biostudies-literatureSpentzos AZUniversity of PennsylvaniaNational Institute of General Medical SciencesNIGMS NIH HHS11487-11499https://www.ebi.ac.uk/biostudies/studies/S-EPMC11071007biostudies-literatureUnknown62(29)This article describes the synthesis, characterization, and S-atom transfer reactivity of a series of <i>C</i>_3<i>v</i>-symmetric diiron complexes. The iron centers in each complex are coordinated in distinct ligand environments, with one (Fe_N) bound in a pseudo-trigonal bipyramidal geometry by three phosphinimine nitrogens in the equatorial plane, a tertiary amine, and the second metal center (Fe_C). Fe_C is coordinated, in turn, by Fe_N, three ylidic carbons in a trigonal plane, and, in certain cases, by an axial oxygen donor. The three alkyl donors at Fe_C form through the reduction of the appended N═PMe₃ arms of the monometallic parent complex. The complexes were studied crystallographically, spectroscopically (NMR, UV-vis, and Mössbauer), and computationally (DFT, CASSCF) and found to be high-spin throughout, with short Fe-Fe distances that belie weak orbital overlap between the two metals. Further, the redox nature of this series allowed for the determination that oxidation is localized to the Fe_C. S-atom transfer chemistry resulted in the formal insertion of a S atom into the Fe-Fe bond of the reduced diiron complex to form a mixture of Fe₄S and Fe₄S₂ products.Inorganic chemistryInvestigating Metal-Metal Bond Polarization in a Heteroleptic Tris-Ylide Diiron System.PMC11071007R01 GM119374R35 GM128794R35GM128794R01GM119374Confer AMSpentzos AZMay SRCarroll PJGau MRGoldberg DPTomson NCfalseInvestigating Metal-Metal Bond Polarization in a Heteroleptic Tris-Ylide Diiron System.This article describes the synthesis, characterization, and S-atom transfer reactivity of a series of <i>C</i>_3<i>v</i>-symmetric diiron complexes. The iron centers in each complex are coordinated in distinct ligand environments, with one (Fe_N) bound in a pseudo-trigonal bipyramidal geometry by three phosphinimine nitrogens in the equatorial plane, a tertiary amine, and the second metal center (Fe_C). Fe_C is coordinated, in turn, by Fe_N, three ylidic carbons in a trigonal plane, and, in certain cases, by an axial oxygen donor. The three alkyl donors at Fe_C form through the reduction of the appended N═PMe₃ arms of the monometallic parent complex. The complexes were studied crystallographically, spectroscopically (NMR, UV-vis, and Mössbauer), and computationally (DFT, CASSCF) and found to be high-spin throughout, with short Fe-Fe distances that belie weak orbital overlap between the two metals. Further, the redox nature of this series allowed for the determination that oxidation is localized to the Fe_C. S-atom transfer chemistry resulted in the formal insertion of a S atom into the Fe-Fe bond of the reduced diiron complex to form a mixture of Fe₄S and Fe₄S₂ products.2023-01-01T00:00:00Z2023 Jul2025-05-18T13:27:18.952Z2025-05-18T13:27:18.952ZS-EPMC110710073742800010.1021/acs.inorgchem.3c01068