Direct Lanthanide−Transition Metal Interactions: Synthesis of (NH3)2YbFe(CO)4and Crystal Structures of {[(CH3CN)3YbFe(CO)4]2·CH3CN}∞and [(CH3CN)3YbFe(CO)4]∞

Publisher Website
Google Scholar
Abstract
The heterometallic complex (NH3)2YbFe(CO)4 was prepared from the reduction of Fe3(CO)12 by Yb in liquid ammonia. Ammonia was displaced from (NH3)2YbFe(CO)4 by acetonitrile in acetonitrile solution, and the crystalline compounds {[(CH3CN)3YbFe(CO)4)]2·CH3CN}∞ and [(CH3CN)3YbFe(CO)4]∞ were obtained. An earlier X-ray study of {[(CH3CN)3YbFe(CO)4]2·CH3CN}∞ showed that it is a ladder polymer with direct Yb−Fe bonds. In the present study, an X-ray crystal structure analysis also showed that [(CH3CN)3YbFe(CO)4]∞ is a sheetlike array with direct Yb−Fe bonds. Crystal data for {[(CH3CN)3YbFe(CO)4]2·CH3CN}∞: monoclinic space group P21/c, a = 21.515(8) Å, b = 7.838(2) Å, c = 19.866(6) Å, β = 105.47(2)°, Z = 4. Crystal data for [(CH3CN)3YbFe(CO)4]∞: monoclinic space group P21/n, a = 8.364(3) Å, b = 9.605(5) Å, c = 17.240(6) Å, β = 92.22(3)°, Z = 4. Electrical conductivity measurements in acetonitrile show that these acetonitrile complexes are partially dissociated into ionic species. IR and NMR spectra of the solutions reveal the presence of [HFe(CO)4]-. However, upon recrystallization, the acetonitrile complexes show no evidence for the presence of [HFe(CO)4]- on the basis of their IR spectra. The solid state MAS 2H NMR spectra of deuterated acetonitrile complexes give no evidence for [2HFe(CO)4]-. It appears that rupture of the Yb−Fe bond could occur in solution to generate the ion pair [LnYb]2+[Fe(CO)4]2-, but then the highly basic [Fe(CO)4]2- anion could abstract a proton from a coordinated acetonitrile ligand to form [HFe(CO)4]-. However, upon crystallization, the proton could be transferred back to the ligand, which results in the neutral polymeric species.

This publication has 42 references indexed in Scilit: