Chemistry of cyclopentadienyliron dicarbonyl dimer and ferrocene in zeolite Y cavities: anchoring organometallic fragments into microporous solids

Abstract

The intracavity chemistry of [CpFe(C0),I2 (1) and ferrocene in different acid forms of zeolite Y has been studied with EXAFS, in situ FTIR, and TPD-MS spectroscopies. Depending on the stoichiometry of zeolite protons vs the amount of starting complex 1, the complex is either oxidatively cleaved into CpFe(CO)3f ( 2 ) and CpFe' coordinated to the zeolite, or protonated to form dimeric [CpFe(C0)2]2H' (3). It is shown that the stability of all complexes is influenced by the intracavity concentration of the zeolite-bridged hydroxyl groups. The cationic monomer 2 is stable up to 500 K in the highly acidic zeolite host, whereas the protonated dimer decomposes above 400 K. At higher temperatures, all carbonyl ligands are split off from the iron complexes, and the remaining dominant fragments are identified as CpFe(OZ), (n = 2-3), bonded to the zeolite host structure via oxygen coordination. Similar fragments are formed upon thermal decomposition of ferrocene in the zeolite.

Preparation, spectroscopy, EXAFS, electrochemistry and pharmacology of new ruthenium(II) carbonyl complexes containing ferrocenylthiosemicarbazone and triphenylphosphine/arsine

“…In the analysis of the complexes 1, 4 and 5 the shell was determined at about 1.99-2.07Å corresponding to Fe-C backscatterers arising from the ferrocenyl unit. This value is in good agreement with the reported value [40]. The EXAFS results indicate the attachment of ten carbon atoms of both the cyclopentadienyl ligand to Fe centre.…”

Development of a Flexible Strategy towards FR900482 and the Mitomycins

“…The analogous surface complexes (SiO) 3 Ti(η 5 ‐C 5 H 5 ) and η 5 ‐CpFe(OZ) 2–3 (Z = Si, or Al) have been reported in the literature by grafting Cp 2 TiCl 2 to MCM‐41 and anchoring [CpFe(CO) 2 ] 2 to HY, respectively at 373–473 K 19b. 44 The calculated structures of this (SiO) 3 Ti(η 5 ‐C 5 H 5 ) intermediate were not, however, in agreement with the experimental EXAFS structure, and force field calculations suggested that the cyclopentadienyl ring is not exactly η 5 ‐bonded to Ti due to steric interactions of the ring with nearby silanols 45.…”

Inclusion of Organometallics in Zeolite Host Structures

“…Reactions of [CpFe(CO)2]2 [23], COTFe(CO)3 [24], CpFe(CO)2CH3 and ferrocene in different acid forms of zeolite Y are described in the following. …”