The Cobalticinium Cation [Co^III(η⁵‐C₅H₅)₂]⁺: A metal‐organic complex as a novel template for the synthesis of clathrasils

Abstract

The cobalticinium cation [ C O "~(~~-C~H~)~] +

SSZ-23: An Odd Zeolite with Pore Openings of Seven and Nine Tetrahedral Atoms

“…The former is probably due to the presence of a very small number of connectivity defects, in agreement with the lower than expected F À ion content. The latter appears in the region expected for pentacoordinated Si atoms: SiO 4 F units in the clathrasil framework structure nonasil (NON) [10] resonate at about d À 144 (SiÀF ca. 1.8 ± 1.9 ), while in TPAF-silicalite a broad hump very similar to the one shown here appears in the region d À 115 to À 135.…”

Computational Study of 19F NMR Spectra of Double Four Ring‐Containing Si/Ge‐Zeolites

“…So far, three general fluoride environments have been reported in pure silica zeolites: 1) Price et al [20] localise F À ions in close proximity to the charged structure-directing agent (SDA) as an ion pair in the main void volume of zeolite, although this result is subject to some controversy, [21] 2) the F À ions are separated from the SDA and are located inside small cages in the zeolite framework, but are not coordinated to any framework atom, [22] and 3) inside small cages but coordinated to a Si atom forming a pentacoordinated [SiO 4/2 F] À unit. [18] Several Si-zeolites such as octadecasil, [22] Ge-zeolites such as ASU-9 [23] and Si/Ge-zeolites [24][25][26] synthesised by the F À route contain the F À ion inside a small cage formed by eight tetrahedral atoms named [4 6 ] [27] or D4R (double four ring) unit, where no pentacoordinated silicon exists and the anion is reported to be in the cavity centre. This unit contains eight tetrahedral atoms that can be Si or Ge.…”

“…Second, it works as a catalyst in the condensation reactions that lead to the formation of SiÀOÀSi bonds. [5,9] Computational techniques, [10,11] NMR spectroscopy [12][13][14][15][16] and X-ray diffraction [9,[17][18][19] have been used to find the location of the fluoride in zeolites. So far, three general fluoride environments have been reported in pure silica zeolites: 1) Price et al [20] localise F À ions in close proximity to the charged structure-directing agent (SDA) as an ion pair in the main void volume of zeolite, although this result is subject to some controversy, [21] 2) the F À ions are separated from the SDA and are located inside small cages in the zeolite framework, but are not coordinated to any framework atom, [22] and 3) inside small cages but coordinated to a Si atom forming a pentacoordinated [SiO 4/2 F] À unit.…”

Assembly of Zeolites and Crystalline Molecular Sieves

“…The energy stabilizations mostly arise from van der Waals interactions. Direct evidence for the effects of multiple weak interactions working cooperatively to stabilize an organic SDA is provided by Behrens et al 22 The single-crystal structure of [Cocp…”