V. N. Khandozhko

Synthesis and structure of metal carbonyl derivatives of lanthanium, samarium and ytterbium

Abstract It has been shown that the reaction of amalgamated lanthanides (Ln) with binuclear carbonyls Co 2 (CO) 8 and [CpMo(CO) 3 ] 2 in THF at room temperature leads, depending on the reagent ratio, to tris-(I) or bis- metal carbonyl(II) complexes of lanthanides, Ln[M(CO) m L] n (Ln = Sm, Yb; M(CO) m L = Co(CO) 4 , Mo(CO) 3 Cp; n = 2,3). II (Ln = Sm, Yb) may also be obtained by reduction of the respective I with naphthalene radical anions in THF. IR and UV spectroscopy proved that these compounds contain a transition metal-lanthanide bond.

Study of the reactions of halogen and mercury halogen derivatives of metal carbonyls with samarium and ytterbium

Conclusions1.The reactions of the metal carbonyl halides L(CO)mMX with lanthanides have been studied for the first time. It has been established that, depending on the condition and the type of the lanthanide, derivatives of the bivalent lanthanides L(CO)mMLnX (Ln=Sm, Yb) are formed or mixtures of mono- and disubstituted metal carbonyl derivatives of the lanthanides (III).2.Reactions of metal carbonyl mercury halides L(CO)mMHgX with zero-valent lanthanides, depending on the nature of the halide, lead to metal carbonyl derivatives of bi- and tervalent lanthanides.

Oxidative addition of zero-valent lanthanides at transition metal-halogen bonds

Alkyl and aryl iodides add to zero-valent lanthanides to form Grignard-like reagents RLnI. The authors have already studied the addition of Ln(0) at the Hg-I bond in HgI/sub 2/ and RHgI compounds to give bimetallic derivatives of divalent lanthanides. In the present work, preliminary results are given for a study of the reactions of rare-earth elements with metal carbonyl halides with the general formula L(OC)/sub m/M-X (I), where L(OC)/sub m/M = Cp(OC)/sub 3/Cr, Cp(OC)/sub 3/Mo, Cp(OC)/sub 3/W, (OC)/sub 5/Mn, (OC)/sub 5/Re, or Cp(OC/sub 2/)Fe and X = Cl, BR, or I.

Lanthanide carbonyl complexes

In the cases of a typical lanthanide (Sm) and atypical lanthanide (Yb), they have shown that activated metallic Sm and Yb react with free CO (p/sub CO/ = 20 atm) at 20/sup 0/C in THF to give carbonyl complexes Ln(CO)/sub m/(THF)/sub n/ (Ln = Sm and Yb) (I). Two bands (1995 and 2020 cm/sup -1/) are found in the IR spectra of solutions of (I) in THF in the stretching band region for the terminal CO ligands. The position and relative intensity of these bands is virtually independent of the nature of the lanthanide (in contrast to the data obtained in a matrix (2)). Complexes (1) are stable in THF for several hours. An attempt to isolate (I) from solution by removal of THF leads to decomposition of the complex and formation of a lanthanide-containing powder insoluble in organic solvents having apparent polymeric structure. The presence of lanthanide was shown by x-ray fluorescence analysis. The IR spectra of these compounds have bands at 1747 and 1754 cm/sup -1/ which may be assigned to stretching vibrations of the bridge CO groups.

Synthesis and properties of the benzenetricarbonylchromium derivatives of divalent samarium, europium, and ytterbium

The title compounds, Ln[PhCr(CO)3]2·n(tetrahydrofuran) Lu = Sm, Eu, Yb, representing a new type of organometallic derivative of divalent lanthanides, were produced by the reaction of Hg[PhCr(CO)3]2 with an excess of Ln0 filings in tetrahydrofuran.

Metal carbonyl derivatives of divalent lanthanoids: bis(tetracarbonylcobalt)-samarium, -europium, and -ytterbium

The first metal carbonyl derivatives, Ln[Co(CO)4]2·(THF)n(THF = tetrahydrofuran; n= 3,4), of divalent lanthanoids Ln(Ln = Sm, Eu, Yb) were prepared by treating Hg[Co(CO)4]2 with an excess of Sm, Eu, or Yb in THF at room temperature; the title complexes were also formed in high yields from the reaction of stoicheiometric amounts of the appropriate Lnl2 compounds and TICo(CO)4.