Syntheses of metal carbonyls .23. Crystal structure and reactivity of heptamethylindenyl carbonyl metal complexes

Reaction of heptamethylindene (C-9(CH3)(7), 1) with Re-2(CO)(10) yields [eta(5)-C-9(CH3)(7)]Re(CO)(3) (2), which reacts with NO+BF4- to form the cationic complex [{eta(5)-C-9(CH3)(7)}Re(CO)(2)NO]+BF4- (3). Irradiation of 2 with UV light in che presence of triethyl phosphite leads to formation of [eta(5)-C-9(CH3)(7)]Re(CO)(2)[P(OC2H5)(3)] (4). Alkylation of (CH3)(3)SnCl with Ind*Li gives [eta(1)-C-9(CH3)(7)]Sn(CH3)(3) (5). All compounds were characterized by spectroscopic methods. The molecular structures of 3 and 5 were determined by single crystal X-ray diffraction (3: P2(1)/n (14), a=1497.7(4) pm, b=879.0(2) pm, c=1609.0(4) pm and beta=110.99(2)degrees, R-1=0.038, wR(2)=0.080; 5: P2(1)/n (14), a=726.1(1) pm, b=2930.7(3) pm, c=930.0(1) pm and beta=112.834(5)degrees, R-1=0.044, R-w=0.048). Complexes 2-4 exhibit a piano stool configuration with a eta(5)-coordinated permethyl-indenyl ligand (Ind*). Compound 5 displays a eta(1)-coordination of the Ind* ligand. Temperature enhancement causes a hapticity change, as observed by NMR spectroscopy.