Octamethyl-1,2,8,9-tetrasila

Figure 22 The structure of 2,2,4,4,6,6,8,8-octamethyl-2,4,6,8-tetrasila-l,5,-dimercuracyclo-octane...

C2oH3flP2Sia f 1,4-Diphenyl-2,2,3,3,5,5,6,6-octamethyl-1,4-diphospha-2,3,5,6-tetrasila-cyclohexane, 456, 752 C2oH4o05Si j 7,8,0-Isopropylidene-6,7,8-trihydroxy-2,2,5,7-tetrameth-yl-3-[ (trimethylsilyl)oxy]-4-decanone, 466, 336 C20H42N2P2S2f 1,2-Dicyclohexyl-1,2-bis(diethylamino-1,2-dithioxo-di-X -phosphane, 466, 682 C2oH4ftIP, Tetraamylphosphonium iodide, 356, 465... 

However, the organosilyl mercury compounds are more conveniently synthesized from haloorganosilanes and a large excess of a sodium amalgam. The sodium in this amalgam is very dilute, but the amount of amalgam used is such that equivalent molar amounts of sodium and halogen are present. In this way bis(trimethylsilyl)mercury [438] m.p. 104°C (Eq.3.232) and 2,2,4,4,6,6,8,8-octamethyl-2,4,6,8-tetrasila-l,5-dimercura-cyclooctane [438] (56% subl.p. 107°C at 0.013 Pa = 0.0001 m Hg). (Eq. 3.233) are made. 

The simple structures of THF-solvated 2,6-di(l-naphthyl)phenyllithium and 2,6-di(phenyl)phenyhithium have been reported to be respectively mono- and dinuclear. The solid-state structure of (DME Li)2C4(SiMc3)4 has recently been found to incorporate DME-chelated metal centres above and below a four-membered, flat cyclobutadienyl ring (within which mean O-C = 1.495 A). A similar structure has also been revealed for (DME Li)2C4Ph2(SiMe2CH2)2. The two electron reduction of 2,3-bis(dimethylsilyl)-l,l,4,4-tetramethyl-l,4-disila-1,4-dihydronaphthalene using elemental lithium affords a complex in which the two metal centres bridge an isolated C = C bond. In the same way, alkali metal ions reside above and below each of two C=C interactions in the tetrametal salt which results from the treatment of 2,3,6,7-tetrakis(trimethylsilyl)-l,l,4,4,5,5,8,8-octamethyl-1,4,5,8-tetrasila- 1,4,5,8-tetrahydroanthracene with Li(0). ... 

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