A convenient and quantitative route to Sn(IV)-M [M = Ti(IV), Nb(V), Ta(V)] heterobimetallic precursors for dense mixed-metal oxide ceramics

作者：Mishra Shashank^*; Jeanneau Erwann; Mangematin Stephane; Chermette Henry; Kalhor Mahboubeh Poor; Bonnefont Guillaume; Fantozzi Gilbert; Le Floch Sylvie; Pailhes Stephane; Daniele Stephane

来源：Dalton Transactions, 2015, 44(15): 6848-6862.

DOI：10.1039/c5dt00339c

The strategy of reacting SnCl4 with M(OR)(x) provided a convenient and quantitative approach to new heterobimetallics with a simple addition formula, [SnCl4M(OR)(x)(HOR)(y)] (M = Ti, Nb, Ta; R = Et, Pr-i, x = 4, 5; y = 0-2) or sometimes an oxo complex [SnCl3(O)Ti-2(OPri)(7)(HOPri)(2)]. The alcoholysis reactions of these heterometallics afforded mixed alkoxo complexes [SnCl4(mu-OEt)(2)M((PrO)-O-i)(x)((PrOH)-O-i)(y)] [M = Ti (x = y = 2), Nb, Ta (x = 3, y = 1)] under mild conditions, or a planar rectangular oxo product [SnCl3(mu-OEt)(2)Nb-(OEt)(2)(EtOH)(mu-O)](2) at refluxing/extended stirring time. DFT calculations shed light on the stability and reactivity of these complexes. The use of these thoroughly characterized heterometallics as sol-gel precursors suppresses the formation of the undesired SnO2 grains, which are difficult to be sintered to a high density. The combined approach of using bottom-up synthesis of mixed Ti0.5Sn0.5O2 nanoparticles and Spark Plasma Sintering allowed the successful densification of chloride-free mixed-metal oxide ceramics. The influence of thermal treatment before sintering on the density and spinodal decomposition of the TiO2-SnO2 pellets is reported.

• 出版日期2015