Nikolay N. Zemlyansky

New stable germylenes, stannylenes, and related compounds 7. Synthesis and structures of compounds Hal—Sn—OCH2CH2NMe2 (Hal = Cl or F)

New stable divalent tin derivatives containing no bulky substituents at the metal atom, Hal—Sn— OCH2CH2NMe2 (Hal = Cl or F), were synthesized, and their crystal structures were studied by X-ray diffraction. Unlike the analogous monomeric divalent germanium derivative Cl—Ge—OCH2CH2NMe2, the new compounds are centrosymmetric dimers formed via two intermolecular Sn←CO coordination bonds.

X-ray diffraction study of the first monomeric dioxygermylene Ge(OCH2CH2NMe2)2 stabilized by two Ge ← N intramolecular coordination bonds: The influence of Ge ← N intramolecular coordination bonds on the structure and packing of molecules in crystals

The molecular and crystal structures of the first monomeric dioxygermylene Ge(OCH2CH2NMe2)2 (I) stabilized by two Ge ← N intramolecular coordination bonds are determined by X-ray diffraction analysis. The Ge ← N bond lengths in two independent molecules are equal to 2.329(2), 2.337(2) and 2.324(2), 2.346(2) Å, respectively. The central germanium atom plays the role of a spiro atom between two five-membered heterocycles in the envelope conformation and adopts a trigonal-bipyramidal configuration with a lone electron pair in the equatorial position. Compound I has two planar-chiral isomers which crystallize jointly. Molecules in the crystal have a layered packing (molecular layers are perpendicular to the [001] direction) composed of four translationally independent equivalent layers. These layers are spaced at 1/4c intervals and displaced with respect to each other by approximately +0.35a, −1/4b, −0.35a, and +1/4b, respectively. The characteristic displacement of the layers and their proper symmetry (pba2) that differs from the symmetry of the crystal (space group P212121) determine a large variety of pseudosymmetry operations.