Interconversion of a monomer and two coordination polymers of a copper(II)-reduced Schiff base ligand-1,10-phenanthroline complex based on hydrogen- and coordinative-bonding

Two compounds, [Cu-3(Sbal)(2)(phen)(H2O)(2)](ClO4)(2). 3H(2)O (1) and [Cu(H (2)Sbal)(2)(phen)](ClO4)(2) (2), were isolated in successive steps, from th e reaction mixture containing Cu(ClO4)(2). 6H(2)O, 1,10-phenanthroline, N-( 2-hydroxy- benzyl)-beta -alanine (H(2)Sbal), and LiOH in the ratio of 1:1:1 :1. When the ratio of the base was doubled, the neutral monomer [Cu(Sbal)(p hen). 2H(2)O (3)] was obtained. The cation in 1 exists as a one-dimensional polymer in the solid state, while weak O-H . .O hydrogen bonds in the cati on of 2 generate Delta Lambda Delta Lambda. type one-dimensional spiral cha ins. Addition Of HClO4 to 3 furnished I and 2, and this mixture can be conv erted back to 3 by the addition of a base. This conversion of a monomer to: two 1-D polymers was found to be reversible. Crystal data for 1: triclinic space group P (1) over bar, a = 12.0353(5) Angstrom, b, = 12.2848(5) Angst rom, c = 15.3185(6) Angstrom,alpha = 84.993(1)degrees, beta = 89.411(1)degr ees, gamma = 67A14(1)degrees, V = 2082.5(2) Angstrom (3), Z = 2, rho (calcd ) = 1.668 g cm(-3). Crystal data for 2: tetragonal space group P4(1)/a, a = 10.8095(1) Angstrom, c = 59.0159(4) Angstrom, V = 6895.7(1) k, Z = 8, rho (calcd) = 1.605 g cm(-3). Crystal data for 3: monoclinic. space group Pn, a = 10.6344(3) Angstrom, b = 5.3953(1) Angstrom, c = 18.1983(1) Angstrom, V = 1029.26(4), Angstrom (3), Z 2, rho (calcd) = 1.526 g cm(-3). When CU(NO3) (2) was used in the place of Cu(ClO4)(2), [Cu-2(Sbal)(phen)(3)](NO3)(2).2.5 H(2)O (4) was the only isolable product for the 1:1:1:1 ratio, and 3 was th e only isolable product for the 1:1:1:2 ratio. Crystal data for 4: trichnic space group P (1) over bar, a = 10.8063(8) Angstrom, b = 13.919(1) Angstro m, c = 16.564(1) Angstrom, alpha = 88.957(2)degrees, beta = 71.008(1)degree s, gamma = 69.829(2)degrees, V = 2198.9(3) Angstrom (3), Z = 2, rho (calcd) = 1.556 g cm(-3). Variable temperature magnetic measurements showed that t he polymeric structure in I behaves, magnetically, as a strongly coupled mu -phenoxo dimer (2J = -390 cm(-1)) plus an isolated monomer.