Boron

Example text, change later.

Boron has two naturally occurring NMR active nuclei. Both nuclei have spins of greater than ½ and are quadrupolar. 11B has a spin of 3/2 and 10B is spin 3. 11B is the better nucleus in all respects, having the lower quadrupole moment and being more sensitive. Regular NMR tubes are made of borosilicate glass and therefore contain boron. As a result there is a broad signal in the spectrum arising from the tube. It is therefore preferable to use quartz tubes that do not contain boron although these are much more expensive and fragile than regular tubes. Both nuclei have the same wide chemical shift range. Each type of signal has a characteristic chemical shift range (fig. 1) which is the same for both nuclei.

Fig. 1. Chemical shift ranges for boron NMR

Observations

10B

Chemical Shift Cq Eta Material Name Composition Group Site Name Reference

11B

Chemical Shift Cq Eta Material Name Composition Group Site Name Reference