Dichlorobis nucleoside palladium II

Two mmoles (0.3546 g) of palladium(II) chloride and about 15 mL of 0.5 N HC1 are placed in a 100-mL beaker equipped with a magnetic stirring bar. The suspension is stirred slowly and heated to boiling, until all of the palladium(II) chloride dissolves. The heating is then stopped and the solution is allowed to cool to room temperature. After cooling, the solution may be filtered, if necessary. 

Two mmoles of the corresponding cis-[dichlorobis(nucleoside)palladium(II)] (1.4274 g for the inosine and 1.4882 g for the guanosine complex) are placed in a 100-mL beaker containing a magnetic stirring bar. Upon addition of about 50 mL of distilled water (with stirring) the initial complex dissolves, and, almost instantaneously (after 10-15 min for inosine), a new, yellow precipitate is formed. The pH of this water suspension becomes acidic, due to the liberation of HC1. The stirring is continued for about two hours to attain completion of the reaction, while the pH is kept between 6.0 and 6.5 by the dropwise addition of a solution of 0.1 N KOH. The final pH value of the suspension should be 6.0-6.5. 

The precipitate is then removed by filtration through a medium glass filter (60 mL) by suction and washed with small quantities (10-20 mL) of ethanol to 

cis- OR lnifK-[BIS(NUCLEOSIDE)BIS(NUCLEOSIDE )-PALLADIUM(II)] DICHLORIDE AND TETRAKIS(NUCLEOSIDE)PALLADIUM(II) DICHLORIDE 

The cis- and rrans-[Pd(nucl-H+)2] complexes can be prepared only when a nucleoside containing an easily ionizable imino proton, such as inosine or guanosine, is used. The pK values of the imino proton of these bases fall in the range 

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