Organically Templated Zirconium Fluorides: Hydrothermal Syntheses, Structural Relationships, and Thermal Behavior of (C2H10N2)Zr2F10·H2O and (C4H12N2)ZrF6·H2O

✍ Scribed by Richard E. Sykora; Michael Ruf; Thomas E. Albrecht-Schmitt

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 403 KB
• Volume: 159
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.2001.9151

✦ Synopsis

The organically templated Zr(IV) 6uorides, (C 2 H 10 N 2 ) Zr 2 F 10 ' H 2 O (AU2-6) and (C 4 H 12 N 2 )ZrF 6 ' H 2 O (AU1-6) have been prepared from the reaction of ZrO 2 with HF and ethylenediamine or piperazine under mild hydrothermal conditions. These compounds were characterized by single-crystal X-ray di4raction, DSC, TGA, and elemental analysis. AU2-6 consists of dodecahedral ZrF 8 units that share three edges with neighboring dodecahedra to form 2 R [Zr 2 F 10 ] 2؊ sheets that are separated by diprotonated ethylenediamine cations. AU1-6 contains edge-sharing ZrF 8 dodecahedra that form 1 R [ZrF 6 ] 2؊ chains that further hydrogen bond with diprotonated piperazinium cations and water molecules. Application of dimensional reduction theory demonstrates that 1 R [ZrF 6 ] 2؊ chains can be derived from the 2 R [Zr 2 F 10 ] 2؊ parent structure through the addition of one equivalent of 6uoride. Thermal analyses indicate that the water molecules in AU2-6 are more tightly bound than those in AU1-6 as endotherms corresponding to water loss occur at 226