




















BH_{3}CO 



















Boron and Deuterium 



Nuclear
Quadrupole Coupling Constants 



in Borane Carbonyl 























Murray and Kukolich [1] measured the boron nqcc in the normal species
and the deuterium nqcc's in the fully deuterated species. A substitution
structure was determined by Venkatachar et al. [2]. 












Calculation of the boron and deuterium nqcc's was made on the substitution
structure, and on the heavy atom substitution structure with BH and CBH
determined by MP2/6311+G(d,p) optimization [3]. The calculated boron
nqcc's are compared with the experimental values in Table 1, deuterium in
Table 2. The complete nqcc tensor has been calculated for deuterium.
Structure parameters and atomic coordinates are given in Tables 3 and 4,
respectively. 





















Table 1. Boron nqcc's in BH_{3}CO (MHz). 











Calc. [a] on the r_{s} structure. 



Calc. [b] on the r_{s}/r_{opt} structure. 













Calc. 

Expt. [1] 










^{11}B 
X_{zz} 

1.624 [a] 

1.6619(23) 





1.675 [b] 












^{10}B 
X_{zz} 

3.369 [a] 

3.4630(80) 





3.473 [b] 
























For ^{11}B, the differences between calculated and experimental
X_{zz} are 0.038 and 0.013 MHz for calculation on the r_{s}
and r_{s}/r_{opt} structures, respectively. And for
^{10}B, these are 0.094 and 0.010 MHz, respectively. 












For deuterium (Table 2, below), the differences between calculated
and experimental X_{uu} are respectively 3.7 and 0.1 kHz for calculation
on the r_{s} and r_{s}/r_{opt} structures. 












In Table 2, the subscripts u,v,w refer to
the coordinate axes defined in Table 4. The uaxis is along the threefold
symmetry axis. The nqcc's given below with these subscripts are those
for the H atom in the uvplane. 





















Table 2. Deuterium nqcc's in BD_{3}CO (kHz). 











Calc. [a] on the r_{s} structure. 



Calc. [b] on the r_{s}/r_{opt} structure. 













Calc. 

Expt. [1] 










^{2}H 
X_{uu} 

 44.8 [a] 
 
48.5(23) 










^{2}H 
X_{uu} 

 48.4 [b] 


48.5(23) 



X_{vv} 

116.5 





X_{ww} 

 68.1 





X_{uv} 

 46.6 













X_{xx} 

 60.6 





X_{yy} 

 68.1 





X_{zz} 

128.8 





ETA 

0.058 





Ø_{z,u} 

72.25 





Ø_{u,BD} 

76.0 





Ø_{z,BD} 

0.75 




























Table 3. Structure parameters, r_{s }[2] and r_{opt}
[3] (Å and degrees). 





BC 
1.534 
[2] 

CO 
1.135 
[2] 

BH 
1.221 
[2] 

BH 
1.205 
[3] 

HBC 
103.79 
[2] 

HBC 
104.0 
[3] 





















Table 4. Atomic coordinates, r_{s}/r_{opt } 
(More figures are shown than are significant.) 











u (Å) 

v (Å) 

w (Å) 









H 
 
1.640673 

1.169206 

0.0 

H 
 
1.640673 
 
0.584603 
± 
1.012562 

B 
 
1.349157 

0.0 

0.0 

C 

0.184843 

0.0 

0.0 

O 

1.319843 

0.0 

0.0 























[1] A.M.Murray and S.G.Kukolich, J.Chem. Phys. 77,4312(1982). 


[2] A.C.Venkatachar, R.C.Taylor, and R.L.Kuczkowski, J.Mol.Struct.
38,17(1977). 


[3] W.C.Bailey, J.Mol.Spectrosc. 190,318(1998). 






















ND_{3} 
CD_{3}Cl 
CD_{3}Br 
CD_{3}CN 


BH_{3}NH_{3} 
(CH_{3})_{3}NBH_{3} 
PF_{3}BH_{3} 
HCCCH_{3} 






















Table of Contents 





Molecules/Deuterium 





Molecules/Boron 






























BH3CO.html 






Last
Modified 26 Oct 2008 









