Potential intercalation

In a similar tandem reaction, ethyl 2-azido-l-methyl-l/7-indole3-carboxylate 364 is converted to indolo[3,2- ]l,2,3-triazolo[l,5- ]pyrimidin-5-ones 366 via triazole intermediates 365 that are not separated (Scheme 58). Products 366 are obtained in 80-90% yield as potential intercalates of DNA <2003H(60)2669>. 

Irrespective of deposition potential, intercalation of deposited metal at SAM/substrate interface and bulk growth are labelled as UPD and OPD, respectively. 

In addition to the kink induced by the primary intercalating residue, a second kink two base steps away from the primary kink is revealed in the crystal structure of a complex of the HMG-D box with linear DNA [32]. The second kink arises from partial secondary intercalation in the minor groove of two adjacent residues, valine and threonine, immediately before the N-terminal end of helix II [32,42]. In the HMG boxes of HMGBl and 2, and other non-sequence-specific HMG proteins, a hydrophobic (and therefore potentially intercalating) residue is almost always found in the position corresponding to the valine in HMG-D [32,42] (residue Y in Table 1 and Fig. 2). In contrast, in the sequence-specific HMG... 

The basis of the preference of the A domain, relative to the B domain, of HMGBl for binding to distorted DNA structures has become apparent from numerous structural and biophysical studies. In contrast to the B domain, the A domain has only the secondary potentially intercalating residue, namely Phe at position Y (Table 1 and Fig. 2). This presumably accounts for the smaller bend angle in the A domain/cisplatin-modified DNA eomplex (61°) than in the B domain complex (80-95°) [34,43]. As yet, there is no strueture of a complex between the A domain and linear DNA. However, in the erystal structure of the A domain complexed with cisplatin-modified DNA the domain binds to one side of the cA-platinum adduet. 

One method is to move away from pseudocapacitance and employ a lithium intercalation system to create a hybrid battery-supercapacitor. In this system, graphite (a common choice in battery systems) is a very low potential intercalation material. By appropriately matching the electrode mass, a stable half cell potential near 0.1 V can be maintained for changing lithium concentration in the electrode (Figure 3.19). The lithium stored acts as a supply for ion pairing at the cathode, which is a high performance carbon double-layer material in the form of active carbon [45] or graphene [46]. 

The complexes Ru(bpy)3 and Ru(phen)3 contain such an aromatic ligand, and therefore can potentially intercalate into the DNA helix. These complexes have the additional advantage over simple aromatic compounds, however, in being chiral and therefore existing as enantiomeric pairs. These complexes therefore not only have the potential of intercalating into DNA, but have the possibility of showing enantiomeric discrimination A or A) in their binding with the DNA strands. " ... 

After several trials and in order to decide about the optimum pH for intercalation we came to the conclusion that the potentially intercalable hydroxy-species of the two cations should have dimensions of a few A, probably less than lOOA. Since the conventional optical or electrophoretic methods are not able to detect such species we reach the conclusion that a way to check approximately the size of the species was electrochemically by adjusting the pH in suitable limits. 

After briefly introducing the main electronic features of CNTs (Sec. 2) and some general aspects of electronic conduction and transmission (Sec.. 1), we will show how complex electrical measurements to perform on such tiny entities are (Sec. 4). Then we will present the main experimental results obtained on the electrical resistivity of MWCNT and SWCNT and the very recent data relative to the thermopower of SWCNT bundles (Sec. 5). We will also discuss the effect of intercalation on the electrical resistivity of SWCNT bundles (Sec. 6). Finally, we will present some potential applications (Sec. 7). 

Carbon will react directly at high temperatures with many elements such as sulphur and iron. It also forms intercalation compounds in which a wide range of molecules enter the interlayer spacing of the graphite. This can lead to disruption of the material but also produces a whole new class of potentially useful materials. 

Carbon materials which have the closest-packed hexagonal structures are used as the negative electrode for lithium-ion batteries carbon atoms on the (0 0 2) plane are linked by conjugated bonds, and these planes (graphite planes) are layered. The layer interdistance is more than 3.35 A and lithium ions can be intercalated and dein-tercalated. As the potential of carbon materials with intercalated lithium ions is low,... 

In redox flow batteries such as Zn/Cl2 and Zn/Br2, carbon plays a major role in the positive electrode where reactions involving Cl2 and Br2 occur. In these types of batteries, graphite is used as the bipolar separator, and a thin layer of high-surface-area carbon serves as an electrocatalyst. Two potential problems with carbon in redox flow batteries are (i) slow oxidation of carbon and (ii) intercalation of halogen molecules, particularly Br2 in graphite electrodes. The reversible redox potentials for the Cl2 and Br2 reactions [Eq. (8) and... 

The quality and quantity of sites which are capable of reversible lithium accommodation depend in a complex manner on the crystallinity, the texture, the (mi-cro)structure, and the (micro)morphology of the carbonaceous host material [7, 19, 22, 40-57]. The type of carbon determines the current/potential characteristics of the electrochemical intercalation reaction and also potential side-reactions. Carbonaceous materials suitable for lithium intercalation are commercially available in many types and qualities [19, 43, 58-61], Many exotic carbons have been specially synthesized on a laboratory scale by pyrolysis of various precursors, e.g., carbons with a remarkably high lithium storage capacity (see Secs. 

Whereas the electrochemical decomposition of propylene carbonate (PC) on graphite electrodes at potentials between 1 and 0.8 V vs. Li/Li was already reported in 1970 [140], it took about four years to find out that this reaction is accompanied by a partially reversible electrochemical intercalation of solvated lithium ions, Li (solv)y, into the graphite host [64], In general, the intercalation of Li (and other alkali-metal) ions from electrolytes with organic donor solvents into fairly crystalline graphitic carbons quite often yields solvated (ternary) lithiated graphites, Li r(solv)yC 1 (Fig. 8) [7,24,26,65,66,141-146],... 

Numerous research activities have focused on the improvement of the protective films and the suppression of solvent cointercalation. Beside ethylene carbonate, significant improvements have been achieved with other film-forming electrolyte components such as C02 [156, 169-177], N20 [170, 177], S02 [155, 169, 177-179], S/ [170, 177, 180, 181], ethyl propyl carbonate [182], ethyl methyl carbonate [183, 184], and other asymmetric alkyl methyl carbonates [185], vinylpropylene carbonate [186], ethylene sulfite [187], S,S-dialkyl dithiocarbonates [188], vinylene carbonate [189], and chloroethylene carbonate [190-194] (which evolves C02 during reduction [195]). In many cases the suppression of solvent co-intercalation is due to the fact that the electrolyte components form effective SEI films already at potential which are positive relative to the potentials of solvent co-intercalation. An excess of DMC or DEC in the electrolyte inhibits PC co-intercalation into graphite, too [183]. 

Carbon dioxide as additive improves the behavior of (Li02C0CH2)2 films formed above intercalation potentials in EC/DEC-based electrolytes due to increased formation of Li 2 CO 3 [200], It is interesting to note that SO2 reduction occurs at quite high potentials, before the reduction of other electrolyte components films contain inorganic and organic lithium salts [201]. 

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