Mapping the synthesis of low nuclearity polyoxometalates from octamolybdates to Mn-Anderson clusters

Rosnes, M.H., Yvon, C., Long, D.L. and Cronin, L. (2012) Mapping the synthesis of low nuclearity polyoxometalates from octamolybdates to Mn-Anderson clusters. Dalton Transactions, 41, pp. 10071-10079. (doi: 10.1039/c2dt31008b)

Abstract

A comprehensive study of the isomer-independent synthesis of TRIS ((HOCH2)3CNH2) Mn-Anderson compounds from Na2MoO4·2H2O, via the corresponding octamolybdate species, is presented. Three octamolybdate salts of [Mo8O26]4− in the β-isomer form, with tetramethylammonium (TMA), tetraethylammonium (TEA) and tetrapropylammonium (TPA) as the counter cation, were synthesised from the sodium molybdate starting material. Fine white powdery products for the three compounds were obtained, which were fully characterised by elemental analysis, TGA, solution and solid state Raman, IR and ESI-MS, revealing a set ratio of Na and organic cations for each of the three compounds; (TMA)2Na2[Mo8O26] (1), (TEA)3Na1[Mo8O26] (2) and (TPA)2Na2[Mo8O26] (3), and the analyses also confirmed that the three compounds all consisted of the octamolybdate in the β-isomeric form. ESI-MS analyses of 1, 2 and 3 show similar fragmentation for these β-isomers compared to the previously reported study for the α-isomer ((TBA)4[α-Mo8O26]) (A) in the synthesis of ((TBA)3[MnMo6O18((OCH2)3CNH2)2]) (B), and compounds 1, 2 and 3 were successfully used to synthesise equivalent TRIS Mn-Anderson compounds: (TMA)3[MnMo6O18((OCH2)3CNH2)2] (4), (TEA)3[MnMo6O18((OCH2)3CNH2)2] (5) and (TPA)2Na1[MnMo6O18((OCH2)3CNH2)2] (6), as well as Na3[MnMo6O18((OCH2)3CNH2)2] (7). This is the first example where symmetric organically-grafted Mn-Anderson compounds have been synthesised in DMF from anything but the {Mo8O26} α-isomer.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Yvon, Miss Carine and Rosnes, Dr Mali and Long, Dr Deliang and Cronin, Professor Lee
• Authors: Rosnes, M.H., Yvon, C., Long, D.L., and Cronin, L.
• Subjects: Q Science > QD Chemistry
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Dalton Transactions
• Publisher: Royal Society of Chemistry
• ISSN: 1477-9226
• Published Online: 16 July 2012