Structural and electronic elucidation of a N-heterocyclic silylene vanadocene adduct

Hänninen, Mikko M.; Baldansuren, Amgalanbaatar; Pugh, Thomas

doi:10.1039/c7dt01226h

Cited by 11 publications

(3 citation statements)

References 31 publications

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“…For the Dipp‐substituted silylene, more examples exist, for example, a three‐coordinate iron(II) silylene complex [Fe(N(SiMe 3 ) 2 ) 2 (Dipp 2 NHSi)] reported by Layfield et al . Another interesting example is the complex [( η 5 ‐C 5 H 5 ) 2 V(Dipp 2 NHSi)], which was obtained by reaction of the silylene with vanadocene, as it was not possible to obtain the analogous product from the corresponding carbene Dipp 2 Im …”

Section: Introductionmentioning

confidence: 99%

N‐Heterocyclic Silylenes as Ligands in Transition Metal Carbonyl Chemistry: Nature of Their Bonding and Supposed Innocence

Krahfuß

Nitsch

Bickelhaupt

et al. 2020

Chemistry A European J

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A study on the reactivity of the N‐heterocyclic silylene Dipp2NHSi (1,3‐bis(diisopropylphenyl)‐1,3‐diaza‐2‐silacyclopent‐4‐en‐2‐yliden) with the transition metal complexes [Ni(CO)4], [M(CO)6] (M=Cr, Mo, W), [Mn(CO)5(Br)] and [(η5‐C5H5)Fe(CO)2(I)] is reported. We demonstrate that N‐heterocyclic silylenes, the higher homologues of the now ubiquitous NHC ligands, show a remarkably different behavior in coordination chemistry compared to NHC ligands. Calculations on the electronic features of these ligands revealed significant differences in the frontier orbital region which lead to some peculiarities of the coordination chemistry of silylenes, as demonstrated by the synthesis of the dinuclear, NHSi‐bridged complex [{Ni(CO)2(μ‐Dipp2NHSi)}2] (2), complexes [M(CO)5(Dipp2NHSi)] (M=Cr 3, Mo 4, W 5), [Mn(CO)3(Dipp2NHSi)2(Br)] (9) and [(η5‐C5H5)Fe(CO)2(Dipp2NHSi‐I)] (10). DFT calculations on several model systems [Ni(L)], [Ni(CO)3(L)], and [W(CO)5(L)] (L=NHC, NHSi) reveal that carbenes are typically the much better donor ligands with a larger intrinsic strength of the metal–ligand bond. The decrease going from the carbene to the silylene ligand is mainly caused by favorable electrostatic contributions for the NHC ligand to the total bond strength, whereas the orbital interactions were often found to be higher for the silylene complexes. Furthermore, we have demonstrated that the contribution of σ‐ and π‐interaction depends significantly on the system under investigation. The σ‐interaction is often much weaker for the NHSi ligand compared to NHC but, interestingly, the π‐interaction prevails for many NHSi complexes. For the carbonyl complexes, the NHSi ligand is the better σ‐donor ligand, and contributions of π‐symmetry play only a minor role for the NHC and NHSi co‐ligands.

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Section: Introductionmentioning

confidence: 99%

N‐Heterocyclic Silylenes as Ligands in Transition Metal Carbonyl Chemistry: Nature of Their Bonding and Supposed Innocence

Krahfuß

Nitsch

Bickelhaupt

et al. 2020

Chemistry A European J

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“…The coordination chemistry of NHCs in transition metal half-sandwich complexes is well studied, whereas only a few examples of NHSi half-sandwich complexes are known. ,, Therefore, we were interested in gaining further insight into the reactivity of N -heterocyclic silylenes with half-sandwich transition metal complexes. Lappert and co-workers described the reaction of [{(η 5 -C 5 H 5 )Fe(CO) 2 } 2 ] with R 2 Im H2 (R = Me, Et) in xylene at 140 °C which led to the isolation of a dark green solid.…”

Section: Resultsmentioning

confidence: 99%

N-Heterocyclic Silylenes as Metal–Metal Bridges and Metal–Halide Activators in Transition Metal Complexes

Krahfuß

Radius

2020

Inorg. Chem.

