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Studies on the reactivity of zinc alkyl compounds towards SO2 are relatively less explored than either oxygenation or hydrolysis reactions. We report on the environmentally friendly and efficient syntheses of a homologous series of [(RSO2)ZnR]n complexes from reactions involving homoleptic R2Zn (R = Me, tBu, Ph) compounds and SO2. Diffusion ordered spectroscopy experiments indicate that the resulting compounds predominately occur as solvated dimers, [(RSO2)ZnR(THF)]2, in THF solution irrespective of the character of the group bonded to the zinc centres. In turn, these organozinc sulfinates exhibit structurally diversified molecular and supramolecular arrangements in the solid state, as evidenced by single-crystal X-ray diffraction studies. The methyl compound crystallises as a one-dimensional polymer, [(MeSO2) ZnMe]n, and the use of tBu2Zn and Ph2Zn leads to molecular aggregates, a tetramer [(tBuSO2)ZntBu]4, and a solvated [(PhSO2)ZnPh]2·2THF dimer, respectively. In addition, new theoretical insights have been gained by modelling the direct trapping of homoleptic organozinc compounds with SO2 using DFT calculations. [ABSTRACT FROM AUTHOR]

Alumoxanes are typically produced via controlled hydrolysis of short-chain alkyl aluminium compounds which leads to oligomeric species that are usually difficult to obtain in crystalline form. Simultaneously, various alternative non-hydrolytic approaches to alumoxanes have also been used. In this work, we report on a new methylalumoxane scaffold derived from the alkylation of a series of dicarboxylic acids: itaconic acid (HO2CCH2C(=CH2)CO2H), succinic acid (HO2CCH2CH2CO2H) and homophthalic acid (HO2CCH2C6H4CO2H). The reactions of AlMe3 with a selected dicarboxylic acid in the molar ratio 4:1 conducted at elevated temperature occur with double methylation of each carboxylic group and provide to the formation of a new methylalumoxane aggregate, Me10Al6O4, flanked by methylaluminium diolate units. We also aimed to obtain dialkylaluminium derivatives of dicarboxylic acids by the controlled reaction of the appropriate acid with AlMe3 in the 1:2 stoichiometry. While the synthesis of organoaluminium derivatives of flexible aliphatic dicarboxylic acids (itaconic and succinic acids) is challenging due to their insolubility, the related homophtalate compound readily forms a molecular tetranuclear cluster, [(homophtalate)(AlMe2)2]2. The molecular and crystal structures of the resulting compounds were determined via NMR spectroscopic analysis and single crystal X-ray diffraction crystallography., (© 2024 Wiley‐VCH GmbH.)

Among numerous catalysts in the ring-opening copolymerization of epoxides with carbon dioxide (CO 2 ), zinc dicarboxylate complexes are the most common type, and in the family of metal-based homogeneous catalysts, zinc and magnesium complexes have attracted widespread attention. We report on the synthesis and structural characterization of a zinc-magnesium benzoate framework templated by the central hydroxide anion with μ 3 -κ 2 :κ 2 :κ 2 coordination mode, [ZnMg 2 (μ 3 -OH)(O 2 CPh) 5 ] n ( n = 1 or 2). The resulting heterometallic system forms stable Lewis acid-base adducts with tetrahydrofuran (THF) and cyclohexene oxide (CHO), which crystallize as the hexanuclear zinc-magnesium hydroxide carboxylate cluster [ZnMg 2 (μ 3 -OH)(O 2 CPh) 5 (L) 2 ] 2 (L = THF or CHO). Their X-ray crystal structure analysis revealed that the Zn center prefers 4-fold coordination and the Mg centers demonstrated the ability to accommodate higher coordination numbers, and as a result, the heterocyclic molecules are exclusively bonded to 6-fold Mg atoms. The heteronuclear carboxylate aggregates appeared active in the copolymerization reaction at elevated temperatures to produce an alternating poly(cyclohexene carbonate).

Studies on the reactivity of zinc alkyl compounds towards SO 2 are relatively less explored than either oxygenation or hydrolysis reactions. We report on the environmentally friendly and efficient syntheses of a homologous series of [(RSO 2 )ZnR] n complexes from reactions involving homoleptic R 2 Zn (R = Me, t Bu, Ph) compounds and SO 2 . Diffusion ordered spectroscopy experiments indicate that the resulting compounds predominately occur as solvated dimers, [(RSO 2 )ZnR(THF)] 2 , in THF solution irrespective of the character of the group bonded to the zinc centres. In turn, these organozinc sulfinates exhibit structurally diversified molecular and supramolecular arrangements in the solid state, as evidenced by single-crystal X-ray diffraction studies. The methyl compound crystallises as a one-dimensional polymer, [(MeSO 2 )ZnMe] n , and the use of t Bu 2 Zn and Ph 2 Zn leads to molecular aggregates, a tetramer [( t BuSO 2 )Zn t Bu] 4 , and a solvated [(PhSO 2 )ZnPh] 2 ·2THF dimer, respectively. In addition, new theoretical insights have been gained by modelling the direct trapping of homoleptic organozinc compounds with SO 2 using DFT calculations.

The distinct research areas related to CO 2 capture and mechanochemistry are both highly attractive in the context of green chemistry. However, merger of these two areas, i.e. , mechanochemical CO 2 capture, is still in an early stage of development. Here, the application of biguanidine as an active species for CO 2 capture is investigated using both solution-based and liquid-assisted mechanochemical approaches, which lead to a variety of biguanidinium carbonate and bicarbonate hydrogen-bonded networks. We demonstrate that in solution, the formation of the carbonate vs bicarbonate networks can be directed by the organic solvent, while, remarkably, in the liquid-assisted mechanochemical synthesis employing the same solvents as additives, the selectivity in network formation is inversed. In general, our findings support the view of mechanochemistry not only as a sustainable alternative but rather as a complementary strategy to solution-based synthesis., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Simple RZnOR' alkoxides are among the first known organozinc compounds, and widespread interest in their multifaced chemistry has been driven by their fundamental significance and potential applications including various catalytic reactions. Nevertheless, their chemistry in solution and in the solid state remains both relatively poorly understood and a subject of constant debate. Herein, the synthesis and structural characterization of long-sought structural forms, a roof-like trimer [(tBuZn) 3 (μ-OC(H)Ph 2 ) 2 (μ 3 -OC(H)Ph 2 )] and a ladder-type tetramer [(PhZn) 4 (μ-OC(H)Ph 2 ) 2 (μ 3 -OC(H)Ph 2 ) 2 ], incorporating diphenylmethanolate as a model alkoxide ligand, are reported. Both novel aggregates are robust in the solid state and resistant towards mechanical force. By using 1 H NMR and diffusion-order spectroscopy, it is demonstrated that new RZnOR' alkoxides are kinetically labile in solution and readily undergo ligand scrambling, such as in the case of Schlenk equilibrium. The elucidated key structural issues, which have remained undiscovered for decades, significantly advance the chemistry of RZnOR' alkoxides and should support the rational design of zinc alkoxide-based applications., (© 2020 Wiley-VCH GmbH.)