TY - JOUR
T1 - Ringerweiterung in spirocyclischen Germanium(II)‐di(phosphanyl)methanid‐Verbindungen durch Einschiebung von Schwefel und Selen in Germanium‐Phosphor‐Bindungen
AU - Karsch, Hans H.
AU - Baumgartner, Gustav
AU - Gamper, Siegfried
AU - Lachmann, Joachim
AU - Müller, Gerhard
PY - 1992/6
Y1 - 1992/6
N2 - Ring Expansion of Spirocyclic Germanium(II) Di(phosphanyl)methanide Complexes by Insertion of Sulfur and Selenium into Germanium‐Phosphorus Bonds Germanium in the intermolecularly stabilized germylene derivative Ge[C(PMe2)2(SiMe3)]2 (2a) is not oxidized by sulfur but the latter inserts 1 to 4 chalcogenide atoms into the Ge–P bonds of the four‐membered chelate (4/4‐) rings to give 4/5‐, 5/5‐, 5/6, and 6/6‐membered spirocycles Ge[C2(SPMe2)n(PMe2)4‐n(SiMe3)2] (n = 1–4: 4, 5a, 6, 7). Only 5a and 7 could be obtained in pure form, whereas compounds 4 and 6 with odd‐numbered chalcogenide atoms are only characterized in solution, where they exist in equilibrium with 2a and 5a or 5a and 7, respectively. All these molecules are fluctional in solution. 7 is also obtained from GeCl2 · dioxane and Li[C(SPMe2)2(SiMe3)]. The selenium compound Ge[C(SePMe2)(PMe2)(SiMe3)]2 (5b) is obtained from 2a and grey selenium in toluene. An X‐ray structure determination of 5b shows a distorted sphenoidal arrangement [approximate C2 symmetry of a spirocyclic germanium center within two five‐membered rings containing a nearly linear Se–Ge–Se unit (Ge–Se 2.712/2.769(1) Å)]. The angle PGeP is 95.9(1)°. A bonding model with a stereochemically non‐active electron lone pair at the formal germanium(II) center may account for this geometry. As byproducts in the sulfurization reactions, bis‐(phosphanyl)methane disulfides are also observed in certain cases, from which H2C(SPMe2)2 has been isolated in pure form and characterized structurally.
AB - Ring Expansion of Spirocyclic Germanium(II) Di(phosphanyl)methanide Complexes by Insertion of Sulfur and Selenium into Germanium‐Phosphorus Bonds Germanium in the intermolecularly stabilized germylene derivative Ge[C(PMe2)2(SiMe3)]2 (2a) is not oxidized by sulfur but the latter inserts 1 to 4 chalcogenide atoms into the Ge–P bonds of the four‐membered chelate (4/4‐) rings to give 4/5‐, 5/5‐, 5/6, and 6/6‐membered spirocycles Ge[C2(SPMe2)n(PMe2)4‐n(SiMe3)2] (n = 1–4: 4, 5a, 6, 7). Only 5a and 7 could be obtained in pure form, whereas compounds 4 and 6 with odd‐numbered chalcogenide atoms are only characterized in solution, where they exist in equilibrium with 2a and 5a or 5a and 7, respectively. All these molecules are fluctional in solution. 7 is also obtained from GeCl2 · dioxane and Li[C(SPMe2)2(SiMe3)]. The selenium compound Ge[C(SePMe2)(PMe2)(SiMe3)]2 (5b) is obtained from 2a and grey selenium in toluene. An X‐ray structure determination of 5b shows a distorted sphenoidal arrangement [approximate C2 symmetry of a spirocyclic germanium center within two five‐membered rings containing a nearly linear Se–Ge–Se unit (Ge–Se 2.712/2.769(1) Å)]. The angle PGeP is 95.9(1)°. A bonding model with a stereochemically non‐active electron lone pair at the formal germanium(II) center may account for this geometry. As byproducts in the sulfurization reactions, bis‐(phosphanyl)methane disulfides are also observed in certain cases, from which H2C(SPMe2)2 has been isolated in pure form and characterized structurally.
KW - Electron pair, „inert”
KW - Germanium(II) complexes
KW - Molecular fluctionality
KW - Phosphanylmethanide ligands
KW - Spiro compounds
UR - http://www.scopus.com/inward/record.url?scp=0000663740&partnerID=8YFLogxK
U2 - 10.1002/cber.19921250606
DO - 10.1002/cber.19921250606
M3 - Artikel
AN - SCOPUS:0000663740
SN - 0009-2940
VL - 125
SP - 1333
EP - 1339
JO - Chemische Berichte
JF - Chemische Berichte
IS - 6
ER -