Isolation and Characterization of a Bismuth(II) Radical

Size Matters: Synthesis of Group 13 Metal‐Substituted Dipnictanes by E‐C Bond Homolysis

“…[ 5,6 ] Consequently, the use of sterically even more encumbering ligands R totally prevented dimerization and enabled the isolation of monomeric pnictanyl radicals R 2 E · in the solid‐state even for the heaviest group 15 elements (Figure 1 c), [ 8 ] as was successfully demonstrated by the isolation of [L(X)Ga] 2 E · (E = As, Sb, Bi; X = Cl, Br, I) [ 9 ] (L = HC[C(Me)N(Dip)] 2 , Dip = 2,6‐ i Pr 2 C 6 H 3 ) and [O{Si(Me 2 )N(Ar)} 2 ]Bi · (Ar = Dip, 2,6‐(CHPh 2 ) 2 ‐4‐ t BuC 6 H 2 ). [ 10 ] The detection of discrete monomeric radicals {H 2 CC(SiMe 3 ) 2 } 2 E · (E = P, As) [ 11 ] in the solid‐state further emphasizes the delicate influence of the ligand's characteristics, as only equilibria were observed for [{(Me 3 Si) 2 CH} 2 E] 2 (E = P, As), [ 5 ] containing a strongly related but less rigid ligand, and [{H 2 CC(SiMe 3 ) 2 } 2 E] 2 (E = Sb, Bi), [ 6 ] comprising the heavier group 15 homologues, which possess enlarged covalent radii ( r cov = 1.11 (P), 1.21 (As), 1.40 (Sb), 1.51 (Bi) Å). [ 12 ]…”

From Dibismuthenes to Three‐ and Two‐Coordinated Bismuthinidenes by Fine Ligand Tuning: Evidence for Aromatic BiC3N Rings through a Combined Experimental and Theoretical Study

“…Importantly, not only a fundamental description of the bonding and the structure of these compounds was targeted, but their reactivity and the coordination ability towards TMs also gained considerable attention 5. Recent examples include the work of Bertrand and co‐workers in carbene‐stabilized low‐valent antimony compounds,6 the stabilization of persistent Sb‐ and Bi‐centered radicals achieved by Ishida, Iwamoto,7a and Coles,7b the isolation of molecular phosphinidenes and arsinidenes and their successful utilization for the coordination of TMs by the groups of Woollins8 and Ragogna 9…”

Synthesis of HeavyN‐Heterocyclic Tetrylenes: Influence of Ligand Sterics on Structure

“…Preparation of NON R ‐supported germylenes, stannylenes and plumbylenes . The synthesis of germanium, tin and lead complexes supported by NON R ‐ligands was similar to the established procedures for [(NON t Bu )Ge] ( VIII ) and [(NON Dipp )Pb] ( IX ) [7a,h] . Dilithiated ligand, [(NON R )Li 2 ], was generated in situ by the addition of two equivalents of n BuLi to the corresponding pre‐ligand, (NON R )H 2 (Scheme 1).…”

“…We have previously reported the synthesis and structural characterisation of monomeric two‐coordinate plumbylenes [(NON Dipp )Pb] ( IX ) and [(NON Ar# )Pb] ( X ) [7a,d] . The solid‐state structures of compounds 1 t Bu ‐Pb , 2 Ph ‐Pb and 3 Dmp ‐Pb were determined using single crystal X‐ray diffraction (Figure 4).…”

“…Coordination of the NON R ‐ligand systems to p‐block metal centres occurs primarily through a bidentate bonding mode involving both nitrogen atoms and the formation of a 6‐membered heterocycle ( C , Figure 1); however, bridging bonding modes involving coordination of the nitrogen atoms to separate metal centres have also been reported [8] . Of relevance to this work, the bulky R=Dipp or Ar # (Ar # =2,6‐(CHPh 2 ) 2 ‐4‐ t BuC 6 H 2 ) derivatives allow isolation of the corresponding hindered N ‐heterocyclic plumbylenes which were characterised spectroscopically and crystallographically [7a,d] . The related [(NON t Bu )Ge] has also been identified spectroscopically, yet the crystal structure remains elusive [7h] .…”