| Cluster is a relative steady microcosmic or sub-microcosmic congeries which is composed of several or even thousands of atoms or molecules through chemical or physical combining force. It has a lot of special structures and properties which are related to its size. And it acts as a bridge between molecule and condensed matter. Researches on clusters originated in 1970s', and then it drawn more and more attention of the scientists of various fields.The alcohol is a important kind of matter containing hydrogen bond, particularly, some simple monohydroxy-alcohol, such as methanol, ethanol and propanol, which are widely used in daily life. They not only can be used in each aspect of the life directly, but also can be used to compose some other organic matters. The research on clusters of monohydroxy-alcohol can be used as the gist to study some other complex alcohols.The present thesis attempts to study clusters of methanol, ethanol and l-propanol by using both laser MPI-MS and the molecular beam technology. Through analyzing the mass spectrums received from different wavelength of the laser beam, a conclusion is gotten that the ionization of clusters of methanol, ethanol and l-propanol undergoes a process of (2+1) resonance. Changing laser energy and the pressure of carrier gas in experiment, we find that the intensity of cluster ions first increases and then decreases as the increase of laser energy or the pressure of carrier gas. In the experiment, a new phenomenon is observed: the position of the peak of mass ions shifts when we change the laser delay time to the molecular beam and keep other conditions unchangeable. The reason is deduced to the voltage fluctuation on the extract electrode of TOF when ions are passing through the grating electrode and parts of them are being absorbed.Studing the typical MPI-MS of methanol, ethanol and l-propanol under the best experimental conditions, we find that the main series of cluster ions are(Ri,2,3OH)n H+ and (Ri,2,3OH)n (H2O)H+. Calculating some molecules, clusters and free radicals at the level of HF/STO-3G and B3LYP/6-31G++, we discover that the main reaction channel of (Ri,2,3OH)n H+contains proton transfer reaction and ion-molecule reaction in clusters. Through analyzing the energy of those ions, we educe that the structure of (Ri(2,3OH)n H+ is some shells around a core of ions, and (Ri^OH^ FT1" completed the first shell properly. Because of solvation, the series of (Ri,2,3OH)n (H20)H+ appear only after n>7. The thesis includes the following aspects:1. The introduction and literature review of cluster and hydrogen-bond cluster are provided. The methods of experiment and theoretical calculation about clusters are offered.2. Experimental equipments, methods and theoretical calculation.3. Study on MS of the alcohols. By changing the experimental conditions and analyzing all the factors which determine the formation of cluster ions, the best conditions in which the cluster ions are formed is obtained. The problem that the shift of the peaks position of mass ions when the laser delay time to the molecular beam is changed and other conditions are retained is explained.4. Reaction of alcohol clusters following multiphoton ionization. Through comparing theoretical calculation with experimental result, the reaction channels cluster ions and their constructs are analyzed.
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