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Several examples are provided that NHSi (N-heterocyclic silylene) ligands are much better metal−metal bridging ligands as compared to NHCs and that NHSi also tends to insert much more easily into metal−halide bonds of transition metal complexes. Dipp 2 NHSi (1,3-bis(2,6-diisopropyphenyl)-1,3-diaza-4silacyclopent-4-en-2-yliden) reacts with [{(η 5 -C 5 H 5 )Fe(CO) 2 } 2 ] and [(η 5 -C 5 H 5 ) 2 Ni] to yield, in contrast to the results obtained for analogous transformations with NHCs, the dinuclear silylene-bridged complexes [{(η 5 -C 5 H 5 )Fe(CO)} 2 (μ-CO)(μ-Dipp 2 NHSi)] ( 1) and [{(η 5 -C 5 H 5 )Ni(μ-Dipp 2 NHSi)} 2 ] (2). The reaction with [(η 5 -C 5 H 5 )Ni(PPh 3 )(Cl)] leads with insertion of the silylene into the nickel− chloride bond to [(η 5 -C 5 H 5 )Ni(PPh 3 )(Dipp 2 NHSi-Cl)] (3). [Mn(CO) 5 (Cl)] reacts with 2 equiv of Dipp 2 NHSi to afford [Mn(CO) 4 (Dipp 2 NHSi)(Dipp 2 NHSi-Cl)] ( 5), in which one of the silylenes has inserted into the Mn−Cl bond and acts as a chloro silyl ligand. The reaction of 2 equiv of Dipp 2 NHSi with the corresponding iodide complex [Mn(CO) 5 (I)] leads to formation of the bis-silylene complex [Mn-(CO) 3 (Dipp 2 NHSi) 2 (I)] (4).

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“…By contrast, vanadocene-NHSi adduct 19 was isolated and structurally characterized, as reported in the recent elaborate study by Hänninen and co-workers (Scheme 10). [50] Like the above-described Cp* 2 V=SiMe 2 , [49] 19 was characterized by the EPR spectroscopy with similar parameters, namely, octet resonance with the isotropic g = 1.995 and isotropic a( 51 V, I = 7/ 2) = 3.10 mT. Despite the trigonal-planar geometry of silicon (Σ Si = 359.97/359.95°, for two independent molecules in the unit cell), the bonding interaction VÀ Si [bond length = 2.3591(8)/ 2.3588(8) Å] is best described as a dative single bond rather than the V=Si covalent double bond, as was evidenced by the calculation of its WBI of 0.90.…”

Section: Silylene Complexes ðAþ V¼simentioning

confidence: 99%

Schrock‐TypeSilylidenesandGermylidenesFound Among the Silylene and Germylene Complexes of the Early and Mid‐Transition Metals

Lee

2022

Eur J Inorg Chem

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The chemistry of Schrock-type silylidene/germylidene complexes is the subject of this review. This is preceded by the general consideration of the prototypical transition metal carbene complexes and their classification as either Fischer or Schrock carbene complexes. Following this background, silylene/germylene complexes of the early (groups 3-4) and mid-(groups 5-7) transition metals are briefly discussed in terms of their synthesis and nature of the transition metal-silylene/ germylene bonding interaction. Major attention will be paid for the preparation, bonding nature, and particular reactivity of those complexes, which, on the basis of their spectroscopic, structural, and computational studies, are reliably categorized as the Schrock-type silylene/germylene transition metal complexes, that is silylidenes/germylidenes.

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Structural and electronic elucidation of a N-heterocyclic silylene vanadocene adduct

Cited by 11 publications

References 31 publications

N‐Heterocyclic Silylenes as Ligands in Transition Metal Carbonyl Chemistry: Nature of Their Bonding and Supposed Innocence

N‐Heterocyclic Silylenes as Ligands in Transition Metal Carbonyl Chemistry: Nature of Their Bonding and Supposed Innocence

N-Heterocyclic Silylenes as Metal–Metal Bridges and Metal–Halide Activators in Transition Metal Complexes

Schrock‐TypeSilylidenesandGermylidenesFound Among the Silylene and Germylene Complexes of the Early and Mid‐Transition Metals

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