| Abstract
| - Two Au(I)-based polymers and an empty iodide-capped metallocryptand cage are formed from simple reactions of the P2pz ligand (P2pz is 3,6-bis(diphenylphosphino)pyridazine) and AuCl(tht) (tht is tetrahydrothiophene). Although the structural motifs of these three complexes differ, the gold-to-ligand ratio remains the same at 2:3. Interestingly, the two Au(I) polymers are interchangeable by simple metathesis reactions.
- 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) toa dichloromethane solution of 1 equiv of P2pz generates the simple (AuCl)2(P2pz) compound, 3. Compound 3contains nearly linear P−Au−Cl units with intermolecular Au···Au separations of 3.570 Å. Au2I2(P2pz)3, 4, is preparedby reacting excess NaI with 2 in a dichloromethane/methanol mixture. Characterization of 1, 2, and 4 by X-raycrystallography confirms the 2:3 gold/ligand ratio of all three complexes. The coordination polymer 1 maintains ahigh degree of solvation in the solid-state with three chloroform adducts hydrogen-bonded to the chloride ligand oneach 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 distortedgold atoms and the nitrogen atoms on the pyridazine rings directed away from the center of the cavity. No metalion 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) of1−4 show broad, nearly featureless absorption bands that tail into the visible with π−π* bands at 296 nm anddiscernible shoulders at 314 nm for 2 and 334 nm for 3. Excitation into the low energy band of 2 produces onlya modest emission in solution at 540 nm (λex 468 nm) and 493 nm (λex 403 nm). Under identical conditions, theP2pz ligand also emits at 540 and 493 nm.
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