Coordination theoretical analysis

In agreement with the theoretical analysis, C2- and /(-symmetric metallocenes scarcely insert ( > and (Z)-butene, respectively, whereas C2- and Cs-symmetric metallocenes insert relevant fractions of (Z)- and (//(-butene, respectively. Moreover, in agreement with QM/MM analysis, when copolymerization experiments are run with a 40% (Z)-2-butene-60% ( )-2-butene mixture, the presence of the better coordinating (Z)-butene inhibits the reaction... 

The potential carbodicarbene C(C(NMe2)2 2 has been known for a long time but no complex has been reported [101, 102]. It adopts a linear allene geometry in the free state but according to theoretical analysis exhibits a strong nucleophilic central carbon atom [4, 97] and can be seen as an allene with a hidden divalent carbon(O) character emerging in the presence of electron deficient electrophiles. Based on these findings a new field of chemistry will be opened and the number of compounds with a coordination mode should increase in the future. 

HD-X induced dipoles. The HD molecule differs from H2 by its greater mass (which is of little concern here), the weak permanent dipole moment which arises from a non-adiabatic mechanism, and a center of mass which does not coincide with the center of electronic charge. Dipole moments are defined with respect to an origin that coincides with the center of mass. The presence of the permanent dipole leads to well-known rotational and rotvibrational spectra of RV(J) lines which show an interesting dispersion shape, arising from the interference of the induced and the allowed dipole spectra. For a theoretical analysis, one needs the induced dipole components of pairs like HD-X, with X = He, Ar, H2 or HD. These have been obtained previously [59] from the ab initio data for the familiar isotopes summarized above, using a simple coordinate transform familiar from potential studies of the isotopes. 

Peacock, R. D. Stewart, B. Chiral molecules spectroscopy. In Comprehensive Coordination Chemistry II From Biology to Nanotechnology. Fundamentals Physical Methods, Theoretical Analysis and Case Studies, Lever, A. B. P, Ed. Elsevier Pergamon, 2004 Vol. 2, pp 65-81. 

One of the most useful static methods of microscopic chemical kinetics is based on the definition of the reaction path as introduced by Fukui. This method offers information on reactions in terms of the intrinsic reaction coordinate (62,144). A theoretical analysis of the minimum energy path was given in Section III,B. Fukui s definition is equivalent to Eq. (34). 

For hexa-coordination, the metal atoms are usually found in their highest oxidation state corresponding to a minimum radius for the element. The experimental results support theoretical analysis [44], in that the optimum arrangement of six monodentate ligands around a metal atom is octahedral. In the case of non-identical ligands, the metal-ligand... 

Proceeding to two rings going-on one class, neutral derivatives of bicyclobutane with the two non-bridgehead carbons replaced by sp hybridized or trigonally coordinated atoms show self-destructive behavior for related reasons (see Chapter 19 by Hoz for a review of bicyclobutanes). Our suicidal species include the hypothetical bicyclobutane-2,4-dione (51) and its 1,3-disubstituted derivatives, recognized as squaraines (52) . The theoretical analysis of the parent diketo compound suggests the non-planar form also lacks the C-C bond. The 2,4-dibora compounds are experimentally known to be... 

This study deals with group-theoretical analysis of JT systems, especially with the prediction of the symmetries of the structures caused by JTE. Two alternative treatments based on JT active coordinates and on the step-by-step splitting degenerate electronic states are explained and their results are compared within several examples. Despite producing equal results for some low-dimensional groups, both treatments have their advantages and shortages. 

In spite of the elimination of formic acid in a couple of steps changing the oxidation number of the rhodium metal center from -nl to -i-3 and vice versa, the reaction could take place by an alternative mechanistic pathway via cr-meta-thesis between the coordinated formate unit and the nonclassical bound hydrogen molecule [48, 49]. Initial rate measurements of a complex of the type 13 show that kinetic data are consistent with a mechanism involving a rate-limiting product formation by liberation of formic acid from an intermediate that is formed via two reversible reactions of the actual catalytically active species, first with CO2 and then with H2. The calculations provide a theoretical analysis of the full catalytic cycle of CO2 hydrogenation. From these results s-bond metathesis seems to be an alternative low-energy pathway to a classical oxidative addition/reductive elimination sequence for the reaction of the formate intermediate with dihydrogen [48 a]. 

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