514791-21-0Relevant articles and documents
Three- and four-coordinate gold(I) complexes of 3,6-bis(diphenylphosphino)pyridazine: Monomers, polymers, and a metallocryptand cage
Catalano, Vincent J.,Malwitz, Mark A.,Horner, Stephen J.,Vasquez, John
, p. 2141 - 2148 (2003)
The slightly yellow polymeric complexes {Au2Cl2(P2pz)3}n, 1·6CHCl3, (P2pz is 3,6-bis(diphenylphosphino)pyridazine) and {[Au2(P2pz)3](PF6)2}n, 2, are prepared by the stoichiometric reaction of AuCl(tht) (tht is tetrahydrothiophene) and P2pz in either dichloromethane or dichloromethane/methanol, respectively. Addition of 2 equiv of AuCl(tht) to a dichloromethane solution of 1 equiv of P2pz generates the simple (AuCl)2(P2pz) compound, 3. Compound 3 contains nearly linear P-Au-Cl units with intermolecular Au...Au separations of 3.570 A. Au2l2(P2pz)3, 4, is prepared by reacting excess Nal with 2 in a dichloromethane/methanol mixture. Characterization of 1, 2, and 4 by X-ray crystallography confirms the 2:3 gold/ligand ratio of all three complexes. The coordination polymer 1 maintains a high degree of solvation in the solid-state with three chloroform adducts hydrogen-bonded to the chloride ligand on each gold atom. These chloroform molecules are sandwiched between the two-dimensional polymeric sheets of 1. The crystal structure of 4 reveals an empty, iodide-capped metallocryptand cage with the tetrahedrally distorted gold atoms and the nitrogen atoms on the pyridazine rings directed away from the center of the cavity. No metal ion encapsulation was observed for complex 4. Complex 2 forms one-dimensional arrays of [Au2(P2pz)2]2+ metallomacrocycles connected to each other by a third P2pz ligand. The electronic absorption spectra (CH2Cl2) of 1-4 show broad, nearly featureless absorption bands that tail into the visible with π-π* bands at 296 nm and discernible shoulders at 314 nm for 2 and 334 nm for 3. Excitation into the low energy band of 2 produces only a modest emission in solution at 540 nm (λex 468 nm) and 493 nm (λex 403 nm). Under identical conditions, the P2pz ligand also emits at 540 and 493 nm.
