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Highlights: [•] The glass transition point of PVC was advanced by addition of FeCl2. [•] FeCl2 caused an earlier degradation and a more effective degradation of PVC. [•] FeCl2 changed the degradation products of PVC. [Copyright &y& Elsevier]

Abstract: The thermal behaviors of homologues, derivatives and adducts of β-cyclodextrin (β-CD) are compared based on thermogravimetry (TG) and gas chromatography coupled to time-of-flight mass spectrometry (GC–TOF-MS) analysis. Our results indicate that the number of glucose units and the introduced groups cause a considerable change in thermal decomposition mechanisms of these carbohydrates. Further, it is observed that the mass loss of the bicomponent aggregate formed by phenylarsonic acid (PAA) and β-CD is larger than that of each of the components at higher temperatures. Additionally, the decomposition of the adduct produces a series of arsenic compounds with high relative abundances, such as AsO+, As2O2 +, As3O4 + and As4O6 +, which is rather different from the decomposition behaviors of free PAA and the adduct of β-CD with sodium arsenite. [ABSTRACT FROM AUTHOR]

Abstract: The second-sphere interactions between ferrocene (Fc, guest) analogs and cyclodextrins (CD, host) have attracted sufficient attention in the past decades. However, there are some unanswered questions related with the interactions. For example, how such interactions are reflected by the thermal decomposition process? The present report describes our efforts to elucidate the correlation between the destruction of a second-sphere complex through the release of its members and the separate destruction of its members by a direct sample introduction device with programmed temperature in a gas chromatography coupled to time-of-flight mass spectrometry. Different kinds of mass spectra are analyzed to elicit accurate details about sample decomposition processes. It is found that on the one hand, the presence of Fc effectively delays the decomposition temperature of the complexed β-CD though a great part of Fc has been released from the complex. On the other hand, the special molecular structure of β-CD has served to prevent the sublimation of Fc to a certain degree. Furthermore, the thermal decomposition mode of the β-CD molecules complexed by Fc is drastically changed compared with that of free β-CD. Also, this study provides a paradigm that ferrocene decomposes in the β-CD cavity through the release of a CpFe+ moiety, and the remaining Cp ring remains contained in the host. [Copyright &y& Elsevier]