Bimetallic Fe-Ir and Trimetallic Fe-Ir-Au Carbonyl Clusters Containing Hydride and/or Phosphine Ligands: Syntheses, Structures and DFT Studies

The reaction of [HFe4(CO)(12)(IrCOD)](2-)(1) with CO at ambient conditions afforded [HFe4Ir(CO)(14)](2-)(2), that, in turn, reacted with HBF4 center dot Et2O affording [Fe4Ir(CO)(15)](-)(3).1reacted with a slight excess of PPh(3)resulting in a mixture of [HFe2Ir2(CO)(10)(PPh3)(2)](-)(ca. 37%) (5) and [H2Fe3Ir(CO)(10)(PPh3)(2)](-)(ca. 63%) (6).5and6co-crystallized as their [NEt4][H1+xFe2+xIr2-x(CO)(10)(PPh3)(2)]center dot CH2Cl2(x = 0.63) salt. The reaction of1with Au(PPh3)Cl afforded [Fe3Ir(CO)(12)(AuPPh3)](2-)(7). The related hydride [HFe3Ir(CO)(12)](2-)(9) was prepared from the reaction of [HFe4(CO)(12)](3-)(8) with [Ir(COE)(2)Cl](2)(COE = cyclo-octene). For sake of comparison, [HFe3Co(CO)(12)](2-)(10) was obtained from8and Co-2(CO)(8). All the new clusters have been fully characterized via IR,H-1,C-13{H-1} and(31)P{H-1} NMR spectroscopies and their structures determined by means of single crystal X-ray crystallography. Possible isomers have been investigated by DFT calculations.

Automated summary

In this study, a variety of iron-iridium alloy cluster compounds were synthesized through different reaction steps, characterized using various NMR spectroscopic methods and single crystal X-ray diffraction, and possible isomers were investigated through DFT calculations.