Crystal structures and spectroscopic analyses of two Co(II) N 6-benzylaminopurine supramolecules

Two mononuclear Co(II) N-6-benzylaminopurine compounds, [Co(6-BA-H-2)(2)(H2O)(4)]center dot(R)(2)center dot 4.5H(2)O (1) and [Co(6-BA-H)(2)(H2O)Cl-3]Cl center dot H2O (2) (6-BA = N-6-benzylaminopurine (C5H2N3NH)(NH)CH2(C6H5), H3R=5-sulfosalicylic acid (C6H3)CO2H(OH)SO3H), are reported. Compound 1 possesses a 3-D supramolecular structure built via H-bond and pi pi stacking interactions that contains a mononuclear six-coordinate [Co(6-BA-H-2)(2)(H2O)(4)](6+). Compound 2 also exhibits a 3-D supramolecular framework with mononuclear six-coordinate cation [Co(6-BA-H)(2)(H2O)Cl-3](+). Luminescence studies at room temperature show that 1 (lambda(ex) = 268 nm) displays two strong fluorescent emissions centered at 326.8nm and 356.9 nm, while 2 (lambda(ex) = 233 nm) exhibits a weaker peak emitted at 342.8 nm upon 6-BA-complexation of two different second ligands H3R/Cl- with Co(II).