Germanium and Tin Ligands

Reaction of the 1-pyrazolines (25) with Fe2(CO)g yields initially (26) and, with excess Fe2(CO), (27) is formed.  

The structure of [p-2,3- 2,3-diazabicyclo[2,2,l]heptane diyl-bis(tricarbonyl-iron)] (28) has been reported the Fe—Fe distance is 2.490 Treatment of dialkyl carbodi-imides (RN=C=NR) with Fe(CO)j in refluxing heptane 

Trimethylsilylazide reacts with Fc2(CO)g at room temperature with the elimination on Nj, the trimethylsilylnitrene so formed being fixed by bonding 

H-Kobayashi-Tamura, T. Watanabe, T. Yoshida, and S. Otsuka, Chem. Comm., 1971, 991. 

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Complexes with carbollide ligands have been prepared according to Eqs. (44) and (45) (232,246). These complexes are light yellow sublimable solids, monomeric in solution, in the gas phase, and presumably also in the solid state. Their stability is lower than that of the corresponding germanium and tin species. Their structures (see Fig. 15) have been deduced from spectroscopic data and by analogy with other metallacarborane species. 

Various monocyclic and bicyclic pentacoordinate anionic germanium and tin complexes are known which possess bidentate dianionic oxo and related ligands, such as aliphatic or aromatic 1,2-diols, a-hydroxy carboxylic acids and their thio analogues (for early references see References 191, 307-309). Anionic mono- and bis-chelated germanium and... 

The bistrimethylsilylmethyl ligand has been utilized by Lappert and coworkers to stabilize a number of unusual valence states for lanthanide and transition metals (65-67). In group IV the bis(bistrimethylsilylmethyl)-germanium(II), tin(II), and lead(II) compounds have all been synthesized and the germanium and tin compound shown to be monomeric in cyclohexane solution (68, 69). 

The general area of germanium and tin coordination by bidentate oxygen donor ligands has been reviewed. ... 

The reactions of aminoalcohols, such as aminoethanol and A-methylamino-ethanol, with a number of metal alkoxides were investigated in our laboratories (6). These alcohols depict an interesting variation in the reactivity pattern and nature of the final product(s). For example, in reactions of boron, aluminum, silicon, titanium, and zirconium alkoxides with these ligands only the hydroxyl group was found to be reactive. However, with niobium, germanium, and tin... 

Interactions of Bivalent Germanium and Tin Compounds, with Transition -metal Derivatives. Several investigators have studied the ligand qualities of... 

The chemistry of silicon, germanium, and tin transition metal compounds has been the subject of several reviews (12, 180). Optically active silyl ligands have been introduced in a transition metal complex by reaction of chiral functional organosilanes. However chiral silyl ligands containing complexes are limited to a few metal centers we shall discuss in turn iron, cobalt, platinum, and manganese complexes. 

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