Series Of Cobalt Complexes Synthesis, Structure And The Spin Transition Phenomenon Of Exploration

Taking the regular and irregular methods , five new cobalt compounds containing transition metal have been synthesized and characterized by single-crystal X-ray four-circle diffraction. Their formulas are presented as following:(1)Co(Imh)6(N03)2(2){ [Co(~jphen)2(H2Q)]2(tpha) } (N03)2.2C2H50H(3)[Co(NH2NHCSNH2)3] [Cr(ox)3].6H20(4)Co(NH2NHCSNH2)3Cl3. 1/2HC1(5)[Et4N] [ Co(NH2NHCSNH2)3] [Mo8026] ?Me2NCHOThe phenomenon of spin tranistion has been found for above five compounds and series of cobalt compounds containing different coordinated atoms (N,O,S,P,Cl) by decreasing temperature increasing temperature and microwave reaction. Those cobalt complexes which coordinated by all nitrogen atoms and all oxygen atoms or their combination show a positive tendency to spin transition. All of them exhibit pronounced color change and reversibility, which show the occurrence of spin transition.In particular, we find compound (2) show pronounced spin transition in the range of 1 OKA 00K by variable-temperature magnetic susceptibility measurements for compound (2) and compound (3) , and a theoretical analysis and explanation is done according to this.In addition, these five compounds have been characterized by IR,UV-VIS-NIR spectroscopes,which provide more evidence for determining their structure and exploring their new properties.The investigation of spin transition in cobalt compounds has just begun in recent two years, but they has shown more unique properties and function than iron compounds. It has more important significance for the further study of new-type molecular-based materials.