Two new one-dimensional compounds with end-to-end dicyanamide as a bridging ligand: Syntheses and structural characterization of trans-[Mn(4-bzpy)(2)(N( CN)(2))(2)]n and cis-[Mn(Bpy)(N(CN)(2))(2)](n), (4-bzpy=4-benzoylpyridine; bpy=2,2 '-bipyridyl)

Two new one-dimensional compounds, trans-[Mn(4-bzpy)(2)(N(CN)(2))(2)](n) (1 ) and cis-[Mn(bpy)(N(CN)(2))(2)](n) (2), have been synthesized and studied from a magnetic point of view (4-bzpy = 4-benzoylpyridine; bpy = 2,2'-bipyr idyl). The crystal structures of 1 and 2 have been solved. Compound 1 cryst allizes in the monoclinic system, P2(1)/n group, a = 6.374(2) Angstrom, b = 7.584(2) Angstrom, c = 26.766(5) Angstrom, beta = 91.87 degrees, and Z = 2 , whereas compound 2 crystallizes in the monoclinic system, C2/c group, a = 6.707(2) Angstrom, b = 17.188(5) Angstrom, c = 13.096(5) Angstrom, beta = 90.54 degrees, and Z = 4. The two compounds consist of chains with double m u(1,5)-dicyanamide bridges between neighboring manganese(II) atoms. The wea k antiferromagnetic coupling found for the two compounds (J = -0.3 cm(-1) f or 1 and -0.4 cm(-1) for 2) has been studied by MO analysis, and the supere xchange pathway through the mu(1,5)-(NCNCN-) bridge has been compared with the shorter mu(1,3)-(NNN-).