| Abstract
| - The syntheses and molecular structures of a number of terphenyl-based samarium compounds vis-a-vis a dianionic ligand system, i.e. the COT dianion (COT = cyclooctatetraene), are reported. Shown is the molecular structure of DanipSm(THF)COT (Danip = 2,6-di(o-anisol)phenyl) in which the terphenyl ligand adopts the meso form.
- The syntheses and molecular structures of a number of terphenyl-based compounds of the lanthanide elementsamarium are reported. Reaction of 2 equiv of DppLi (Dpp = 2,6-diphenylphenyl) with 1 equiv of SmCl3 intetrahydrofuran at room temperature yields (Dpp)2SmCl(μ-Cl)Li(THF)3 (1). The one-pot reaction of 1 equiv of K2COT (COT2- = cyclooctatetraenyl dianion) with 1 equiv SmCl3 in tetrahydrofuran at room temperature followed byaddition of 1 equiv of terphenyllithium salt DppLi, DmpLi (Dmp = 2,6-dimesitylphenyl), or DanipLi (Danip = 2,6-di(o-anisol)phenyl) produces DppSmCOT(μ-Cl)Li(THF)3 (2), DmpSm(THF)COT (3), and DanipSm(THF)COT (4),respectively. In the case of the Danip-based compound 4 the order of addition of reagents can be reversed producingthe same compound, however, in considerably lower yield. Compound 2 can also be prepared by reaction of 1 with1 equiv of K2COT in tetrahydrofuran. The molecular structure of the bis(terphenyl) compound 1 exhibits a formallyfour-coordinate metal atom. The molecular structures of the terphenyl COT compounds 2−4 feature monomericcomplexes which are obtained either as a lithium chloride adduct (2) or as tetrahydrofuran adducts (3, 4). In 4 theDanip ligand adopts the meso form.
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