Complexes of scandium

The guanidinate-supported titanium imido complex [Me2NC(NPr02l2Ti = NAr (Ar = 2,6-Me2C6H3) (cf. Section IILB.2) was reported to be an effective catalyst for the hydroamination of alkynes. The catalytic activity of bulky amidinato bis(alkyl) complexes of scandium and yttrium (cf. Section III.B.l) in the intramolecular hydroamination/cyclization of 2,2-dimethyl-4-pentenylamine has been investigated and compared to the activity of the corresponding cationic mono(alkyl) derivatives. 

PYBOX complexes of scandium(III) triflate act as enantio- and diastereo-selective catalysts of ene reactions, including examples with trisubstituted alkenes.207... 

There have been a couple of studies on triple decker benzene complexes of scandium and related transition metals M2(C6H6)3 (M = Sc, Ti, V). Stern-Gerlach measurements have shown that the magnitudes of their magnetic moments are reduced from their spin-only values by a factor of 1/4 for M = Sc and Ti, and 3/5 for V.87 Ab initio calculations have given insight into... 

Preparation and characterization of l,l -diphosphaferrocenes with linear fused six-membered carbocycles <2007JOM55>. Synthesis and reactivity of trimethylsilyl-substituted phosphametallocenes <2007EJI553>. Synthesis and reactivity of tetramethylphospholyl complexes of scandium <2007JOM4595>. 

Table 7.3 lists in parallel corresponding binary compounds and complexes of scandium, lanthanum, and lutetium. As expected on steric grounds, the smaller scandium generally... 

F. G. N. Cloke, Zero Oxidation State Complexes of Scandium, Yttrium and the Lanthanide Elements, in Comprehensive Organometallic Chemistry IF, eds. F. G. A. Stone, G. Wilkinson, and E. W. Abel, Pergamon Press, Oxford, 1995, Vol. 4, Chap. 1 p. 1. 

Roussel, R, Alcock, N.W., and Scott, P. (1998) Triamidoamine complexes of scandium, yttrium and the lanthanides. Chemical Communications, 801. 

Zeimentz, P.M., Arndt, S., Elvidge, B.R. etal. (2006) Cationic organometallic complexes of scandium, yttrium, and the lanthanoids. Chemical Reviews, 106, 2404. 

Although some crown ether complexes of scandium were made at the time that the lanthanide complexes were first made, it is only recently that they have been investigated systematically and definitive structural information has become available, mainly due to Willey and co-workers... 

No carbonyl chemistry of scandium and yttrium has been reported yet and there is also no cyanide chemistry of these two elements although thiocyanato complexes of scandium [Sc(NCS)6]3 (bonded through nitrogen) are known. The important developments involving scandium or yttrium with carbon have involved the fullerene derivatives of these elements. There have been some scandium carbide systems prepared but these will be highlighted in the chemistry of the halides. 

Porphyrins, hydroporphyrins, azaporphyrins, phthalocyanines, corroles, corrins, and related macrocycles were discussed in CCC (1987).144 The octaethylporphyrin complexes of scandium were also previously mentioned in CCC (1987).1 The octaethylporphyrin (oep) scandium chloride complex (oep)ScCl, prepared by the reaction of the dilithium porphyrin with ScCl3(thf)3, has proved... 

Many of the early reports of complexes with bidentate oxygen ligands involved acac complexes and the /3-diketonate and related ligands were discussed in CCC (1987).210 The /3-diketonate complexes of scandium and yttrium and the lanthanides were also discussed in CCC (1987).1 Many reported systems contained adducts formed by the metal /3-diketonate complexes. In solution some of the complexes with bidentate ligands can expand their coordination number to seven by coordination to a suitable donor ligand. A solvent extraction method has been used to show that Sc(acac)3 does not form an adduct with trioctylphosphine oxide but tris(tropolonato)scandium(III) and tris-(ethylmatolato)scandium(III) do coordinate with trioctylphosphine oxide.211... 

Crown ethers and the lanthanide complexes were extensively covered in CCC (1987)218 but complexes of scandium and yttrium were not mentioned with the exception of [Y(NCS)3(18-crown-6].1... 

