Ligand Effects on the Electronic Structure of Heteroleptic Antimony‐Centered Radicals. (10th March 2020)

• Record Type: Journal Article
• Authors: Helling, Christoph; Cutsail, George E.; Weinert, Hanns; Wölper, Christoph; Schulz, Stephan
• Is Part Of: Angewandte Chemie. Volume 132:Number 19(2020)
• Page Start: 7631
• Page End: 7638
• Publication Date: 2020-03-10
• Subjects: Antimon -- ESR-Spektroskopie -- Hauptgruppenelemente -- Radikale -- Röntgenbeugung; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202000586
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: We report on the structures of three unprecedented heteroleptic Sb‐centered radicals [L(Cl)Ga](R)Sb . (2‐R, R=B[N(Dip)CH]2 2‐B, 2, 6‐Mes2 C6 H3 2‐C, N(SiMe3 )Dip 2‐N ) stabilized by one electropositive metal fragment [L(Cl)Ga] (L=HC[C(Me)N(Dip)]2, Dip=2, 6‐ i ‐Pr2 C6 H3 ) and one bulky B‐ (2‐B ), C‐ (2‐C ), or N‐based (2‐N ) substituent. Compounds 2‐R are predominantly metal‐centered radicals. Their electronic properties are largely influenced by the electronic nature of the ligands R, and significant delocalization of unpaired‐spin density onto the ligands was observed in 2‐B and 2‐N . Cyclic voltammetry (CV) studies showed that 2‐B undergoes a quasi‐reversible one‐electron reduction, which was confirmed by the synthesis of [K([2.2.2]crypt)][L(Cl)GaSbB[N(Dip)CH]2 ] ([K([2.2.2]crypt)][2‐B ]) containing the stibanyl anion [2‐B ] −, which was shown to possess significant Sb−B multiple‐bonding character. Abstract : Radikal reduziert : Drei beispiellose heteroleptische Stibanyl‐Radikale wurden synthetisiert und ihre elektronischen Strukturen mittels Einkristall‐Röntgenbeugung, ESR‐ und UV/Vis‐Spektroskopie, Cyclovoltammetrie und DFT‐Rechnungen aufgeklärt. Das Boryl‐substituierte Radikal vollzieht eine Ein‐Elektronen‐Reduktion zum entsprechenden Stibanyl‐Anion, welches partiellen Sb‐B‐Doppelbindungscharakter besitzt.