Are Ligand-Stabilized Carboxylic Acid Derivatives with Ge═Te Bonds Isolable?

Bonding Relationship between Silicon and Germanium with Group 13 and Heavier Elements of Groups 14-16

The topic of heavier main group compounds possessing multiple bonds is the subject of momentous interest in modern organometallic chemistry. Importantly, there is an excitement involving the discovery of unprecedented compounds with unique bonding modes. The research in this area is still expanding, particularly the reactivity aspects of these compounds. This article aims to describe the overall developments reported on the stable derivatives of silicon and germanium involved in multiple bond formation with other group 13, and heavier groups 14, 15, and 16 elements. The synthetic strategies, structural features, and their reactivity towards different nucleophiles, unsaturated organic substrates, and in small molecule activation are discussed. Further, their physical and chemical properties are described based on their spectroscopic and theoretical studies.

The Reactivity of Germanium Phosphanides with Chalcogens

The reactivity of germanium phosphanido complexes with elemental chalcogens is reported. Addition of sulfur to [(BDI)GePCy₂] (BDI = CH{(CH₃)CN-2,6-iPr₂C₆H₃}₂) results in oxidation at germanium to form germanium(IV) sulfide [(BDI)Ge(S)PCy₂] and oxidation at both germanium and phosphorus to form germanium(IV) sulfide dicylohexylphosphinodithioate complex [(BDI)Ge(S)SP(S)Cy₂], whereas addition of tellurium to [(BDI)GePCy₂] only gives the chalcogen inserted product, [(BDI)GeTePCy₂]. This reactivity is different from that observed between [(BDI)GePCy₂] and selenium. Addition of selenium to the diphenylphosphanido germanium complex, [(BDI)GePPh₂], results in insertion of selenium into the Ge-P bond to form [(BDI)GeSePCy₂] as well as the oxidation at phosphorus to give [(BDI)GeSeP(Se)Ph₂]. In contrast, addition of selenium to the bis(trimethylsilyl)phosphanido germanium complex, [(BDI)GeP(SiMe₃)₂], yields the germanium(IV) selenide [(BDI)Ge(Se)P(SiMe₃)₂].

Reactivity Study of a Pyridyl-1-azaallylgermanium(I) Dimer: Synthesis of Heavier Ether and Ester Analogues of Germanium

The reactivity study of a pyridyl-1-azaallylgermanium(I) dimer LGe-GeL [1; L = N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)] with different stoichiometric ratios of elemental selenium and tellurium is described. The reactions of 1 with 1 equiv of selenium and tellurium afforded the first examples of heavier ether analogues of germanium, bis(germylene) selenide and telluride LGe(μ-E)GeL [E = Se (2) and Te (3)], respectively. Meanwhile, the reactions of 1 with 2 equiv of selenium and tellurium gave the heavier ester analogues LGe═E(μ-E)GeL [E = Se (4) and (5)]. All compounds have been characterized by X-ray crystallography and multinuclear NMR spectroscopy.

Concise access to iminophosphonamide stabilized heteroleptic germylenes: chemical reactivity and structural investigation

A heteroleptic three coordinate germylene monochloride, its adduct with a Lewis acid, and germaacid-chloride & -ester derivatives with sulfur and selenium have been reported.

Mixed guanidinato-amido Ge(iv) and Sn(iv) complexes with GeE (E = S, Se) double bond and SnS4, Sn2Se2 rings

The oxidative addition of chalcogens (S and Se) to the guanidinate supported Ge(ii) and Sn(ii) amide complexes.

Single-step conversion of silathiogermylene to germaacid anhydrides: unusual reactivity

Single-step conversion of germylene (2) to germaacid anhydrides (3 and 4) is achieved through oxidative-addition with S/Se that involves condensation for the first time.