Silandiol

This common way of synthesis has to cope with the problem that the reaction is nearly uncontrollable because of polycondensation [1], Intermediates, e.g., chlorosilanols, cannot be proved or isolated. However, starting with the alkaline hydrolysis of fluorosilanes, halosilanols, silandiols, and aminosilanols can be prepared and stabilized by bulky groups. 

The same procedure works for the transformation of the ferrio-dichloro- and trichlorosilanes C5R5(OC)2FeSiCl2(R1) (R = H, Me R1 = Me, Cl) into the ferrio-silandiol 3 or ferrio-silantriols 4a,b. 

Similar reactions of the ferrio-silandiols and -triols afford the ferrio-trisiloxane, 16 or the iron-/tungsten-substituted tetrasiloxanes 17a,b respectively. 

Synthesis methods a, -oligodihydridedimethylsiloxanes were synthesized by the methods described in ref [11]. 1,3-tetramethyldisiloxane was obtained by hydrolysis of dimethylchlorinesilane [10], 1,5-trimethyltriphenyltrisiloxane has been synthesized by reduction of 1,5-dichlorine-1,3,5-trimethyltriphenyltrisiloxane with LiAlH4 [10], 1,5-tetra-methyl-3,3-diphenyltrisiloxane was obtained via interaction of (Me)2SiHCl with diphenyl-silandiol [7],... 

The synthesis of (Ph2Si0)8[A10(0H)]4 is performed by reaction of diphenyl-silandiol Ph2Si(OH)2 in diethyl ether with fert-butoxy alane (tBuO-AlH2)2.73 As may be seen from Eq. (1) the products of this reaction are, besides (Ph2SiO)8 [A10(0H)]4, dihydrogen and ferf-butanol.70... 

Polycondensations between silandiols yield straight-chain pol3Tners R... 

In a similar manner the ferriodihydridosilane 4b was converted to the corresponding silandiol 5b (Eq. 5). Unlike species A in Eq. 4 the trimetallosilane 6, which features a structure with a bridged Co2(CO)7 unit and a direct Co-Co bond, could be isolated and characterized [6]. The hydrolysis of 6 in diethyl ether forms the silanediol 5b in 72 % yield within 30 min. 

A tetrafluoro-functional eight-membered SiO ring is formed in the reaction of the dilithiated silandiol with tetrafluorosilane (e.g. as in Scheme 2). The structure of the product is represented by Fig. 5. 

Bianhydro-tris-fdibenzyl-silandiol] 16 1 535. CuH4404Sn, Dianhydro-tria-[dibenzyI-zinn< fflhytMxyd] IS 1532. 

---