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

Abstract

Cyclopentyl substituted silanetriol can be prepared and isolated. Its condensation yields the corresponding disiloxanetetrol as a primary condensation product. Further condensation leads to the hexameric polyhedral silsesquioxane cage T 6 . The latter has been mentioned in the literature before however, lacking structural data. All compounds have been characterized with multinuclear NMR spectroscopy and, in addition, the molecular structures have been determined in the case of the disiloxanetetrol and the hexasilsesquioxane via single crystal X-ray diffraction.

Azido-Functionalized Aromatic Phosphonate Esters in RPOSS-Cage-Supported Lanthanide Ion (Ln = La, Nd, Dy, Er) Coordination

“…In comparison to the free ligands, the ν as (N 3 ) vibrations generally experience a slight shift to higher wavenumbers while the ν s (N 3 ) modes are mostly unaffected by the lanthanide ion coordination. The 29 Si NMR resonances of the protonated POSS cages can be found with a ratio of (31), Er (32)) crystallize in the monoclinic space group P2 1 /n (Figure 6). On the one hand, these compounds exhibit two terminal, 6-foldcoordinated Ln 3+ cations (Ln1) where each is exclusively coordinated by a T 7 (O − ) 3 cage, by the two T 6 (OH) 2 (O − ) 2 Hydrogens and phenyl substituents are omitted for clarity.…”

“…Herein, we present a modified procedure for the preparation of L1 as well as the synthesis of three new 4- or 4′-azido functionalized phosphonate ester ligands L2 – L4 comprising different aromatic backbones. In combination with our expertise in POSS (polyhedral oligomeric silsesquioxane)-cage chemistry, − these ligands are then applied in R POSS-cage-supported (R = i Bu, Ph) Ln 3+ ion coordination to function as anchor groups for future immobilization of these complexes on (In/Ga)P semiconductor surfaces and subsequent evaluation of their potential as optically switchable isolated molecular quantum bits. In this context, an azido functionalization at the 4- or 4′-position of L1 – L4 is expected to be the most suitable to avoid steric congestion between a semiconductor surface and the rest of the POSS-cage-supported complexes.…”

“…Er 2 {T 7 (O) 3 }{T 6 (OH) 2 (O) 2 }(μ 3 -OH)(L2)] 2(32) Average values are given for compounds with more than one molecule in the asymmetric unit or for more than one ligand of the same kind attached to a lanthanide ion.…”

Coordination Chemistry of Silicon

“…The conversion of this disilene into the corresponding potassium disilenide and its reactivity towards various electrophiles are also described. Von Hänisch's group discusses the incorporation of a disilane unit into crown ether, leading the preparation of 1,2-disila [18]crown-6, as well as 1,2-disila-benzo [18]crown-6 [17]. The complexation ability with ammonium cations by these disilane-containing crown ethers is examined, and corresponding complexes are successfully isolated.…”

“…The complexation ability with ammonium cations by these disilane-containing crown ethers is examined, and corresponding complexes are successfully isolated. Pietschnig and coworkers highlight the synthesis of cyclopentyl-substituted silanetriol and its condensation that leads to the isolation of corresponding disiloxanetetrol and also hexameric polyhedral silsesquioxane cage T 6 [18].…”