MCl3 react with o-C6H4(EMe)(2)(E i= S, Se) or o-C6H4(CH2ER)(2)(E = S, R = Me or Et; E = Se, R = Me) in anhydrous CH2Cl2 or MeCN to give the yellow (Bi) or white (Sb) complexes, [MCl3{o-C6H4(EMe)(2)}], [(MCl3)(2){o-C6H4(CH2SMe)(2)}(3)], [MCl3{o-C6H4(CH2SEt2}], and l(SiCl3)(4){o-C6H4(CH2SeMe)(2)}(3)], which were characterized by IR/Raman, 111 NMR spectroscopy, and microanalysis. The corresponding reactions with AsCl3 gave oils. Using the tetrachalcogenoethers, 1,2,4,5-C6H2(CH2EMe)(4) (E = S or Se), gave [(MCl3)2{1,2,4,5-C6H2(CH2EMe)(4)}] (E = S: M = As, Sb or Bi; E = Se: M = As) as powdered solids. ThEi structures adopted are extremely diverse within this related series. Crystal structure determinations show infinite chains for [MCl3{o-C6H4(EMe)(2)}] (M = Bi, E = S or Se; M = Sb, E = S), although the structures differ significantly in detail. [BiCI3{o-C6H4(SMe)(2)}] is formed through chains of orthogonal p-Bi2Cl2 units linked together, with one dithioether ligand chelating per Bi atom, and seven-coordinate Bi; [SbCl3{o-C6H4(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. [BiCl3{o-C6H4(SeMe)(2)}] comprises distorted square pyramidal units involving pyramidal BiCl3 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 [(MD3)(2){o-C(6)Fl(4)(CH2SMe)(2)}(3]) (M = Bi or Sb) are isostructural, and also show one-d mensional polymers, but this time the coordination is based upon pyramidal MCl3 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 thioetheranalogue gives the 1:1 [MCl3{o-C6H4(CH2SEt2}] for both Bi and Bb; 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 [(BiCl3)(4)] {o-C6H4(CH2SeMe)(2)}(3)] complexes are based upon a central BiCl6 octahedron linked to each of the other three Bi atoms via twci 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 ne:work. [(A(5)Cl(3))(2)1,2,4,5-C6H2(CH2SMe)(4)}] also forms an infinite network based upon square pyramidal As(III), and conprises pyramidal AsCl3 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, [(AsCl3)2{1,2,4,5-C6H2(CH2SeMe)(4)}] forms an infinite chain based upon distorted octahedral coordir ation at As through three terminal (pyramidal) Cl atoms, two Se atoms from K-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 intermolacular interactions and crystal packing.