Cleavage of phosphorus-sulfur bond and formation of (μ-S)Fe core from photochemical reactions of Fe(CO)5 with [(RO)2PS2]2; (R = Me, Et, iPr)

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.

Stabilization of dichalcogenide ligands in the coordination sphere of a ruthenium system

The synthesis, structure and electronic properties of tetraruthenium dichalcogenide complexes displaying the exclusive coordination mode of dichalcogenide ligands have been discussed. The reactions of Li[BH₂E₃] (E = S or Se) with [ClRu(μ-Cl)(p-cymene)]₂ (p-cymene = η⁶-{p-C₆H₄(ⁱPr)Me}) at room temperature yielded tetrametallic dichalcogenide complexes [{Ru₂Cl₂(p-cymene)₂}₂(μ₄,η²-E₂)], 1-2 (E = S (1) and Se (2)). The solid-state X-ray structure of 1 shows that two {(p-cymene)RuCl}₂ moieties are bridged by a S-S bond. In addition to 2, the reaction of Li[BH₂Se₃] with [ClRu(μ-Cl)(p-cymene)]₂ also yielded a mononuclear tris-homocubane analogue [Ru(p-cymene){Se₇(BH)₃}] (3) which is an analogue of 1,3,3-tris-homocubane and possesses D₃ symmetry. In order to isolate the Cp* analogue of 1, the reaction of [Cp*Ru(μ-Cl)Cl]₂ with Li[BH₂S₃] was carried out, which led to the formation of bis/tris-homocubane derivatives [(Cp*Ru)₂{μ-S_n(BH)₂}] (n = 7 (4) and 6 (5)) along with the formation of ruthenium disulfide complexes [(RuCp*)₂(μ,η²:η²-S₂)(μ,η¹:η¹-S₂)] and [(RuCp*)₂(μ-SBHS-κ¹B:κ²S:κ²S)(μ,η¹:η¹-S₂)]. Complexes 1-5 have been characterized by multi-nuclear NMR, IR, UV-vis spectroscopy, and mass spectrometry and their molecular formulations (except 2) have been determined by single crystal X-ray crystallography. Furthermore, DFT calculations were performed that rationalize the stabilization of the dichalcogenide units (E₂^2-) by the tetrametallic systems in 1-2.

Chalcogen-atom abstraction reactions of a Di-iron imidophosphorane complex

Reaction of the complexes [Fe2(μ2-NP(pip)3)2(NP(pip)3)2] (1-Fe) and [Co2(μ2-NP(pip)3)2(NP(pip)3)2] (1-Co), where [NP(pip)3]1- is tris(piperidinyl)imidophosphorane, with nitrous oxide, S8, or Se0 results in divergent reactivity. With nitrous oxide, 1-Fe forms [Fe2(μ2-O)(μ2-NP(pip)3)2(NP(pip)3)2] (2-Fe), with a very short Fe3+-Fe3+ distance. Reactions of 1-Fe with S8 or Se0 result in the bridging, side-on coordination (μ-κ1:κ1-E22-) of the heavy chalcogens in complexes [Fe2(μ-κ1:κ1-E2)(μ2-NP(pip)3)2(NP(pip)3)2] (E = S, 3-Fe, or Se, 4-Fe). In all cases, the complex 1-Co is inert.