A series of Ni complexes [Ni(Cl)₂(PR₃)₂] with R = Me (1-Me), ⁿPr (1-ⁿPr), and ⁿBu (1-ⁿBu) and nickelocenes [Ni(η⁵-C₅H₄R′)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)(η⁵-C₅H₄R′)] R = Me, R′ = H (3-Me), R= ⁿBu, 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 Ni–Ni bonds [{Ni(η⁵-C₅H₅)(PR₃)}₂], with R = Me (7-Me) and R = ⁿPr (7-ⁿPr) being structurally characterized by single crystal X-ray diffraction. In order to probe the effect of bridging ligands on the Ni–Ni bond, the bridged complex [{Ni(μ:η⁵-C₅H₄CH₂CH₂P(^tBu)₂)}₂] (8) was synthesized from the monomeric precursor [Ni(Cl)(κ¹-η⁵-C₅H₄CH₂CH₂P^tBu₂)] (6). The Ni–Ni distances in 7-Me, 7-ⁿPr, and 8 were found to be 2.407(1), 2.3931(6), and 2.6027(17) Å, 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 σ-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 Ni–Ni bond.

中文翻译：

---

环戊二烯基和膦配体集支持的桥式和非桥式镍-镍键

一系列Ni络合物[Ni（Cl）₂（PR ₃）₂ ]，其中R = Me（1-Me），ⁿ Pr（1- ⁿ Pr）和ⁿ Bu（1- ⁿ Bu）和全新世[Ni（ η ⁵ -C ₅ H ^ ₄ R'）₂ ]其中R'= H（2-H ）中，Me（2-ME），和森达₃（2-森达₃）的合成和表征。从这些配合物，镍配合物的合成[的NiCl（PR ₃）（η ⁵ -C ₅ H ^₄ R'）] R = Me，R'= H（3-Me），R = ⁿ Bu，R'= H（3- ⁿ Bu），R = ⁿ Pr，R'= H（3- ⁿ Pr） ，R ＝ Et，R′＝ Me（4），并且R ＝ Et，R′＝ SiMe ₃（5）。所有配合物均得到充分表征，包括单晶X射线晶体学。配合物3-R ，4，和5然后用来获得homobimetallic镍配合物的非桥连镍Ni键[{镍（η罕见例子⁵ -C ₅ H ^ ₅）（PR ₃）} ₂]，其中R =我（7-ME）和R = ^Ñ PR（7- ^Ñ镨）在结构上被其特征在于，单晶X射线衍射。为了探索在镍Ni键桥连配体的作用，所述桥连络合物[{的Ni（μ：η ⁵ -C ₅ H ^ ₄ CH ₂ CH ₂ P（^吨丁基）₂）} ₂ ]（8）为从单体前体合成[镍（CL）（κ ¹ -η ⁵ -C ₅ H ^ ₄ CH ₂ CH ₂ P^吨卜₂）]（6）。在镍Ni的距离7-ME，7- ^Ñ镨，和8被发现是2.407（1），2.3931（6），和2.6027（17）A，分别，后者比起另两个由于看似加长桥接配体的束缚性质。DFT计算确认的Ni原子之间未桥连的σ-键在存在7-ME和7- ^Ñ镨和显示的是，在桥连配体8对镍Ni键的字符的影响最小。