Organometallic structures

The two major databases containing information obtained from X-ray structure analysis of small molecules are the Cambridge Structural Database (CSD) [25] and the Inorganic Crystal Structure Database (ICSD) [26] both are available as in-house versions. CSD provides access to organic and organometallic structures (mainly X-ray structures, with some structures from neutron diffraction), data which are mostly unpublished. The ICSD contains inorganic structures. 

A priori borataethenes would be expected to be much more stable than the corresponding boraethenes because, as Rundle presciently noted about organometallic structures,50 all low-lying atomic orbitals are involved in the bonding. In fact, the stabilization of 52 is the driving force for the acidity of C—H bonds of proper orientation a to tricoordinate boron. Such acidity was first detected by Rathke and Kow through the treatment of B-methyl-9-borabicyclo[3.3.1] nonane (53) with hindered lithium amides, such as lithium 2,2,6,6-tetramethylpiperidide51 (Eq. 18) ... 

Alkali Metal Organometallics - Structure and Bonding, Pages 1-65, K. Ruhlandt-Senge, K.W. Henderson and P.C. Andrews... 

Another kind of problem may be when some types of models are entirely left out of consideration. Examples for this may be found, e. g., among organometallic structures including those discussed in this review. It seems to me that more benefit of the doubt should be given to more models especially in areas which are new to stmctural elucidation. 

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