| Abstract: Two novel cyclic Au(Ⅰ) complexes based on flexible bisimidazole-containing ligand, namely,[Au2(m-bitmb)2] [AuCl2]Cl·2CH3OH (1) and[Au2(m-bitmb)2] [AuCl2]2·2CH3CN (2) (m-bitmb=1,3-bis(imidazol-1-ylmethyl)-2,4,6-trimethylbenzene), respectively, were obtained by diffusion method, which were further characterized by X-ray single crystal diffraction, elemental analysis, XRD and fluorescence spectroscopy. Complex 1 crystallizes in space group P2/c with a=0.895 6(9) nm, b=1.129 0(12) nm, c=2.166 3(2) nm, β=91.934(19)°, V=2.182 1(4) nm3, Z=2, Dc=2.012 g·cm-3, F(000)=1 248, the final R=0.036 6, wR=0.091 0. Complex 2 crystallizes in space group P1 with a=0.847 16(13) nm, b=1.168 82(17) nm, c=1.183 72(17) nm, α=97.132 0(10)°, β=96.872(2)°, γ=95.391(2)°, V=1.147 6(3) nm3, Z=1, Dc=2.275 g·cm-3, F(000)=728, the final R=0.038 1, wR=0.087 8. Both the title complexes have similar cyclic M2L2 structural units. The m-bitmb in 1 and 2 all adopt cis-conformation to coordinate to Au(Ⅰ) centers. The cyclic units in 1 and 2 are regularly arranged through π-π stacking interaction to form one-dimensional chain structures. Complex 1 has stronger π-π stacking effect than 2, but its aurophility is slightly weaker. The structural diversities of title complexes may be caused by the different solvents used in the synthesis process. Fluorescence results show that the aurophilic interactions in title complexes play important roles on their fluorescence properties. |