Edelmann FT (2006) Complexes of scandium, yttrium and lanthanide elements. In Crabtree RH, Mingos DMP (eds) Comprehensive organometaUic chemistry 111, vol 3, Elsevier, Oxford, p 1... 

In indirect methods for determination of fluoride, aluminium complexes with Eriochrome Cyanine R (ECR) [58] and Xylenol Orange [59] have been applied. The sensitivity of the ECR method increases considerably in the presence of CP [60]. The complexes of scandium with Methylthymol Blue (e = 1.07-10 at 590 nm) and Pyrocateehol Violet [61] have also been recommended. 

Chemical Studies.—The sulphitoacido-complexes of scandium, neodymium, and yttrium were reported to be more amenable to complete extraction than the analogous sulphato complexes, and the hexameric scandium caprate has been shown to be responsible for the extraction of scandium with capric acid. ... 

No complexes of scandium or of yttrium are known. The complexes of the lanthanides and of the actinides will be considered in Sections I and J. 

F.G.N. Cloke (1995) Zero oxidation state complexes of scandium, yttrium and the lanthanide elements in Comprehensive... 

Complexes of metals in low oxidation state induce rearrangements and isomeiizations of strained and unsaturated hydrocarbons which occur with C-C bond cleavage [68] (Scheme IV.35). 1,4-Pentadiene can be isomerized (with splitting C-C bonds) under the action of hydride cyclopentadienyl complexes of scandium [69a]. Hydrogenolysis of C-C bonds in saturated hydrocarbons has been described in the presence of the system H2-Re2(CO)io-AI2O3 [69b, ... 

In this paper on the formation of acetate complexes of scandium and thorium in water and aqueous ethanol mixtures at / = 0.05 M and 25°C, Usherenko and Skorik [1971USH/SKO] used preliminary hydrolysis constants of logn, Vn (Th(OH) = -3.15 (water, / = 0.05 M), -2.77 (25 vol.%/19.8 mass.% ethanol) and -2.17 (50 vol.%/40.3 mass% ethanol). The experimental determination of the hydrolysis constants is reported in a later paper of these authors [1972USH/SKO]. 

Aziz, A., Lyle, S. J., Equilibrium constants for aqneons fluoro complexes of scandium, yttrium, americium(III) and cnrium(III) by extraction into di-2-ethylhexyl phosphoric acid, J. Inorg. Nucl. Chem., 31, (1969), 3471-3480. Cited on page 599. 

Usherenko, L. N., Skorik, N. A., Stabihty of acetate complexes of scandium and thorium in water and aqueous ethanol mixtures, Sov. Radiochem., 13, (1971), 646-648. Cited on pages 156, 534. 

Chemical Studies.—Mixed ligand complexes of scandium have been obtained containing edta and either Tiron, sodium 2,3-dihydroxynaphthalene-6-sulphonate, or pyrocatechol. These mixed complexes are generally more stable than their yttrium analogues, but are more susceptible to hydrolysis. The stability of tartrate complexes has also been investigated. ... 

F.G.N. Cloke (1995) Zero oxidation state complexes of scandium, yttrium and the lanthanide elements in Comprehensive Organometallic Chemistry II, eds G. Wilkinson, F.G. A. Stone and E.W. Abel, Pergamon, Oxford, vol. 4, p. 1. 

HEAT CAPACITY, ENTROPY. ENTHALPY. FREE ENERGY. AND HEAT OF FUSION OF THE TRIS/ACETYLACETONATO/ COMPLEXES OF SCANDIUM/III/. VANADIUM/III/. MANGANESE/III/. 

Finally some homoleptic alkyne complexes of scandium and some rare earths are known. Tris(phenylethynyl) scandium is formed as a dark brown product after treatment of phenylethyne with butyl lithium at — 78°C in hexane, followed by the addition of scandium trichloride at room temperature. The compound is inflammable in air (Hart and Saran, 1968 Hart et al., 1970). The reaction of the anionic... 

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