Syntheses,Crystal Structures,DFT Calculation and Optical Properties of a Schiff Base and Its Dinuclear Mercury(Ⅱ) Complex

A pyridine-contained Schiff base ligand L(L =(pyridine-2-vinyl)hydrazine) has been synthesized and fully characterized. By self-assembly of the ligand with HgI_2, a binuclear complex Hg_2I_4L(C) was obtained. The structures of L and C were analyzed through single-crystal X-ray diffraction. L crystallizes in monoclinic, space group P21/n with a=11.286(5), b=3.981(5), c=23.865(5) ?, β=100.043(5)°, V=1056(1) ?~3, Z=4, Dc=1.323 g/m~3, F(000)=440, Μr=210.24, μ=0.084 mm~(-1), the final R=0.0928 and w R=0.2867 for 6955 observed reflections with I 2(I). The complex is of monoclinic system, space group P21/n with a=8.706(5), b=17.468(5), c=14.675(5) ?, β=93.922(5)°, V=2227(2) ?~3, Z=4, Dc=3.338 g/m~3, F(000)=1928, Μr=1119.02, μ=19.321 mm~(-1), the final R=0.0366 and w R=0.1276 for 3920 observed reflections with I 2(I). The structural analysis revealed that the molecule of L possesses a well planar structure. However, in the complex, the coordinated ligand distorts greatly. The absorption spectra of L and the complex in ethanol were experimentally and theoretically studied. The result indicates that the complex exhibits different absorption spectrum compared with the free ligand.