TY - JOUR
T1 - Synthesis and structures of tetranuclear 2-(dimethylamino)ethanethiolato complexes of zinc, cadmium and mercury involving both primary and secondary metal-halogen bonding
AU - Casals, Isidre
AU - González-Duarte, Pilar
AU - Clegg, William
AU - Foces-Foces, Concha
AU - Cano, Félix Hernández
AU - Martínez-Ripoll, Martín
AU - Gómez, Montserrat
AU - Solans, Xavier
PY - 1991/12/1
Y1 - 1991/12/1
N2 - Two series of complexes of Zn, Cd and Hg with 2-(dimethylamino)ethanethiolate (L) ligands have been prepared. Complexes [M4L4X4] (series I) (X = Cl or Br) are obtained from anhydrous MX2, HL·HX and triethylamine in acetonitrile, and also from the metal acetate, HL·HX and sodium hydroxide in aqueous solution. Treatment of [Cd4L4X4] with NaL in acetonitrile-methanol gives [Cd4L6X2] (series II, Cd only). The structures of two complexes of series I, [Cd4L4Br4] 1 and [Hg4L4Cl4] 2, and of the series II complex [Cd4L6Cl2] 3, have been determined crystallographically, and are probably representative of the two series. All have a central centrosymmetric M4S4eight-membered ring in an extended-chair conformation with two opposite M atoms disposed one on each side of the M′2S4plane, and with aminothiolate ligands which are both S,N-chelating to M′ atoms and S-bridging between M and M′ atoms. The additional L ligands in 3 chelate the out-of-plane M atoms. The halogen atoms in 1 and 2 are terminally bonded to the M atoms, but two of them are also weakly bonded to both M′ atoms to give incipient triple bridging. In complex 3 the Cl atoms bridge the two M′ atoms and are only weakly bonded to one M atom each. These patterns of primary and secondary M-X bonding are compared with those in other structures having a similar central X2M2M′2S4core.
AB - Two series of complexes of Zn, Cd and Hg with 2-(dimethylamino)ethanethiolate (L) ligands have been prepared. Complexes [M4L4X4] (series I) (X = Cl or Br) are obtained from anhydrous MX2, HL·HX and triethylamine in acetonitrile, and also from the metal acetate, HL·HX and sodium hydroxide in aqueous solution. Treatment of [Cd4L4X4] with NaL in acetonitrile-methanol gives [Cd4L6X2] (series II, Cd only). The structures of two complexes of series I, [Cd4L4Br4] 1 and [Hg4L4Cl4] 2, and of the series II complex [Cd4L6Cl2] 3, have been determined crystallographically, and are probably representative of the two series. All have a central centrosymmetric M4S4eight-membered ring in an extended-chair conformation with two opposite M atoms disposed one on each side of the M′2S4plane, and with aminothiolate ligands which are both S,N-chelating to M′ atoms and S-bridging between M and M′ atoms. The additional L ligands in 3 chelate the out-of-plane M atoms. The halogen atoms in 1 and 2 are terminally bonded to the M atoms, but two of them are also weakly bonded to both M′ atoms to give incipient triple bridging. In complex 3 the Cl atoms bridge the two M′ atoms and are only weakly bonded to one M atom each. These patterns of primary and secondary M-X bonding are compared with those in other structures having a similar central X2M2M′2S4core.
U2 - 10.1039/DT9910002511
DO - 10.1039/DT9910002511
M3 - Article
SP - 2511
EP - 2518
IS - 10
ER -