GROUP IB ORGANOMETALLIC CHEMISTRY. XXXIII. ArAuPPh3, ArAu(CNR), (ArAu)n AND Ar4CuAu2 COMPOUNDS IN WHICH THE ARYL GROUP CONTAINS 2-MeO, 2,6-(MeO)2, 2-Me2N, 2-Me2NCH2 AND (S)- OR (R)-2-Me2NCHMe SUBSTITUENTS AS POTENTIAL LIGANDS

Article abstract of DOI:10.1016/S0022-328X(00)82423-7

The synthesis and structural characterization by 1H NMR and 197Au Moessbauer spectroscopy as well as by chiral labelling of the built-in ligands of three different types of arylgold(I) compounds is described. 197Au Moessbauer data revealed that the benzyl- and arylgold(I) triphenylphosphine complexes which bear potential coordinating substituents at an ortho position still contain linearly coordinated Au^I with 2c-2e gold(I)-carbon bonds.The observation of isochronous NMe resonances in (S)-2-Me2NCH(Me)C6H4AuPPh3 confirms that no additional intramolecular Au-N coordination occurs in solution.Preliminary results of an X-ray diffraction study of 2,6-(MeO)2C6H3AuPPh3 are reported (R=0.040, PAuC₁ angle 172.6 deg.Unsymmetrical AuC₁C₂ and AuC₁C₆ angles of 126.4 and 117.4 deg, respectively).Pure, uncomplexed arylgold(I) compounds have been isolated from the reaction of diarylgoldlithium compounds (arylaurates) with trimethyltin bromide. (S)-2-Me2NCHMeC6H4Au has a dimeric structure which most likely consists of two monomeric units associated by intermolecular Au-N coordination thus forming a ten-membered chelate ring.The structure of insoluble 2-Me2NCH2C6H4Au and 2-Me2NC6H4Au are less clear.The former compound probably has a structure similar to (S)-2-Me2NCHMeC6H4Au (IS/QS values for two-coordinate Au^I centers).However, the strongly deviating IS and QS values of 2-Me2NC6H4Au indicate that a polynuclear structure for this compound similar to that proposed for 2-Me2NC6H4Cu cannot be excluded (a polymeric structure containing 2-Me2NC6H4 groups which span three Au atoms by 3c-2e Au2C bonds and Au-N coordination).The mixed Au/Cu cluster (2-Me2NCH2C6H4)4Au2Cu2 is accessible via the 1/2 reaction of (2-Me2NCH2C6H4)4Au2Li2 with CuI.Molecular weight and 1H NMR studies point to a tetranuclear structure in solution, while mass spectrometry shows fragment ions with m/e corresponding to (2-Me2NCH2C6H4)3Au2Cu2⁺, (2-Me2NCH2C6H4)2Au⁺.