Correlating Local Geometry to ¹¹B NMR Chemical Shifts of Tetrahedrally Coordinated Boron in Molecular Sieves

The average B–O–T angles (B, O, and T denote boron, oxygen, and tetrahedrally coordinated atoms, respectively) are used as local geometric parameters for framework-incorporated B-sites within crystalline, borosilicate molecular sieves and are obtained from density-functional theory (DFT) calculations. The linear relationship between the B–O–T angles and the 11B NMR chemical shifts reported previously for smaller angles in minerals is shown here to extend to the larger angles more typical within crystalline molecular sieves. In total, the correlation can be employed to investigate tetrahedrally coordinated B atoms for the entire class of three-dimensional, crystalline borosilicates.