Cadmium-nucleobase interactions

Estimated precision is the same as of eq. (10), i.e., 0.16, but, as expected, the coefficients are slightly higher and reflect the extra-contribution of the nucleobase/cadmium interaction to the overall stability of CdL species. 

Examples are known where the non-natural nucleobase 2,6-diaminopurine coordinates in cationic or anionic forms. In the compound [Cd(H2dap)-(H20)2(tp)]2(tp)-2H20 n [12], the diaminopurinium(l+) cation binds cadmium through the Cd-N7 bond (2.342 A) in cooperation with the intramolecular interligand N6-H---0(coord., tp) interaction (2.923 A, 146.6°). The anionic form dap builds the polymer [Cd3(p3-ap)2(p3-N3,N7,N9-dap)2(H20)2]-H20 n [12]. Note that this polymer is closely related to that described above for adeninate (Cd-N3 2.586 A, Cd-N7 2.298 A, Cd-N9 2.387 A). 

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