σ-borane complexes of iridium: Synthesis and structural characterization
σ-borane complexes of iridium: Synthesis and structural characterization
复制标题
DOI：
10.1021/ja801898m
复制
发表时间：
2008-08-13
影响因子：
15
通讯作者：
Heinekey, D. Michael
中科院分区：
文献类型：
--
作者：
Hebden, Travis J.;Denney, Melanie C.;Heinekey, D. Michael
NaBH4与(TBuPOCOP)IrHCI反应生成(TBuPOCOP)-IrH2(BH3)(1)(tBuPOCOP=kappa(3)-C6H3-1，3-[OP(TBU)(2)](2))。由中子衍射数据确定的1的结构中含有与Ir的B-H sigma键，延长的B-H键距为1.45(5)埃。化合物1的晶胞参数为：a=1256.2(5)埃，b=12.264(5)埃，c=13.394(4)埃，V=13.394(1)埃(3)(30K)。化合物1也可以由BH3中心点THF与(TBuPOCOP)IrH2反应得到。(TBuPOCOP)IrH2与频那醇硼烷反应，初步得到化合物2，根据光谱测定，其结构与化合物1相似。配合物2在室温下析出H-2，生成硼烷配合物3，当2处于动态真空时，生成干净的硼烷配合物3。通过X-射线衍射法确定了化合物3的结构，其结构由(TBuPOCOP)Ir核和Sigma结合的片呐醇硼烷配体组成，形成一个近似正方形的平面络合物。化合物3属C2/c空间群(Z=4)，晶胞参数为a=41.2238(2)埃，b=11.1233(2)埃，c=14.6122(3)埃，V=14.6122(19)埃(3)(130K)。在四氢呋喃溶液中，(TBuPOCOP)IrH2与9-BBN反应生成配合物4。配合物4与(TBuPOCOP)IrH2在四氢呋喃溶液中以平衡状态存在。
Reaction of NaBH4 with (tBuPOCOP)IrHCI affords the previously reported complex (tBuPOCOP)-IrH2(BH3) (1) (tBuPOCOP = kappa(3)-C6H3-1,3-[OP(tBU)(2)](2)). The structure of 1 determined from neutron diffraction data contains a B-H sigma-bond to iridium with an elongated B-H bond distance of 1.45(5) angstrom. Compound 1 crystallizes in the space group P(1)over bar (Z = 2) with a = 8.262 (5) angstrom, b = 12.264 (5) angstrom, c = 13.394 (4) angstrom, and V= 1256.2 (1) angstrom(3) (30 K). Complex 1 can also be prepared by reaction of BH3 center dot THF with (tBuPOCOP)IrH2. Reaction of (tBuPOCOP)IrH2 with pinacol borane gave initially complex 2, which is assigned a structure analogous to that of 1 based on spectroscopic measurements. Complex 2 evolves H-2 at room temperature leading to the borane complex 3, which is formed cleanly when 2 is subjected to dynamic vacuum. The structure of 3 has been determined by X-ray diffraction and consists of the (tBuPOCOP)Ir core with a sigma-bound pinacol borane ligand in an approximately square planar complex. Compound 3 crystallizes in the space group C2/c (Z= 4) with a = 41.2238 (2) angstrom, b = 11.1233 (2) angstrom, c = 14.6122 (3) angstrom, and V= 6700.21 (19) angstrom(3) (130 K). Reaction of (tBuPOCOP)IrH2 with 9-borobicyclononane (9-BBN) affords complex 4. Complex 4 displays H-1 NMR resonances analogous to 1 and exists in equilibrium with (tBuPOCOP)IrH2 in THF solutions.