Electronic configuration and reactivity

In summary, it appears that the chemical activity of the elements is based primarily on electron configuration and then on outermost electron distance from the nucleus. Mostly because of their electron configuration, the transition metals, in the middle of the periodic table (next to the noble gases), are the most stable elements. They are not very reactive with other elements. This is why these transition metals, the so-called heavy metals, make such good jewelry material. However, other important factors are their shiny luster, ductility, and malleability. 

Vibrationally equilibrated electronic excited states in molecules are unique chemical species. These are metastable species with unusual electronic configurations, and on this basis alone they might be expected to exhibit unusual patterns of reactivity. However, it is probably a more striking feature... 

Some groups or families are given special names and have certain properties that should be addressed. But first you must understand why elements are put into the same group. Think about a family you know, not a chemical family, but a human family. Children look like their parents. They learn to do things from their parents and do them in the same way. The same holds true for the elements in the families of the periodic table they react the same way (for the most part). As you learned in the last chapter, each element has a certain number of valence electrons. As you will learn in the next chapter, it is the number of valence electrons of an atom that determines its chemical reactivity. Because the elements in a family have the same number of valence electrons, they will have a similar chemical reactivity. For example, Na and K can be compared in electron configuration and ions formed ... 

Compounds containing silicon bonded to only one other atom are unstable and are usually only generated and observed as reactive intermediates of short half-life. Silicon compounds subjected to flash photolysis or electrical discharges in the gas phase produce short-lived species SiX (X = H, F, Cl, Br, I, C, Si, etc.), the band structure of which have been studied in detail. The structures, electronic configurations, and so on of Six (X = H, F, Cl, Br, I, N, O, etc.) have also been the subject of MNDO (modified neglect of diatomic overlap) and other calculations. ... 

The analogy developed above between pentacoordinated complexes and organic free radicals is capable of meaningful extension to coordination compounds of other electron configurations and coordination numbers see Table III). Thus, similar reasoning leads to the expectation of similarities between the reactivity patterns of tetracoordi-nated d complexes and carbenes, pentacoordinated d complexes and carbanions, and pentacoordinated d complexes and carbonium ions. In each case the stoichiometries of the reactions which restore the stable closed-shell configurations are the same for both species hence the similarity of reactivity patterns. 

The existence of relatively stable but highly reactive complexes of transition metals which, by virtue of their electron configurations and... 

Problem 2.3 Besides free radicals, we shall encounter two other kinds of reactive particles, carbonium ions (positive charge on carbon) and carbanions (negative charge on carbon). Suggest an electronic configuration, and from this predict the shape, of the methyl cation, CHj of the methyl anion, CH3 . 

The configuration and reactivity of methyl radical-cyanide ion pairs produced by dissociative electron capture in the two solid phases of CH3CN have been studied by e.s.r. techniques using CD313CN.103 The results indicate that the radical configuration is planar and that the reactivity of the radical (as estimated from hydrogen-abstraction rates) in crystal I is at least 10 times greater than in crystal II. 

Which group of elements is called the halogen elements Describe their electron configurations and discuss their reactivity. Name two elements that belong to this group. 

The halogens—fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At)—are active nonmetals. Because of their chemical reactivity, they don t exist as free elements in nature. Their chemical behavior is characterized by a tendency to gain one electron to complete their valence-electron configuration and form a 1 — ion with a noble-gas configuration. Chlorine, for example, has the configuration [Ne]3s 3p. ... 

Abstract The transition metal complexes of the non-innocent, electron-rich corrole macrocycle are discussed. A detailed summary of the investigations to determine the physical oxidation states of formally iron(IV) and cobalt(IV) corroles as well as formally copper(III) corroles is presented. Electronic structures and reactivity of other metallocorroles are also discussed, and comparisons between corrole and porphyrin complexes are made where data are available. The growing assortment of second-row corrole complexes is discussed and compared to first-row analogs, and work describing the synthesis and characterization of third-row corroles is summarized. Emphasis is placed on the role of spectroscopic and computational studies in elucidating oxidation states and electronic configurations. 

The sequence of reactivity of the divalent first-row transition metal ions does not correlate with the radii of the ions and is largely independent of the reaction mechanism. The rate constants are sensitive to the electron configuration and semi-quantitatively coincide with predictions based on ligand field activation energies and molecular orbital calculations [23, 33, 34]. 

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