Coordination chemistry guanine

Amino complexes of Ru +/Ru + act similarly to their platinum relatives, Pt +/Pt + see Ruthenium Inorganic Coordination Chemistry). Although coordination of [(NH3)5Ru] + to N7 of guanine residues in DNA does not... 

SER effects have been observed for a number of adsorbates on copper hydro-sols. Triphenylphosphine, diphenyl sulfide, and benzotriazole all partially displace adsorbed pyridine from colloidal copper and result in SER spectra which contain both pyridine bands and those of the coadsorbate. Diphenyl sulfide and thio-phenol were found to displace pyridine. [207] A similar displacement of pyridine by thiophenol was observed with copper organosols. [218] Tliese results exemplify the potential of this technique for investigating the surface coordination chemistry of colloidal metals. SER spectra of cytosine and of guanine and their derivatives on copper and on silver have been reported. [219, 220]... 

Of all the known sites for metal-ion binding to the heteroatoms of DNA bases, G-N3 is the most elusive. The adjacent 2-amino group is often considered to offer steric hindrance to binding at this site. However, while this undoubtedly influences the chemistry it does not preclude binding. The tri-metalated [ [Pt(N]3(9-Et G N1,N3,N7)]5 compound has for many years been the only structurally characterized example of an N3-coordinated guanine (66). A second example has now been reported, the tetranuclear octacation 16 (56). In this complex both the N7 and N3 atoms are bound to Pd2+ (Fig. 22). The molecule presents an interesting new architecture for a guanine-tetramer. Such structures are well known in DNA chemistry and are almost inevitably metal-ion stabilized (67,68). 

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