36647-97-9Relevant articles and documents
Weakly coordinating anions: Crystallographic and NQR studies of halogen-metal bonding in silver, thallium, sodium, and potassium halomethanesulfonates
Wulfsberg, Gary,Parks, Katherine D.,Rutherford, Richard,Jackson, Debra Jones,Jones, Frank E.,Derrick, Dana,IIsley, William,Strauss, Steven H.,Miller, Susie M.,Anderson, Oren P.,Babushkina,Gushchin,Kravchenko,Morgunov
, p. 2032 - 2040 (2002)
35Cl, 79,81Br, and 127l NQR (nuclear quadrupole resonance) spectroscopy in conjunction with X-ray crystallography is potentially one of the best ways of characterizing secondary bonding of metal cations such as Ag+ to halogen donor atoms on the surfaces of very weakly coordinating anions. We have determined the X-ray crystal structure of Ag(O3SCH2Cl) (a = 13.241(3) A; b = 7.544(2) A; c = 4.925(2) A; orthorhombic; space group Pnma; Z = 4) and compared it with the known structure of Ag(O3SCH2Br) (Charbonnier, F.; Faure, R.; Loiseleur, H. Acta Crystallogr., Sect. B 1978, 34, 3598-3601). The halogen atom in each is apical (three-coordinate), being weakly coordinated to two silver ions. 127I NQR studies on Ag(O3SCH2I) show the expected NQR consequences of three-coordination of iodine: substantially reduced NQR frequencies v1 and v2 and a fairly small NQR asymmetry parameter ν. The reduction of the halogen NQR frequency of the coordinating halogen atom in Ag(O3SCH2X) becomes more substantial in the series X = Cl + strengthens in this series, as expected from hard-soft acid-base principles. The numbers of electrons donated by the organic iodine atom to Ag+ have been estimated; these indicate that the bonding to the cation is weak but not insignificant. We have not found any evidence for the bonding of these organohalogen atoms to another soft-acid metal ion, thallium. A scheme for recycling of thallium halide wastes is included.
