Tito Salvatori

The chemistry and the stereochemistry of poly(N-alkyl-iminoalanes) : I. Synthesis and physicochemical characterization of poly(N-alkyliminoalanes)☆

Abstract The structural features of poly( N -alkyliminoalanes) (PIA) and their dependence on the method of preparation as well as on the amine have been investigated. Different PIA have been synthesized from ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl and cyclohexylamine, and have been characterized by X-ray diffraction, mass spectrometry, 1 H and 13 C NMR. In general all the results agree with the formation of oligomers of-HAlNR-units, with three dimensional structures made up by four and six membered rings. In particular a cage structure has been found for (HAlN- iso -C 3 H 7 ) 6 by X-ray diffraction on a single crystal.

The chemistry and the stereochemistry of poly(N-alkyliminoalanes) : IX. Hexameric organoaluminum imides by reaction of (HAIN-iso-C3H7)6 with trialkylaluminums

Abstract (HAlN-iso-C 3 H 7 ) 6 reacts with Al(CH 3 ) 3 or Al(C 2 H 5 ) 3 to give compounds in which the hydridic hydrogens are partially or completely replaced by alkyl groups. The degree of alkylation depends on the reaction conditions and on the nature of the trialkylaluminum. Pure crystalline (CH 3 AlN-iso-C 3 H 7 ) 6 , its crystallization product with [(CH 3 AlN-iso-C 3 H 7 ) 5 (HAlN-iso-C 3 H 7 )] and a mixture of [(C 2 H 5 AlN-iso-C 3 H 7 ) 4 (HAlN-iso-C 3 H 7 ) 2 ] isomers have been isolated. The reaction of Al(CH 3 ) 3 or Al(C 2 H 5 ) 3 with iso-C 3 H 7 NH 2 gives tetramers (CH 3 AlN-iso-C 3 H 7 ) 4 and (C 2 H 5 AlN-iso-C 3 H 7 ) 4 .

The chemistry and the stereochemistry of poly(N-alkyliminoalanes) : VI. A novel synthesis of poly(N-alkyliminoalanes) by reaction of alkali metal alanates with primary amines

Abstract A novel synthesis of poly(N-alkyliminoalanes) (PIA) is reported. This involves the reaction in hydrocarbon solvents of LiAlH4 or NaAlH4 with primary amines having a nitrogen with α- or β- secondary carbon atoms or with tertbutylamine. Complexes of iminoalanes with alkali metal hydrides are obtained from linear amines. The same reaction carried out in polar solvents always gives complexes of PIA with LiH or NaH and the solvent. This new synthesis is simpler and convenient for producing soluble and well characterized PIA, some of which are not obtainable by other methods.

The chemistry and the stereochemistry of poly(N-alkyliminoalanes) : VII. The chlorination of poly(N-alkyliminoalanes)☆

Abstract Reactions of poly( N -alkyliminoalanes) (PIA) such as (HAlN-t-Bu) 4 , (HAlN-i-Pr) 4 , (HAlN-i-Pr) 6 and (HAlN-n-Pr) 8 with HCl, HgCl 2 and TiCl 4 have been investigated. Two reaction paths are observed which involve either the simple substitution of hydridic hydrogens with chlorine or the same reaction accompanied by the cleavage of AlN bonds with subsequent rearrangement of the molecular structure of the PIA. In both cases the reaction depends on the chlorination agent and the molecular features of the poly( N -alkyliminoalanes). Poly( N -alkyliminoalanes) have been obtained with partial and complete chlorination that include (ClAlN-t-Bu) 4 , (ClAlN-iPr) 4 , (ClAlN-i-Pr) 6 , which were separated as crystalline products and fully characterized.

The chemistry and the stereochemistry of poly(N-alkyliminoalanes) : XII. 1H-NMR features☆

This paper discusses the results of 1H-NMR studies of poly(N-alkyliminoalanes) prepared from various amines; in particular, the relationship between the NMR parameters and molecular structure is examined. Also, the effects of polar solvents and of partial or complete replacement of hydridic hydrogens by chlorine atoms and alkyl groups on characteristic features of the spectra are reported.

Synthesis and properties of poly(N-alkyliminoalanes) in tetrahydrofuran

Abstract A correspondence has been found between the conductimetric trends observed during the reaction of AlH3 with different primary amines and the structure of the resulting poly(N-aikyliminoalanes) (PIA). The conductivity measurements proved also to be effective in showing the formation of PIA having the same structural features from different synthetic methods as well as the interaction of PIA with AlH3.

The chemistry and stereochemistry of poly(N-alkyliminoalanes). XVII. The syntheses of poly(N-alkyliminoalanes) from dimethylamino- or methoxy-propylamines

Abstract 3-Dimethylamino-n-propylamine, 2-dimethylamino-isopropylamine and 3-methoxy-n-propylamine have been used to synthesize poly(N-alkyliminoalanes) (PIA) by different routes. These amines yielded PIA with open cage structures, in some cases even under the rather drastic conditions of direct synthesis from aluminum, amine and hydrogen. Reaction between LiAIH4 and mines gave open cage complexes with LiH.

Synthesis of N-(dimethylamino)propyliminodialanes

Abstract Stable new N-alkyliminodialanes [(CH 3 ) 2 N(CH 2 ) 3 N(AlH 2 ) 2 ] 2 ·THF and [(Ch 3 ) 2 NCH 2 (CH 3 )CHN(AlH 2 ) 2 ] 2 ·THF have been prepared from AlH 3 ·THF (or NaAlH 4 ) and the corresponding amine(or hydrochloride derivative). These products have been characterized principally by mass spectrometry.