Syntheses and Chemistry of Methylantimony and Methylbismuth Dihalides:  An Extended Two-Dimensional Framework in the Crystal Structure of CH₃BiCl₂ and Molecular Units in the Structures of [CH₃ECl₂(2,2‘-bipyridine)] (E = Sb, Bi)

Abstract

CH 3 SbPh 2 reacts with HCl to give CH 3 SbCl 2 . CH 3 BiCl 2 and CH 3 BiBr 2 are formed by reaction of CH 3 -BiPh 2 with HCl or HBr. The adducts [CH 3 ECl 2 (bipy)] (E ) Sb, Bi, bipy ) 2,2′-bipyridine) are obtained by combining the components in diethyl ether or tetrahydrofuran. The crystal structures of CH 3 BiCl 2 and [CH 3 -ECl 2 (bipy)] (E ) Sb, Bi) have been determined by singlecrystal X-ray diffraction.

Lewis base complexes of methyldihalobismuthines BiMeX2 (X = Cl or Br)

“…The chain structure is similar to that found in BiPh 2 Cl [18], whereas Bi(mesityl) 2 Br is better described as composed of trigonal pyramidal monomers with very long Bi···Br (3.795 Ǻ) contacts linking them into chains [19]. The BiÀC distances in BiMe 2 Br of 2.235(7)À2.256(6) Ǻ, are shorter than in BiMeCl 2 (2.330(1) Ǻ) [10], but similar to those in Bi(mesityl) 2 Br (2.268(12), 2.270(10) Ǻ) [19]. However, in the latter the BiÀBr distance (within the trigonal pyramidal monomer) is significantly shorter (2.696(2) Ǻ) than in the chain structure of BiMe 2 Br presented here (2.8438(8)À3.0169(8) Ǻ).…”

“…Methylhalobismuthines can be prepared by comproportionation of BiMe 3 and BiX 3 (X ¼ Cl, Br or I), by cleavage of Ph groups from BiPh 3-n Me n (n ¼ 1 or 2) with HX (X ¼ Cl or Br), or by reaction of BiX 3 with a stoichiometric amount of MeLi at low temperatures [10,12,15,16]. We have found the last of these to be most effective in this work (Section 3).…”

“…We have found the last of these to be most effective in this work (Section 3). The structure of BiMeCl 2 contains puckered nets of Bi 4 Cl 4 units linked into sheets with longer Cl···Bi contacts producing double sheets with the Me groups axial and directed away from the double sheets [10]. In contrast, BiMeI 2 consists of BiMe(m 2 -I) 2 units in chains containing square pyramidal bismuth centres; the structures of BiMeBr 2 and BiMe 2 Cl are unknown [11].…”

“…AlkylÀbismuth bonds are more fragile than their aryl analogues and few examples of BiMeX 2 complexes are known, although one structurally authenticated example is the dimeric [{BiMeCl 2 (2,2 0 -bipy)} 2 ], which contains square pyramidal bismuth coordination with an apical Me group and basal chlorines (2.709(3), 2.678(3) Ǻ). The molecules are then weakly associated into dimers via very long Bi···Cl contacts (3.63(3), 3.95(5) Ǻ) [10]. The [{BiMeBr 2 (thf) 2 } 2 ], which crystallises from BiMeBr 2 solutions in thf, is a centrosymmetric dimer, with square pyramidal units weakly associated through long Bi···Br bridges (3.97(2) Ǻ) [11].…”

Synthesis and characterization of methylbismuth(III) complexes containing dithio ligands: 2. Crystal and molecular structure of [MeBiCl(S2CNEt2)] and transformation of some to Bi2S3

“…All manipulations involving the preparations of dithiocarbamates [8] and methylbismuth dichloride [9] were carried out under anhydrous and inert conditions. IR spectra were recorded as Nujol mulls between CsI plates in the range 4000-200 cm À1 .…”