Structural Characterization of D<sub>2</sub> in Cu<sub>3</sub>(1,3,5-Benzenetricarboxylate)<sub>2</sub> Using Neutron Powder Diffraction

Abstract

Sorption of ten different quantities of D2 within the porous coordination metal framework Cu3(1,3,5-benzenetricarboxylate)2 were studied using neutron powder diffraction. D2 sorption in the porous material reached saturation (at 25 K) at an amount equivalent to ~6.5 wt. % H2. Rietveld analyses revealed that at saturation there are two saturated small pore and three saturated large pore sites, in addition to the primary site at the coordinatively unsaturated Cu. We reveal that the linked bimodal pore system provides up to nine distinct sites for D2, at moderate D2 concentrations up to saturation. Intermediate sites are attributed to local D2-D2 interaction within the confined pore spaces. Within the small and large pores one, and two, intermediate sites are identified, respectively. The population of D2 at each site was found to affect the host lattice.