六硝酸银合乙炔银的晶体结构的重新测定和修正

The Structure Determination and Refinement of Silver Acetylide-Silver Nitrate (1:6)

六硝酸银合乙炔银由配离子[Ag_8C_2]^(5+)和六个NO_3^-组成。C_2^(2-)离子无序地分布在由八个Ag^+离子组成的菱面体笼内,晶胞中的[Ag_8C_2]^(6+)配离子通过NO_3^-联结成三维整体。八个Ag^+离子分成两组,处于三重反轴上的两个Ag^+离子与C_2^(2-)离子的距离为2.45和2.56 A,表明Ag^+和C_2^(2-)之间存在σ-π配键,其余六个Ag^+离子处于一般位置。光电子能谱证实了此结果。从配离子[Ag_8C_2]^(6+)的结构,可推测乙炔银的结构是3。数据收集范围O°<2θ<70°,用Mo Ka射线共收集可观察衍射1188个。修正的最终偏离因子R=0.063。

Silver acetylide-silver nitrate(l:6) consists of the complex ion (Ag_8C_2)^(6+) and six nitrates NO_3^-. The C_2^(2-) ion is in the rhombohedral cage which consists of eight Ag^+ ions and links with nitrates to form a three dimentional crystal. There are two kinds of silver ions which was confirmed by photoelectron spectroscopy. Two Ag^+ ions which are on the threefold inversion axes are 2.45 and 2.56(?) from the C_2^(2-) ion, which shows that there is a δ-π coordination bond between Ag^+ and C_2^(2-) ions. The other six Ag^+ ions which are in general positions are from silver nitrate. It can be deduced from the structure of(Ag_8C_2)^(6+) ion that the strncture of silver acetylide is 3. 1188 observed reflections were collected with MoKa radiation in range of O^o <20<70~o. The final discrepancy factor after refinement wasc R= 0.063.