Bis(triazenide), tris(triazenide), and lantern-type of triazenide iron complexes: Synthesis and structural characterization

摘要

A commercially available triazine, PhNNN(H)Ph, served as a monoanionic bidentate ligand upon deprotonation using Fe[N(SiMe3)(2)](2). By simply using different ethereal solvents, the bis(diethylether) and bis (tetrahydrofurane) complexes of Fe[PhNNNPh](2), 1 and 2, can be prepared successfully. The structures of 1 and 2 were confirmed by single crystal X-ray diffraction studies and supported by NMR spectroscopy and elemental analysis. Interestingly, the solid-state structure of 1 exhibits two Et2O ligands coordinated to Fe(II) in a trans manner, whereas 2 shows two THF solvents bound to Fe(II) in a cis fashion. The tris (homoleptic) Fe(III) complex 3 was obtained upon oxidation in air, and the one electron reduced counterpart 4 can be synthesized when treating 3 with KC8. One of the reduced by-products was crystallized and confirmed as a lantern-type diiron complex [Fe-2(mu-N,N'-PhNNNPh)(4)], 5, by single crystal X-ray diffraction. Remarkably, the Fe-Fe bond of 2.1901(4) angstrom in 5 is among the shortest Fe(II)-Fe(II) bond. (C) 2018 Elsevier B.V. All rights reserved.