Synthesis, Crystal Structures, and Spectroscopic Properties of Novel Gadolinium and Erbium Triphenylsiloxide Coordination Entities

Abstract

In alkali metal and lanthanide coordination chemistry, triphenylsiloxides seem to be unduly underappreciated ligands. This is as surprising as that such substituents play a crucial role, among others, in stabilizing rare oxidation states of lanthanide ions, taking a part of intramolecular and molecular interactions stabilizing metal-oxygen cores and many others. This paper reports the synthesis and characterization of new lithium [Li4(OSiPh3)4(THF)2] (1), and sodium [Na4(OSiPh3)4] (2) species, which were later used in obtaining novel gadolinium [Gd(OSiPh3)3(THF)3]·THF (3), and erbium [Er(OSiPh3)3(THF)3]·THF (4) triphenylsiloxides. Crystal structures were determined for all 1–4 compounds, and in addition, IR, Raman, absorption spectroscopy studies were conducted for 3 and 4 lanthanide compounds. Furthermore, direct current (dc) variable-temperature magnetic susceptibility measurements on polycrystalline samples of 3 and 4 were carried out in the temperature range 1.8–300 K. The 3 shows behavior characteristics for the paramagnetism of the Gd3+ ion. In contrast, the magnetic properties of 4 are dominated by the crystal field effect on the Er3+ ion, masking the magnetic interaction between magnetic centers of neighboring molecules.

Low‐Coordinated Iron(II) Siloxide Complexes – Structural Diversity and Reactivity Towards O2 and Oxygen Atom Transfer Reagents

“…Preparation of Ph 3 SiONa, LNa : To a solution of NaH (86.8 mg, 3.61 mmol) (a previous report used NaOEt) [30] in thf (30 mL) a solution of triphenylsilanol, LH (1.00 g, 3.61 mmol, 1.0 equiv.) in thf (10 mL) was added dropwise via a syringe.…”

Structures and magnetic properties of two series of Schiff base binuclear lanthanide complexes

“…[55][56][57][58] For complex 3, the χ M T value gently declines to 13.05 cm 3 K mol À1 at 12 K, then goes down abruptly to 5.79 cm 3 K mol À1 at 2 K, attributing to intramolecular antiferromagnetic interactions of the Gd (III) ion. [59][60][61][62] The χ M T values for complexes 4-6 (Figure 3b) are 28.03 (4), 26.81 (5) and 15.67 (6) cm 3 K mol À1 at room temperature, which are also slightly lower than the theoretical values for two noninteracting Dy (III) (28.34 cm 3 K mol À1 ), Ho (III) (28.14 cm 3 K mol À1 ), and Gd (III) (15.78 cm 3 K mol À1 ) ions. Similar to complexes 1-3, with decreasing temperature, the χ M T value of complexes 4-6 gradually descend at a certain rate, followed by a rapidly decline before achieving their minimum of 18.41, 8.30, and 9.54 cm 3 K mol À1 at 2 K, respectively.…”