Crystal structure of p-bis(dimethylhydroxysilyl)-benzene, a monomeric model of polytetramethyl-p-silphenylenesiloxane

p-Bis-(trimethylsilyl)benzene

“…The average of the aromatic C-C lengths is normal (1-388 A), the length of the pair parallel to the molecular axis being the shortest (1.376 A). In p-bis(dimethylhydroxysilyl)benzene (DMHSB) the C-C distance parallel to the long axis is larger (1.398 A) than the other four (average 1.377 A) (Alexander, Northolt & Engmann, 1967). In the trimethylsilyl group of PBTMSB, the average of the Si-C distances is 1.870 A, comparable with that found in other trimethylsilyl derivatives (e.g.…”

2,2'-(p-Phenylene)di-2-propanol

“…The averages of the aromatic and aliphatic C-C bond lengths are normal: 1-387 and 1.520A, respectively. In the benzene rings no significant differences exist between the bond lengths parallel to the long axes of the molecules and those inclined to these directions by about 60 °, in contrast to DHMSB, where the lateral bonds show considerable shortenings (Alexander, Northolt & Engmann, 1967). The structure of the title compound is very similar to that of DHMSB (Alexander, Northolt & Engmann, 1967), though no isomorphism exists between the two crystals.…”

“…In the benzene rings no significant differences exist between the bond lengths parallel to the long axes of the molecules and those inclined to these directions by about 60 °, in contrast to DHMSB, where the lateral bonds show considerable shortenings (Alexander, Northolt & Engmann, 1967). The structure of the title compound is very similar to that of DHMSB (Alexander, Northolt & Engmann, 1967), though no isomorphism exists between the two crystals. An essential difference is that in DHMSB each of the three molecules in the unit cell is located at a centre of inversion, so the asymmetric part consists of three half-molecules.…”

“…The aim of the structure determination was (a) a comparison of the structure with that of the Si-analogue compound 1,1'-(p-phenylene)bis(dimethylsilanol) (DHMSB), which is the monomer of disilanol type of poly[oxy(dimethylsilyl)-p-phenylene-(dimethylsilyl)] (Alexander, Northolt & Engmann, 1967), and (b) to obtain a key to the interpretation of the vibration spectra of PDHIPB (Zelei & Dobos, 1979). The sample was prepared by Dr B. Zelei in the Institute of Inorganic Chemistry of the Hungarian Academy of Sciences by the method of Mitin (1958).…”

Structure of cyclo-1,1',4,4'-bis(1,1,3,3-tetramethyl-1,3-disiloxanediyl)dibenzene

“…1. The structure is discussed in comparison with three closely related structures: p-bis(hydroxydimethylsilyl)benzene (II) (Alexander, Northolt & Engmann, 1967), 1,1,2,2, 9,9,10,10-octamethyl-1,2,9,10-tetrasila[2.2]-paracyclophane (III) (Sakurai, Hoshi, Kamiya, Hosomi & Kabuto, 1986) and p-bis(tetramethylsilyl)benzene (IV) (Menczel & Kiss, 1975). The Si to the phenyl-ring C bonds are in good agreement with their counterparts in (II), (III) and (IV).…”