Germylenes structure

VIII. MICROWAVE SPECTRA OF GERMYLENES. STRUCTURES OF SHORT-LIVED CARBENE ANALOGS... 

Whether these results will also have an impact on the theory of metallaallenes is difficult to predict at least for the compounds Cp (CO)2Mn = M = Mn(CO)2Cp, (M = Ge, Sn, Pb) a linear structure is established and also linear p-carbido complexes are known [198], Recently, a germanium compound has been synthesized which is directly comparable with 22. In this case, the starting material for the synthesis is not a monomeric base adduct, but a dimeric germylene complex which is cleaved by Na2Fe(CO)4 in pyridine to form 72 [199],... 

A bis(chelate) structure was found for the closely related germylene [MeC(NPr )2]2Ge, which was also made from GeCl2(dioxane) and 2 equivalents of the lithium amidinate (colorless crystals, 81%). The same synthetic approach was used to make bis(amidinato) metal dichlorides of silicon and germanium in high yields (83-95%). Rapid oxidative addition of chalcogen atom sources (styrene sulfide and elemental Se) to the germylene derivatives resulted in a series... 

The stability of molecules depends in the first place on limiting conditions. Small, mostly triatomic silylenes and germylenes have been synthesized successfully at high temperatures and low pressures, 718). Their reactions can be studied by warming up the frozen cocondensates with an appropriate reactant, whereas their structures are determined by matrix techniques 17,18). In addition, reactions in the gas phase or electron diffraction are valuable tools for elucidating the structures and properties of these compounds. In synthetic chemistry, adequate precursors are often used to produce intermediates which spontaneously react with trapping reagents 7). The analysis of the products is then utilized to define more accurately the structure of the intermediate. 

Bis(amido)-germylene and -stannylene react with [Pt(COD)2] to give the platinum(O) complexes [Pt(M NTMS 2)3], M = Ge or Sn.78 The stannylene complex has a trigonal-planar structure with Pt—Sn bond lengths of 2.47-2.50 A.79... 

Germylene 185 can be reduced with substoichiometric amounts of KCg to give the cyclotrigermenyl radical 186, which has been structurally characterized (Equation (329)), while reaction of 185 with an excess (2 equiv.) of KC8 produces 187 which is the germanium analog of the allyl anion (Equation (330)).400 The structure of 187 has been obtained as well. 

Four new stable digermenes 66-69 were synthesized from dichlorogermanes and sodium in toluene or lithium naphthalenide (Scheme 10). 66 and 68 have been characterized by X-ray61 (see Section III,B,1). 66-6851 keep their digermene structure in solution, in contrast to 6960 (probably the E isomer due to the steric hindrance in the Z isomer), for which an interconversion with the corresponding germylene was observed. 

STRUCTURES OF SILYLENES AND GERMYLENES 3.1. Singlet and Triplet States... 

Their structures had been much less explored than those of their heavier congeners such as germylenes and stannylenes. Although dodecamethylsilicocene (19), formally also a silylene, has been known since 1986, compound 19 is stabilized by ri -coordination of pentamethylcyclopentadienyl ligands and is not a congener of a carbene. 

As for stable diarylgermylenes, three examples (146, 147, ° and 148, Scheme 14.65) have been structurally analyzed by X-ray crystallographic analysis. The solid-state structure of germylene 146 indicated that its remarkable stability is mainly the result of intramolecular coordination of the fluorine atoms of the -CF3... 

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