Beryllium derivatives

In addition, one must consider the possibility of interaction between adjacent groups. This is of particular importance when dealing with the beryllium derivatives in which the metal nucleus is very small and may also be of significance in other systems such as the lithium aggregates. Unfortunately, little quantitative information has appeared with regard to this feature other than statements of distance observed in a few systems. 

The structural data for these systems are collected in Table V along with data for several other beryllium derivatives including the simple hydrides that also form electron-deficient bridged systems of high stability. 

Limited theoretical studies (31, 89) on the electron-deficient beryllium derivatives have been interpreted to imply that extensive Be—Be bonding occurs. If such bonding does occur, the increased bond length observed in the phenylethynyl(methyl)beryllium trimethylamine adduct takes on additional significance since the Be—Be distance in this derivative is increased by almost 0.3 A over that observed in dimethyl-and diethylberyllium. Moreover, if cyclic trimers are formed, then increased metal-metal distances would be likely, thus reducing the probability of stabilization of the bridged system by Be—Be bonding. Additional studies will be required both on structures and of spectroscopic properties of the species to answer these questions. 

The Mg—C distance in the bridge are somewhat longer than the Mg—C single-bond distances observed in the Grignard-type reagents, but comparisons cannot be made with a simple dialkyl since none of the structures have been reported. The Mg—Mg distance is about 2.70 A, which is relatively short and could permit metal-metal interaction for stabilization of the polymeric materials, as suggested for the beryllium derivatives, but neither sufficient experimental data nor theoretical calculations (90) are available to confirm or refute this possibility. 

For s fairly complete discussion of basic beryllium derivatives of organic adds, see reference 2. 

Acids, nomenclature of isopoly and heteropoly, 2 263 nomenclature of oxygen, 2 260 organic, basic beryllium derivatives of, 3 4, 6... 

Barium hexafluorosilicate, preparation of, for decomposition to silicon tetrafluoride, 4 145 Barium paraperiodate (orthoperiodate), Ba3H4(I06)2, 1 171 Barium dezZro-tartrate, for resolution of tris(ethylenediamine)-cobalt(III) ion, 6 184 Barium thiocyanate, 3 24 Benzalazine, in recovery of hydrazine residues, 1 92 Benzoylacetone, beryllium derivative of, 2 19... 

Be(C6H903)2 Beryllium derivative of ethyl acetoacetate, 2 19 Be (Ci oHa02) 2 Beryllium derivative of benzoylacetone, 2 19 Be(Ci5Hu02)2 Beryllium derivative of dibenzoylm ethane, 2 19 (BeO)a,-(BeCOs) Beryllium carbonate, 3 10... 

Very few theoretical studies concern these systems. An example using TD-DFT and the localized density matrix (LDM) method approaches to calculate the electronic spectra of 2-(2 -pyridyl)benzimidazole (111) and its boron and beryllium derivatives 112-114 has been reported recently (10THE(955)7). 

Note The beryllium derivatives of benzoylacetone, dibenzoylmethane, and ethyl acetoacetate are similar to beryllitim acetylacetonate and can be prepared in a similar manner. ... 

Basic beryllium derivatives of organic acids, synthesis 2... 

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