Scandium sulfate

Scandium sulfate [Scj(SO )j] 2Sc + 3SO —> Sc lSO l This compound is used in the germination of seeds for agricultural plants. 

Dilute solutions of scandium sulfate, when applied to com, peas and wheat, increase the number of seeds which germinate successfully (Emsley 2001). 

Moreover, a new type of catalyst, scandium tris(dodecyl sulfate) [Sc(03S0Ci2H25)3,Sc(DS)3] has been developed.62. The catalyst (a Lewis Acid-Surfactant Combined Catalyst, LASC) acts both as a catalyst and as a surfactant, and aldol reactions proceed smoothly in the presence of a catalytic amount of Sc(DS)3 in water, without using any organic solvents (Scheme 16). 

With these results in hand, we have next introduced new types of Lewis acids, e.g scandium tris(-dodecyl sulfate) (4a) and scandium trisdodecanesul-fonate (5a) (Chart 1).[1S1 These Lewis acid-surfactant-combined catalysts (LASCs) were found to form stable colloidal dispersions with organic substrates in water and to catalyze efficiently aldol reactions of aldehydes with very water-labile silyl enol ethers. 

S. Kobayashi, T. Wakabayashi, Scandium Tridodecyl-sulfate (STDS). A New Type of Lewis Add That Forms Stable Dispersion Systems with Organic Substrates in Water and Accderates Aldol Readions Much Faster in Water Than in Organic Solvents Tetrahedron Lett. 1998, 39, 5389-5392... 

Scandium forms all its compounds in 3+ oxidation state. This is the only valence known for the metal. These compounds include the oxide, SC2O3 hydroxide, Sc(OH)3 chloride, ScCls fluoride, ScFs sulfate, Sc2(S04)3, and the nitrate salt, Sc(N03)s. 

Scandium salts are colorless, and give gelatinous precipitates with potassium hydroxide and sodium carbonate. The sulfate crystallizes with difficulty. 

The amount of catalyst (scandium trisdodecyl sulfate) and ligand, (14), in the ring opening of czT-1,2-disubstituted oxiranes with primary and secondary aromatic amines in water were varied to maximize the yields.33 In all but two cases, the reaction, under ideal conditions, yielded the j3-amino alcohols in >81% yield with enantioselectivity ... 

Fig. 6 (a). Three-dimensional Ni(ll) sulfate in [C4N2H 2][Ni2F4(S04) HjO], XIX, showing 10-membered elliptical channels from ref. 66, (b) Polyhedral view of ihree-dimensional zinc sulfate comprising Zn04 and SO,L letrahedra in [(CN J Vbl Zn(S04Jij, XX, redrawn from ref, 78, Note the presence of 12-membered channels, (c) Three-dimensional structure of scandium with mixed sulfate and phosphate telrahedra in XXI, redrawn from ref, 81, copyrighl (2002) from the Royal Society of Chemistry. 

The surfactant-aided Lewis acid catalysis was first demonstrated in the model reaction shown in Table 13.1 [22]. While the reaction proceeded sluggishly in the presence of 10 mol% scandimn triflate (ScfOTOs) in water, a remarkable enhancement of the reactivity was observed when the reaction was carried out in the presence of 10 mol% Sc(OTf)3 in an aqueous solution of sodium dodecyl sulfate (SDS, 20 mol%, 35 mM), and the corresponding aldol adduct was obtained in high yield. It was found that the type of surfactant influenced the yield, and that Triton X-100, a non-ionic surfactant, was also effective in the aldol reaction (but required longer reaction time), while only a trace amount of the adduct was detected when using a representative cationic surfactant, cetyltrimethylammonium bromide (CTAB). The effectiveness of the anionic surfactant is attributed to high local concentration of scandium cation on the surfaces of dispersed organic phases, which are surroimded by the surfactant molecules. 

The results mentioned above prompted us to synthesize a more simplified catalyst, scandium tris(dodecyl sulfate) (Sc(DS)3) [23,24]. This new type of catalyst, Lewis acid-surfactant-combined catalyst (LASC) , was expected to act both as a Lewis acid to activate the substrate molecules and as a surfactant to form emulsions in water. Eng-berts and co-workers also reported a surfactant-type Lewis acid, copper bis(dodecyl sulfate) (Cu(DS)2) [25]. Although they studied detailed mechanistic aspects of Diels-Alder... 

Scandium oxide is a refractory white solid (mp 3100 °C) formed on ignition of either the metal or appropriate compounds such as the nitrate, sulfate, and hydroxide. It has amphoteric tendencies denoted by its solubihty in excess alkali from which compounds like K3[Sc(OH)6], containing octahedrally coordinated scandium, have been isolated. In the solid state it has six-coordinate scandium in the Mu203 structure. 

The chemical properties of the transition elements do not change so strikingly with change in atomic number as do those of the other elements. In the series potassium, calcium, scandium the normal salts of the elements correspond to the maximuni oxidation numbers given by the positions of the elements in the periodic system, 1 for potas Slum, 2 for calcium, and 3 for scandium the sulfates, for example, of these elements are KoSO, CaSOj, and The fourth element,... 

Furthermore, we have introduced new types of Lewis acids, scandium tris(do-decyl sulfate) (5a) and scandium trisdodecanesulfonate (6a) (Chart 14-1) [36]. 

Simple imines undergo Diels-Alder reactions in the presence of suitable catalysts. Lanthanide triflates, which are stable in water, are especially effective. Thus in the presence of 10 mol% of ytterbium or scandium triflate, Danishefsky s diene 4 reacts with benzylideneaniline in acetonitrile at 0 °C to give the dihydropyridone 76 quantitatively (equation 50) analogous products are obtained from 4 and furylideneaniline, benzyli-denebenzylamine and pentyIidenebenzylamine. In a one-pot version of the reaction, a mixture of an aldehyde, an amine and the diene 4 in acetonitrile containing magnesium sulfate is treated with 10 mol% ytterbium triflate to afford the dihydropyridone in ca 80% yield. Even phenylglyoxal monohydrate can be employed. ... 

KOL/IVA] Kolosov, I. V., Ivanov-Emin, B. N., Korotaeva, L. G., Tetsu, K., Study of the complex formation of scandium with selenate and sulfate ions, Radiokhimiya, 9, (1967), 473-478, in Russian, English translation in [67KOL/IVA2], Cited on pages 355, 493. 

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