Crystal structure and molecular configuration of an asymmetric 1,2-dimethyl-1,2-dicarbollide complex of nickel, racemic(3,4')-[(CH3)2B9C2H9]2NiIV
Crystal structure and molecular configuration of an asymmetric 1,2-dimethyl-1,2-dicarbollide complex of nickel, racemic(3,4')-[(CH3)2B9C2H9]2NiIV
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镍不对称 1,2-二甲基-1,2-二碳内酯络合物的晶体结构和分子构型，外消旋(3,4)-[(CH3)2B9C2H9]2NiIV
DOI：
10.1021/ja00708a011
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发表时间：
1970
影响因子：
15
通讯作者：
Karen Gold
中科院分区：
文献类型：
--
作者：
M. Churchill;Karen Gold
[(CHA^BgQHgJsNflv)以前已经被证明存在于两种修饰中，其中一种(异构体B)在其磁共振光谱中显示四种类型的甲基质子，并且可以通过相应的{[(CH3)2BgC2Hg]2NIN11-阴离子被拆分成对映体。外消旋B的X-射线结构研究表明，其结构为3，4‘-COMO-[1，2-二甲基-L，2-二碳杂-3-镍-c/异十二硼烷]-[L’，2‘-二甲基-1’，2‘-二碳杂-4’-镍-c/正十二硼烷]。该化合物属中心对称单斜晶系，空间群为P2i/n(C2H5；NO14)，晶胞参数为a=13.489±0.010，b=20.223±0.012，c=7.626±0.006，？，V=2076，Z=4。利用三维计数器数据对SIN-0.75(CuKA辐射)进行了所有非氢原子的定位，对于1396个独立的非零反射，最终的偏差指数为Rp=8.64%。[(CH3)2B9C2H9]2NiIV的离散分子单元以正常的范德华距离分开。NiIVion被夹在两个相互交错的1，2-二甲基-L，2-二羧酸配体之间，是两个二十面体的共同(3，4‘)顶点。因此，在一个双碳化合物配体中，C(L)和C(2)都在基五角形的键面上，而在另一个配体中，只有C(1‘)直接与镍键合，C(2’)在这个二十面体的上五方平面上。这两个双卡伯林配体的键面之间有1451‘的夹角。
[(CHa^ BgQHgJsNflvhas previously been shown to exist in two modifications, one of which (isomer B) shows four types of methyl protons in its magnetic resonance spectrum and may be resolved into enantiomers via the corresponding {[(CH3) 2BgC2Hg] 2Ninl1-anion. An X-ray structural study of racemic isomer B shows it to be 3, 4'-commo-[1, 2-dimethyl-l, 2-dicarba-3-nickela-c/oso-dodecaborane]-[l', 2'-dimethyl-1', 2'-dicarba-4'-nickela-c/osododecaborane]. The complex crystallizes in the centrosymmetricmonoclinic space group P2i/n (C2h5; no. 14) with a= 13.489±0.010, b= 20.223±0.012, c= 7.626±0.006 Á, ß= 93.62±0.05, V= 2076 Á3, Z= 4. Observed and calculated densities are 1.23±0.05 and 1.215 g cm-3, respectively. The use of three-dimensional counter data to sin-0.75 (Cu Ka radiation) has led to the location of allnonhydrogen atoms, the final discrepancy index being RP= 8.64% for the 1396 independent nonzero reflections. The discrete molecular units of [(CH3) 2B9C2H9] 2NiIV are separated by normal van der Waals distances. The NiIVion is “sandwiched” between two mutually staggered 1, 2-dimethyl-l, 2-dicarbollide ligands and is the common(3, 4') apex of the two icosahedra. Thus, in one dicarbollide ligand, both C (l) and C (2) are in the basal pentagonal bonding face, whereas in the other ligand only C (1') is directly bonded to the nickel, with C (2') being in the upper pentagonal plane of this icosahedron. There is an angle of 14 51'between the bonding faces of the two dicarbollide ligands.