Stibane and the anions SbCO- and SbH2- as synthetic building blocks in organometallic molecular chemistry

• Applicant: Professor Dr. Carsten von Hänisch
• Subject Area: Inorganic Molecular Chemistry - Synthesis and Characterisation
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 503970736

Antimony compounds have many applications and can be found in a wide variety of household items such as rewritable DVDs or as fire retardants in furniture or electrical appliances. All common syntheses of antimony compounds start from the element, the oxides and sulphides, the antimony halides or substituted stibanes such as Sb(SiMe3)3. In contrast, the ions PCO- and AsCO- have established themselves as versatile synthesis building blocks in arsenic and especially phosphorus chemistry in recent years. However, a corresponding synthetic building block is not yet known in antimony chemistry. This project pursues two goals, both of which are based on stibine as starting compound. The project is based on the experience of the working group on the application of antimony hydrogen in molecular chemistry. In subproject A, the SbH2- anion will be synthesised by mild deprotonation of SbH3 at low temperatures. This will then be used for the targeted synthesis of new primary stibanes and new antimony-bridged coordination compounds. For this purpose, different salts of the type [M(L)SbH2] with different ligands (L) and different alkali metal cations (M) will be prepared and investigated concerning their stability and reaction behaviour. Subproject B deals with the preparation of the anions SbCE- (E = O, S, Se) and their use in synthesis. The preparation of these ions is investigated starting from SbH3 and starting from the compounds of the type [M(L)SbH2] prepared in subproject A. Subsequently the synthetic potential of these SbCE- ions is investigated which opens up new avenues in antimony chemistry. For example, it is possible to synthesise low-valent species by transferring "Sb-" ions, the production of new coordination compounds with the ions mentioned or cycloaddition reactions to produce completely new organic compounds of antimony. This will open up versatile antimony chemistry that is not accessible with the previously common starting compounds of this element.The subprojects A and B are preceded by investigations into the resource-efficient production of SbH3 and its storage.

• DFG Programme: Research Grants