Dimetallic Complexes with Bridging Seven‐membered Cycloolefins. Synthesis, Multinuclear NMR.‐Spectroscopic Properties and Structure

Abstract

SummaryThe synthesis of dimetallic olefin complexes of the type L'M'C7H7M2L2 (M' = Fe, Co, Rh; M2= Rh, Ir, Pd; L' = CO, C5H5; L2= diene, allyl, P (OR),) is described. The fluxional structures were investigated by I3C-, 57Fe-and Io3Rh-NMR.-spectroscopy, and a cisoid dimetallic coordination, including a (metal, metal)-bond, can be deduced for the C,H,-ring. 57Fe-and Io3Rh-chemical shifts give indications for the charge distribution in the 34e-complexes. The homodimetallic complex (Cp) Rh (tropone) Rh (Cp) (13, Cp = cyclopentadienyl) and the corresponding 2-methoxytropone complex 14 were synthesized in addition to the above mentioned complexes. A fluxional bis (1-3-~-allyl)-coordination of the two Rh-atoms was derived from the temperature-dependent 13C-NMR.-spectra. A spin simulation of the (Cp)-multiplets of 12 and 13 yields information about (Rh,Rh)-spin-coupling which amounts to z 5 Hz at 30".

Rh NMR studies of organometallic rhodium(I) derivatives

“…Chemical shifts, 6 (ppm), are related to the rhodium metal frequency and are positive €or a frequency higher than the reference. Compound 1 was used as a secondary reference (64K data points; spectral width, 40 000 Hz; digital resolution, 1.2 Hz; pulse width, ca 30"; exponential filter, 1 Hz; no relaxation delay).…”

Vom Tripeldecker zum Metallabenzol: eine neue Generation von Sandwichkomplexen

“…), 52.1 (CCH,), 25.0 (CH,). MS (70 eV): m/z (%): 384 (100, M + ) , 368 (64), 353 (18). 352 (12), 351 (8).…”