Table 1.

GIAO-MP2/tzp/dz calculated and estimated NMR chemical shifts^*

No.	a, δ13C (GIAO-MP2)	b, δ11B (GIAO-MP2)	b, δ11B (estimated)†
1	−11.5	−28.8	−33.8
2	−25.7	−32.4	−38.5
3	−13.0	−35.6	−34.3
4	332.9	62.4	79.8

^*Calculated ¹³C and ¹¹B NMR chemical shifts were referenced to tetramethylsilane and BF₃:OEt₂, respectively. 

^†Estimated by using Eq. 2.