Scandium complexes formates

The complex formation between Sc and SeOj" was studied by measurement of the distribution of Sc between the aqueous phase and a cation exchanger at selenate concentrations in the range 0 to 0.167 M. Sodium perchlorate was added to keep the ionic strength at / = 0.5 M. The radioactive nuclide Sc was used to follow the distribution ratio at a total scandium concentration of 2 x 10 M. Measurements were carried out at 298.15, 308.15, and 318.15 K and the pH was adjusted to 4.0 to 4.5. No disturbance from the hydrolysis of Sc occurs at this pH according to the paper although this would be expected from the data in [76BAE/MES]. 

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. 

TBP (3.4 to 2.9), 50% TBP solution in CCI4 (2.4 to 2.8), and TVEX-TBP (2.8-1.9) and has fractional value indicating simnltaneous formation of several scandium complexes in organic phase and different ratio between them. In addition, the ASN value depends on the metal concentration in the resin phase and decreases for TVEX-TBP resins and increases for 50% TBP solution in CCI4 with scandium content increase. 

A conceptually similar approach was reported recently by Wolf and coworkers. 1,8-Diacridylnaphthalene A,A -dioxide derivative 11, described in Fig. 5a, was found to bind selectively scandium(III) ions, giving rise to fluorescence enhancement [64]. The addition of amino alcohols induced a quenching of the fluorescence of this complex, which was found to be due to ternary scandium-ligand-analyte complex formation, followed by scandium(III) scavenging by the analyte, thus... 

For example, the treatment of the scandium complex 5 (L)ScR (R = —CH2CMc3 or — CH2SiMe3) with one equivalent of trimethylsilyl chloride (or iodide) resulted in the formation of intermediate 6 in which one NHC has been displaced and binds the TMS group. The compoimds slowly converted into the corresponding (L)ScX (X = C1 or I) complex 7 and the product of C—Si bond formation (Me3CCH2SiMe3 or Me3SiCH2SiMc3) [20]. 

Rare earth arene complexes are good precursors for difficult-to-synthesize rare earth compounds (Bochkarev, 2002) and the same was true for the scandium arene complexes supported by NN . Hessen previously showed that a scandium complex of the 2,2 -bipyridyl radical anion could be readily accessed from a reduced 1,3-diene scandium complex (Beetstra et al., 2003). Similarly, the addition of 2,2 -bipyridine to a CeDs solution of Sc2-naph (Scheme 3A) led to the formation of the previously reported radical anionic bipyridyl complex (NN )Sc(2,2 -bipyridine) (Williams et al., 2010). 

Huang W, Diaconescu PL. Visible-hght-induced reversible C-C bond formation of an imidazole-derived scandium complex. Inorg Chim Acta. 2012 380 274-277. 

Scandium A computational study on the C-H addition of a-picoline (2-MeC5H3N) and other pyridine derivatives to terminal olefins RCH=CH2, catalysed by cationic scandium complexes, has demonstrated that the reaction rate is controlled by generation of the active metal-pyridyl species and an insertion step. In agreement with the experimental observation, formation of the branched product 6-[RCH(Me)-(2-MeC5H3N)] is both kinetically and energetically favourable over that of the linear product. ... 

Cyclocondensations of NADH analogues with / ara-benzoquinone are described in [368, 369]. For example, upon addition of dihydropyridine 338 to an acetonitrile solution of 339 in the presence of scandium trifluoromethane-sulfonate, the cycloaddition reaction occurs efficiently at room temperature, yielding cycloadduct 340 [368] (Scheme 3.113). This reaction passes via formation of a complex between azine and scandium trifluoromethanesulfonate. 

The reaction of a cyclopentadienyl scandium acac complex [(C5Me5)Sc(acac)3] with tetra-phenyldisiloxanediol (Ph2Si0H)20 results in displacement of the cyclopentaidiene group and the formation of a siloxane complex, [ (Ph2SiO)2OSc(acac)2 2Sc(acac)].19... 

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