Reactivity of pyrazolylborate complexes of samarium with transition metal carbonyls

Reductive Trapping of [(OC)5W–W(CO)5]2− in a Mixed‐Valent SmII/III Calix[4]pyrrolide Sandwich

“…The two kinds of C−O bonds show intense stretching vibrations, respectively at 1668 cm −1 (isocarbonyl) and 1899, 1923, and 1946 cm −1 (terminal carbonyl) in the IR spectrum. Similar behavior has been observed in relevant compounds, for example, [(Cp* 2 Sm) 2 P 6 (Cp*Mo(CO) 2 ) 2 ] and [(Tp Me,Me ) 2 Sm( μ ‐CO)(CpCr(CO) 2 )] . The carbonyl groups have displayed CO bands at 1885, 1967, and 2073 cm −1 in the Raman spectrum.…”

The approach to 4d/4f-polyphosphides

“…The Ln–O bond distances of the isocarbonyl bridges (Sm–O2 2.359(5) Å and Sm–O4 2.389(5) Å; Yb–O2 2.231(5) Å and Yb–O4 2.246(5) Å) are in the range of other isocarbonyl compounds, e.g. [(Tp Me,Me ) 2 Sm(μ-CO){Cp Me Mo(CO) 2 }] (2.335(4) Å; Tp Me,Me = (2,4-dimethylpyrazolyl) 3 borate, Cp Me = MeC 5 H 4 ); 22 and [(SmI 2 (thf) 4 )(μ-CO)(CpMo(CO) 2 )] (2.41(2) Å and 2.49(2) Å). 20 The lanthanide atoms are coordinated to two isocarbonyl ligands and two Cp* rings, resulting in a distorted tetrahedral coordination geometry.…”

“…1650 cm À1 in [(Tp Me,Me ) Sm(m-CO){Cp Me Mo(CO) 2 }]. 22 As a result of weak ligand eld splitting, Sm 3+ complexes exhibit a characteristic absorption pattern in the NIR spectrum even in the presence of strong visible absorption. 25,26 The spectrum obtained for 1a shows spectral patterns that are comparable to Sm 3+ /POCl 3 /ZrCl 4 (ref.…”

“…[(Cp* 2 -Yb)(m-CO) 2 Mn(CO) 3 ] 2 and [(Tp Me,Me ) 2 Sm(m-CO)(CpCr(CO) 2 )]. 16,22 Scheme 3 Synthesis of 4 and 5.…”

Unprecedented Transformation of a Hydrotris(pyrazolyl)borate Ligand at a Metal Center: Synthesis and Rearrangement of the First Mixed Tp/Cp Lanthanide Complex, Sm(TpMe2)2(Cp)

“…Given the demonstrated importance of steric factors in lanthanide chemistry, the design and use of alternatives to the C 5 Me 5 ligand have become an area of active investigation. , In this context, we 10 and Sella et al have initiated an extensive investigation into the synthesis and reactivity of hydrotris(pyrazolyl)borate (Tp R,R‘ ) anchored lanthanide(II) complexes. It was shown that Sm(Tp Me 2 ) 2 ( 1 ), despite its insolubility, undergoes one-electron-transfer reactions with a variety of reagents yielding soluble compounds which have proven amenable to structural characterization. , The compound is particularly suitable to isolate a series of Sm(Tp Me 2 ) 2 L derivatives, where L is the radical anionic form of the ligand (L = azobenzene, quinones, benzophenone, dioxygen).…”