Profile volume

Fig. 6. A volume profile for the substitution of Hipt on [Be(H20)J2 to form lBe(H20)2ipt]+ (73).

Fig. 9. Reaction volume profile for the substitution of [Fe(DMF)6]2+ by trans-pyridine-2-azo( p-dimethylaniline), pada (147).

The volume profiles for the ligand substitutions on [Pd(H20)4]2+, shown in Fig. 12, exhibit an overall contraction in the transition state (AVfi) as DMSO substitutes for H20, a smaller one as MeCN substitutes, and a yet smaller one as water substitutes. The three negative AV values are identical within experimental error and also indicate a contraction to the transition state. It is particularly interesting that the difference in volume between the transition state and the reactants is independent of the leaving ligand when the entering ligand is water. Release of either DMSO or MeCN into bulk solution would produce a... 

St. Pierre, C. C., and S. G. Bankoff, 1967, Vapor Volume Profiles in Developing Two-Phase Flow, Int. J. Heat Mass Transfer 10 231. (3)... 

Based on the reaction network in Example 18-8, calculate and plot the temperature (7)-volume (V) profile and the concentration (c,)-volume profiles for a set of independent species in a PFR operated adiabatically. Consult the paper by Spencer and Pereira (1987) for appropriate choice of feed conditions and for kinetics data For thermochemical data, consult the compilation of Stull et al. (1969), or an equivalent one. 

Fig. 2. Volume profiles, connected to the transition states, for the spectrum of solvent exchange processes.

Detailed kinetic studies of the reaction of Fe(II) in cyclophane hemes with 02 and with CO probed polarity and steric effects the effects of deformation of the porphyrin skeleton from planarity were assessed for one compound (121). Volume profiles have been established for reactions of a lacunar Fe(II) complex with CO (122 for myoglobin with 02 and with CO and for hemerythrin with 02 (123). 

Figure 13. The overall density (volume fraction) profile for DMPC bilayers is shown here. Apart from the distribution of the overall DMPC molecules, the density distribution of the head-group units (including the choline group, the phosphate group and the oxygens of the glycerol unit), and the end groups of the lipid tails are also indicated. In addition, the free-volume profile and the water profile are depicted...

Carbon-graphite fibers, 24 614 Carbon-graphite materials, 12 747-748 Carbon-half moly, 17 16 Carbonic acid, 4 805 6 290 Carbonic anhydrase (CA) inhibitors, antihypertensives, 5 169 Carbonic anhydrase volume profile,... 

The pressure dependence of the forward and reverse reactions resulted in significantly positive volumes of activation (36), and the volume profile reported in Fig. 1 clearly demonstrates the dissociative nature of the substitution process. Such conclusions can more easily... 

Fig. 4. Volume profile for the two-step reversible aquation of [Pt(R1-en)Cl2], where Rren = (lR,2R,4S)-exo-2-(ammomethyl)-2-amino-7-oxabicyclo[2.2. ljheptane. 

Fig. 5. Volume profile for the reaction of aquacobalamine with 3-acetylpyridine.

In a recent publication from our laboratory (87), the substitution behavior of the Cu(II) complex of the trimethylated tren (Me3tren, each amino-terminal nitrogen is monomethylated) was studied. The substitution of the coordinated water molecule by pyridine was only slightly slower than in the tren case. The activation volumes of -8.7 4.7 cm3 mol-1 for the forward reaction and -6.2 1.1 cm3 mol-1 for the reverse aquation reaction (see the volume profile in Fig. 7) indicate that substitution occurs via an associative pathway and that the steric influence is not as significant as in the case of Me6tren. 

Reviews on the activation of dioxygen by transition-metal complexes have appeared recently 9497 ). Details of the underlying reaction mechanisms could in some cases be resolved from kinetic studies employing rapid-scan and low-temperature kinetic techniques in order to detect possible reaction intermediates and to analyze complex reaction sequences. In many cases, however, detailed mechanistic insight was not available, and high-pressure experiments coupled to the construction of volume profiles were performed in efforts to fulfill this need. 

Fig. 14. Volume profile for the carbonic anhydrase catalyzed hydration of C02 and dehydration of HC03. ...

It has in general been the objective of many mechanistic studies dealing with inorganic electron-transfer reactions to distinguish between outer- and inner-sphere mechanisms. Along these lines high-pressure kinetic methods and the construction of reaction volume profiles have also been employed to contribute toward a better understanding of the intimate mechanisms involved in such processes. The differentiation between outer- and inner-sphere mechanisms depends... 

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