Linear CuI2Pd0, CuIPd02, and AgI2Pd0 Metal Chains Supported by Rigid N,N′‐Diphosphanyl N‐Heterocyclic Carbene Ligands and Metallophilic Interactions

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Abstract Selective copper(I) to palladium(0) transmetallation of P‐donors from the rigid N,N′‐diphosphanyl‐imidazol‐2‐ylidene C3H2[NP(tBu)2]2 (PCNHCP) was observed when known [Cu3(μ3‐PCNHCP,κP,κCNHC,κP)2](OTf)3 was reacted with [Pd(PPh3)4]. When 1.2 equivalents of [Pd(PPh3)4] was used, the product [Cu2Pd(μ3‐PCNHCP,κP,κCNHC,κP)2](OTf)2 (2(OTf)2) was obtained, which features a CuI–CuI–Pd0 chain and appears to be the first linear heterotrinuclear complex with d10–d10 interactions between Pd0 and CuI. When the Cu3 precursor was reacted with 3.0 equivalents of [Pd(PPh3)4], the complex [CuPd2(μ3‐PCNHCP,κP,κCNHC,κP)2](OTf)2 (3(OTf)2) was obtained, which, on the basis of magnetic measurements, DFT calculations, and computed nuclear shieldings, was formulated as containing a Pd0–CuI–Pd0 chain with an electron hole delocalized over the whole cation, including the metal chain. Similarly, selective transmetallation of the P‐donors in [Ag3(μ3‐PCNHCP,κP,κCNHC,κP)2](OTf)3 from silver to palladium (originating from [Pd(PPh3)4]) gave the linear chain [Ag2Pd(μ3‐PCNHCP,κP,κCNHC,κP)2](OTf)2 (5(OTf)2), which on the basis of NMR spectroscopy comprises an AgI–AgI–Pd0 metal core. However, X‐ray diffraction data collected on various samples of 5(OTf)2 were modeled with 50:50 metal disorder at the terminal positions, corresponding to a (AgI/Pd0)–AgI–(AgI/Pd0) formulation. Upon standing in solution, 5(OTf)2 transformed to 6(OTf)2, the regioisomer of 5(OTf)2 in which the Pd center has migrated to the central position of an AgI–Pd0–AgI chain. Prolonged standing in CH2Cl2 or by reaction with [PtCl2(NCMe)2] converts complex 6(OTf)2 to the AgI/PdII complex [Ag2PdCl2(μ3‐PCNHCP,κP,κCNHC,κP)2](OTf)2 (7(OTf)2). The structural data of 2(OTf)2, 3(OTf)2, and 7(OTf)2 establish significant heterometallophilic interactions.

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