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Levason W, Maheshwari S, Ratnani R, Reid G, Webster M, Zhang W: Structural diversity in supramolecular complexes of MCl (3) (M = As, Sb, Bi) with constrained thio- and seleno-ether ligands. Inorg Chem. 2010 Oct 4;49(19):9036-48.
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 mu-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 kappa (2)-mu (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. |
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