C8H11NO3














 









Nitrogen


Nuclear Quadrupole Coupling Constants


in Pyridoxine


 


















Calculations of the nitrogen nqcc tensors in Pyridoxine was made on B3P86/6-31G(3d,3p) optimized molecular structures (ropt) of the conformers shown below.   These calculated nqcc's are compared with the experimental results of Alonso, et al. [1] in Tables 1 and 2.  Structure parameters are given in Table 3,  rotational constants in Table 4.

 








                      Conformer I

     Conformer II                             











































In Tables 1 and 2, subscripts a,b,c refer to the principal axes of the inertia tensor; x,y,z to the principal axes of the nqcc tensor.  ETA = (Xxx - Xyy)/Xzz. 


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 for the B3PW91/6-311+G(df,pd) model for calculation of the nitrogen  efg's/nqcc's.

 








 








   






Table 1.  Nitrogen nqcc's in Conformer I of Pyridoxine (MHz).  Calculation was made on ropt molecular strcuture.
   









Calc
Rotamer I [1]
   






14N Xaa -
 0.680
 -
 0.61867(833)


Xbb -
 2.484
 -
 2.44587(815)


Xcc
3.164
3.06453(815)


Xab
2.959




Xac -
 0.668




Xbc
0.734












RMS
0.071 (2.4 %)




RSD
0.030 (1.3 %)












Xxx
1.505




Xyy
3.293




Xzz -
 4.798




ETA
0.372












 








 







 
   






Table 2.  Nitrogen nqcc's in Conformer II of Pyridoxine (MHz).  Calculation was made on ropt molecular strcuture.
   









Calc
Rotamer II [1]
   






14N Xaa -
 0.611
 -
 0.53100(1000)


Xbb -
 2.609
 -
 2.6313(182)


Xcc
3.220
3.1623(182)


Xab -
 2.992




Xac
0.062




Xbc -
 0.383












RMS
0.059 (2.7 %)




RSD
0.030 (1.3 %)












Xxx
1.501




Xyy
3.273




Xzz -
 4.774




ETA
0.371












 








 












Table 3. Pyridoxine:  B3P86/6-31G(3d,3p) optimized structure parameters.





 C
 C,1,B1
 C,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 C,4,B4,3,A3,2,D2,0
 N,5,B5,4,A4,3,D3,0
 H,1,B6,6,A5,5,D4,0
 C,5,B7,4,A6,3,D5,0
 H,8,B8,5,A7,4,D6,0
 H,8,B9,5,A8,4,D7,0
 H,8,B10,5,A9,4,D8,0
 O,4,B11,3,A10,2,D9,0
 H,12,B12,4,A11,3,D10,0
 C,3,B13,2,A12,1,D11,0
 H,14,B14,3,A13,2,D12,0
 H,14,B15,3,A14,2,D13,0
 C,2,B16,1,A15,6,D14,0
 H,17,B17,2,A16,1,D15,0
 H,17,B18,2,A17,1,D16,0
 O,14,B19,3,A18,2,D17,0
 H,20,B20,14,A19,3,D18,0
 O,17,B21,2,A20,1,D19,0
 H,22,B22,17,A21,2,D20,0
 Conformer I








 B1=1.38862731
 B2=1.40229365
 B3=1.39483638
 B4=1.40710975
 B5=1.32933752
 B6=1.08883704
 B7=1.49566865
 B8=1.09424768
 B9=1.0938899
 B10=1.08929508
 B11=1.35234381
 B12=0.97636483
 B13=1.50674294
 B14=1.09473849
 B15=1.09108469
 B16=1.50371356
 B17=1.09361195
 B18=1.09716719
 B19=1.4329799
 B20=0.96317413
 B21=1.42270832
 B22=0.96248292
 A1=117.90719144
 A2=117.73713501
 A3=120.00180803
 A4=121.50594664
 A5=116.04778359
 A6=119.86423437
 A7=111.11309238
 A8=111.06429916
 A9=109.31778238
 A10=122.46584064
  A11=107.35535574
 A12=122.58060799
 A13=109.98961134
 A14=110.97160259
 A15=119.73669461
 A16=111.63838898
 A17=109.09776249
 A18=112.58532253
 A19=107.8517851
 A20=112.89277066
 A21=107.4811201
 D1=-0.74442454
 D2=1.09543736
 D3=-0.59292798
 D4=-179.4722054
 D5=179.14931085
 D6=-61.27829269
 D7=56.90548009
 D8=178.01687413
 D9=-179.7610921
 D10=16.73208308
 D11=177.02194844
 D12=-103.3744596
 D13=16.55233092
 D14=-179.21755672
 D15=-125.87316467
 D16=-7.97696989
 D17=140.39908653
 D18=-69.29214378
 D19=115.82883838
 D20=-57.27850384









