boron11

Boron-11 (11B) is one of the two stable isotopes of boron, having mass number 11 and atomic number 5. In naturally occurring boron, 11B accounts for about 80 percent of the element, with the remainder being the lighter isotope boron-10. Both isotopes are stable and non-radioactive, so boron itself has no natural radioactive decay.

Nuclear properties of 11B include a nonzero nuclear spin (I = 3/2) and a quadrupolar nucleus. These features influence how 11B behaves in nuclear magnetic resonance (NMR) experiments and affect its interactions in solids and liquids. Because of its relatively high natural abundance and favorable NMR characteristics, 11B NMR is a common analytical tool in inorganic, organoboron, and materials chemistry.

Chemically, 11B behaves similarly to other boron isotopes, forming a wide range of boron-containing compounds such as boranes, borates, and boron acids. Isotopic substitution has only small effects on chemical reactivity and bonding, though subtle isotopic differences can be used in specialized isotopic studies and tracing experiments.

Applications and significance: 11B is widely used as a nucleus in NMR spectroscopy to characterize boron-containing compounds. In geochemistry and environmental science, the 11B/10B isotopic ratio is used to study processes such as water-rock interactions and boron cycling. In contrast, boron-10 is the isotope employed in neutron capture applications and boron neutron capture therapy due to its large thermal neutron capture cross-section; 11B has a much lower cross-section and is not used for BNCT.

Occurrence and production: boron is found in minerals such as borax and kernite, and is extracted for industrial use. 11B-rich materials are produced from natural boron sources and refined for chemical, medical, and research applications.