A comprehensive collection of solid-state 31P NMR spectra of aluminophosphate zeolites

Abstract

Solid-state nuclear magnetic resonance (SSNMR) spectroscopy is a valuable technique for characterizing the structural features of zeolites. In recognition of this, the International Zeolite Association's online Database of Zeolite Structures has recently been expanded to incorporate representative SSNMR spectra of zeolites. This paper reports a comprehensive collection of 73 31 P SSNMR spectra of aluminophosphate zeolites with 31 framework types that has been added to database. The scientific literature on aluminophosphate zeolites was extensively searched for 31 P SSNMR spectra with resolution such that the number of peaks in the spectrum ideally corresponded with the number of P sites in the reported crystal structures. These spectra were digitized, fit with a model spectrum informed by the known crystal structure, then added to the Database of Zeolite Structures . This comprehensive collection of 31 P SSNMR spectra and crystal structures enabled an investigation of the relationship between various parameters describing the geometry around the P sites and the 31 P chemical shifts. It was found the 31 P chemical shifts are best correlated to the average P–O–Al bond angles. The correlation equation presented here is based on the largest available collection of spectra with corresponding crystal structures determined from single-crystal X-ray diffraction. It is expected that this comprehensive collection of 31 P SSNMR spectra and the chemical shift-to-structure correlation equation derived from it will be of interest and utility to the zeolite research community. • Comprehensive survey of solid-state NMR and crystal structures of aluminophosphate zeolites. • Database of Zeolite Structures now includes 31 P solid state NMR spectra. • New equation for relating 31 P chemical shifts to average P–O–Al bond angles.