Guanine complexes

Fig. 29. Molecular structure of the C8-palladated guanine complex, 28. Reproduced with permission from Ref. (56). Copyright 2001, Wiley-VCH.

For the second substitution reaction, we have chosen to start from the guanine complex of conformer 1 only. The optimized geometric structures for the reactant complexes, transition states,... 

In the SBDD project that produced (86), the design work was initiated through use of the X-ray structure of the PNP apoenzyme, but was more successful when the structures of the PNP-guanine complex and other complexes were available (199). The PNP-guanine crystal structure showed no important interactions with N9, and indicated a potential for hydrophobic interaction in the vicinity of the substrate ribose (Fig. 10.19). To test this, the 9-deaza compound (87) was synthe-... 

The X-ray structure of the complex between PNP and (87) showed that the hydro-phobic interaction dominated the binding mode, and resulted in the disruption of the hydrogen bonding interactions seen in the guanine complex (i.e., Fig. 10.19). To increase the spacing between the hydrophobe and the purine mimetic, compounds (88) and (89)... 

There is a comparatively rich literature on Cu complexes with nucleic acid bases and nucleotides. Mono- and bis-adenine complexes with Cu exhibit N7 coordination (Figure 14)7 as does the bis-guanine complex." With cytosine, both N3 and 02 positions are found to coordinate Cull 80,81 [Cu (NH3)2] has also been observed in square planar geometry bound to... 

Mo2] with a metal-metal quadruple bond has shown bis-adenine coordination in a bidentate N7, N6 bridging mode and head-to-head arrangement. The bis-guanine complex has also been prepared, showing coordination to 06 and N7 in head-to-head arrangement as observed for the dirhodium complex (see Figure 19). ... 

M. Enescu, B. Levy, and V. Gheorghe, Molecular dynamics simulation of methylene blue-guanine complex in water The role of solvent in stacking,]. Phys. Chem. B 104(5), 1073-1077 (2000). 

A second determination of the structure of the centrosymmetric dimeric guanine complex [CuCl3(C6HeN6O)]2,H20 (75) is in excellent agreement with an earlier analysis. The co-ordination at each copper atom is approximately trigonal-bipyramidal the equatorial sites are occupied by chlorine atoms, the terminal Cu-Cl bonds of 2.369(1) and 2.326(1) A being shorter... 

Stabilization energies of the platinum-base complexes In dependence on the total charge of the (a) adenine and (b) guanine complex... 

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