CH2CH2CHN=C=O





 








 








Nitrogen

Nuclear Quadrupole Coupling Constants


in Cyclopropyl Isocyanate


 


















14N nqcc's in both "cis" and trans conformers of cyclopropyl were determined by Heldmann and Dreizler [1]. 












"cis"

trans

































At the MP2/6-311+G(3df,3pd) level of theory, Ecis <  Etrans by 0.03 kJ/mole.

 








Calculation of the nitrogen nqcc tensor in "cis" and trans cyclopropyl isocyanate was made here on molecular structures given by B3LYP/6-311+G(3df,3pd) and MP2/6-311+G(3df,3pd) optimizations.  Calculated and experimental nqcc's are compared in Tables 1and 2.  Structure parameters are given in Z-matrix format in Table 3, rotational constants in Table 4.

 








In Tables 1 and 2, 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.   ETA = (Xxx - Xyy)/Xzz, Ø (degrees) is the angle between its subscripted parameters.  RMS is the root measn square difference between calculated and experimental diagonal nqcc's.  RSD is the residual standard 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 cis Cyclopropyl Isocyanate (MHz).  Calculation was made on B3LYP/6-311+G(3df,3pd) and MP2/6-311+G(3df,3pd) optimized molecular structures.
   









Calc /B3LYP
Calc /MP2
Expt. [1]
   







Xaa
2.603
2.534
2.5647(49)

Xbb -
 1.130
 -
 1.030
 -
 1.0624(75)

Xcc -
 1.474
 -
 1.504
 -
 1.5022(75)

|Xab|
1.064
1.152



 







RMS
0.048 (2.8 %)
0.026 (1.5 %)



RSD
0.030 (1.3 %)
 0.030 (1.3 %)


 







Xxx -
 1.411
 -
 1.370



Xyy -
 1.474
 -
 1.504



Xzz
2.885
2.874



ETA
0.0215
0.0467



Øz,a
14.84
16.44



Øa,N=C
33.39
35.90



Øz,N=C
18.55
19.46



 








 








 








   







Table 2.  14N nqcc's in trans Cyclopropyl Isocyanate (MHz).  Calculation was made on B3LYP/6-311+G(3df,3pd) and MP2/6-311+G(3df,3pd) optimized molecular structures.
   









Calc /B3LYP
Calc /MP2
Expt. [1]
   







Xaa
2.668
2.672
2.6306(26)

Xbb -
 1.393
 -
 1.422
 -
 1.3839(31)

Xcc -
 1.275
 -
 1.250
 -
 1.2467(31)

|Xac|
0.797
0.725



 







RMS
0.028 (1.6 %)
0.032 (1.8 %)



RSD
0.030 (1.3 %)
 0.030 (1.3 %)


 







Xxx -
 1.430
 -
 1.380



Xyy -
 1.393
 -
 1.422



Xzz
2.823
2.882



ETA -
 0.0130
0.0148



Øz,a
11.01
10.15



Øa,N=C
10.19
11.10



Øz,N=C
21.20
21.25



 








 








 








 




Table 3.  B3LYP/6-311+G(3df,3pd) and MP2/6-311+G(3df,3pd) optimized structure parameters (Å and degrees).
 





cis Cyclopropyl Isocyanate








 C
 C,1,B1
 C,1,B2,2,A1
 H,1,B3,2,A2,3,D1,0
 H,2,B4,1,A3,3,D2,0
 H,3,B5,1,A4,2,D3,0
 H,2,B6,1,A5,3,D4,0
 H,3,B7,1,A6,2,D5,0
 N,1,B8,2,A7,3,D6,0
 C,9,B9,1,A8,2,D7,0
 O,10,B10,9,A9,1,D8,0








