Kohlenwasserstoffverbrückte Metallkomplexe, XVIII. Heterometallische Ethylen‐verbrückte Komplexe (OC)₅ReCH₂CH₂Mn(CO)₅, (OC)₅ReCH₂CH₂Ru(CO)₂Cp, (OC)₅ReCH₂CH₂Os(CO)₄CH₂CH₂Re(CO)₅und (OC)₅ReCH₂CH₂CH₂Os(CO)₄Os(CO)₄(CO)₄Os(CO)₄CH₂CH₂Re(CO)

Abstract

der Ziegler-Natta-Polymerisation von Ethylen 61, der Platin-katalysierten Umlagerung von Kohlenwasserstoffen 7, und der OlefinMetathese*).C2-Verbruckte Komplexe sind vom Typ A -C bekannt.

Active‐Site‐Matched Fluorescent Probes for Rapid and Direct Detection of Vicinal‐Sulfydryl‐Containing Peptides/Proteins in Living Cells

“…For (OC) 5 Mn–CH 2 CH 2 –Re(CO) 5 a dyotropic exchange of the pentacarbonylmetal groups could be observed at room temperature by NMR experiments,93 a dynamic behavior, which was defined by Reetz 94. This 1, 2‐exchange was previously observed for (OEP)Rh–CH 2 CH(Me)–Rh(OEP) (OEP = octaethylporhyrinate) 95…”

Manganese Alkyls and Hydrides

“…Thus, to the extent that this result is general, catalysts such as polar solvents and OPPh 3 exercise their influence not by increasing the concentration of solvate (54) (or (52a(S))), but by catalyzing the formation of the unsaturated intermediates (53) (or (52a)). If this result is general, the stereochemistry of the CO insertion at the metal is a reflection o f the geometry of intermediate (52a) or (53) and not (52a(S)), (54), or (52c). In addition, the lifetime o f the intermediate actually being trapped would generally be less than a nanosecond rather than o f the order of microseconds, as is usually inferred.…”

“…With most other traps, such as PPh 3 or MnH(CO) 5 , product formation is much too fast compared with reversion of the intermediate to starting material for the kinetic analysis to work. Their kinetic results clearly show that it is intermediate (53), not (54), which is trapped by the hydride. Thus, to the extent that this result is general, catalysts such as polar solvents and OPPh 3 exercise their influence not by increasing the concentration of solvate (54) (or (52a(S))), but by catalyzing the formation of the unsaturated intermediates (53) (or (52a)).…”

“…The insertion step is accelerated by donor solvents, but even more by nucleophilic catalysts such as OPPh 3 . An important feature of this reaction is that MnH(CO) 4 (PMe 2 Ph) traps intermediate (53) or (54) sufficiently slowly that rates of product formation and starting material reformation are comparable. With most other traps, such as PPh 3 or MnH(CO) 5 , product formation is much too fast compared with reversion of the intermediate to starting material for the kinetic analysis to work.…”

The controlled synthesis of triosmium chain clusters

“…eq-C1 and ax-SnC1,R) at the linear triosrnium centre (10). Other important triosrnium dodecacarbonyl chain derivatives prepared include 1,3-ax,a~-Cl~SiOs~(CO)~~SiCl~ (1 1) from 0s3(CO),, and HSiCl, and 1 ,3-eq,eq-(CO),ReCH2CH20s3(CO) ,,CH2-CH,Re(CO), from H20s3 (CO),, via deprotonation with KH (12). The reaction of 0s3(CO),, with ClAuPPh, was originally reported to yield ClOs3(C0),,AuPPh, (13) but this compound was later found to be 0s3(CO),,(~-AuPPh,)(p,-C1) with a triangulo structure (14).…”