PNNL

Abstract

Solid-state NMR (SSNMR) spectroscopy was used to measure the dynamics of three diamines appended to the metal–organic framework Mg2(dobpdc). These diamines possess both bound and free nitrogen environments within the MOF pores. Herein, we present variable temperature 15N SSNMR experiments that quantify the rates and energetics for exchange between the two environments, which are consistent with density functional theory calculations and molecular dynamics simulations. The activation energy for this exchange provides a measurement of the metal–amine bond strength and is connected to the CO2 adsorption properties of these materials.