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Acids and Bases
Published in Michael B. Smith, A Q&A Approach to Organic Chemistry, 2020
Both BCl3 (boron trichloride) and AlCl3 (aluminum trichloride) are Lewis acids. Both boron and aluminum are in Group 13 of the periodic table. They can form three covalent bonds, using the three valence electrons, to generate a neutral molecule. These atoms can attain the octet only by accepting an electron pair from another molecule (a Lewis base). Therefore, both B and Al are electron deficient in these compounds. What is a Brønsted–Lowry base?
Al, 27]
Published in Alina Kabata-Pendias, Barbara Szteke, Trace Elements in Abiotic and Biotic Environments, 2015
Alina Kabata-Pendias, Barbara Szteke
Aluminum (Al) is a metal of the group 13 in the periodic table of elements. It is the third most abundant element in the Earth’s crust, occurring at about 8%, and up to 5% in soils. It reveals lithophile properties, and is common in both igneous and sedimentary rocks. In coal, its contents vary from 1.5% to >10%. Due to its low content, but important functions in plants and humans, it is included in the trace elements group.
Future of photovoltaic materials with emphasis on resource availability, economic geology, criticality, and market size/growth
Published in CIM Journal, 2023
G. J. Simandl, S. Paradis, L. Simandl
Gallium is a metal with atomic number 31 and atomic weight of 69.732. It is part of group 13 (Boron group) of the periodic table; it sits below Al, above In, to the right of Zn, and to the left of Ge. Its physical properties are similar to those of Al and In. Gallium is considered nontoxic in its elemental form and despite its low melting point (29.76 °C), it is safe to handle. Nevertheless, some Ga compounds are mildly toxic, and others are corrosive (e.g., gallium chloride). For an in-depth review of its toxicity and potential impacts on the environment, see Jabłońska-Czapla and Grygoyć (2021), Nguyen et al. (2020), and Nkuissi et al. (2020).
Mechanistic insight into water exchange and aqua/fluoride ligand substitution reactions on aqueous species of Al, Ga and In
Published in Journal of Coordination Chemistry, 2018
Xiao-Yan Jin, Hui-Quan Li, Zheng-Jie Huang, Xue-Yue Jiang
Aluminum, gallium, and indium possess similar properties since they all belong to group 13 in the periodic table. For example, they can exist in the form of octahedral hexaqua cations M(H2O)63+ (M = Al, Ga, In) in aqueous solutions and the high charge of +3 prompts the cations or its hydrolyzed species to polymerize, ultimately forming a variety of hydroxide polyoxocations [5–13]. Among them, aluminum attracts more concern because of its abundance in the Earth’s crust and toxicity toward animals and humans. For years, a series of hydroxyl/aquaaluminum polyoxometalate species, such as Al2(OH)2(H2O)84+ [14], Al4(OH)6(H2O)126+ [15], Al8(OH)14(H2O)1810+ [16], Keggin-[AlO4Al12(OH)24(H2O)12]7+ [17] and Flat-[Al13(OH)24(H2O)24]15+ [18–20], has been synthesized and characterized. With respect to the aluminum monomer and the most commonly observed Keggin-[AlO4Al12(OH)24(H2O)12]7+, simple ligand substitution reactions (water exchange and aqua/fluoride substitution) have been investigated by many experimental and theoretical techniques [21–29], and the activities of bound water molecules as well as the mechanism of substitution reactions were revealed. However, the mechanism of the ligand substitution reactions on other aluminum species is not clear. In the case of gallium and indium, despite abundance in nature less than aluminum, they are key components for III/V semiconductors and hydroxide polymeric gallium and indium nanoclusters are regarded as precursors for indium–gallium-oxide (IGO) thin films [30]. A few studies have reported on facile synthesis and characterization of hydroxide polymeric Ga13-xInx (0 ≤ x ≤ 6) [30–33]. However, mechanistic exploration of the ligand substitution reactions is difficult experimentally due to the instability of clusters in aqueous solutions. In this case, theoretical calculation is a powerful tool for the ligand substitution mechanism of polymeric gallium and indium clusters, which is helpful to recognize the bond making or breaking on the molecular scale. Moreover, the rich experimental data on the ligand substitution reactions of monomeric aluminum and Keggin-Al13 guarantee the appropriateness of theoretical methods. Both molecular cluster method and molecular dynamics simulation are the common theoretical methods for mechanistic attribution. The former can approximately give the real situation of atoms and attribute the mechanisms according to the obtained Gibbs-free energies, and molecular dynamics simulation can differentiate mechanism by the coordination number and free energy computation in light of the residence time.