Tertiary phosphine adducts of manganese(II) dicyclopentadienide. Magnetic studies and structural characterization of tilted cyclopentadienyl rings

Mono‐ and Dinuclear High‐Spin Half‐Sandwich Manganese(II) Complexes Containing Acetylide and TMEDA Ligands

“…On the basis of known, facile methylcyclopentadienyl replacements in [Mn(MeC 5 H 4 ) 2 (dmpe)], [63,103,105] where one of the methylcyclopentadienyl rings is bound to the manganese center in an η 5 fashion and the other in an η 2 fashion, [103,105] we thought that it should be even easier to replace one of the methylcyclopentadienyl rings in [Mn(MeC 5 H 4 ) 2 (tmeda)] [106] (1), which comprises two η 1 -methylcyclopentadienyl rings bound to the manganese center, by an acetylide ligand. Raman spectroscopy showed characteristic bands for the ν(CϵC) vibrations for these complexes between 2000 and 2100 cm…”

“…[63,104] The mononuclear complexes were obtained by the reaction of [(MeC 5 H 4 ) 2 Mn(tmeda)] [105,106] …”

Facile Access to Redox‐Active C2‐Bridged Complexes with Half‐Sandwich Manganese End Groups

“…The X-ray crystal structure of this d 5 high-spin complex was determined ( Figure 1). Remarkably, one of the methylcyclopentadienyl rings is coordinated to the metal center in an h 2 fashion, rather than in the h 5 mode suggested by Wilkinson et al [88] This is also in contrast to the structures of related complexes [(h 5 -C 5 H 5 ) 2 Mn(dmpe)] (dmpe = 1,2-bis(dimethylphosphino)ethane), [85,86] [(h 5 [88,89] in which other hapticities of the Cp rings occur. It was not possible to provide evidence for the hapticity of the cyclopentadienyl rings in solution, since the 1 H NMR spectrum shows strong line broadening due to the paramagnetism of these species.…”

“…Dichloromethane was distilled first from P 2 O 5 , and then prior to use from CaH 2 . Literature procedures were used to prepare the following compounds: 1,2-bis(dimethylphosphanyl)ethane (dmpe), [108] [(MeC 5 H 4 ) 2 Mn], [85,86] [(MeC 5 H 4 ) 2 Mn(dmpe)], [88] Preparation of Me 3 SnCCSnMe 3 : According to the literature procedure [110] acetylene (1 equiv) was introduced into a solution of nBuLi (2.1 equiv, 1.6 m) in hexane and diethyl ether at À70 8C under nitrogen. After stirring the resulting white suspension for 1 h at this temperature, Me 3 SnCl (2.1 equiv) in diethyl ether was added, and the reaction mixture was stirred for 1 h at room temperature.…”

“…[87] Results and Discussion [88] The compound was crystallized from diethyl ether/pentane at À30 8C. The X-ray crystal structure of this d 5 high-spin complex was determined ( Figure 1).…”