Atom Insertion

Benzonitrile with [(i -Cp )P W(CO)5 2] gives 82, the result of migration of the phosphorus atom, insertion of the nitrile moiety into the P-C bond and further C-H bond activation (01AGE3413). 

A positive value of ME means that the insertion of a hetero atom or group makes the molecule more lipophilic. If ME is negative, the hetero surfactant is more hydrophilic. In general, hetero atom insertion hydrophilizes the surfactant molecule as does the shift of the hetero group to the middle of the carbon chain [71]. ME values are temperature-dependent. / and ME values can also be useful to take into account the influence of various cations on the critical micelle concentration. 

The mechanism involves a metal atom insertion into the O—H bond, thus resulting in the formation of an adsorbed metal—OH species (at the same or similar binding site) and a new metal—H bond. This is a classic bond activation process, which involves a significant stretch of the O—H bond in order to lower the antibonding ooh orbital to enable it to accept electron density from the metal. The reaction has been calculated by DFT to be endothermic by +90 kJ/mol over Pt(lll) surfaces with an activation barrier of +130 kJ/mol [Desai et al., 2003b]. 

In addition to halogen bonded complexes or ionic salts, it is also possible for sulfur and selenium electron donors to form complexes in which the electron donor atom inserts into the X2 bond, giving a hypervalent donor atom with a T-shaped geometry. It has been recently reported [147] that for dibromine and selenium, this type of complex is favored over halogen bonded complexes. While no purely halogen bonded complex is reported for dibromine, there is one complex (IRABEI) in which one selenium atom of each of several selenanthrene molecules in the asymmetric unit does insert into a Br2 bond, but for one of the molecules, the other selenium atom forms a halogen bond with a Br2 molecule to form a simple adduct (A). 

Dislocations are line defects that occur in crystals. There are many types of dislocation. The easiest to visualize are the edge dislocation, which consists of an extra half-plane of atoms inserted into a crystal and the screw dislocation that resembles... 

This structure can be considered a superstructure of the AuCu(I) type with 1N atom inserted in an octahedral interstice. This structure, as the previously described cP5-Fe4N type, can be considered an interstitial ordered phase. 

In a defect tetrahedral structure not all the four vertices are occupied by an atom. A filled tetrahedral structure contains extra-atoms inserted in a normal tetrahedral structure. The bonding mechanism, however, may be different from that of the other tetrahedral structures and, generally, less simple relations are observed between the number of valence electrons and structure. 

The activated oxygen atom inserts itself into a C-H bond in the substrate, thereby forming an OH group. 

The balanced reaction must have equal loss and gain of electrons, so there must be two times as many N atoms as Cu atoms. Insert a coefficient of 2 in front of NO3 and NOj ... 

Isaacs, N. W. and Agarwal, R. C. (1985). Free atom insertion and refinement as a means of extending and refining phases. Methods Enzymol. 115,112-117. 

As already briefly mentioned, the oxygen-atom insertion into Si—H bonds of silanes constitutes a selective method for the chemoselective preparation of silanols, which has been much less studied compared to the CH oxidation. This unique oxyfunctionalization of silanes is also highly stereoselective (equation 35) since, like the CH insertions, it proceeds with complete retention of configuration. A novel application of the SiH insertion process is the synthesis of the unusual iron complex with a silanediol functionality, in which selectively both Si—H bonds of the silicon atom proximate to the iron ligand are oxidized in the silane substrate (equation 36). ... 

The MgO+ ion has significant radical character and reacts via electron transfer (equation 32). It is also a potent H atom acceptor, readily reacting with water via H atom abstraction (equation 33, X = HO). A recent combined experimental and theoretical study reveals that the MgO+ ion readily activates the C—H bond of methane to yield MgOH+ as the major product ion (equation 33, X = CH3) as well as Mg+ as a minor product ion via O atom insertion into the C—H bond (equation 34). ... 

Fig. 1. Schematic energy profile for Co atom insertion into 2HP +ZPE in kcal mol 1 at B3LYP/6-31G(d) (first entry), B3LYP/6-31G(d,p) +LANL2DZ (second entry), and B3LYP /6-31G(d) (third entry) (113).

By far the most common way for organic molecules to enter late transition metal catalyzed reactions is oxidative addition. In this process a low valent palladium(O)3 or nickel(O) atom inserts into a carbon-heteroatom bond, usually of an aryl halide or sulfonate (Figure 1-2). The formation of the carbon-metal bond is accompanied by an increase in the oxidation number of the metal by 2. There are a series of factors determining the speed of the process. 

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