266 - 3.309
Øz,a 5.7 6.43 5.8
Øa,CO 1.9 2.02 1.9
Øz,CO 3.8 4.41 3.9
 
 
* Calculated here from the experimental diagonal nqcc's and the calculated off-diagonal nqcc of 0.316 MHz.
 
 
Table 7.  Molecular structure parameters, (Å and degrees).
 
 rs [5]  re [6]  re [7]
HN 0.9946 1.0037 1.0030(20)
NC 1.2140 1.2148 1.2145(6)
CO 1.1664 1.1641 1.1634(4)
HNC 123.9 123.444 123.34(20)
NCO 172.6 172.393 172.22(20)
 
 

[1] N.Heineking, M.C.L.Gerry, and H.Dreizler, Z.Naturforsch. 44a,577(1989); H.Dreizler, Z.Naturforsch. 47a,342(1992).
[2] W.H.Hocking, M.C.L.Gerry, and G.Winnewisser, Can.J.Phys. 53,1869(1975).
[3] M.C.L.Gerry, S.J.Howard, N.Heineking, and H.Dreizler, Z.Naturforsch. 44a,1187(1989).
[4] S.G.Kukolich, A.C.Nelson, and B.S.Yamanashi, J.Amer.Chem.Soc. 93,6769(1985).
[5] K.Yamada, J.Mol. Spectrosc. 79,323(1980).
[6] J.Demaison, L.Margulès, and J.E.Boggs, Chem.Phys. 260,65(2000).
[7] A.L.L.East, C.S.Johnson, and W.D.Allen, J.Chem.Phys. 98,1299(1993).
 
"Electric and magnetic properties ... from ab initio CCSD(T) studies" M.Mladenović, M.Elhiyani, and M.Lewerenz, J.Chem.Phys. 131,034302(2009).
L.Fusina and I.M.Mills, J.Mol.Spectrosc. 86,488(1981): rz structure.

 








 








ClNCO HNCS HNCSe HNSO
 

 








Table of Contents



Molecules/Deuterium
Molecules/Nitrogen
Molecules/Oxygen
 

 













DNCO.html






Last Modified 26 Sept 2009