10.1021/jacs.5b10074.s002 Balazs Pinter Balazs Pinter Kyle T. Smith Kyle T. Smith Masahiro Kamitani Masahiro Kamitani Eva M. Zolnhofer Eva M. Zolnhofer Ba L. Tran Ba L. Tran Skye Fortier Skye Fortier Maren Pink Maren Pink Gang Wu Gang Wu Brian C. Manor Brian C. Manor Karsten Meyer Karsten Meyer Mu-Hyun Baik Mu-Hyun Baik Daniel J. Mindiola Daniel J. Mindiola Cyclo‑P<sub>3</sub> Complexes of Vanadium: Redox Properties and Origin of the <sup>31</sup>P NMR Chemical Shift American Chemical Society 2015 monomeric species 1 31 P NMR resonances nacnac 31 P NMR spectroscopic signature endocyclic angle Redox Properties redox behavior NMR spectroscopic signature structure analysis Structural metrics novel complexes chemical shifts 31 P NMR Chemical ShiftThe synthesis DFT calculations 2015-12-09 00:00:00 Dataset https://acs.figshare.com/articles/dataset/Cyclo_P_sub_3_sub_Complexes_of_Vanadium_Redox_Properties_and_Origin_of_the_sup_31_sup_P_NMR_Chemical_Shift/2101057 The synthesis and characterization of two high-valent vanadium–<i>cyclo</i>-P<sub>3</sub> complexes, (nacnac)­V­(<i>cyclo</i>-P<sub>3</sub>)­(Ntolyl<sub>2</sub>) (<b>1</b>) and (nacnac)­V­(<i>cyclo</i>-P<sub>3</sub>)­(OAr) (<b>2</b>), and an inverted sandwich derivative, [(nacnac)­V­(Ntolyl<sub>2</sub>)]<sub>2</sub>(μ<sub>2</sub>-η<sup>3</sup>:η<sup>2</sup>-<i>cyclo</i>-P<sub>3</sub>) (<b>3</b>), are presented. These novel complexes are prepared by activating white phosphorus (P<sub>4</sub>) with three-coordinate vanadium­(II) precursors. Structural metrics, redox behavior, and DFT electronic structure analysis indicate that a [<i>cyclo</i>-P<sub>3</sub>]<sup>3–</sup> ligand is bound to a V­(V) center in monomeric species <b>1</b> and <b>2</b>. A salient feature of these new <i>cyclo</i>-P<sub>3</sub> complexes is their significantly downfield shifted (by ∼300 ppm) <sup>31</sup>P NMR resonances, which is highly unusual compared to related complexes such as (Ar­[<sup>i</sup>Pr]­N)<sub>3</sub>Mo­(<i>cyclo</i>-P<sub>3</sub>) (<b>4</b>) and other <i>cyclo</i>-P<sub>3</sub> complexes that display significantly upfield shifted resonances. This NMR spectroscopic signature was thus far thought to be a diagnostic property for the <i>cyclo</i>-P<sub>3</sub> ligand related to its acute endocyclic angle. Using DFT calculations, we scrutinized and conceptualized the origin of the unusual chemical shifts seen in this new class of complexes. Our analysis provides an intuitive rational paradigm for understanding the experimental <sup>31</sup>P NMR spectroscopic signature by relating the nuclear magnetic shielding with the electronic structure of the molecule, especially with the characteristics of metal–<i>cyclo</i>-P<sub>3</sub> bonding.