Iron complexes with terminal and nonbridging phosphanido ligands

Adaptive Coordination Behavior of Bisphosphanylphosphanido-Ligands Toward Group 2, 11 and 12 Metal Ions

A series of alkaline earth metal complexes (Mg-Ba) with the anionic ferrocenylene-bridged bisphosphanylphosphanide ligand [Fe(C5H4PC4H9)2P]- has been prepared by metalation of the corresponding bisphosphanylhydrophosphane (Fe(C5H4PC4H9)2PH). The resulting complexes have been characterized by multinuclear NMR spectroscopy and SC-XRD. Furthermore, the closely related zinc phosphanide, and rare, mononuclear coinage metal phosphanides were synthesized and investigated for comparison. The range of coordination modes observed for the phosphanide ligand included mono-, bi-, and tridentate modi and their respective combinations, whereas no μ2-bridging of the phosphanide center has been observed. The value of the 1JPP coupling constant was found to be a good probe to track the coordination motif consistent with the situation in solid state.

Three-Coordinate Monomeric Phosphido Complexes of Ni(II)

This paper reports the synthesis of the first series of terminal phosphido Ni(II) complexes supported by the β-diketiminato ligand [iPrNN] (where iPrNN = 2,4-bis(2,6-diisopropylphenylimido)pentyl). Neutral mononuclear Ni(II) complexes [iPrNN]Ni-PPh2 (2) and [iPrNN]Ni-PAd2 (3) were obtained from the reaction of [iPrNN]NiBr2Li(thf)2 (1) with the R2PM (R = Ph, 1-adamantyl (Ad); M = Li, K) phosphide reagents. The structures of the synthesized compounds were determined by single-crystal X-ray diffraction, which revealed that the Ni center in these terminal phosphido complexes is three-coordinate with an almost planar geometry when R = Ph and a pyramidal geometry when R = Ad. The reactivity of the synthesized complexes was also studied in a range of bond forming reactions, including P-C and P-P bonds.

Panoply of P: An Array of Rhenium-Phosphorus Complexes Generated from a Transition Metal Anion

We expand upon the synthetic utility of anionic rhenium complex Na[(BDI)ReCp] (1, BDI = N,N'-bis(2,6-diisopropylphenyl)-3,5-dimethyl-β-diketiminate) to generate several rhenium-phosphorus complexes. Complex 1 reacts in a metathetical manner with chlorophosphines Ph2PCl, MeNHP-Cl, and OHP-Cl to generate XL-type phosphido complexes 2, 3, and 4, respectively (MeNHP-Cl = 2-chloro-1,3-dimethyl-1,3,2-diazaphospholidine; OHP-Cl = 2-chloro-1,3,2-dioxaphospholane). Crystallographic and computational investigations of phosphido triad 2, 3, and 4 reveal that increasing the electronegativity of the phosphorus substituent (C < N < O) results in a shortening and strengthening of the rhenium-phosphorus bond. Complex 1 reacts with iminophosphane Mes*NPCl (Mes* = 2,4,6-tritert-butylphenyl) to generate linear iminophosphanyl complex 5. In the presence of a suitable halide abstraction reagent, 1 reacts with the dichlorophosphine iPr2NPCl2 to afford cationic phosphinidene complex 6+. Complex 6+ may be reduced by one electron to form 6•, a rare example of a stable, paramagnetic phosphinidene complex. Spectroscopic and structural investigations, as well as computational analyses, are employed to elucidate the influence of the phosphorus substituent on the nature of the rhenium-phosphorus bond in 2 through 6. Furthermore, we examine several common analogies employed to understand metal phosphido, phosphinidene, and iminophosphanyl complexes.