- Microporous thermosetting film constructed from hyperbranched polyarylate precursors containing rigid tetrahedral core: Synthesis, characterization, and properties
-
Porous organic thermosetting film with pore size smaller than 20 A was constructed through the self-cross-linking reaction from hyperbranched polyarylate precursors with rigid tetrahedral skeleton. Using hydroquinone diacetate as the A2 monomer
- Zhang, Bufeng,Wang, Zhonggang
-
-
Read Online
- Tetra-p-tolyl-Verbindungen p-Tol4Si und p-Tol4Ge: ein Beitrag zur Konfiguration der Tetraaryl-Methan-Analog Ar4M (M = C, Si, Ge, Sn, Pb)
-
p-Tol4Si and p-Tol4Ge have been obtained from the reaction of p-TolLi with SiCl4 and of p-TolMgBr with GeCl4, respectively.The crystal structures have been determined and compared with those of the homologous compounds p-Tol4Sn and p-Tol4Pb.The latter two
- Charisse, Michael,Roller, Stefan,Draeger, Martin
-
-
Read Online
- Central-atom size effects on the methyl torsions of group XIV tetratolyls
-
The Group XIV tetratolyl series X(C6H4-CH 3)4 (X=C, Si, Ge, Sn, Pb) were studied by using inelastic neutron scattering to measure the low-energy phonon spectra to directly access the methyl-group torsional modes. The effect of increased molecular radius as a function of the size of the central atom was shown to have direct influence on the methyl dynamics, reinforced with the findings of molecular dynamics and contact surface calculations, based upon the solid-state structures. The torsional modes in the lightest analogue were found to be predominantly intramolecular: the Si and Ge analogues have a high degree of intermolecular methyl-methyl group interactions, whilst the heaviest analogues (Sn and Pb) showed pronounced intermolecular methyl interactions with the whole phonon bath of the lattice modes. Size matters! The size of the central atom in the Group XIV tetratolyls was shown to determine the solid-state structures courtesy of the effect that it has on the overall size of the molecules (see figure). Because the outer-most methyl groups enter into close intermolecular interactions (for the Si and Ge analogues), the structure is driven to lower symmetry; as a consequence, the smallest (C) and largest (Sn and Pb) analogues are isostructural. Copyright
- Ng, Maggie C. C.,Harper, Jason B.,Stampfl, Anton P. J.,Kearley, Gordon J.,Rols, Stephane,Stride, John A.
-
-
Read Online
- METHOD OF PREPARING A METAL ORGANIC FRAMEWORK
-
The present invention relates to a method of preparing a metal organic framework comprising metal ions and carboxylate ligands; the method comprises: reacting (i) a source of metal ions, with (ii) a carboxylic acid precursor of a the carboxylate ligands,
- -
-
Page/Page column 18; 19
(2015/12/11)
-
- The central atom size effect on the structure of group 14 tetratolyls
-
The tetraphenyl derivatives of the Group 14 elements are of great potential interest as supramolecular constructs in extended porous networks. The tetratolyl Group 14 compounds were synthesized by using a general reaction scheme involving the nucleophilic addition of an organometallic reagent to the electrophilic center of the Group 14 element. The tetrachloride derivatives were used for the synthesis of the silane, germane and stannane compounds. Sn(Tol)4 was found to have tunnel splittings much smaller than the minimum line width available on IN16, whereas the lighter analogues displayed a remarkable size effect of the central atom. The tunneling peaks were observed to persist up to around 30 K, before softening and extending into the limit of quasielastic diffusion in which the rotors undergo thermally excited rotation.
- Ng, Maggie C. C.,Craig, Donald J.,Harper, Jason B.,Van-Eijck, Lambert,Stride, John A.
-
supporting information; experimental part
p. 6569 - 6572
(2010/02/28)
-
- Two-dimensional lattice of superboats composed of silicon-centered tetrahedra
-
Four benzenecarboxylic acid groups attached to silicon, (4-CO2HC6H4)4Si, form an infinite two-dimensional pleated sheet in the solid state composed of cyclic units of 78 heavy atoms in the shape of a large boat-
- Lambert, Joseph B.,Zhao, Yan,Stern, Charlotte L.
-
p. 229 - 232
(2007/10/03)
-
- SELECTIVE REDISTRIBUTION REACTIONS OF ORGANOSILANES IN THE PRESENCE OF CHLOROPLATINIC ACID
-
Tetrasubstituted silanes of the general formula R2SiR'2 undergo redistribution reactions quite selectively in the presence of SiHCl3 and chloroplatinic acid.It is the smallest and seemingly the least hindered of the R groups on the tetrasubstituted silane which exchange most readily with a chloro group on trichlorosilane.
- Benkeser, Robert A.,Yeh, Ming-Hsiung
-
p. 239 - 244
(2007/10/02)
-