(2,2-Bipyridyl)bis(η⁵-pentamethylcyclopentadienyl)strontium(II)

Abstract

In Cp* 2 Sr(bipy) the Cp* rings are completely staggered (see Fig. 1). Cg1 and Cg2 are the centroids of the rings defined by C1-C5 and C6-C10 respectively. The two pyridine rings in the bipyridine ligand are almost coplanar (the N-CC -N torsion angle is 2.2 (4)°). The least squares plane formed by the 12 atoms of the pyridine ring is tilted 10.7° relative to the plane formed by Sr,N1, and N2. This is larger than the equivalent angle in any other Cp* 2 M(bipy) in the Cambridge Structural Database (Allen, 2002). The closest is 5.1° in [Cp* 2 Yb(bipy)][Cp* 2 YbCl 2 ] (Schultz et al. 2002). The reason for this tilting is unclear as the Sr is d 0 and therefore electronic effects should be minor. At the same time it is unclear what steric reason could lead to this tilt. S2. Experimental Cp* 2 Sr(bipy) was prepared according to literature procedures (Burns and Andersen, 1987) S3. Refinement All non-hydrogen atoms were refined anisotropically. Hydrogen atoms were fixed based on the expected geometry of the carbon atoms to which they were attached. supporting information sup-2 Acta Cryst. (2008). E64, m1134 supporting information sup-9

Metalation of 2‐Quinolyl‐Linked (Boranophosphinoyl)methane −Alkali Metal, Alkaline Earth Metal, and Ytterbium(II) Complexes of Monoanionic [CH(iPr2P−BH3)(C9H6N‐2)]− Ligand

“…The Sr⋅⋅⋅B distances of 2.934(3)–3.112(3) Å in 8 are similar to the corresponding distances reported for (boranophosphinoyl)methanide complexes such as [[PhP(BH 3 ){CH(SiMe 3 )} 2 ]Sr(THF) 1.75 (OEt 2 ) 0.25 ] 2 [2.992(3) Å] and [[PhP(BH 3 ){CH(SiMe 3 )} 2 ] 2 Sr 3 K 2 (OEt 2 )(THF) 2 ] 2 ⋅Et 2 O [2.980(3)–3.028(3) Å] [21c] . The of Sr−N quinolyl bond distances [2.563(1) and 2.559(1) Å] are close to those of 2.624(3) and 2.676(3) Å reported for [Sr(C 10 H 15 ) 2 (C 10 H 8 N 2 )] [37] and 2.538(7) Å in Sr[N(SiMe 3 ) 2 ] 2 (DME) 2 [38] . The Sr(1)⋅⋅⋅C(10) [3.038(3) Å] and Sr(1)⋅⋅⋅C(26) [3.093(3) Å] distances in 8 are long, excluding any bonding between the Sr(II) ion and these carbon atoms.…”

“…No short contact between Ca(1) and C(10) was observable. The anionic charge delocalized onto the quinolyl ring and the phosphorous atom, leading to shorter C(9)À C(10) [1.378(3) Å] and P(1)À C(10) [37] and 2.538 (7) Å in Sr[N-(SiMe 3 ) 2 ] 2 (DME) 2 . [38] The Sr(1)•••C (10) C(25)À C(26) 1.395(3) Å, are comparable to the corresponding distances found in 3-8.…”

Alkaline-Earth-Metal-Induced Liberation of Rare Allotropes of Elemental Silicon and Germanium from N-Heterocyclic Metallylenes

“…Noteworthy is the rather acute bite angle of the chelating C 2 N 2 ligand (62.36°). The Sr–N1 and Sr–N2 bond lengths (2.7451(13), 2.7538(13) Å, respectively) are slightly longer in comparison to the only existing complex with which a meaningful comparison can be made: Sr­(η 5 -C 5 Me 5 ) 2 (κ 2 -{Bipy}) (Bipy = bipyridine), where Sr–N = 2.624(3) and 2.676(3) Å, respectively …”

Direct Synthesis of Pentaarylcyclopentadienyl Sandwich and Half-Sandwich Complexes of s-, p-, and d-Block Metals

“…weak intermolecular interactions similar to agostic interactions, and most importantly London dispersion-type H···H interactions between the methyl groups . While solid-state structures of donor-free Cp 2 Sr and Cp* 2 Sr have not been reported, many adducts of Cp* 2 Sr, which also form bent structures, have been studied. − …”