 


 C
 C,1,B1
 C,2,B2,1,A1
 C,3,B3,2,A2,1,D1,0
 C,4,B4,3,A3,2,D2,0
 N,5,B5,4,A4,3,D3,0
 H,1,B6,6,A5,5,D4,0
 C,5,B7,4,A6,3,D5,0
 H,8,B8,5,A7,4,D6,0
 H,8,B9,5,A8,4,D7,0
 H,8,B10,5,A9,4,D8,0
 O,4,B11,3,A10,2,D9,0
 H,12,B12,4,A11,3,D10,0
 C,3,B13,2,A12,1,D11,0
 H,14,B14,3,A13,2,D12,0
 H,14,B15,3,A14,2,D13,0
 C,2,B16,1,A15,6,D14,0
 H,17,B17,2,A16,1,D15,0
 H,17,B18,2,A17,1,D16,0
 O,14,B19,3,A18,2,D17,0
 H,20,B20,14,A19,3,D18,0
 O,17,B21,2,A20,1,D19,0
 H,22,B22,17,A21,2,D20,0
 Conformer II








 B1=1.38800423
 B2=1.40294327
 B3=1.3955853
 B4=1.40791668
 B5=1.32881281
 B6=1.08870803
 B7=1.49582194
 B8=1.09424592
 B9=1.0938661
 B10=1.08932195
 B11=1.3516256
 B12=0.97582679
 B13=1.50315159
 B14=1.09808753
 B15=1.09307989
 B16=1.50100534
 B17=1.09711761
 B18=1.09478511
 B19=1.43277398
 B20=0.961196
 B21=1.42216487
 B22=0.96260435
 A1=118.18762906
 A2=117.5625114
 A3=119.82302487
 A4=121.83629728
 A5=116.14691775
 A6=119.64433199
 A7=111.16113061
 A8=111.01288681
 A9=109.26800366
 A10=123.20290687
  A11=107.12864766
 A12=121.08863794
 A13=109.47167028
 A14=110.68019439
 A15=119.88113982
 A16=109.2475334
 A17=111.18379102
 A18=109.55201146
 A19=108.53407876
 A20=113.05362415
 A21=107.52998328
 D1=-0.67649778
 D2=0.48912079
 D3=-0.02520425
 D4=-179.67784932
 D5=179.51172819
 D6=-60.65971065
 D7=57.54289193
 D8=178.56480226
 D9=179.53343308
 D10=14.76970211
 D11=176.47456552
 D12=-93.30515665
 D13=24.47169463
 D14=178.82207353
 D15=5.31822772
 D16=123.11880695
 D17=145.86607822
 D18=169.14642811
 D19=-118.89630856
 D20=57.85471889







 













Table 4:  Pyridoxine, Rotational Constants (MHz).

 





   ropt Rotamers I and II [1]






Conformer I
 A   1269.
 1270.140(51)


B     827.
   819.4662(129)


C     528.
   528.02708(293)






Conformer II
 A
   1253. 1235.998(53)


B
     830.   820.7567(117)


C
     527.   525.66684(293)


 








 








[1] E.R.Alonso, I.León, and J.L.Alonso, Abstract TK12, 73rd ISMS, Champaign-Urbana, Illinois, 2018.

 








 








Table of Contents




Molecules/Nitrogen




 








 













Pyridoxine.html






Last Modified 12 Nov 2018