Triple-quantum magic angle spinning (27)Al NMR of aluminum hydroxides.
We show that (27)Al triple-quantum magic angle spinning (3Q-MAS) experiments alleviate the second-order quadrupolar broadening to reveal the structure-building units of nonequivalent aluminum octahedra in the most extensively studied aluminum hydroxides, namely, gibbsite, bayerite, and boehmite. Further, aided by ab initio calculations of the electric field gradient tensors, the 3Q-MAS/MAS results are shown to lead to the assignment of (27)Al isotropic resonances to the aluminum positions in their X-ray-determined structures. The present work paves the way for future studies on various structurally transformed materials derived from these basic aluminum hydroxides.
Damodaran
Krishnan
K
National Chemical Laboratory, Pune 411008, India, Unilever Research India, Mumbai 400 099, India.
Rajamohanan
Pattuparambil R
PR
Chakrabarty
Debojit
D
Racherla
Uday Shankar
US
Manohar
Venkat
V
Fernandez
Christian
C
Amoureux
Jean-Paul
JP
Ganapathy
Subramanian
S