The Structure and Reactivity

Hammen equation A correlation between the structure and reactivity in the side chain derivatives of aromatic compounds. Its derivation follows from many comparisons between rate constants for various reactions and the equilibrium constants for other reactions, or other functions of molecules which can be measured (e g. the i.r. carbonyl group stretching frequency). For example the dissociation constants of a series of para substituted (O2N —, MeO —, Cl —, etc.) benzoic acids correlate with the rate constant k for the alkaline hydrolysis of para substituted benzyl chlorides. If log Kq is plotted against log k, the data fall on a straight line. Similar results are obtained for meta substituted derivatives but not for orthosubstituted derivatives. 

Section 20 2 The structure and reactivity of carboxylic acid derivatives depend on how well the atom bonded to the carbonyl group donates electrons to it... 

Likewise complexes of CSe and CTe have been characterized/ The structure and reactivity of... 

This summary of X-ray investigations of aromatic diazonium salts will concentrate on those results that are essential to understanding the structure and reactivity of these compounds. Most important are, first of all ... 

The experimental work of the groups of Swain and Zollinger on the dediazoniation mechanism of arenediazonium ions, which started in 1975, provided good evidence for the existence of aryl cations as steady state intermediates (see Sec. 8.3). These results also initiated theoretical work on aryl cations, in part combined with further calculations on the structure and reactivity of arenediazonium ions. Publications that contain data on arenediazonium ions and aryl cations will therefore be discussed in the chapter on dediazoniation reactions (Sec. 8.4). In the rest of this section we will concentrate on investigations that are concerned with the geometries and electron densities of diazonium ions but not, or only marginally, with energetics of the dediazoniation reaction. 

The structure and reactivity of dioxygen complexes of the transition metals, M. H. Gubelmann and A. F. Williams, Struct. Bonding (Berlin), 1983,55,1-65 (529). 

The above review on the uses of the CP/MAS NMR techniques in the study of the structural and reactivity properties of various types of carbohydrates and aromatic polymers indicates that despite their limitations, the methods have a wide range of applications. 

Decaborane-14 and Its Derivatives M. Frederick Hawthorne The Structure and Reactivity of Organophosphorus Compounds R. F. Hudson... 

Dechnicke K, Shihada A-F (1976) Structural and Bonding Aspects in Phosphorus Chemistry-Inorganic Derivates of Oxohalogeno Phosphoric Acids. 28 51-82 Denning RG (1992) Electronic Structure and Bonding in Actinyl Ions. 79 215-276 Dhubhghaill OMN, Sadler PJ (1991) The Structure and Reactivity of Arsenic Compounds. 

Taylor CD, Neurock M. 2005. Theoretical insights into the structure and reactivity of the aqueous/metal interface. Curr Opin Solid State Mater Sci 9 49-65. 

Taylor C, Kelly RG, Neurock M. 2009b. First principles modeling of the structure and reactivity of water at the metal/water interface. Submitted. 

In the mechanism of an interfacial catalysis, the structure and reactivity of the interfacial complex is very important, as well as those of the ligand itself. Recently, a powerful technique to measure the dynamic property of the interfacial complex was developed time resolved total reflection fluorometry. This technique was applied for the detection of the interfacial complex of Eu(lII), which was formed at the evanescent region of the interface when bathophenanthroline sulfate (bps) was added to the Eu(lII) with 2-thenoyl-trifuluoroacetone (Htta) extraction system [11]. The experimental observation of the double component luminescence decay profile showed the presence of dinuclear complex at the interface as illustrated in Scheme 5. The lifetime (31 /as) of the dinuclear complex was much shorter than the lifetime (98 /as) for an aqua-Eu(III) ion which has nine co-ordinating water molecules, because of a charge transfer deactivation. 

Consider the effects of the N-R group on the structure and reactivity of polysilazanes as susceptible to hydrogen bonding effects. These effects alone should favor ring closure over the respective siloxane analogs. Moreover, for R = H, a new type of depolymerization reaction, analogous to reaction (4), is available as illustrated in reaction (35). Thus, reaction (35) could also contribute to the... 

Significant recent advances have occured with phosphazenes (J ) and to a lesser extent silizanes (6) in contrast, polymers based on phosphorus(III) and nitrogen are virtually unknown. Because such systems offer opportunities for metal coordination, and in their oxidized forms could be valuable polymer precursors to PON ceramics (2), we have begun systematic studies of the structural and reactivity factors necessary for their formation. 

Langeland and Werstuik <2003CJC525> used ab initio and AIM (atoms-in-molecules) methods to study the structures and reactivity of various phosphate ozonides. Activation energies of the bicyclic complexes (4-ethyl-l-phospha-2,6,7-trioxabicyclo[2.2.2]octane ozonide, l-phospha-2,6,7-trioxabicyclo[2.2.2]octane ozonide, and 1-phos-pha-2,8,9-trioxadamantane ozonide) were found to be significantly higher than the monocyclic structures studied. 

The hydrogen-bonding interactions within the complexes W2CI4-(y-OR)2(OR)2(ROH)2 and V Cli y-OR)2(ORT)2(Rf0H)2 may provide the molecular analogues with which to model the structure and reactivities of transition metal oxide catalysts that possess surface hydroxyl groups. The thermal treatment which is often carried out in the pretreatment of metal oxides (leading to the loss of -OH... 

The data on the structure and reactivity of organoelement betaines I and II presented in the review shows that they lie at the very vivid crossroads of chemical ways, which open alluring new challenges for mutual transitions... 

The mechanisms by which an inhibitor adds to an oxidized hydrocarbon exerts its influence may differ depending on the reaction conditions. If the rate constants of the elementary reactions of RH, InH, R02 , In, ROOH, and 02 are known, the kinetics of the inhibited oxidation of RH can mathematically be described for any conditions. However, such an approach fails to answer questions how the mechanism of inhibited oxidation is related to the structure and reactivity of InH, RH, and R02 or what inhibitor appears the most efficient under the given conditions, and so on. At the same time, these questions can easily be clarified in terms of a topological approach whose basic ideas are the following [43-45,70-72] ... 

Although we are not specifically concerned here with kpp and the kinedcs of carbene-pyridine ylide formation, we note that the magnitude of is directly related to the structure and reactivity of the carbene. fcpyr ranges from 105 M s-1 for ambiphilic alkoxycarbenes to 109-10I° M-1 s 1 for electrophilic halocarbenes or alkylcarbenes. Very nucleophilic carbenes (MeOCOMe) do not react with pyridine.13... 

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