GOLD(I) COMPLEXES OF OPEN-CHAIN AND CYCLIC DI-SECONDARY AMINES

Treatment of N,N'-diisopropyl-ethylenediamine or 1,4-piperazine with t wo equivalents of [(Ph(3)P)Au](+) BF4- leads to binuclear complexes of the diamines: {[(Ph(3)P)Au]HN((1)Pro)NCH2-)(2)(2+) 2 BF4- (1) and {[( Ph(3)P)Au]HNCH2CH2}(2)(2+) 2 BF4- (2), respectively. In the products e ach quaternary ammonium center bears one gold ligand, one hydrogen ato m and two alkyl substituents. The crystal structures of both compounds have been determined. Compound 1 contains discrete ion-triples. The e thylene bridge in the dications is in an unfolded conformation, with a crystallographic center of inversion, and allows for weak hydrogen bo nding N-H-F [2.085 Angstrom; N-H--F 169.2''1 between the NH functions and the counterions. The existing distant contacts F-Au [3.599 A] are probably less significant for the aggregation of the ion triples, but will contribute through Coulomb forces. Compound 2 crystallizes with t wo solvent molecules CH2Cl2. The dication has a crystallographic cente r of inversion with the piperazine ring in a chair conformation and th e gold atoms in equatorial positions. There are hydrogen bonds N-H-F [ 2.076 and 2.457 Angstrom] between the dication and the anions which le ad to the formation of ion-triples, with further contacts between the BF4- anions and the solvent molecules [C-H-F 2.340 and 2.446 Angstrom] .