New stereoregular cyclic polysilanols of the general formula [PhSi(O)OH]n (n = 6 and 12) have been selectively obtained in high yields by the reaction of cagelike oligophenylmetallasiloxanes with dilute solutions of hydrochloric acid at low temperatures. An alternative method was used to prepare cis-[PhSi(O)OH](4) from sodium phenylsiloxanolate, cis-[(Na(+))(4)[PhSi(O)O(-)](4)].(1-butanol)(x). All compounds were fully characterized by NMR and IR spectroscopy and molecular weight determinations. The structure of cis-[PhSi(O)OH](6) was confirmed by single-crystal X-ray analysis. Furthermore, a series of stereoregular cyclosiloxanes containing triorganylsiloxy groups at each silicon atom was prepared by the reactions of the cyclic polysilanols with triorganylchlorosilanes Me(3)SiCl, Me(2)ViSiCl, and Me(2)(CH(2)Cl)SiCl.
The reaction of anhydrous [12]crown-4 with a 1:1 ethanol adduct of the three-mercury anticrown (o-C 6 F 4 Hg) 3 (1) under Ar results in the formation of a double-decker sandwich complex {[(o-C 6 F 4 Hg) 3 ] 2 ([12]crown-4)} ( 4). The molecule of the crown ether in 4 is located between the mutually parallel planes of two mercury macrocycles and is coordinated to each of them through Hg-O secondary interactions. In the crown ether ligand, all four oxygen atoms are involved in the bonding to the molecules of 1, while in each anticrown species only two Hg centers take part in the coordination. If aqueous [12]crown-4 is used in the reaction with 1, the other double-decker sandwich, {[(o-C 6 F 4 Hg) 3 ] 2 ([12]crown-4)(H 2 O) 2 } (5), containing one crown ether molecule and two molecules of H 2 O in the space between the planes of the anticrown units, is produced. Every water molecule in this supramolecular aggregate is cooperatively bound through the oxygen atom by three Lewis acidic Hg sites of the neighboring anticrown, whereas one of the water protons forms the hydrogen bond with the oxygen atom of the crown ether. An additional contribution in the bonding is made by the interaction of one of the Hg centers of each anticrown unit with the nearest oxygen atom of [12]crown-4. The complex of analogous composition and close structure is formed in the reaction of 1 with aqueous [18]crown-6. However in this sandwich, {[(o-C 6 F 4 Hg) 3 ] 2 ([18]crown-6)(H 2 O) 2 } (6), both protons of each water species are involved in the formation of the H-bonds with the crown ether, while the bonding of each mercuramacrocycle to the crown ether is accomplished due to the coordination of two of its Hg atoms with two oxygen atoms of the crown compound. From the interaction of 1 3 EtOH with 1,3,5-trioxane, a 1:1 complex, {[(o-C 6 F 4 Hg) 3 ](CH 2 O) 3 } (7), having a cage structure, has been isolated. The synthesized adducts are the first complexes of crown ethers with an anticrown.
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