PHOTOCHEMICAL-REACTIONS OF TRANSITION-MET AL ORGANYL COMPLEXES WITH OLEFINS .11. PHOTOCHEMICALLY INDUCED C-C COUPLING OF L-ETA(5)-2,4-DIMETHYL-2,4-PENTADIEN-1-YL-MANGANESE WITH 1-DIMETHYLAMINO-2-PROPYNE - SYNTHESIS OF A TA(5)-7-DIMETHYLAMINO-N-2,4-HEPTADIEN-1-YL-CHELATE COMPLEX

UV irradiation of l-eta(5)-2,4-dimethyl-2,4-pentadien-1-yl-manganese ( 2) in THF at 208 K yields solvent-stabilized thyl-2,4-pentadien-1-yl-t etrahydrofurane-manganese (3), which reacts in situ with two equivalen ts of 1-dimethylamino-2-propyne (4) to -dimethylamino-deca-2,4,6,8-tet raen-1-yl-manganese (5). The crystal and molecular structure was deter mined by an X-ray diffraction analysis. Complex 5 crystallizes in the monoclinic space group P2(1)/c, a = 1109.9(2) pm, b = 836.0(2) pm, c = 2156.9(4) pm, beta = 93.23(3)degrees, V = 1.9982(7) nm(3), Z = 4. Com plex 5 was also studied in solution by IR and NMR spectroscopy. A poss ible formation mechanism of 5 will be discussed.