Series Of Ni (im) With The Hydrogen Bonds In The Development And Structure Of The Material

Taking regular and irregular methods, four Ni (im) compounds have been synthesized from phthalic acid,imidazole and Ni(N03)2. The series of complexes were Charaterised by UV-VIS-NIR and IR spetroscopic studies. And their crystal structures were determined by single-cyrstal X-xay methods. The formulas of the four compounds are as follows:(1) [Ni (im)6] (NO3) (OH) (H2O)4(2) [Ni(im)4 (H20)2]LC6H4 (COO)2](3) [Ni(im)6][C6H4 (COO)2] (H2OX(4) [Ni(im)6] (NO3)2Structures of the four compounds contains infinit three-dimensional H-bond networks except (3). The existence of the three-dimensional H-bond networks not only stablized the structures greatly but also linked the molecule even the metal ions together, which made electron transfer and proton transfer easier. And magnetic properties of the above four compounds may be affected accordingly.The variable temperature magnetic susceptibilities of all the complexes have been measured and studied in the range of 1. 5~?OOK compared with each other. The exact correlation between H-bond modes and magnetic properties of the compounds were tried to be found. The distanse of the H-bonded chain between two Ni ( 11) is the shortest in compound (1) and (2) ,which may account for the antiferromagnetic coupling between Ni (11) for compound (1) and (2). The nonexistence of three-dimensional H-bond network in (3) and longer distance of H-bonded chain between Ni( 11) in (4) may be the reasons for paramagnatic property of Ni( 11 ) without coupling for (3) and (4).Although the definition of hydrogen bond was put forward 80 years ago, but systimetic reports are few. This paper has a important significance for further Investigation of H-bond especially its role in super-molecular self-assembling.