论文部分内容阅读
(C_5H_7S_2)_3[Mo_3(μ_3-S)(μ_2-S_2)_3Cl_7]晶体的空间群为Pnam;晶胞参数:a=17.226(4),b=14.306(7),c=15.074(4);z=4,ρ_(obs)=2.03克/厘米~(-3),ρ_(calc)=2.063克/厘米~(-3)。晶体结构由重原子法解出,并经全矩阵最小二乘方精修,偏离因子R值为0.068。研究结果显示出,晶体结构由三核钼簇阴离子[Mo_3(μ_3-S)×(μ_2-S_2 )_3Cl_7]~(3-)以及环绕着它的平面状的阳离子(C_5H_7S_2)~+所组成。簇阴离子中,三个处在等边三角形顶点的Mo原子,由一个μ_3—S原子将其联系在一起,同时,每两个Mo原子之间还由一个S_2基团桥联,Mo—Mo间距分别为2.755(1),2.755(1),2.743(1)。此外,每个Mo原子还由两个Cl原子配位,使得Mo原子近邻的所有配位原子一起,形成接近五角双锥构型。簇阴离子中还有一个不与Mo原子直接配位的Cl原子,处在三个μ_2—S_2基团之间,而且与这三个S_2的一端S原子有一定程度的成键。簇阴离子整体接近c_(3v)对称性。用Cottonm~([1])等简化量化方法定性地分析了{Mo_3}体系的M—M成键情况,满意地解释了Mo—Mo间距和分子的磁性。
The space group of (C_5H_7S_2) _3 [Mo_3 (μ_3-S) (μ_2-S_2) _3Cl_7] crystals is Pnam. The unit cell parameters are a = 17.226 (4), b = 14.306 (7), c = 15.074 (4) z = 4, ρ obs = 2.03 g / cm 3, ρ calc = 2.063 g / cm -3. The crystal structure was solved by heavy atom method, and was refined by the least squares of the whole matrix. The deviation factor R value was 0.068. The results show that the crystal structure is composed of tri-molybdenum anions [Mo_3 (μ_3-S) × (μ_2-S_2) _3Cl_7] ~ (3-) and its planar cations (C_5H_7S_2) ~ +. Among the cluster anions, three Mo atoms at the apexes of the equilateral triangle are connected by a μ_3-S atom. At the same time, every two Mo atoms are bridged by one S_2 group. The Mo-Mo spacing Respectively 2.755 (1), 2.755 (1), 2.743 (1). In addition, each Mo atom is also coordinated by two Cl atoms such that all the coordination atoms in the vicinity of the Mo atom together form a nearly pentagonal bipyramid configuration. Among the cluster anions, there is another Cl atom that does not directly coordinate with the Mo atom, which is located between three μ_2-S_2 groups and has some degree of bonding with one S atom of the three S_2. Cluster anions close to the overall c_ (3v) symmetry. The M-M bond of {Mo_3} system was qualitatively analyzed by the simplified quantification method such as Cottonm ~ ([1]), which satisfactorily explained the Mo-Mo spacing and molecular magnetism.