Despite the long-standing history and remarkable stability of low-valent mercury compounds, their use in molecular reduction chemistry has remained largely unexplored. In particular, the ability of me...

The β-diketiminato calcium hydride dimer, [(BDI)CaH]2 (BDI = HC{(Me)CNDipp}2; Dipp = 2,6-i-Pr2C6H3), reacts with [ZnTMP2] in the presence of terminal alkynes to provide a structurally diverse series of heterobimetallic calcium–zinc acetylide derivatives. Reactions employing two equivalents of alkyne yield the dialkynyl(hydrido)zincates, [(BDI)Ca(μ-C≡CR)(μ-TMP)Zn(μ-H)]2 (R = nBu, Ph), which undergo ligand redistribution to afford the corresponding β-diketiminato calcium acetylides. Conversely, use of four equivalents of alkyne results in further substitution at zinc to provide the tetrakis(alkynyl)zincates, [(BDI)Ca(μ-C≡CnBu)2Zn(μ-H)]2 and [(BDI)Ca(μ-C≡CPh)2Zn(μ-C≡CPh)2Ca(BDI)]. In contrast, an attempt to synthesize a similarly higher order calcium zincate but containing differentiated alkynyl substituents, by reaction of [(BDI)Ca(μ-C≡CnBu)(μ-TMP)Zn(μ-H)]2 and PhC≡CH, provided [(THF)2Ca(μ-C≡CPh)3Zn(CH2Ph)]2, resulting from toluene activation and after addition of THF as the only identifiable product.

PhD Project - Fully Funded Phosphazene Stabilised Ylids as Ligands for Aluminium Catalysis at University of Greenwich, listed on FindAPhD.com

Alkali-metal benzyl complexes derived from toluene are known to vary their metal–ligand coordination mode as a function of the alkali-metal, with the metal transitioning from a typical σ bond to the anionic CH2 for lithium toward an interaction with the delocalized pi system of the aromatic ring as the metal gets larger and softer. Here, by switching to cumene, we report the charge-localizing effect of replacing the hydrogen atoms at the formally carbanionic carbon CH2 with electron-donating methyl groups in C(Me)2. NMR spectroscopic studies reveal competitive ring-metalation occurs, at the meta and para positions, alongside α-metalation on using an alkyl lithium base, with the meta- and α-isomers crystallographically characterized as a solvated dimer and monomer, respectively. Using Lochmann-Schlosser type base pairs to access the heavier alkali-metal complexes unveils only α-metalation. The presence of the methyl groups limits the variation in metal–ligand bonding, their electron-donating properties forcing the delocalization of the negative charge into the ring resulting in M-Ph interactions and sp2 hybridization at the formally deprotonated α-carbon regardless of the metal used. Considerable variation in aggregation state is observed with monomeric (Na), polymeric (K, Cs) and tetrameric (Rb) motifs identified in the solid-state.

Since the isomerization of C–C multiple bonds is a powerful strategy in organic synthesis, in this study we have investigated the isomerization upon metalation of 1-phenylpropyne with alkyllithium bas...

PhD Project - Sustainable Catalysis with Sb and Bi Pincer Complexes at The University of Manchester, listed on FindAPhD.com

We describe the synthesis of a phosphanyl-functionalized 1,3,5-triphosphabenzene that exhibits remarkably large indirect spin-spin coupling (432 Hz) between phosphorus-31 nuclei. The magnitude of this...

Nature Synthesis - Dynamic Al–Cd frameworks

Hidden catalysis plagues catalyst development and occurs when an impurity or species generated in situ facilitates the reaction instead of the intended catalyst. Current methods to identify hidden cat...

The reaction of [K(thf)0.33][Co(η4-cod)2] (E; cod = 1,5-cyclooctadiene) with 0.5 equiv of MgCl2 led to the isolation of the magnesium dicobalt complex Mg[Co(η4-cod)2]2 (1). Complex 1 forms a tight ionic complex in the solid state and in toluene solution due to electrostatic interactions between the Mg2+ cation and the [Co(η4-cod)2]− anions. The complex is a successful precatalyst for the hydrogenation of sterically challenging tri- and tetra-substituted alkenes, surpassing the catalytic capabilities of related alkali metal and β-diketiminate magnesium complexes.

Previous studies have hinted at the similarities of Mn(II) and Mg alkyl complexes. Advancing this field, here we present a comparative study of tetra(n-butyl) lithium manganate(II) and magnesiate. Com...

Low-valent cadmium compounds have remained largely unexplored as electron reservoirs, with no precedent for their use in reduction or bond activation chemistry. Here, we address this gap by integratin...

The β-diketiminato calcium hydride, [(BDI)CaH]2 (BDI = HC{(Me)CNDipp}2, where Dipp = 2,6-i-Pr2C6H3), reacts with [Zn{N(SiMe3)2}2] and [Zn(TMP)2] (TMP = 2,2,6,6-tetramethylpiperidide) to provide labile...

Rationalized by a thermochemical evaluation using both theoretical (DFT) and empirical data, we show that the arene-encapsulated M+ cations of the group 1 alumanyls, [{SiNDipp}AlM]2 ({SiNDipp} =  {CH...