Beryllium bonding

The Alkaline-Earth Metals.—Magnesium, calcium, strontium, and barium form essentially ionic bonds with the more nonmetallic elements. Beryllium bonds have the following amounts of ionic character Be—F, 79 percent Be—O, 63 percent Be—Cl, 44 percent Be—Br, 35 percent Be—I, 22 percent. 

P.J. Bruna et al., Beryllium-beryllium bonding. 1. Energetics of protonation and hydrogenation of beryllium dimer and its ions. J. Phys. Chem. 96, 6269-6278 (1992)... 

Divalent beryllium bonds through two equivalent sp, or tSgonal, hybrids. The appropriate Kxiizaiion energy therefore is not that of ground state beryllium, but an average of those energies necessary to remove electrons from the promoted, valence state ... 

These pictures clearly do not individually correspond to two sp hybridized orbitals on beryllium bonding as a result of an overlap with two Is orbitals on hydrogen. However, if they are equally weighted, their positive and negative contributions give the same final result, which may be viewed as the sum of Rgure 1.14c or, more traditionally, as Figure 1.14d. 

Since beryllium bonds have attracted much attention in recent years, the first part of this study will focus on the information that the CD scheme provides on these kind of linkages, when the base that interacts with the beryllium derivative presents as basic sites first or second-row atoms. In particular, we have studied the beryllium bond between BeH2 or BeF2 and H2O, SH2, NH3 and PH3. 

The optimized geometries of the binary complexes under scmtiny, indicating the corresponding beryllium bond distances, are represented in Pig. 17.1. 

The 3D contour plots of the electron density changes accompanying the beryllium bond formation in H2Be-OH2 and p2Be-OH2 are reported in Pig. 17.2, as a suitable example. Beryllium bonds for both the complexes are characterized by significant electron density rearrangements all over the whole molecular region of... 

Cooperativity Between Beryllium Bonds and Halogen Bonds. The F2Be FCl NCH Complex... 

Fig. 17.10 Solid lines are the CD functions for the formation of the Be - F bond in F2Be FCl NCH black) and F2B FC1 green). The dotted black line corresponds to the formation of the beryllium bond in the binary complex when atomic positions are frozen to the ones of the ternary complex. In all cases, the z-axis is the one joining the beryllium and the fluorine atom (FCl) and the Be atom lies in the raigin black dot in the z axis). The vertical line identifies the isodensity boundary of the ternary complex...

In the BeF2 FCl binary complex, the formation of the Be bond leads to a distortion of the toms associated with the disynaptic F-Cl basins of the isolated molecule. This distortion, due to the polarization effects associated with the beryllium bond, increases on going from the BeF2 FCl binary complex to the BeF2 FCl N-base ternary ones. Note that for the particular case of NHCH2, where cooperativity is stronger, the ELF shows the formation of a Be-F disynaptic basin. 

Yanez M, Sanz P, Mo O, Alkorta I, Elguero J (2009) Beryllium bonds, do they exist J Chem Theor Comput 5 2763-2771... 

Fernandez Villanueva E, Mo O, Yanez M (2014) On the existence and characteristics of pi-beryllium bonds. Phys Chem Chem Phys 16 17531-17536... 

Mo O, Yanez M, Alkorta 1, Elguero J (2012) Modulating the strength of hydrogen bonds through beryllium bonds. J Chem Theory Comput 8 2293-2300... 

Yanez M, Mo O, Alkorta 1, Elguero J (2013) Can conventional bases and unsaturated hydrocarbons be changed into gas-phase superacids stronger than most of the known oxyacids the role of Beryllium bonds. Chem Eur J 35 11637-11643. doi 10.1002/chem. 201300808... 

Montero-Campillo MM, Lamsabhi AM, Mo O, Yanez M (2013) Modulating weak intramolecular interactions through the formation of beryllium bonds complexes between squaric acid and BeH2. J Mol Model 19(7) 2759-2766. doi 10.1007/s00894-012-1603-0... 

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