Cationic manganese(I) tricarbonyl complexes with group 15 and 16 donor ligands: synthesis, multinuclear NMR spectroscopy and crystal structures

The compound [MnBr(CO)(5)] reacted with [10]aneS(3) (1,4,7-trithiacyclodeca ne) in dmf solution to yield fac-[Mn(CO)(3)([10]aneS(3))]Br. The compounds fac-[Mn(CO)(3)(L)]CF3SO3 (L = MeS(CH2)(2)S(CH2)(2)SMe, MeSe(CH2)(3)Se(CH2)( 3)SeMe, MeC(CH2SMe)(3), MeC(CH2SeMe)(3), MeC(CH2TeMe)(3), MeC(CH2TePh)(3), MeC(CH2PPh2)(3) MeC(CH2AsMe2)(3) or Ph2P(CH2)(2)PPh(CH2)(2)PPh2) were readi ly obtained by treatment of fac-[Mn(CO)(3)(Me2CO)(3)]CF3SO3 with L at room temperature in Me2CO solution. Similar reactions using three molar equivale nts of PPh2H, PCy2H or PPhH2 (L) yielded fac-[Mn(CO)(3)(L)(3)]CF3SO3 as pal e yellow solids. The compounds have been characterised by analysis, IR and multinuclear NMR spectroscopy (H-1, C-13-{H-1}, P-31-{H-1}, Mn-55, Se-77-{H -1} and Te-125-{H-1}), mass spectrometry and by single crystal X-ray diffra ction studies on seven examples. The compounds all adopt a distorted octahe dral arrangement with C-3v local symmetry at Mn-I, and three mutually fac c arbonyl ligands. The delta(Mn-55) linewidths are very dependent upon subtle changes in the electric field gradient and for some of the phosphine compl exes quartet coupling to P-31 is clearly resolved giving (1)J(MnP) ca. 200 Hz. The spectroscopic data are discussed in terms of the relative bonding p roperties of the Group 15 or 16 donor ligands within the manganese(I) catio n.