| Abstract: | Zinc Coordination Compounds with Imidazoline and Imidazole Donor Ligands . By reaction of the two bidentate bisimidazoline ligands 1,2-bis(2-imidazoline-2-yl)ethan (BIE) and 1,2-bis(2-imidazoline-2-yl)benzene (BIB) with zinc bromide under various reaction conditions the complexes [ZnBr2(BIE)] ( 1 ), [ZnBr2(BIB)] ( 2 ), [Zn(BIE)2]Br2 ( 3 ) and [Zn(BIB)2](BPh4)2 ( 4 ) were synthesized and characterized. In all compounds the zinc atom is tetrahedrally coordinated, either by a bidentate ligand and two bromine ligands, or by two of the chelate ligands. Zn? N? bond distances for 1 – 4 range from 1.966(2) to 2.013(3) Å, and the Zn? Br distances from 2.372(1) to 2.403(1) Å. [3-(imidazole-1-yl)-1-oxopropyl]benzene (IOB) was prepared as a novel imidazole ligand which carries a keto-O atom in 1,5-position to the pyridine-N atom. The zinc in [ZnCl2(IOB)2] ( 5 ) is coordinated by two ligands and two Cl atoms forming a distorted tetrahedral ZnN2Cl2 unit (Zn? N: 2.013(3) and 2.029(2) Å; Zn? Cl: 2.226(1) and 2.242(1) Å). The colourless compounds 1 – 5 were characterized by IR, 1H-NMR, X-ray absorption spectra and single-crystal X-ray structure analysis. Space groups and structural data: 1 : P21/c, a = 7.717(2), b = 22.814(5), c = 8.026(2) Å, β = 117.58(2)° (140 K), R = 0.0283; 2 : Cc, a = 11.831(3), b = 11.677(1), c = 11.846(1) Å, β = 114.55(2)°, R = 0.0237; 3 : P42/n, a = 7.931(1), c = 16.945(1) Å, R = 0.0312; 4 : P21/c, a = 18.666(2), b = 16.615(2), c = 19.786(2) Å, β = 99.17(1)°, R = 0.0472; 5 : P21/c, a = 9.173(2), b = 9.230(1), c = 28.357(3) Å, β = 96.63(1)°, R = 0.0317. |
