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The electron ionization mass spectrometric behaviour of a new series of hafnocene and zirconocene diadamantanolates is discussed. They are also compared on the basis of mass-analyzed ion kinetic energy spectrometry. Fragmentation patterns of the complexes in question give relevant information on their gas-phase behaviour as MOJMC (M= Zr, Hf) precursors for metal-organic chemical vapour deposition.

The electron ionization mass spectrometric behaviour of a series of dimethylindium derivatives with piperidine, pyrrolidine, azetidine and methylaziridine were investigated. These data have been compared with data from mass-analysed ion kinetic energy spectrometry. Fragmentation patterns of the complexes in question give information relevant to their gas-phase behaviour as precursors for III-V semiconducting materials via metalorganic chemical vapour deposition.Design of new high technologies in semiconductor technique and optoelectronics is based on high quality films and coatings. It is possible to obtain these with a whole range of values for universal qualitative indices such as homogeneity, stability, and specific electro-physical characteristics using modem equipment for metal-organic chemical vapour deposition. On the other hand, for a precursor, chemical composition and structure play a cardinal role in the above process and therefore present a motivation for a constant search for new materials that are able to form functional films with predetermined properties. From this point of view the famous Russian physicist Abram Ioffe had already said, in 1957 'the potential of organometallic compounds is practically infinite both because of their multiformity and because of the possibility of predicting their decomposition pathways on the basis of their physicochemical properties considered together with fundamental chemical structure theory '.' In the light of the comments above, detailed mass spectrometric studies of organometallics became of extreme importance. Previously, these investigations were mainly directed towards the structural determination of new organic compounds, while our main goal is the elucidation of their behaviour and decomposition in the vapour phase. For these purposes we use mass-analysed ion kinetic energy (MIKE) spectroscopy to provide indispensable information to help predict the composition of products that are deposited from the vapour phase and for a better design of the deposition processes as well.The present paper deals with new dimethylindium imino derivatives which have recently attracted special attention as precursors for advanced N-based 111-V semiconducting materials. They exhibit promising optical and electronic properties and offer the possibility of fabricating alloys with a range of energy gap values from 2 to 6eV.2 Cyclic iminoderivatives of dimethylindium, in our opinion, possess several advantages with respect to classic alkylindium compounds due to a shielding effect of the aliphatic rings and the presence of a direct In-N bond.

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The electron ionization mass spectrometric behaviour of a new series of hafnocene and zirconocene dialcoholates is discussed. Deprotonized norborneol and 3-methyl-2-norbornanemethanol were used as lateral Ligands. These data are also compared to those of mass-analysed ion kinetic energy spectrometry. Fragmentation patterns of the complexes in question give relevant information on their gas-phase behaviour and on an influence of the ligand's structure on decomposition pathways as well.Development of co-ordination chemistry in the gas phase is one of the most promising methods for the solution of a number of problems related to modem techniques.' For example, deposition of inorganic films and powders by thermal decomposition of volatile co-ordination and organometallic compounds is of particular interest as a practical method in research in this area. Such processes, usually referred to as MOCVD processes, allow the generation of functional materials and coatings with a set of predetermined major properties, such as: corrosion, erosion and thermal protection, wear resistance, dielectricity and conductivity?Data about the pathways and mechanisms of thermal dissociation in the precursors used are needed for the further development of MOCVD technologies. In this case, mass spectrometry methods, in particular mass-analysed ion kinetic energy spectroscopy (MIKES), have proven to be the most informative methods and are widely used. They provide an opportunity to follow the rules of fragmentation as it function of the nature of both the central metal atom and the ligands.Organometallic compounds for use in MOCVD processes have to satisfy a set of suitability criteria with high voltatility together with enough thermal stability as principal riter ria.^ From this point of view, complexes of heavy transition metals with bulky mono-or polycyclic shielding ligands drew our special attention recently4 because of a particular interest in zirconium and hafnium oxides and carbides derived from precursors in the gas phase. The possibility of controlling both thermal decomposition passways and the chemical composition of the products obtained by changing the structure of the ligand or the organometallic molecule as a whole prompted us to undertake systematic studies of the mass spectrometric behaviour of a new family of zirconocene and hafnocene dialcoholates. Previously5 we have described the mass spectra of dicyclopentadienylhafnium derivatives, Cp,HfX,,where the X-ligands were deprotonated exo-and endonorborneols. Thus the investigation of analogous zirconium compounds and the related 3-methyl-2-norbornanemethanol derivatives of both Z r and Hf appeared to be expedient.