Themed collection Organometallic and coordination chemistry of the s-block metals

Welcome to this issue of Dalton Transactions featuring the themed issue ‘Organometallic and Coordination Chemistry of the s-Block Metals’.

This Perspective compares the chemistries of s-block metal complexes of isoelectronic PC(H)P- and PNP-bridged, chalcogen-centred monoanions with a focus on the unique behavior of the C(H)-bridged systems.

A facile synthesis for anhydrous berylliumhalides is presented and their vibrational spectra have been measured for the first time.

Very stable 1 : 1 and 1 : 2 complexes between oxyacid beryllium salts and H₂ are found.

TpBeI undergoes a spontaneous ion separation upon treatment with THF, yielding [TpBe(thf)]I, which represents a rare example of a cationic beryllium complex.

Alkaline earth metal chemistry with the anion [N(C₆F₅)₂]⁻ has been explored. Complexes are stabilized by metal⋯F interactions. Mg[N(C₆F₅)₂]₂ is a stronger Lewis acid than B(C₆F₅)₃.

Cationic β-diketiminate Mg complexes with the bulky ^tBuBDI ligand and the weakly coordinating anion B(C₆F₅)₄⁻ have been prepared by the reaction of (^tBuBDI)MgnBu with [Ph₃C]⁺[B(C₆F₅)₄]⁻; ^tBuBDI = CH[C(tBu)N-Dipp]₂ and Dipp = 2,6-diisopropylphenyl.

We have carried out a theoretical investigation of benzene substituted with BeO to assess stability and aromatic properties (with 1–3 BeO units in a six-membered ring); C₄H₄BeO, C₂H₂Be₂O₂, and Be₃O₃.

Amidine ligands with various rigidity of backbone substituents were used to synthesize heteroleptic calcium complexes with different solvation and aggregation. These complexes unprecedentedly catalyze “immortal” ROP of lactide in the presence of excess PhOH.

Catalytic hydroboration of aldehydes and ketones with pinacolborane (HBpin) and catalytic cyanosilylation of carbonyl compounds with trimethylsilyl cyanide using alkali metal (Li, Na, K) complexes as precatalysts under mild conditions are reported.

Insertion of CS₂ into the Mg–H bond of [Tism^PriBenz]MgH affords [Tism^PriBenz]Mg(κ²-S₂CH), the first structurally characterized magnesium dithioformate compound.

The first examples of Ca and Sr amido complexes built on a cyclooctatetraenyl platform are reported.

A series of new alkali metal complexes containing deprotonated bisheterocyclomethanide were synthesised and the potassium derivatives were exposed to hydrolysis.

Hetero-cubane structures were revealed for the tert-amyloxide compounds of potassium, rubidium, and caesium.

Heteroleptic Ca(II) amides coordinated by multidentate phenolato ligands proved to be efficient catalysts for catalytic cross-dehydrogenative coupling of amines with silanes.

2,2,5,5-Tetramethyl-THF (thf*) is a very bulky ether with a rather poor binding tendency due to weak basicity and steric hindrance. In the solid state, thf* complexes are observed whereas in solution these complexes dissociate.

Single-crystalline [MgMe₂]_n is obtained via crystallization from neat GaMe₃, the formation of transient Mg(GaMe₄)₂ being indicated by the serendipitous isolation of octametallic [Mg(GaMe₄)(OMe)]₄.

Magnesium triphenylsilyl complexes [Mg(SiPh₃)₂(THF)₂] and [(Me₃TACD)Mg(SiPh₃)] ((Me₃TACD)H = 1,4,7-trimethyl-1,4,7,10-tetraazacyclododecane) serve as precursors for 1,4-dihydropyridyl complexes of magnesium which are active in the hydroboration of pyridine.

Efficient synthesis and structure elucidation of carbon–calcium σ-bonded compounds are of remarkable interest and importance in organometallic chemistry of the heavier s-block metals.

Several preconditions are required to allow a high-yield synthesis of 2-thienylcalcium halide including protection of the 5-position by a methyl group and formation of a tetrahydropyran adduct.

A series of bulky bis(silyl)amide ligands have been utilised to stabilise rare examples of formally 2-coordinate linear or near-linear Mg and Ca complexes.

The alkali metal arsinoamide complexes [(Mes₂AsNPh){Li(OEt₂)₂}], [(Mes₂AsNPh){Na(OEt₂)}]₂, and [(Mes₂AsNPh){K(THF)}]₂ were synthesized.