Synthesis of bimetallic iron-nickel carbonyl clusters: crystal structure of the iron-nickel carbonyl cluster [N(CH3)3CH2Ph][Fe3Ni(CO)8(.mu.-CO)4(.mu.3-H)

Abstract

Redox condensation of (Fe/sub 3/(CO)/sub 11/)/sup 2 -/ with Ni(CO)/sub 4/ in tetrahydrofuran affords the tetranuclear dianion (Fe/sub 3/Ni(CO)/sub 12/)/sup 2 -/. Subsequent protonation with acids results in formation of the corresponding (Fe/sub 3/Ni(CO)/sub 12/H)/sup -/ anion. This monoanionic species has also been obtained by reaction of (Fe/sub 3/(CO)/sub 11/)/sup 2 -/ with NiCl/sub 2/.xEtOH. Both Fe/sub 3/Ni systems have been isolated in the solid state in high yield with a variety of tetrasubstituted ammonium and phosphonium salts. An X-ray diffraction study of the trimethylbenzylammonium salt of (Fe/sub 3/Ni(CO)/sup 12/H)/sup -/ reveals a structure with a tetrahedron of metal atoms surrounded by eight terminal and four edge-bridging carbonyl groups. The hydride ligand has been located over the center of an Fe/sub 2/Ni face at a distance of 0.60 (3) A from the trimetal plane. The corresponding (Fe/sub 3/Ni(CO)/sub 12/)/sup 2 -/ dianion is suggested to possess an analogous structure on the basis of its IR spectrum. Crystallographic data for (C/sub 10/H/sub 16/N)/sup +/(C/sub 12/HFe/sub 3/NiO/sub 12/)/sup -/: fw 713.64, triclinic, space group P1, Z = 2, a = 7.416 (1) A, b = 13.849 (2) A, c = 14.108 (2) A, ..cap alpha.. = 103.13 (2)/sup 0/, ..beta.. = 103.14 more » (2)/sup 0/, ..gamma.. = 99.23 (2)/sup 0/, R(F/sup 2/) = 0.030 for 3860 reflections measured at room temperature. 18 references, 3 figures, 4 tables. « less