Structure of the first homoleptic manganese–phosphine complex, [Mn(Me2PC2H4PMe2)3][BF4]

Toupadakis, Andreas; Scott, Brian L.; Kubas, Gregory J.

doi:10.1023/b:jocc.0000022422.09931.39

Cited by 2 publications

(3 citation statements)

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“…The average P−Re−P bite angles (69.16° ± 0.91 and 68.66° ± 0.57) are significantly smaller owing to the shorter methylene bridge between the chelating phosphorus atoms. The closely related manganese analogue [Mn(dmpe) 3 ] + exhibits a highly symmetrical Mn−P 6 core and crystallizes in space group P 31 c . The Mn−P bond distances are on average 0.1 Å shorter than those for [Re(dmpe) 2 (depe)] + , while the comparable angles are essentially the same.…”

Section: Resultssupporting

confidence: 89%

Luminescent Low-Valent Rhenium Complexes with 1,2-Bis(dialkylphosphino)ethane Ligands. Synthesis and X-ray Crystallographic, Electrochemical, and Spectroscopic Characterization

2010

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A series of low-valent rhenium phosphine complexes with the general formula [Re(dmpe)(3-x)(depe)(x)](2+/+) (x = 0-3), where dmpe is 1,2-bis(dimethylphosphino)ethane and depe is 1,2-bis(diethylphosphino)ethane, were synthesized and characterized. The reaction of [Re(benzil)(PPh(3))Cl(3)] with the appropriate phosphine yielded the homoleptic tris complexes [Re(dmpe)(3)](+) and [Re(depe)(3)](2+), while the mixed-ligand complexes [Re(dmpe)(2)(depe)](+) and [Re(dmpe)(depe)(2)](2+) were prepared from [Re(dmpe)(2)Cl(2)](+) and [Re(depe)(2)Cl(2)](+), respectively. The oxidation state of the final product strongly depends on the donating properties of the ligand. Each complex, however, exhibits a diffusion-controlled, reversible one-electron transfer between Re(I) and Re(II) with formal reduction potentials, E degrees ', ranging from -0.09 to -0.28 V versus a ferrocene external standard. Subsequent oxidation to Re(III) was found to be chemically irreversible. UV-vis and luminescence spectroelectrochemical techniques were used to study the spectral properties of the Re(I) and Re(II) forms. The Re(II) complexes are red in color and exhibit absorption features from 350 to 600 nm; the lowest-energy transition was assigned as a sigma(P) to dpi(Re) ligand-to-metal charge-transfer (LMCT) transition. Excitation into the lowest-energy absorption band revealed rare examples of luminescent (Phi approximately 0.07) LMCT excited states from d(5) transition-metal complexes in a room temperature solution. Structural characterization of salts of both oxidation states of [Re(dmpe)(2)(depe)](2+/+) was also performed.

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Section: Resultssupporting

confidence: 89%

Luminescent Low-Valent Rhenium Complexes with 1,2-Bis(dialkylphosphino)ethane Ligands. Synthesis and X-ray Crystallographic, Electrochemical, and Spectroscopic Characterization

2010

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“…25 In light of the general reversibility of [(PP) 3 Re] 2+/+ redox couples (vide infra), simple stoichiometric one-electron chemical oxidants were used to prepare the corresponding [(PP) 3 Re] 2+ complexes in good yield (66−95%, Scheme 2). For the more readily oxidized complexes [(PP) Mn, 52 Re, 25,53,54 Fe, 55−57 Rh, 58 Co, 59 Cr, 60−64 Mo, 60,63,65−67 W, 56,60,63,68,69 V, 63,70 Nb and Ta, 63 Zr, 71 and Ru. 72 73 reflect a lower effective bond order for Re 2+ relative to Re + (0.829 vs 0.896).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…As a general class of coordination compounds, structurally characterized six-coordinate phosphine complexes [(R 3 P) 6 M] have been reported for Mn, Re, ,, Fe, − Rh, Co, Cr, − Mo, ,,− W, ,,,, V, , Nb and Ta, Zr, and Ru . Structural data for tris phosphine chelate Re complexes have been reported for [(dppm) 3 Re] + and for the redox pairs [(dmpe) 2 (depe)Re] 2+ and [(dmpe) 2 (depe)Re] + .…”

Section: Resultsmentioning

confidence: 99%

Homoleptic Tris-Diphosphine Re(I) and Re(II) Complexes and Re(II) Photophysics and Photochemistry

Adams¹,

Arulsamy²,

Sullivan³

et al. 2015

Inorg. Chem.

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The ligand-to-metal charge transfer state (LMCT) of [(dmpe)3Re](2+) (dmpe = 1,2-bis(dimethylphosphino)ethane) has been demonstrated to be a potent oxidant (E(0)(Re(2+*)/Re(+)) = 2.61 V vs standard calomel electrode). This complex has been traditionally prepared by nontrivial routes in low yields, and very little has been achieved in optimizing the ground state and emission energy properties of the general class of complexes [(PP)3Re](2+) (PP = chelating diphosphine) through phosphine modification. Improved syntheses for Re(I) tris-homoleptic diphosphine complexes [(PP)3Re](+) (PP = 1,2-bis(dimethylphosphino)ethane (dmpe), 1,2-bis(diethylphosphino)ethane (depe), bis(dimethylphosphino)methane (dmpm), bis(diphenylphosphino)methane (dppm), Me2PCH2PPh2, 1,3-bis(dimethylphosphino)propane (dmpp), or 1,2-bis(dimethyl-phosphino)benzene (dmpb)) were achieved by single-pot reactions exploiting the reducing potential of the phosphines when reacted with Re(V) oxo-complexes in 1,2-dichlorobenzene at 160-180 °C. Single-electron chemical oxidation of [(PP)3Re](+) yields luminescent Re(II) analogues; appropriate use of Ph3C(+), Cp2Fe(+), or (4-BrC6H4)3N(+) B(C6F5)4(-) salts produced [(PP)3Re](2+) complexes in good yields. Crystallographic trends for the Re(+)/Re(2+) pairs show significantly lengthened Re(2+)-P bonds for [(PP)3Re](2+) relative to the corresponding [(PP)3Re](+) system. The redox and luminescence behavior of the complexes indicates the luminescence is from a ligand P(σ)-to-metal (Re(dπ)) charge transfer ((2)LMCT) state for all the complexes. Structured luminescence at 77 K is postulated to originate from relaxation of the (2)LMCT state into two spin-orbit coupled states: the ground state and a state ∼ 3000 cm(-1) above the ground state. The excited-state reduction potential (Re(II*/I)) for [(depe)3Re](2+) was determined from the free energy dependence of luminescence quenching rate constants. Yields for formation of charge separated ions were determined for three of the complexes with a variety of electron donors. Despite favorable electrostatics, no charge separated ions were observed for radical ion pairs for which the energy of back electron transfer exceeded 1.1 V.

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Structure of the first homoleptic manganese–phosphine complex, [Mn(Me₂PC₂H₄PMe₂)₃][BF₄]

Cited by 2 publications

References 4 publications

Luminescent Low-Valent Rhenium Complexes with 1,2-Bis(dialkylphosphino)ethane Ligands. Synthesis and X-ray Crystallographic, Electrochemical, and Spectroscopic Characterization

Luminescent Low-Valent Rhenium Complexes with 1,2-Bis(dialkylphosphino)ethane Ligands. Synthesis and X-ray Crystallographic, Electrochemical, and Spectroscopic Characterization

Homoleptic Tris-Diphosphine Re(I) and Re(II) Complexes and Re(II) Photophysics and Photochemistry

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