Structural and surface patterning studies of N3-metalated adenine–copper complexes involving metal–olefin interaction

We report the synthesis, solid state structural characterization and direct surface patterning of two adenine–copper(I) complexes. The ligand, 9-allyladenine, exhibits Cu(I) coordination via an N3–M–N7 mode by invoking participation from an allylic double bond and acetonitrile solvent molecule to result in an EPR silent complex. Detailed crystal structure studies of the coordination polymer thus formed were followed by NMR to ascertain the Cu(I)–olefin interaction occurring via an allylic substituent at the N9 position. On air exposure, acetonitrile molecule was substituted by a water molecule affording a unique example of a water-bound Cu(I) complex. Direct deposition of these complexes on graphite surface resulted in a pattern which could be readily correlated to the crystal structure.