Heteroatomige Silicium‐Sauerstoff‐Achtringe – Sn₂O₄Si₂, ElO₄Si₃ (El  Si, Ge, P, As, Ti) – Synthese eines cyclischen Silylesters der Phosphorigen Säure

Abstract

Die Reaktion des dilithiierten Di‐tert.‐butylsilandiols mit Cl2SnMe2 führt im molaren Verhältnis 1:1 zur Bildung des 1,5‐Disila‐3,7‐distanna‐2,4,6,8‐tetraoxans (1). Das Dilithiumsalz des 1,1,5,5‐Tetra‐tert.‐butyl‐3,3‐dimethyltrisiloxans reagiert mit mehrfunktionellen Elementhalogeniden – Cl2SiMe2, GeCl4, PF3, AsF3, TiCl4 – glatt zu den achtgliedrigen 1‐Element‐3,5,7‐trisila‐2,4,6,8‐tetrasiloxanen – ElO4Si3 (2–6). Die Hydrolyse des PF‐haltigen Ringes führt zur Bildung des stabilen, cyclischen Silylesters der Phosphorigen Säure 7.

Hetero- and Metallasiloxanes Derived from Silanediols, Disilanols, Silanetriols, and Trisilanols

“…In contrast, the reaction of the dilithium salt 50 of a more sterically hindered disiloxanedisilanol 47 with TiCl 4 leads to the formation of the monocyclic titanasiloxane Cl 2 Ti(OSi(t-Bu) 2 OSiMe 2 OSi(t-Bu) 2 O] (53), leaving two unreacted chlorine atoms on titanium. 56 Reactivity of ZrCl 4 and HfCl 4 with the dilithium salt 48 in pyridine is different from the reactions of TiCl 4 . Thus, the reactions of MCl 4 (M ) Zr 55 or Hf 53 ) with 48 lead to the formation of complex cage structures Li 2 [M(OSiPh 2 OSiPh 2 O) 3 ]‚(py) 3 (54,55).…”

“…Additionally, X-ray diffracton studies of this compound revealed the presence of two pyridine molecules coordinated to the central titanium atom. In contrast, the reaction of the dilithium salt 50 of a more sterically hindered disiloxanedisilanol 47 with TiCl 4 leads to the formation of the monocyclic titanasiloxane Cl 2 Ti(OSi( t -Bu) 2 OSiMe 2 OSi( t -Bu) 2 O] ( 53 ), leaving two unreacted chlorine atoms on titanium 11

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“…The reactions of the dilithium salt 50 with the reactants containing dihalo functionality (Me 2 SiCl 2 , GeCl 4 , PF 3 , AsF 3 ) give rise to the cyclic siloxanes X n M[OSi(t-Bu 2 )OSiMe 2 OSi(t-Bu 2 )O] (67-70) respectively 56 (Scheme 17). These compounds contain eight-membered heterosiloxane rings.…”

Straightforward synthesis of novel cyclic metallasiloxanes supported by an N,C,N-chelating ligand

“…Synthesis of cyclo-Ph 2 Si(OSnL(Ph)O) 2 SiPh 2 (5). A solution of 1 (209 mg, 0.47 mmol) in CH 2 Cl 2 (20 mL) was added to a stirred solution of Ph 2 Si(OH) 2 (101 mg, 0.47 mmol) in CH 2 Cl 2 (10 mL) at room temperature.…”

“…4 The importance of cyclo-siloxanes for the production of polysiloxanes initiated activities concerning the synthesis, structural characterization and reactivity of cyclo-metallasiloxanes. The first example of such tin-containing species, namely cyclo-t-Bu 2 Si(SnMe 2 O) 2 Sit-Bu 2 , was prepared by Klingebiel et al 5 in 1986, but it was not completely characterized. In 1997, the syntheses and molecular structures of the cyclo-stannasiloxanes cyclo-t-Bu 2 Sn(OSit-Bu 2 ) 2 O (A) and cyclo-t-Bu 2 Si(OSnt-Bu 2 O) 2 Sit-Bu 2 (B) (Fig.…”