Ming-Chu Hsien, H. Kao, K. Lii
Jul 3, 2001
Citations
0
Influential Citations
8
Citations
Journal
ChemInform
Abstract
A new gallophosphate, (4-HAP)2[Ga4O(PO4)4(H2O)4] (designated NCUGa-1), has been synthesized in the presence of 4-aminopyridine as the structure-directing agent. The structure consists of discrete Ga4(PO4)4(H2O)4 double-four-ring (D4R) units hosting O2- anions. Charge compensation is achieved by the monoprotonated amine. Each D4R unit is linked to adjacent units and the organic cations via hydrogen bonding. Crystal data: (C5H7N2)2[Ga4O(PO4)4(H2O)4], orthorhombic, space group Aba2 (no. 41), a = 18.879(4) A, b = 18.481(4) A, c = 7.469(1) A, V = 2606.1(9) A3, Z = 4, R1 = 0.025, and wR2 = 0.062. 1H MAS NMR confirms that protonation is on the pyridine nitrogen in aminopyridine. The proton-decoupled 31P MAS NMR spectrum exhibits two resonances at 3.8 and 3.4 ppm with an intensity ratio of 1:1, corresponding to two distinct crystallographic 31P sites. The information obtained from 1H → 31P CP/MAS NMR experiments provides insight into the interaction between the hydrogen atoms of the water molecules and/or the am...