Structural and Spectroscopic Trends in a Series of Half-Sandwich Scorpionate Complexes

Liang, Shengwen; Wang, Haoshuang; Deb, Tapash; Petersen, Jeffrey L.; Yee, Gordon T.; Jensen, Michael P.

doi:10.1021/ic301409s

Cited by 19 publications

(11 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…−0.025 au with respect to free acetonitrile at zero field. The same order of magnitude of these values (20–30 cm −1 ) is observed experimentally, though in some cases much higher values have been measured [17c,d] . The equilibrium bond length of CN is minimal at about the same value of the electric field (Fig.…”

Section: Perturbation By Electron Acceptors: Protonation Proton Intesupporting

confidence: 76%

Estimating local bonding/antibonding character of canonical molecular orbitals from their energy derivatives. The case of coordinating lone pair orbitals

Chaquin

Canac

Lepetit

et al. 2016

Int. J. Quantum Chem.

View full text Add to dashboard Cite

International audienceAccording to Koopmans theorem, the derivative of the energy of a canonical MO with respect to nuclear coordinates quantifies its bonding/antibonding character. This quantity allows predictions of bond length variation upon ionisation in a panel of 19 diatomic species. In polyatomic molecules, the derivative of a MO energy with respect to a given bond length reveals the nature and the degree of the bonding/antibonding contribution of this MO with respect to this bond. Accordingly, the HOMO “lone pairs” of CO and CN and the HOMO-2 of CH3CN are found to be antibonding with respect to the C-X bond (X = N, O), whereas the HOMO of N2 is found to be bonding. With the same approach, the variation of the bonding character in the MOs of CO and CH3CN upon interaction with an electron acceptor (modelled through the approach of a proton) or by applying an electric field was studied

show abstract

Section: Perturbation By Electron Acceptors: Protonation Proton Intesupporting

confidence: 76%

Estimating local bonding/antibonding character of canonical molecular orbitals from their energy derivatives. The case of coordinating lone pair orbitals

Chaquin

Canac

Lepetit

et al. 2016

Int. J. Quantum Chem.

View full text Add to dashboard Cite

show abstract

“…50−55 We have reported high activity for tosylnitrene transfer using the solvated half-sandwich scorpionato-iron(II) complexes [ ( T p m M e , M e ) F e ( N C M e ) 3 ] 2 + a n d [ ( T p M e , M e ) F e -(NCMe) 3 ] + . 56,74,81 Several examples of olefin aziridination were obtained using PhINTs as an N-tosylnitrene donor, along with competitive allylic C−H amination of cyclohexene. Competitive aromatic and benzylic amination was observed for alkylbenzenes, which yielded mixtures of anilines and benzylamines.…”

Section: Introductionmentioning

confidence: 99%

Competitive Intramolecular Amination as a Clock for Iron-Catalyzed Nitrene Transfer

2019

Self Cite

View full text Add to dashboard Cite

Reaction of the complex [(TpPh,Me)FeII(NCMe)3]BF4, where TpPh,Me = hydrotris(3-phenyl,5-methyl-1-pyrazolyl)borate, with the iodonium heteroylide PhINTs (1.5 equiv) is proposed to result in the insertion of N-tosylnitrene into one C–H bond at the ortho ring position of a 3-pyrazole phenyl substituent; subsequent deprotonation of the nascent aniline and one-electron oxidation of iron forms TsNH2 (0.5 equiv) as a coproduct. The covalent ligand modification and oxidation results in an intense purple-brown anilinato–iron(III) LMCT chromophore. This intramolecular reaction is utilized as a consistent clock to determine relative rates of competitive intermolecular nitrene transfer to added substrates, specifically to para-substituted styrenes and thioanisoles. Prior addition of substrate to the reaction of PhINTs with the iron(II) complex attenuates the CT absorbance of the equilibrium solution. Fitting of the concentration-dependent absorption data gives the ratio of intra- versus intermolecular nitrene transfer. Because the former is independent of substrate, ratios for various substrates are directly comparable, and this approach enables acquisition of data for a single substrate under nearly stoichiometric, as opposed to competitive catalytic, conditions. Hammett analyses of such data are consistent with an electrophilic intermediate consistent with known or suspected imidoiron(IV) complexes. Because this intermediate was not observed directly, plausible geometric and electronic structures were modeled and assessed using density functional theory.