     B3LYP
      MP2








 B1=1.50407173
 B2=1.50407173
 B3=1.07962823
 B4=1.08049999
 B5=1.08049999
 B6=1.08061004
 B7=1.08061004
 B8=1.41634284
 B9=1.19551466
 B10=1.17259758
 A1=60.20388674
 A2=117.11708043
 A3=117.12640833
 A4=117.12640833
 A5=117.8431123
 A6=117.8431123
 A7=121.03816032
 A8=142.48051506
 A9=174.19928947
 D1=107.27020882
 D2=107.70415146
 D3=-107.70415146
 D4=-109.00210821
 D5=109.00210821
 D6=-110.41758309
 D7=35.82756339
 D8=180.
  B1=1.50081172
 B2=1.50081172
 B3=1.07822086
 B4=1.0794625
 B5=1.0794625
 B6=1.07900642
 B7=1.07900642
 B8=1.41630881
 B9=1.20815235
 B10=1.17870743
 A1=60.39362331
 A2=117.69480681
 A3=116.38874539
 A4=116.38874539
 A5=117.76691641
 A6=117.76691641
 A7=119.92041223
 A8=137.93206369
 A9=173.28649674
 D1=107.7857045
 D2=107.57316388
 D3=-107.57316388
 D4=-108.43931621
 D5=108.43931621
 D6=-109.56681765
 D7=35.47284361
 D8=180.

 




 




trans Cyclopropyl Isocyanate








 C
 C,1,B1
 C,1,B2,2,A1
 H,1,B3,2,A2,3,D1,0
 H,2,B4,1,A3,3,D2,0
 H,3,B5,1,A4,2,D3,0
 H,2,B6,1,A5,3,D4,0
 H,3,B7,1,A6,2,D5,0
 N,1,B8,2,A7,3,D6,0
 C,9,B9,1,A8,2,D7,0
 O,10,B10,9,A9,1,D8,0








     B3LYP
      MP2








 B1=1.50318859
 B2=1.50318859
 B3=1.08177473
 B4=1.0797214
 B5=1.0797214
 B6=1.08037307
 B7=1.08037307
 B8=1.42067312
 B9=1.19759401
 B10=1.17150163
 A1=60.11190754
 A2=117.61571032
 A3=116.73007811
 A4=116.73007811
 A5=117.62177726
 A6=117.62177726
 A7=118.26507715
 A8=139.26345349
 A9=163.69633967
 D1=107.62072099
 D2=107.95281457
 D3=-107.95281457
 D4=-109.013801
 D5=109.013801
 D6=-108.12660664
 D7=-145.34403207
 D8=180.
  B1=1.49967412
 B2=1.49967412
 B3=1.08042991
 B4=1.07849454
 B5=1.07849454
 B6=1.07880151
 B7=1.07880151
 B8=1.41877313
 B9=1.20874042
 B10=1.1778709
 A1=60.31983637
 A2=118.03896954
 A3=116.11052304
 A4=116.11052304
 A5=117.48674948
 A6=117.48674948
 A7=117.16157174
 A8=137.28355927
 A9=163.67785427
 D1=108.02739293
 D2=107.72986544
 D3=-107.72986544
 D4=-108.53114072
 D5=108.53114072
 D6=-107.34597567
 D7=-145.61941446
 D8=180.

 





 








 



Table 4.  Cyclopropyl Isocyanate.  Rotational Constants (MHz).  Calc = B3LYP/6-311+G(3df,3pd) and MP2/6-311+G(3df,3pd) optimized molecular structures.







Calc /B3LYP Calc /MP2 Expt. [1]





   cis A
      10806.
    10304.
 10235.(3)

B
        2089.
      2179.
   2186.556(3)

C
        2034.
      2098.
   2106.168(3)





   trans A
      17300.
    17226.
 16941.865(3)

B
        1764.
      1772.
   1784.3117(2)

C
        1700.
      1708.
   1716.1281(3)



  








[1] C.Heldmann and H.Dreizler, Z.Naturforsch. 45a,1175(1990).

 








 








HNCO
CH3NCO
 (CH3)3CN=C=O

CH3CH2NCO
CH2=C(H)NCO
 Phenyl Isocyanate










 








Table of Contents




Molecules/Nitrogen




 








 













CH2CH2CHNCO.html






Last Modified 7 Jan 2016