Hydrothermal Synthesis and Structural Characterization of Two Layered Diamine Pentamolybdates: (C2H10N2)[Mo5O16] and (C4H12N2)[Mo5O16]

✍ Scribed by Nathalie Guillou; Gérard Férey

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 263 KB
• Volume: 147
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8244

✦ Synopsis

The two diamine pentamolybdates, (C 2 H 10 N 2 ) [Mo 5 O 16 ] and (C 4 H 12 N 2 ) [Mo 5 O 16 ], have been hydrothermally synthesized (1803C, 24 h, autogenous pressure). The ethylenediamine pentamolybdate was powdered and its structure was solved ab initio from conventional X-ray powder di4raction. Single crystals of piperazine pentamolybdate could be isolated. Despite a similar topology, the structures crystallize in di4erent unit cells: ethylenediamine pentamolybdate crystallizes in the monoclinic system with a ‫؍‬ 15.801(1) A s , b ‫؍‬ 5.5878(4) A s , c ‫؍‬ 9.3743(7) A s , and ‫؍‬ 116.321(6)3, space group is P2/n with Z ‫؍‬ 2; piperazine compound is also monoclinic, space group C2/c with a ‫؍‬ 23.3997(3) A s , b ‫؍‬ 5.6222(1) A s , c ‫؍‬ 14.4131(2) A s , ‫؍‬ 115.960(1)3 and Z ‫؍‬ 4. Both structures are built from [Mo 5 O 16 ] 2؊ layers composed of stripes of ReO 3 -type, as already found in Cs 2 Mo 5 O 16 . Diamine cations are located between the layers and ensure the connectivity of the structure via hydrogen bonds. The relationship between the two structures is discussed.