Crystal and Molecular Structures of Octaisopropylcyclotetragermane, [(i-Pr)2Ge]4

Abstract

The crystal and molecular structures of octaisopropylcyclotetragermane, [(i-Pr)2Ge]4 have been determined by X-ray diffraction at room temperature. The triclinic structure was refined by the full matrix least-squares method to a final R = 0.049 for 5091 reflections. The Ge–Ge distances are in the range 2.47—2.48 Å. The Ge4 ring is nonplanar with a dihedral angle of ca. 17°. The Ge–Ge–C and C–Ge–C bond angles appear to bend away due to the steric repulsion of the isopropyl group.

Synthesis and Photochemistry of 1,2-Digermacyclohexa-3,5-dienes and Related Compounds

“…The dihedral angles and the Ge−Ge−C bond angles in 1a are largely distorted due to steric repulsion by the four phenyl groups. The Ge−Ge bond lengths of 1a and 2 are 2.39−2.40 Å, shorter than those of Ph 6 Ge 2 (2.437 Å) and cyclic polygermanes (2.45−2.48 Å). ,

1 ORTEP drawing of the molecular structure of 1a with atoms represented as 50% probability ellipsoids.

2 ORTEP drawing of the molecular structure of 2 with atoms represented as 50% probability ellipsoids.

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Small Inorganic Rings in the 21st Century: From Fleeting Intermediates to Novel Isolable Entities

“…The final entries in Table represent a collection of structurally authenticated cyclotetragermanes [R 2 Ge] 4 reported in the literature. ,− The photochemistry of octaisopropylcyclotetragermane, [ i Pr 2 Ge] 4 ( 553 ), was investigated recently by laser flash photolysis and accompanying trapping experiments. It was concluded from this study that the ring-opening of [ i Pr 2 Ge] 4 ( 553 ) occurs via a 1,4-biradical intermediate as neither free germylene [:Ge i Pr 2 ] nor the dimeric digermene [ i Pr 2 GeGe i Pr 2 ] could be detected in appreciable amounts, ruling out heterolytic Ge–Ge σ-bond cleavage pathways in this process …”

Germanium Organometallic Compounds: Classification and Analysis of Crystallographic and Structural Data

“…Four derivatives [310][311][312][313] havea tetragermanering. In Ge 4 (Bu) 4 CI 4 [310] theGe 4 ring is puckered with a dihedral angle of 21° between Ge(l)-Ge(3>Ge (2) and Ge(l)-Ge(3>Ge (2).…”

“…In Ge 4 (Pr) 8 [312] theGe 4 ring is non-planar with a dihedral angle of 17.5 between folded wings. The Ge-Ge distances are in jhe range 247 to 248 pm.…”