Structural diversity in supramolecular complexes of MCl(3) (M = As, Sb, Bi) with constrained thio- and seleno-ether...

MCl(3) react with o-C(6)H(4)(EMe)(2) (E = S, Se) or o-C(6)H(4)(CH(2)ER)(2) (E = S, R = Me or Et; E = Se, R = Me) in anhydrous CH(2)Cl(2) or MeCN to give the yellow (Bi) or white (Sb) complexes, [MCl(3){o-C(6)H(4)(EMe)(2)}], [(MCl(3))(2){o-C(6)H(4)(CH(2)SMe)(2)}(3)], [MCl(3){o-C(6)H(4)(CH(2)SEt)(2)}], and [(BiCl(3))(4){o-C(6)H(4)(CH(2)SeMe)(2)}(3)], which were characterized by IR/Raman, (1)H NMR spectroscopy, and microanalysis. The corresponding reactions with AsCl(3) gave oils. Using the tetrachalcogenoethers, 1,2,4,5-C(6)H(2)(CH(2)EMe)(4) (E = S or Se), gave [(MCl(3))(2){1,2,4,5-C(6)H(2)(CH(2)EMe)(4)}] (E = S: M = As, Sb or Bi; E = Se: M = As) as powdered solids. The structures adopted are extremely diverse within this related series. Crystal structure determinations show infinite chains for [MCl(3){o-C(6)H(4)(EMe)(2)}] (M = Bi, E = S or Se; M = Sb, E = S), although the structures differ significantly in detail. [BiCl(3){o-C(6)H(4)(SMe)(2)}] is formed through chains of orthogonal μ-Bi(2)Cl(2) units linked together, with one dithioether ligand chelating per Bi atom, and seven-coordinate Bi; [SbCl(3){o-C(6)H(4)(SMe)(2)}] comprises weakly associated Sb(2)Cl(6) dimer units linked into chains by weakly bridging dithioethers, where both available lone pairs on each S atom are used. [BiCl(3){o-C(6)H(4)(SeMe)(2)}] comprises distorted square pyramidal units involving pyramidal BiCl(3) primary coordination and a weakly chelating diselenoether ligand, and assembled into infinite chains through long bridging Bi···Cl interactions via all three Cl's. The 2:3 M:L complexes [(MCl(3))(2){o-C(6)H(4)(CH(2)SMe)(2)}(3)] (M = Bi or Sb) are isostructural, and also show one-dimensional polymers, but this time the coordination is based upon pyramidal MCl(3) units, with secondary bonding via three long M···S contacts from bridging dithioethers, and a further long M···Cl bridge which completes a distorted seven-coordinate environment at M. The Et-substituted thioether analogue gives the 1:1 [MCl(3){o-C(6)H(4)(CH(2)SEt)(2)}] for both Bi and Sb; the former showing a chain polymer structure based upon seven-coordinate Bi and bridging dithioethers and the latter a weakly Cl-bridged dimer with distorted octahedral coordination at Sb, with a chelating dithioether. The 4:3 [(BiCl(3))(4){o-C(6)H(4)(CH(2)SeMe)(2)}(3)] complexes are based upon a central BiCl(6) octahedron linked to each of the other three Bi atoms via two bridging Cl atoms; the outer Bi atoms are also bonded to two mutually trans Se donor atoms from distinct diselenoethers, and two terminal Cl atoms, giving a distorted octahedral coordination environment at Bi. One of the two crystallographically independent tetrabismuth units is discrete, while the other shows further Cl-bridges to adjacent units giving an infinite network. [(AsCl(3))(2){1,2,4,5-C(6)H(2)(CH(2)SMe)(4)}] also forms an infinite network based upon square pyramidal As(III), and comprises pyramidal AsCl(3) units each weakly coordinated to two (mutually cis) S-donor atoms from two different thioether ligands. The Sb-analogue is structurally very similar; however, in this case a solvent MeCN occupies the sixth coordination site. Finally, [(AsCl(3))(2){1,2,4,5-C(6)H(2)(CH(2)SeMe)(4)}] forms an infinite chain based upon distorted octahedral coordination at As through three terminal (pyramidal) Cl atoms, two Se atoms from κ(2)-μ(2)-selenoethers, although unexpectedly the chelation is through Se atoms that are mutually meta on the aromatic ring; with one Se atom on each ligand using both of its lone pairs to bridge (weakly) between two As atoms. These MCl(3)-chalcogenoether adducts are mostly weakly associated, and lead to very diverse structures which result from a combination of intra- and intermolecular interactions and crystal packing.