Late-Metal Diphosphinosulfinyl S(O)P2 Pincer-type Complexes

The preparation of a new tridentate diphosphinosulfinyl ligand is described as well as the synthesis and properties of some of its Rh, Ir, Ni, Pd, and Pt complexes. The ligand binds in a κ3-PS­(O)P fashion in all cases. The M–S lengths in (SOP2)­RhCl and (SOP2)­IrCl (2.1340(8) and 2.1341(5) Å, respectively) are the shortest of all crystallographically characterized Rh– and Ir–S­(O)­R2 complexes, which illustrates the significant M–S­(O) π-backbonding for these metals. Akin to Vaska’s complex, (SOP2)­IrCl binds O2 to yield a peroxide complex with an O–O length of 1.465(3) Å and ν(O–O) = 847 cm–1. The C–O stretches of (SOP2)­M­(CO) (M = Ni, Pd, Pt) are ∼30–40 cm–1 higher than those of the analogous (PPh3)3M­(CO). A number of divalent group 10 complexes of the form [(SOP2)­MX]+ for Ni (X = Cl), Pd (X = Cl, Me), and Pt (X = Cl, Me) are reported, as well as the highly electrophilic complex [(SOP2)­Pd­(NCCH3)]2+. An analysis of the S–O length as a function of the M–S length for all d8 SOP2 Rh, Ir, Pd, and Pt complexes reveals that the electron-withdrawing capabilities of the sulfinyl group are mediated largely through π-backbonding for Rh and Ir and mostly through poor σ-donation for Pd and Pt.

本文报道了一种新型三齿二膦亚磺酰基配体的制备方法，以及其与铑(Rh)、铱(Ir)、镍(Ni)、钯(Pd)、铂(Pt)形成的部分配合物的合成与性质。该配体在所有配合物中均以κ³-PS(O)P的配位模式与金属中心结合。(SOP2)RhCl与(SOP2)IrCl中的M-S键长分别为2.1340(8) Å和2.1341(5) Å，为所有经晶体学表征的Rh-和Ir-S(O)R₂配合物中最短的，这表明这两种金属与S(O)之间存在显著的M-S(O) π反馈键。与瓦斯卡配合物(Vaska's complex)类似，(SOP2)IrCl可与O₂结合生成过氧配合物，其O-O键长为1.465(3) Å，O-O伸缩振动波数为847 cm⁻¹。(SOP2)M(CO)（M=Ni、Pd、Pt）的C-O伸缩振动波数比结构类似的(PPh₃)₃M(CO)高出约30~40 cm⁻¹。本文还报道了一系列通式为[(SOP2)MX]⁺的第10族二价配合物：其中Ni对应的X为Cl，Pd对应的X为Cl或甲基，Pt对应的X为Cl或甲基；此外还得到了高亲电性配合物[(SOP2)Pd(NCCH₃)]²⁺。对所有d⁸构型的SOP2类Rh、Ir、Pd、Pt配合物的S-O键长与M-S键长的相关性进行分析后发现，亚磺酰基的吸电子能力对于Rh和Ir主要通过π反馈键介导，而对于Pd和Pt则主要通过较弱的σ配位给予作用实现。