Synthesis, reactivity and comparative structural studies on copper(I) and gold(I) halo complexes with tripodal polyphosphines in 1:1 metal to ligand ratio. The X-ray crystal structures of three mononuclear neutral compounds

Cu(I) and Au(I) halides interact with equimolecular amounts of tripodal polyphosphines as CH3C(CH2PPh2)3(CP3) in CHCl3, N(CH2CH2PPh2)3(NP3) in CH2Cl2 or CH2Cl2–S (S=MeOH, Et2O) and P(CH2CH2PPh2)3 (PP3) in CH2Cl2 to form Cu(CP3)X [X=Br (1), I (2)], [Au3(CP3)2Cl2]Cl (3), [Au3(CP3)3X]X2 [X=Br (4), I (5)], Cu(NP3)X [X=Cl (6), Br (7), I (8)], [Au2(NP3)2]X2 [X=Cl (9), Br (10)], Au(NP3)I (11), [Cu2(PP3)2X]X [X=Cl (12), Br (13)] and [Au2(PP3)2]X2 [X=Br (14), I (15)]. Complexes 1, 7 and 11 were shown by X-ray diffraction to consist of neutral monomers with distorted tetrahedral geometry around the metal and the phosphine acting as tridentate chelating ligand. The mass spectra, conductivity measurements and 31P{1H} NMR studies for 9 and 10 are indicative of a coexistence with mononuclear forms. Complexes 3, 9 and 14 were also achieved in solution by addition of the appropriate polyphosphine to the compounds Au3(CP3)Cl3 (3a), Au3(NP3)Cl3 (9a) and Au4(PP3)Br4 (14a), respectively, involving ring-closure reactions. Likewise, crystals of 1 were obtained both from solutions of this compound in CH2Cl2–EtOH and from solutions in CHCl3 of (1a)·2.5Et2O (1a=Cu3(CP3)Br3). Further additions of the appropriate polyphosphine to 9 and 14 give complexes with new “MP4” environments and dangling phosphorus that for 14 involve ring-opening processes. By reaction of 3 with CP3 the complex [Au3(CP3)3Cl]Cl2, isostructural with 4 and 5, is afforded in solution. The reaction of Cu(CP3)Cl (I) with CP3 followed by 31P{1H} NMR seems to occur with retention in part of the starting CuP3 core and formation of other species containing linear arrangements for Cu(I). No reaction was observed between 6 or 13 and NP3 or PP3, respectively.