Synthesis and reactions of organotransition metal complexes
The insertion of bivalentorganotin derivatives (bis- pentamethylcyclopentadienyl, cyclopentadienyl chloride and bromide) into the iron-iron bond of diiron nonacarbonyl yields three dimeric bridging complexes. These complexes were charac- II terized by infrared, tin-119m Mossbauer, proton and carbon-13 NMR spectroscopy. The structures of these complexes contain a four membered ring framework containing two atoms of tin and iron with monohapto pentamethylcyclopentadienyl or cyclopentadienyl and halide ligands on each tin and four carbonyl ligands on each iron. These complexes undergo ring fission in bases yielding a monomeric, base stabilized species. Attempts to react these bivalentorganotin ligands with other metal-carbonyl compounds failed to give terminal or base-stabilized coordination products. Platinum and nickel complexes of 2-phenylmethylenecyclo- propane were prepared from the displacement reaction of ethylene-metal compounds with 2-phenylmethylenecyclopropane. The cyclopropane ring in these complexes is not opened when they are heated in aromatic solvents; instead free triphenylphosphine and triphenylphosphine-metal complexes are formed. No cycloaddition reaction takes place between the complexes with dimethylfumarate or norbornene. Attempts failed to prepare exo-unsaturated metalla- cyclobutane and pentane complexes of platinum or zirconium from the reaction of modified isobutylene and 2,3-dimethyl-l 3-butadiene dianions with corresponding metal-dichloride. The 2,3-dimethyl(tri-methylsilyl)-1,3-butadiene dianion also failed to give metallacyclopentane complexes.