Organometallic bonds

Organometallic Bonding and Ractivity Fundamental Studies Volume Editor J.M. Brown, R Hofmann... 

Organometallic Bonding and Reactivity. Fundamental Studies, Brown, J. M. Hofmann, P., Eds., Top. Organomet. Chem. Vol. 4, Springer-Verlag Heidelberg, 1999. 

Macchi P, Sironi A (2004) Variable-temperature X-ray crystallographic studies a complementary tool for charge-density investigation of soft (organometallic) bonds. Acta Crystallogr A 60 502-509... 

It is of considerable interest to understand under what conditions such an unusual organometallic bond is produced. Not surprisingly, such a bond does not result from the addition of adenosine to the vitamin. It has been demonstrated that the formation of the bond, starting with the hydroxo form of the vitamin, requires ATP (7,51) (and a metal ion), and that the triphosphate is split from the ATP in two steps (7) (Figure 11). In the first step the ATP loses orthophosphate, yielding ADP, which probably becomes bound to the cobalt through the pyro-... 

The polymerization of olefinic materials by organometallic catalysts involves different types of initiation, transfer and termination reactions. In the past discussion we have referred to chain transfer which involved the exchange of one organometallic bond for another in the active catalyst species. This involved the equilibrium exchange of alkyl metals. However, another group of important reactions include the formation and destruction of alkyl bonds. These reactions follow the same ionic factors which apply to polymerization reactions. 

A possible explanation for the discrepancy between our findings and those of others must first be sought in terms of both the solid treatment and the purity of the polymerization system. It is generally accepted (3) that an organometallic bond (whether in form of A1—C or Ti—C) is essential for polymerization. The amount of organometallics in a separated solid is very... 

D. Braga and F. Grepioni, in Organometallic Bonding and Reactivity - Fundamental Studies, Eds J. M. Brown and P. Hofmann, Springer, Berlin, 1999, p. 47. 

During the last 10 years, significant advances have been made in the area of organometallic bonding energetics. Most data were obtained from solution calorimetric studies. In the present chapter, a compilation of thermochemical data on organometallic systems is presented. This account represents a survey and is by no means exhaustive yet we have endeavored to provide the reader with as much data as possible in an effort to complement the contribution found in the first edition. 

In these cases, the carbon atom is at the negative end of the bond. This means that it is liable to be attacked by positive species, or that the carbon is on the way to becoming a carbanion. This is the case for organometallic bonds in general. 

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