At the Edge of Stability – Preparation of Methyl‐substituted Arylsilanetriols and Investigation of their Condensation Behavior

Abstract

Abstract.A series of arylsilanetriols [Aryl-Si(OH) 3 , Aryl = 2,6-dimethylphenyl, 2,4,6-trimethylphenyl 2,3,5,6-tetramethylphenyl] with two, three, and four methyl groups at the phenyl ring was prepared from the corresponding trichlorosilanes. While the durene substituted silanetriol was formed exclusively, the other silanetriols were obtained together with their primary condensation products in a constant ratio 4:1. For the mesityl-substituted derivative an alternative synthetic ac-

Preparation and Molecular Structure of a Cyclopentyl-Substituted Cage Hexasilsesquioxane T6 (T = cyclopentyl-SiO1.5) Starting from the Corresponding Silanetriol

“…The resulting tetrahydroxydisiloxane 2 has been identified as primary condensation product and was characterized by NMR and IR spectroscopy, mass spectrometry and single crystal X-ray diffraction. The 29 Si-NMR chemical shift at −51.8 ppm in THF solution is in good agreement with the known chemical shifts of other alkylsubstituted disiloxane tetrols [14,16], resonating at slightly lower field compared with aryl substituted disiloxane tetrols [17,18]. Compound 2 could be obtained as single crystals suitable for X-ray diffraction as two polymorphs, one crystallizing in a monoclinic, the other in an orthorhombic crystal system both confirming the constitution of 1,3-di-cyclopentyl-1,1,3,3-tetrahydroxysiloxane.…”

“…All four OH groups in orthorhombic 2 are equivalent by symmetry and are involved in two hydrogen bonds [O2···O2′ 2.670(2)Å, O2-H3···O2′ 169(2)°; O2···O2″ 2.678(2)Å, O2-H2···O2″ 172.5(19)°] forming two-dimensional aggregates, in which each molecule is connected to six neighbors, showing a two-dimensional closest packing almost identical to monoclinic 2 ( Figure 2). In addition, the supramolecular hydrogen bonding the bond distances and angles of the central RSi(OH)2O-units are in the typical range of such disiloxanetetrols [14,[16][17][18][19][20]. Prolonged condensation of 1 in THF over five months resulted in a mixture containing mainly disiloxane 2 and the corresponding hexasilsesquioxane 3 in a 2:1 ratio.…”

Synthesis, structure and catalytic properties of bis[2‐(trifluoromethyl)phenyl]silanediol

“…The C─Si─C and C─Si─Cl bond angles in 1 are comparable with those in other dichlorosilanes, while the Cl─Si─Cl bond angle of 105.74(3)° is the smallest of these. As in other CF 3 ‐substituted aryldichlorosilanes,[6a] the Si─Cl bond lengths of 2.0483(8) and 2.0536(8) Å are slightly shorter than those in non‐perfluoro‐substituted aryldichlorosilanes [6a,8]…”

The Syntheses and Crystal Structures of the First Disiloxane‐1,3‐dithiol and Its Cadmium Complex

“…[8][9][10][11][12][13][14][15][16][17][18][19] More-peculiar compounds such as six-coordinate silicon complexes with sulfur ligands and increased stability in the presence of water have also been reported. Such protection allows the isolation of relatively stable, molecular compounds with -OH/SH functional groups attached directly to silicon atoms.…”

“…[32] The luminescence and magnetic properties of metal complexes with soft silanethiolate ligands have also been studied. [18,19,[71][72][73] The application of sterically expanded terpenyl substituents has recently allowed the isolation and characterization of an unusual twocoordinate silylene with two Si-S bonds. [36][37][38][39][40] Sulfur analogs of Si-O species include cyclosilthianes, [7,[41][42][43][44][45][46][47][48] silanethiols (characterized mainly as their metal salts), [8,15,16,[36][37][38][39][40][49][50][51][52][53][54][55][56][57][58][59][60] silanedithiols, [14,61,62] silyl sulfides, [63][64][65] di-and polysulf-ides, [66][6...…”