Two Polymeric Linear Tri-nickel(II) Complexes: [Ni(#mu#_3-dpa)_4(C_4O_4Me)]_n(BF)_n and [Ni_3(#mu#_3-dpa)_4(N_3)]_n(PF_6)_n Synthesis, Structural Characterization and Magnetic Properties

摘要

Two new lienar tri-nickel(II) complexes with an infinite polymeric chain, [Ni_3(#mu#_3-dpa)_4(C_4O_4Me)](BF_4) 1 and [Ni_3(#mu#_3-dpa)_4(N_3)](PF_6) 2, [dpa~- = di(#alpha#-pyridyl)amido anion], have been synthesized and their structures were determined by X-ray diffraction. Compound 1 crystallizes in the monoclinic system, space grouop C2/c, with a = 19.9078(3), b = 13.2986(2), c = 37.6622(5)A, #beta# = 91.091(1)°,Z =8. Compound 2 crystallizes in the monoclinic system, space group P2_1, with a = 13,323(4), b = 23.217(3), c =17.528(5)A, #beta# = 94.42(3) °, Z = 4. The two complexes are described as one-dimensional systems with the (C_4O_4Me)~-,1, or N_3~_, 2, serving as a #mu#-(1,3) bridged ligand at the two axial sites of each [Ni_3(#mu#_3-dpa)_4]~92+) fragment. The Ni-Ni distances of 2.400(1) and 2.402(1) in 1 and 2.389(2), 2.385(2) in 2 are obviously shorter than those of 2.4325(7), 2.4356(7) in the monomeric complex [Ni_3(#mu#-dpa)_4(N_3)_2] 3. The magnetic properties of complexes 2 and 3 were studied by susceptibility measurements vs temperature. The #chi#-M vs T plots of both complexes show a strong anti-ferromagnetic behavior. The simulated J_13 values are-95 cm~(-1) and -97 cm~(-1) for 2 and 3, respectively.