Structural Studies of β‐Cyclodextrin and Permethylated β‐Cyclodextrin Inclusion Compounds of Cyclopentadienyl Metal Carbonyl Complexes

Abstract

[CpM(CO) n Cl] complexes with M = Fe (n = 2) and Mo (n = 3) have been immobilised in plain β-cyclodextrin (β-CD) and permethylated β-CD (TRIMEB) by methods tailored according to the stabilities and solubilities of the individual components. Four adducts were obtained with a 1:1 host/guest stoichiometry. The compounds were studied by powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), 13 C{ 1 H} CP/MAS NMR and FTIR spectroscopy. A comparison of the experimental powder XRD data for the TRIMEB/[CpMo-(CO) 3 Cl] inclusion compound with reference patterns re-

Cyclodextrins improve the antimicrobial activity of the chloride salt of Ruthenium(II) chloro-phenanthroline-trithiacyclononane

“…In these compounds, b-CD molecules are arranged in a cage packing mode, not much different from that found for pure b-CD, thus indicating that inclusion of the guest 2 has not significantly altered the structure of this host. This kind of packing, although seemingly surprising for bulky guests, was already observed for the compound b-CDÁ[CpMo(CO) 3 Cl] in a previous work (Braga et al 2006a).…”

“…Nevertheless, we found that it works particularly well for the methylated cyclodextrin, TRIMEB, due to its high solubility in these media. In fact, the same method has been previously successfully employed by some of us (Braga et al 2006a;Pereira et al 2007). The adduct b-CDÁ[Ru( [9]aneS 3 )phenCl]Cl (4) was prepared by co-dissolution in water/ethanol (50/50) followed by freeze-drying to obtain an orange microcrystalline solid.…”

“…The microcrystalline material present in this compound has the most intense reflections at 11.4, 12.5, 13.2 and 13.9 2h degrees; this set bears similarities to the reflections (at 7.7, 7.9, 8.4 and 8.6 2h degrees) found for TRIMEBÁ[CpMo(CO) 3 Cl], although shifted to higher angle. It is thus feasible that compound 3 features a molecular organization similar to that of the reference compound, in which the guest molecules are isolated from each other by the network of TRIMEB host molecules, arranged along the b axis in a zigzag mode to form distorted columns (Braga et al 2006a).…”

“…Cyclodextrins are water soluble cyclic oligosaccharides capable of forming inclusion compounds with a wide range of organic molecules, inorganic ions and metalloorganic species (Szejtli 1998;Saenger 1980). We have used CDs to encapsulate metal guests owing to these hosts' ability to improve guest properties such as luminescence, pharmaceutical activity or catalysis, showing that encapsulation of CpMo(CO) 3 Cl (Braga et al 2006a;Balula et al 2007) and CpMo(CO) 3 CH 2 CONH 2 (Braga et al 2006b) resulted in a markedly different catalytic activity.…”

New Aspects for Modeling Supramolecular Interactions in Vanadium Haloperoxidases: β‐Cyclodextrin Inclusion Compounds of cis‐Dioxovanadium(V) Complexes

“…[10] Moreover, CDs are known to bind organometallic complexes containing aromatic constituents and such encapsulated complexes often exhibit markedly different physical and chemical properties. [11] Nevertheless, only very few examples of such inclusion complexes reported in the literature have been successfully characterized by single-crystal X-ray diffraction. [12] We have recently reported the application of the N-salicylidene hydrazide ligand system for generating vanadium(V) complexes with a variety of functional groups attached to the ligand core.…”