Ligand Effects on the Electronic Structure of Heteroleptic Antimony‐Centered Radicals

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‐Mes(2)C(6)H(3) 2‐C, N(SiMe(3))Dip 2‐N) stabilized by one electropositive metal fragment [L(Cl)Ga] (L=HC[C(Me)N(Dip)](2), Dip=2,6‐i‐Pr(2)C(6)H(3)) 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.