Template Effect of Chain-Type Polyamines on Pore Augmentation: Five Open-Framework Zinc Phosphates with 16-Ring Channels

Five new zinc phosphates with differently unique 3D framework topologies, (H 3 dien)[Zn 3 (HPO 4 ) 3 (PO 4 )] ( 1 ), (H 2 dien) 1.5 [Zn 3 (HPO 4 ) 3 (PO 4 )] ( 2 ), (H 3 dien)[Zn 3 (H 2 PO 4 )(HPO 4 )(PO 4 ) 2 ] ( 3 ), (H 3 dien)[Zn 3 (HPO 4 ) 3 (PO 4 )]·1.5H 2 O ( 4 ), and (H 4 tepa) 0.5 [Zn 2.5 (HPO 4 ) 2 (PO 4 )]·1.5H 2 O ( 5 ), where dien = H 2 NC 2 H 4 NHC 2 H 4 NH 2 and tepa = H 2 N(C 2 H 4 NH) 3 C 2 H 4 NH 2, have been synthesized under mild hydrothermal or solvothermal conditions and characterized by single-crystal X-ray diffraction, thermal analysis, solid-state NMR, UV–vis, or photoluminescence spectroscopy. Both the 7-atom-skeleton-long dien and the 13-atom-skeleton-long tepa have created 16-membered ring (16R) channels as a common feature in structures 1 – 5 . Their inorganic frameworks are built up with tetrahedra of ZnO 4, PO 4, and HPO 4 (plus H 2 PO 4 in 3 ) and may all be described as constructed from two-dimensional nets and one- or zero-dimensional units as linkers. Compounds 1 – 4 have the same Zn/P ratio but possess varied amount of nonframework volume. They are the first examples with dien as template in extra-large-channel structures of zincophosphates. In comparison, the framework of 5 contains a higher value in Zn/P and larger nonframework volume than that in the 24R-channel structure of ND-1. The 16R channels in 1 and 2 are one-dimensional while those in 3, 4, and 5 are unprecedentedly two-dimensional. In this paper, the synthesis, thermal property, NMR, reflectance UV–vis absorption, and photoluminescence study of 1 – 5 are described; framework topologies, structure relationship, the charge and location of templates, and channel characteristic vs nonframework volume are discussed.