show abstract

“…9 Six-coordinate ML 4 X 2 [Tp*Fe(NCMe) 3 ]BF 4 is isolable from [Fe(NCMe) 6 ][BF 4 ] 2 , and acetonitrile ligands are labile. 10 Four-coordinate heteroleptic structures, however, are supported by sterically encumbered ligands containing 3,5-diisopropyl-pyrazolyl and 3-tert-butyl-pyrazolyl substitution.…”

Section: Introductionmentioning

confidence: 99%

“…9 Sixcoordinate ML 4 X 2 [Tp*Fe(NCMe) 3 ]BF 4 is isolable from [Fe(NCMe) 6 ][BF 4 ] 2 , and acetonitrile ligands are labile. 10 The two additional bonds of six-coordinate metal centers, in comparison to a four-coordinate species, will contribute to stabilizing the mono-tris(pyrazolyl)borate ML 3 X 3 and ML 4 X 2 species against the redistribution into Tp 2 M and MX 2 shown in Scheme 1. The most desirable four-coordinate heteroleptic structures from the perspective of reactivity, however, are supported by sterically encumbered ligands containing 3,5diisopropyl-pyrazolyl and 3-tert-butyl-pyrazolyl substitution (Figure 1B).…”

Section: ■ Introductionmentioning

confidence: 99%

“…The preparation of iron compounds containing one small Tp ligand may be accomplished in ML 3 X 3 six-coordinate, trivalent compounds [TpFeX 3 ] − and [Tp*FeX 3 ] − (X = Cl, N 3 ) . Six-coordinate ML 4 X 2 [Tp*Fe(NCMe) 3 ]BF 4 is isolable from [Fe(NCMe) 6 ][BF 4 ] 2 , and acetonitrile ligands are labile . The two additional bonds of six-coordinate metal centers, in comparison to a four-coordinate species, will contribute to stabilizing the mono-tris(pyrazolyl)borate ML 3 X 3 and ML 4 X 2 species against the redistribution into Tp 2 M and MX 2 shown in Scheme .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Heteroleptic Four-Coordinate Tris(oxazolinyl)borato Iron(II) Compounds

2019

View full text Add to dashboard Cite

The reaction of FeBr 2 and 1 equiv. of thallium tris(4,4-dimethyl-2oxazolinyl)phenylborate (TlTo M ) in THF provides To M FeBr (1), whereas FeBr 2 and 2 equiv. of TlTo M react to give (To M ) 2 Fe (2). Two ν CN bands at 1604 and 1548 cm -1 indicated bidentate coordination of To M to iron in 2. Homoleptic 2 and FeBr 2 react in THF overnight through an unusual comproportionation process to give compound 1, which is apparently the thermodynamic product. The salt metathesis reaction of 1 and KCH 2 Ph affords To M FeCH 2 Ph (3).The effective magnetic moments of compounds 1 -3 range from 4.9 to 5.4  B , and these values are consistent with high-spin iron(II) (S = 2). A single 1 H NMR signal assigned to the methyl groups of the To M ligand suggested tridentate coordination of the To M ligand to iron in 1 and 3.X-ray crystallography studies of 1 -3 establish their structure as four-coordinated tetrahedral iron complexes. To M FeBn and CO (1 atm) react to afford isolable To M Fe{C(=O)Bn}(CO) 2 (4) as a yellow solid. Complex 4 is diamagnetic (S = 0), and the three distinct methyl signals in the 1 H

show abstract

Structural and Spectroscopic Trends in a Series of Half-Sandwich Scorpionate Complexes

Cited by 19 publications

References 82 publications

Estimating local bonding/antibonding character of canonical molecular orbitals from their energy derivatives. The case of coordinating lone pair orbitals

Estimating local bonding/antibonding character of canonical molecular orbitals from their energy derivatives. The case of coordinating lone pair orbitals

Competitive Intramolecular Amination as a Clock for Iron-Catalyzed Nitrene Transfer

Heteroleptic Four-Coordinate Tris(oxazolinyl)borato Iron(II) Compounds

Contact Info

Product

Resources

About