Synthesis and anion binding properties of (thio)urea functionalized Ni(II)-salen complexes.

Salen ligands (salen = ,'-ethylenebis(salicylimine)) are well-known for their versatility and widespread utility in chelating metal complexes. However, installation of hydrogen-bonding units on the salen framework, particularly functional groups that require amine-based precursors such as (thio)ureas, is difficult to achieve without the use of protecting group strategies. In this report, we show that the phenylketone analog of salicyladehyde is a stable alternative that enables the facile installation of hydrogen bonding (thio)urea groups on the salen scaffold, thus imparting anion binding abilities to a metal salen complex.

Synthesis of (2,6-Diadamantyl Aryloxide) Ln(II) Complexes of Samarium, Europium, and Ytterbium and Their Ln(III) Precursors.

The syntheses of Ln(II) (aryloxide) complexes of Sm, Eu, and Yb have been examined with the bulky aryloxide ligand (OCH-2,6-Ad-4-Bu) [(OAr*); Ad = 1-adamantyl]. These Ln(OAr*)(THF) complexes were pursued for comparison with the (aryloxide) Ln(II) complexes [Ln(OAr*)] (Ln = La, Ce, Nd, Gd, Dy, and Lu), which have 4f5d electron configurations, and with 4f [Yb(OAr*)]. Although the Ln(II) chemistry of Sm, Eu, and Yb is often similar since they all adopt 4f electron configurations, their chemistry is surprisingly diverse with (OAr*).

Synthesis of Crystallographically Characterizable Bis(cyclopentadienyl) Sc(II) Complexes: (CHBu)Sc and {[CH(SiMe)]ScI}.

The synthesis of previously unknown bis(cyclopentadienyl) complexes of the first transition metal, i.e., Sc(II) scandocene complexes, has been investigated using CH(Bu) (Cp), CMe (Cp*), and CH(SiMe) (Cp) ligands.

Synthesis and Crystallographic Characterization of a Reduced Bimetallic Yttrium -Metallocene Hydride Complex, [K(crypt)][(μ-Cp)Y(μ-H)] (Cp = MeSi[CH(SiMe)-3]), with a 3.4 Å Yttrium-Yttrium Distance.

The reduction of a bimetallic yttrium -metallocene hydride was examined to explore the possible formation of Y-Y bonds with 4d Y(II) ions. The precursor [CpY(μ-H)(THF)] (Cp = MeSi[CH(SiMe)-3]) was synthesized by hydrogenolysis of the allyl complex CpY(η-CH)(THF), which was prepared from (CH)MgCl and [CpY(μ-Cl)]. Treatment of [CpY(μ-H)(THF)] with excess KC in the presence of one equivalent of 2.

Room-Temperature Stable Ln(II) Complexes Supported by 2,6-Diadamantyl Aryloxide Ligands.

The sterically bulky aryloxide ligand OAr* (OAr* = OCH-Ad-2,6Bu-4; Ad = 1-adamantyl) has been used to generate Ln(II) complexes across the lanthanide series that are more thermally stable than complexes of any other ligand system reported to date for 4fd Ln(II) ions. The Ln(III) precursors Ln(OAr*) () were synthesized by reacting 1.2 equiv of Ln(NR) (R = SiMe) with 3 equiv of HOAr* for Ln = La, Ce, Nd, Gd, Dy, Yb, and Lu.