Bridged and Unbridged Nickel-Nickel Bonds Supported by Cyclopentadienyl and Phosphine Ligand Sets
Bridged and Unbridged Nickel-Nickel Bonds Supported by Cyclopentadienyl and Phosphine Ligand Sets
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DOI：
10.1021/acs.organomet.0c00708
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发表时间：
2020-12-18
期刊：
影响因子：
2.8
通讯作者：
Liddle, Stephen T.
中科院分区：
文献类型：
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作者：
Cleaves, Peter A.;Ayres, Alexander J.;Liddle, Stephen T.
R = Me （1-Me）、Pr-n （1-nPr）和nBu （1-nBu）的一系列Ni配合物[Ni(Cl)(2)(PR3)2]和镍茂烯[Ni(？合成了具有R′= H （2-H）、Me （2-Me）和SiMe3 （2-SiMe3）的5- c (5)H4R′)2]。从这些配合物中，合成了Ni配合物[NiCl(PR3)(？5度(5)H4R”)]R =我,R ' = H (3-Me), R = Bu-n, R ' = H (3-nBu), R = nPr, R ' = H (3-nPr), R =等,”=我(4),R =, R ' = SiMe3(5)。所有配合物都进行了完整的表征，包括单晶x射线晶体学。然后用配合物3-R、4和5得到具有罕见的非桥接Ni键的同双金属Ni配合物[{Ni(？5- c (5)H5)(PR3)}2]，用单晶x射线衍射对R = Me （7-Me）和R = Pr-n （7-nPr）进行了结构表征。为了探究桥接配体对NiNi键的影响，将桥接配合物[{Ni(mu:？5- c (5)H4CH2CH2P(Bu-t)(2))}2](8)由单体前驱体[Ni(Cl)(?1-？5度(5)H4CH2CH2P布鲁里溃疡(t)(2)(6)。7-Me、7-Pr-n和8的NiNi距离分别为2.407(1)、2.3931(6)和2.6027（17）埃，由于桥接配体的系链性质，后者似乎比其他两个更长。DFT计算证实了7-Me和7-nPr中Ni原子之间存在未桥接的s键，并表明8中的桥接配体对Ni键的性质影响很小。
A series of Ni complexes [Ni(Cl)(2)(PR3)2] with R = Me (1-Me), Pr-n (1-nPr), and nBu (1-nBu) and nickelocenes [Ni(?5-C(5)H4R')2] with R' = H (2-H), Me (2-Me), and SiMe3 (2-SiMe3) were synthesized and characterized. From these complexes, the synthesis of the Ni complexes [NiCl(PR3)(?5-C(5)H4R')] R = Me, R' = H (3-Me), R= Bu-n, R' = H (3-nBu), R = nPr, R' = H (3-nPr), R = Et, R' = Me (4), and R = Et, R' = SiMe3 (5) was achieved. All complexes were fully characterized, including single crystal X-ray crystallography. Complexes 3-R, 4, and 5 were then used to obtain homobimetallic Ni complexes with rare examples of unbridged NiNi bonds [{Ni(?5-C(5)H5)(PR3)}2], with R = Me (7-Me) and R = Pr-n (7-nPr) being structurally characterized by single crystal X-ray diffraction. In order to probe the effect of bridging ligands on the NiNi bond, the bridged complex [{Ni(mu:?5-C(5)H4CH2CH2P(Bu-t)(2))}2] (8) was synthesized from the monomeric precursor [Ni(Cl)(?1-?5-C(5)H4CH2CH2P(t)Bu(2))] (6). The NiNi distances in 7-Me, 7-Pr-n, and 8 were found to be 2.407(1), 2.3931(6), and 2.6027(17) angstrom, respectively, the latter seemingly lengthened compared to the other two due to the tethered nature of the bridging ligand. DFT calculations confirm the presence of unbridged s-bonds between the Ni atoms in 7-Me and 7-nPr and show that the bridging ligand in 8 has a minimal effect on the character of the NiNi bond.