Crystal structure of the new palladium complexes tetra­kis­(1,3-di­methyl­imidazolium-2-yl­idene)palladium(II) hexa­deca­carbonyl­tetra­rhenium diethyl ether disolvate and octa-μ-carbonyl-di­carbonyl­tetra­kis­(tri­phenyl­phosphane)palladium­dirhenium (unknown solvate)

The investigation of the coordination chemistry of heterometallic transition-metal complexes of palladium (Pd) and rhenium (Re) led to the isolation and crystallographic characterization of tetra­kis­(1,3-di­methyl­imidazolium-2-yl­idene)palladium(II) hexa­deca­carbonyl­tetra­rhenium diethyl ether disolvate, [Pd(C(5)H(8)N(2))(4)][Re(4)(CO)(16)]·2C(4)H(10)O or [Pd(IMe)(4)][Re(4)(CO)(16)]·2C(4)H(10)O, (1), and octa-μ-carbonyl-di­carbonyl­tetra­kis­(tri­phenyl­phosphane)palladium­dirhenium, [Pd(4)Re(2)(C(18)H(15)P)(4)(CO)(10)] or Pd(4)Re(2)(PPh(3))(4)(μ-CO)(8)(CO)(2), (2), from the reaction of Pd(PPh(3))(4) with 1,3-di­methyl­imidazolium-2-carboxyl­ate and Re(2)(CO)(10) in a toluene–aceto­nitrile mixture. In complex 1 the Re—Re bond lengths [2.9767 (3)–3.0133 (2) Å] are close to double the covalent Re radii (1.51 Å). The palladium–rhenium carbonyl cluster 2 has not been structurally characterized previously; the Pd—Re bond lengths [2.7582 (2)–2.7796 (2) Å] are about 0.1 Å shorter than the sum of the covalent Pd and Re radii (1.39 + 1.51 = 2.90 Å). One carbene ligand and a diethyl ether mol­ecule are disordered over two positions with occupancy ratios of 0.5:0.5 and 0.625 (15):0.375 (15) in 1. An unidentified solvent is present in compound 2. The given chemical formula and other crystal data do not take into account the unknown solvent mol­ecule(s). The SQUEEZE routine [Spek (2015 ▸). Acta Cryst. C71, 9–18] in PLATON was used to remove the contribution of the electron density in the solvent region from the intensity data and the solvent-free model was employed for the final refinement. The cavity with a volume of ca 311 Å(3) contains approximately 98 electrons.