Aspects of the Chemical Energetics of Carbon–Aluminum Bonded Species

Abstract

The current chapter discusses the chemical energetics of carbon‐aluminum bonded species, both the “conventional” trivalent organoaluminum compounds such as monomeric Me 3 Al and its dimer and a variety of species of often surprising stoichiometry and structure. The study begins with the “simple” binary aluminum carbides, starting with AlC (neutral and ions). Incorporation of hydrogen leads to consideration of dimethylaluminum ionic compounds derived from the cationic [Me 2 Al] + and anionic [Me 2 AlO] − . Methyldialuminum species with one Al–Al bond and at least one Al–C bond, ranging from [Al 2 Me] + to [Al 2 Me 7 ] − , are then examined. The experimental enthalpies of formation, vaporization and dimerization of trialkylalanes are tabulated. The most recent enthalpy of formation value for Et3Al is used to recommend slightly revised enthalpies of formation for trialkylalanes and the related alkylaluminum hydrides and halides. The interplay of aluminum and aromaticity is reviewed in the context of aluminum rich rings and clusters, relatively classical heterocycles such as aluminoles, and binding of neutral and cationic monoatomic Al with aromatics. The chapter closes with a discussion of aluminum halide complexes of benzene and cyclobutadiene derivatives.

Steroids Bearing Heteroatom as Potential Drugs for Medicine

“…Aluminum (Al) is a paramagnetic metal known for its high thermal conductivity, electrical conductivity, and resistance to corrosion. When exposed to oxygen, aluminum forms a strong oxide film on its surface, which protects it from further interaction with the environment [275,276]. Although aluminum has various industrial applications, such as in construction, packaging, and electrical transmission lines, its incorporation into organic compounds, particularly steroids, is not a common occurrence.…”

“…Biological activities of steroids bearing tellurium atom(268)(269)(270)(271)(272)(273)(274)(275)(276)(277)(278)(279)(280) [260].Figure 44. 3D graph illustrating the predicted and calculated activity of steroids bearing tellurium atom (271, 272, 274, 275, and 294) with a maximum of over 96% confidence, which can be used to treat Alzheimer's, Parkinson's, and other neurodegenerative diseases.…”

Synthesis and biological activities of organoaluminum steroids

“…By using 5-cholestan-3-ol (1) as a starting, intermediate products (2, 3 and 4) were provided. Thespiro derivative (5), which contains a fragment of methylidenecyclobutane, was obtained by the olefination of ketone (4) with Ph 3 P = CH 2 . The reaction between methylidenecyclobutane spiro adduct (5) with Et 3 Al with Cp 2 ZrCl 2 as a catalyst gives cycloalumination of two independent molecules (6 and 7) which have the same structure of the cyclic system and differ only in the conformation.…”

“…Thespiro derivative (5), which contains a fragment of methylidenecyclobutane, was obtained by the olefination of ketone (4) with Ph 3 P = CH 2 . The reaction between methylidenecyclobutane spiro adduct (5) with Et 3 Al with Cp 2 ZrCl 2 as a catalyst gives cycloalumination of two independent molecules (6 and 7) which have the same structure of the cyclic system and differ only in the conformation. [16] Also, we reported that 2'methylidene-2',3'-ethano-(5)-cholestane (9) reacts with a threefold excess of Et 3 Al in the presence of 10 mol% of Cp 2 ZrCl 2 (5): (Et 3 Al:Cp 2 ZrCl 2 = 10:30:1, r.t., hexane, 8 h) giving rise to spiro[2',3'-ethano-(5)-cholestane-2',3''-aluminacyclo-pentane] (10) (scheme 1).…”

“…[3] Organoaluminum chemistry is part of the organometallic chemistry that studies the compounds of aluminum and carbon, as well as their chemical bonds (C-Al). [4][5][6] A large number of articles devoted to the study of organic compounds of aluminum have been published in the past almost two hundred years, the citation of which is not possible. However, it should be noted that the last 10 years have been published two monographs, which are devoted exclusively to the chemistry of organoaluminum compounds, and include the citation of previous publications.…”