Azacrown Ether Pillared Layered Zirconium Phosphonates and the Crystal Structure of N,N'-Bis(phosphonomethyl)-1,10-diaza-18-crown-6
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- 作者：Abraham Clearfield ; Damodara M. Poojary ; Baolong Zhang ; Baiyi Zhao ; and Agnes Derecskei-Kovacs
- 刊名：Chemistry of Materials
- 出版年：2000
- 出版时间：September 2000
- 年：2000
- 卷：12
- 期：9
- 页码：2745 - 2752
- 全文大小：474K
- 年卷期：v.12,no.9(September 2000)
- ISSN：1520-5002
文摘
The synthesis of N,N'-bis(phosphonomethyl)-1,10-diaza-18-crown-6 tetrahydrate (6) fromthe corresponding diazacrown ether is described and the crystal structure of this diphosphonicacid determined. The crystals are triclinic, P
with a = 8.1829(8), b = 8.3092(10), c =9.1429(10) Å, 
= 85.286(9)
, 
= 84.736(9), 
= 73.158(7), and Z = 1. The center of theazacrown ether ring coincides with the center of symmetry, requiring that the CH2PO3Hgroups lie trans to each other. One of the acid protons of each phosphonic acid group resideson the aza nitrogens, resulting in a zwitterion arrangement. There are four water moleculesper unit cell that participate in an extensive system of hydrogen bonding. An importantfeature of the H-bonding is that between adjacent phosphonic acid groups to form linearchains along the unit cell diagonal. Reaction of 6 with Zr(IV) in the presence of H3PO4 yieldszirconium phosphate-type layers cross-linked by the crown ether groups. The types of layersformed were deduced by a combination of 31P NMR and X-ray data. Affixing phosphonicacid groups onto the aza crown ether results in a more rectangular shape to the ring, whichis further distorted by the cross-linking of the layers.
with a = 8.1829(8), b = 8.3092(10), c =9.1429(10) Å, = 85.286(9), = 84.736(9), = 73.158(7), and Z = 1. The center of theazacrown ether ring coincides with the center of symmetry, requiring that the CH2PO3Hgroups lie trans to each other. One of the acid protons of each phosphonic acid group resideson the aza nitrogens, resulting in a zwitterion arrangement. There are four water moleculesper unit cell that participate in an extensive system of hydrogen bonding. An importantfeature of the H-bonding is that between adjacent phosphonic acid groups to form linearchains along the unit cell diagonal. Reaction of 6 with Zr(IV) in the presence of H3PO4 yieldszirconium phosphate-type layers cross-linked by the crown ether groups. The types of layersformed were deduced by a combination of 31P NMR and X-ray data. Affixing phosphonicacid groups onto the aza crown ether results in a more rectangular shape to the ring, whichis further distorted by the cross-linking of the layers.