Syntheses and Crystal Structures of Two New Zinc（ II ） Nitroxide Radical Complexes Bridged by Isophthalate

Two novel complexes [Zn(NIT3-py)(ip)]n 1 and [Zn(im3-py)(ip)]n 2 (NIT3-py = 2-(3’-pyridyl)-4,4,5,5,-tetramethylimidazoline-1-oxyl-3-oxide, im3-py = 2-(3’-pyridyl)-4,4,5,5-te-tramethylimidazoline-1-oxyl, ip = isophthalate) have been synthesized and structurally determined by X-ray diffraction. Crystal data for 1: C32H36N6O8Zn, Mr = 698.04, monoclinic, space group Cc with a = 23.600(3), b = 10.2073(12), c = 13.4027(16) , β = 92.586(2)°, V = 3225.3(7) 3, Dc = 1.438 g/cm3, F(000) = 1456, μ(MoKα) = 0.822 mm-1, Z = 4, the final R = 0.0390 and wR = 0.1032 for 6037 independent reflections with Rint = 0.0214. Crystal data for 2: C32H36N6O6Zn, Mr = 666.04, monoclinic, space group C2/c with a = 24.434(4), b = 13.543(2), c = 10.2379(16) , β = 109.024(2)°, V = 3202.8(9)3, Dc = 1.381 g/cm3, F(000) = 1392, μ(MoKα) = 0.820 mm-1, Z = 4, the final R = 0.0304 and wR = 0.0658 for 2833 independent reflections with Rint = 0.0307. X-ray analysis reveals that both Zn(Ⅱ) ions are four-coordinated by two pyridyl-N atoms from nitroxide radicals and two carboxylate oxygen atoms to form distorted tetrahedral geometries. Each iso-phthalate dianion binds two Zn(Ⅱ) ions in a monodentate mode, leading to a 1-D chain structure.