Lutetium hydride

Synthesis and reactivity of the yttrium hydride dimer [Cp Y(OAr)(/i-Fl)]2 (Ar = 2,6-Bu2C6H3) have been investigated in detail.294 295 Synthetic routes leading to tetranuclear yttrium and lutetium hydride clusters have been worked out. The complexes are accessible by reacting precursors of the type (CsMe4SiMe2R)Ln(CFI2SiMe3)2(TF[F)... 

The lutetium hydride complex [Cp 2Lu(/t-H)]2 efficiently cleaves the Si-C bond of PhSiH3 to produce benzene and cross-linked polysilanes (SiHJ (Scheme 290).604 Formation of Ph2SiH2 and SiH4 has also been observed during the samarium-catalyzed redistribution of PhSiHj.545... 

Besides, alkyne derivatives [(RCMT)2LnH], [8] and the ionic tricyclopentadienyl lutetium hydride [(Cp3Lu)2H] are known [11]. 

The H-H and C-H activation reactions at lutetium hydride Cp2LuH and the plausible electronic structure of reaction intermediates have been considered using the theory of isolobal analogy of frontier orbitals [52]. 

The comparison of frequencies shown in Table V.2. indicates that the highest Ln-H frequency is observed in the ytterbium and lutetium hydrides, but the lowest one is... 

Why does the a-bond metathesis between a metal-boryl species give the alkyl-borane and the metal-hydride and not the borane and the metal-alkyl, whereas the a-bond metathesis between a lutetium-methyl and methane (Chap. 3) does not also give a lutetium hydride and ethane, but only degenerate metathesis ... 

Different lutetium hydride species can be obtained according to the following reactions (Schumann et al. 1986a). 

Metathetical routes using bulky lithium guanidinates as starting materials have also been employed to synthesize bis(guanidinato) lanthanide halides as well as reactive alkyls and hydrides. Scheme 63 shows as a typical example the formation of the lutetium chloro precursor, which was isolated in 76% yield. ... 

These results at least demonstrate that ethylene can be polymerized by an alkylidene hydride catalyst, probably by forming a metallacyclobutane hydride intermediate. The extent to which this is relevant to the more classical Ziegler-Natta polymerization systems (27) is unknown. Recent results in lutetium chemistry (28), where alkylidene hydride complexes are thought to be unlikely, provide strong evidence for the classical mechanism. 

The same group also showed that mono(cyclopentadienyl) mixed hydride/ aryloxide dimer complexes of several lanthanide elements (Y, Dy, Lu) could be synthesized easily by the acid-base reaction between the mixed hydride/alkyl complexes and an aryl alcohol [144]. These complexes reacted with C02 to generate mixed formate/carboxylate derivatives, which were moderately active initiators for the copolymerization of C02 and cyclohexene oxide, without requiring a co-catalyst. The lutetium derivative 21 was the most active (at 110°C, TOF = 9.4 h ), yet despite a good selectivity (99% carbonate linkages), the molecular weight distribution remained broad (6.15) (Table 6). 

The catalysts are Tim hydrides which are generated in situ by reduction of enantio-merically pure L TiCl2 with butyllithium and PhSiH3 they are also highly effective in the asymmetric hydrogenation of imines and enamines.20 The lutetium ansa-metallocene complex (22-XVII) catalyzes the deuteration of 1-pentene (63% e.e.)21 Related samarium compounds hydrogenate imines.22... 

Figure 1 displays the plots of the TCATC/G quantity as a function of ATC derived from our experimental results for the R2Fei4B compounds and their hydrides. The data for the lutetium compounds (TCo = 535 K for Lu2Fei4B and Tco = 620 K for Lu2Fe14BH2 5) have been adopted as a TCo- It is known that the 4f electron shell of the Lu3+ (4f14) - ion has no magnetic moment. Therefore, in our case, the Lu compound models the iron sublattice magnetization for the whole series of R-Fe compounds under consideration. 

The lanthanides and actinides are also active in electrophilic attack on arenes. Bis(pentamethylcyclopentadienyl)lutetium methyl or hydride complexes react readily with benzene to give phenyl complexes and methane or dihydrogen . Similar reactions are observed for Sc and Th In a remarkable reaction benzene can be dimetallated by Lu, yielding II ... 

Lutetium(III) chloride does not give stable organolutetium compounds with EtLi, instead of them ethane, ethene and unidentified hydrides of Lu have been obtained [106]. 

As a rule, they are isolated from the reaction mixture without coordinated solvent and appear to be nonassociated compounds. In the reversible reaction of hydride (Me5C5)2LuH with di(pentamethylcyclopentadienyl)phenyl lutetium in hexane an interesting binuclear compound containing Lu atoms in para-position of benzene ring has been obtained [197] ... 

At the same time the thermolysis of tert-butyl derivatives is of great significance for the synthesis of hydrides of III group metals, since it allowed to prepare the first complexes of a new type containing a 113-bridged hydrogen atom [9]. It has been found that the decomposition of Cp2ErBu-t(THF) in the presence of LiCl leads to an ionic complex with a trinuclear anion A. The decomposition of lutetium etherate... 

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