Zerovalent Nickel Compounds Supported by 1,2-Bis(diphenylphosphino)benzene: Synthesis, Structures, and Catalytic Properties.
Zerovalent Nickel Compounds Supported by 1,2-Bis(diphenylphosphino)benzene: Synthesis, Structures, and Catalytic Properties.
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1,2-双（二苯基膦）苯负载的零价镍化合物：合成、结构和催化性能。
DOI：
10.1021/acs.inorgchem.7b02636
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发表时间：
2018
影响因子：
4.6
通讯作者：
G. Parkin
中科院分区：
文献类型：
--
作者：
Michelle C. Neary;Patrick J. Quinlivan;G. Parkin
通过dppbz对Ni(PMe3)4的反应，得到了以1,2-双（二苯基膦）苯为特征的零价镍化合物（dppbz），依次得到（dppbz）Ni(PMe3)2和Ni(dppbz)2。此外，CO与（dppbz）Ni(PMe3)2反应可得到羰基衍生物（dppbz）Ni(PMe3)（CO）和（dppbz）Ni(CO)2。合成这些羰基化合物的其他方法包括(i)通过Ni(PPh3)2(CO)2与dppbz反应生成（dppbz）Ni(CO)2和（ii）通过（dppbz）Ni(CO)2与PMe3反应生成（dppbz）Ni（PMe3)(CO)）。比较（dppbz）Ni(CO)2与其他（二膦）Ni(CO)2化合物的ν(CO) IR光谱数据，为评价dppbz的电子性质提供了一种手段。具体来说，与（dppe）Ni(CO)2的比较表明，邻苯连接剂产生的电子给体比乙烯连接剂产生的电子给体略少。dppbz配体相对于其他二膦配体的空间影响也根据其埋藏体积（%Vbur）和空间图进行了评估。（dppbz）Ni(PMe3)2的镍中心在室温下可被甲酸质子化生成[(dppbz)Ni(PMe3)2H]+，但在高温下会影响甲酸对H2的催化释放。对Ni(dppbz)2和Ni(PMe3)4的类似研究表明，这些化合物中镍中心质子化能力的增强顺序为Ni(dppbz)2 < (dppbz)Ni(PMe3)2 < Ni(PMe3)4；相应的，质子化衍生物的pKa值以[Ni(dppbz)2H]+ < [(dppbz)Ni(PMe3)2H]+的顺序递增。（dppbz）Ni(PMe3)2和Ni(PMe3)4还可以通过(i) PhSiH3和Ph2SiH2对PhCHO进行硅氢化反应和（ii） PhCH2OH与PhSiH3和Ph2SiH2的脱氢偶联反应生成烷氧基硅烷。
Zerovalent nickel compounds which feature 1,2-bis(diphenylphosphino)benzene (dppbz) were obtained via the reactivity of dppbz towards Ni(PMe3)4, which affords sequentially (dppbz)Ni(PMe3)2 and Ni(dppbz)2. Furthermore, the carbonyl derivatives (dppbz)Ni(PMe3)(CO) and (dppbz)Ni(CO)2 may be obtained via the reaction of CO with (dppbz)Ni(PMe3)2. Other methods for the synthesis of these carbonyl compounds include (i) the formation of (dppbz)Ni(CO)2 by the reaction of Ni(PPh3)2(CO)2 with dppbz and (ii) the formation of (dppbz)Ni(PMe3)(CO) by the reaction of (dppbz)Ni(CO)2 with PMe3. Comparison of the ν(CO) IR spectroscopic data for (dppbz)Ni(CO)2 with other (diphosphine)Ni(CO)2 compounds provides a means to evaluate the electronic nature of dppbz. Specifically, comparison with (dppe)Ni(CO)2 indicates that the o-phenylene linker creates a slightly less electron donating ligand than does an ethylene linker. The steric impact of the dppbz ligand in relation to other diphosphine ligands has also been evaluated in terms of its buried volume (%Vbur) and steric maps. The nickel center of (dppbz)Ni(PMe3)2 may be protonated by formic acid at room temperature to afford [(dppbz)Ni(PMe3)2H]+, but at elevated temperatures, effects catalytic release of H2 from formic acid. Analogous studies with Ni(dppbz)2 and Ni(PMe3)4 indicate that the ability to protonate the nickel centers in these compounds increases in the sequence Ni(dppbz)2 < (dppbz)Ni(PMe3)2 < Ni(PMe3)4; correspondingly, the pKa values of the protonated derivatives increase in the sequence [Ni(dppbz)2H]+ < [(dppbz)Ni(PMe3)2H]+ < [Ni(PMe3)4H]+. (dppbz)Ni(PMe3)2 and Ni(PMe3)4 also serve as catalysts for the formation of alkoxysilanes by (i) hydrosilylation of PhCHO by PhSiH3 and Ph2SiH2 and (ii) dehydrocoupling of PhCH2OH with PhSiH3 and Ph2SiH2.