1 Supporting Information High-Yield Synthesis and Reactivity of Stable Diiron Complexes with Bent-Phosphinidene Bridges Celedonio M. Alvarez, M. Angeles Alvarez, M. Esther García, Rocío González, Miguel A. Ruiz,* Hayrullo Hamidov and John C. Jeffery † . Departamento de Química Orgánica e Inorgánica/IUQOEM, Universidad de Oviedo, E-33071 Oviedo, Spain. † School of Chemistry, University of Bristol, Bristol BS8 1TS, UK. • Preparative Procedures and Spectroscopic Data for New Compounds. • Structure Solution and Refinements for compounds 3b and 5a • CIF file for compounds 3b and 5a.