New alternating ferro- and antiferromagnetic one-dimensional complexes. Synthesis, characterization, crystal structure, and magnetic properties of [M(4,4 '-dimethylbipyridine)(N-3)(2)](n) [M = Cu(II), Mn(II), Ni(II), Fe(II)]

The preparation, X-ray crystal structure, and magnetic properties of altern ating 1,1- and 1,3-azido-bridged copper-(II) complex [Cu(4,4'-dmbpy)(N-3)(2 )](n) (1, 4,4'-dmbpy = 4,4'-dimethylbipyridine) have been reported. It crys tallizes in triclinic system, space group P (1) over bar, a = 7.9903(1) Ang strom, b = 9.3545(9) Angstrom, c = 10.754(2) Angstrom, c = 10.754(2) Angstr om,alpha = 113.485(1)degrees, beta = 101.399(1)degrees, gamma = 101.897(1)d egrees, Z = 2. The magnetic properties of 1 have been investigated in the t emperature range 1.5-300 K. Alternating antiferromagnetic (-J = 191.0 cm(-1 )) interaction through a 1,3-N-3(-) bridge and ferromagnetic (J = 297.1 cm( -1)) interaction through a 1,1-N-3(-) bridge are obtained for 1 by analyzin g the magnetic susceptibility data with the Hamiltonian (H) over cap = -J S igma((S) over cap(2i)(S) over cap(2i-1) - alpha (S) over cap(2i)(S) over ca p(2i+1)). It's derivatives ({Mn(4,4'-dmbpy)(N-3)(2)}(n) (2), {Ni(4,4'-dmbpy )(N-3)(2)}(n) (3), and {Fe(4,4'-dmbpy)(N-3)(2)}(n) (4) and the heterometall ic derivatives {NiMn(4,4'dmbpy)(2)(N-3)(2)}(n) (5) and {CuMn(4,4'-dmbpy)(2) (N-3)(4)}(n) (6) have also been synthesized and characterized by electronic and IR spectra. The X-ray powder diffraction and the magnetic properties o f 6 have also been discussed.