Laser vaporization of metallic tin is used to generate Sn, molecules in effusive and supersonic expansions. Laser-induced fluorescence studies using isotopic samples of '"Sn established the correct vibrational numbering in the excited FO; and determined the Sn, molecular constants. From the convergence limit of the upper state the Sn, dissociation energy was determined to be 15 330*25 cm-', in good agreement with recent ab initio theoretical predictions.

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JV-Methyl-2-pyrrolidinone (NMP) is widely used in coal extraction. It has been shown that NMP is strongly retained in coal extracts and the retained NMP affects the character of the extracts. In order to calculate the actual extraction yield and understand the interaction between NMP and coal, the amount of NMP retained by its coal extracts must be quantified. TGA-FTIR has been applied to the quantitative analysis of NMP. Neutral aluminum oxide with 4.74% NMP added was used as a standard, and a linear calibration curve for the area of the NMP profile and the retained NMP weight was obtained. Several NMP-soluble coal extracts were tested by this method. The percentage of the NMP retained by these extracts varied from 1.08 to 3.40% with deviations ( = 2) within 0.25%. The detection limit can be as low as 5 µg with a S/N of 5 when the C=0 stretching band of NMP is used.

The triatomic oxide Al2O was prepared by oxidation of laser vaporized aluminum, or by direct vaporization of aluminum oxide, and detected by laser induced fluorescence. The fluorescence excitation and resolved emission spectra of a transition located near 38 249 cm−1 are consistent with a linear, centrosymmetric Al–O–Al structure. Analysis of the spectrum yields an AlO bond length of 0.164 nm and values of 525 (Σ+g), 99 (Πu), and 992 cm−1 (Σ+g) for the ground state fundamental vibrations, in good agreement with theoretical predictions.

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Aluminum is an element of considerable importance in chemistry and technology. Simple aluminum containing molecules, including Al2 dimer were therefore extensively studied, both experimentally1-3 and theoretically.4-8 While some theoretical studies and a previous gas phase study suggested a ground state of 3∑g symmetry, and some matrix studies claimed a 1∑ ground state, other theoretical works predicted an X 3πu ground state.