The ligand ttd(ttd=1,4,8,9-Tetraaza-triphenylene-2,3-dicarbonitrile) and a novel spin crossover complex [Fe(ttd)2(NCS)2]·H2O were synthesized, and charac terized by elemental analysis, IR, MS, and UV-vis spectroscopy. The temperature dependence of magnetic susceptibility shows that there are a little break betwe en 150～190K and an unusual step transition with a 50K width between 190～240K. Compared with the other complexes with the resemble structure, it can be found t hat the influence of ligand is very notable.
A new large conjugated ligand 1′,8′-diaza-anthreceno-\-1,10-phenanthroline(dap) and its Fe(Ⅱ) complex have been synthesized from phenanthroline and 2,3-diaminonphthalene. The structures and properties of the ligand and the complex were characterized by elemental analysis, IR, MS, UV-vis spectrometry. The study of magnetic susceptibility of the complex indicated the complex lies mainly in low spin state between 80～300 K, while a spin crossover occurs in high temperature region as a result of the stronger ligand field of this ligand than those of dipyrido\[3,2-a:2′phenazine and dipyrazine\,3′h\]quinoxaline.
