Neue Verbindungen aus 1,4‐Diaza‐1,3‐dienen und Eisencarbonylen: Hexacarbonyl(1,4‐diazadien)dieisen und substituierte 2(<i>3H</i>)‐Imidazolone

Frühauf, Hans‐Werner; Landers, Armin; Goddard, Richard; Krüger, Carl

doi:10.1002/ange.19780900117

Cited by 58 publications

(9 citation statements)

References 5 publications

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“…The pattern of the absorptions is identical to that of [M 2 (CO) 6 (R-DAB/R-Pyca)] (M ϭ Fe, Ru, Os and FeRu). [6,[56][57][58][59] This strongly suggests that these complexes are isostructural, which is corroborated by the 1 H-and 13 C-NMR-spectroscopic data. The substituents on the α-imino ketone show only a marginal influence on the frequency of the CO absorption bands of complexes 7.…”

Section: Ir Uv/vis Spectroscopy and Elemental Analysissupporting

confidence: 65%

Preparation and Properties of Carbonyliron Complexes of 1-Aza-4-oxa-1,3-butadiene (α-Imino Ketone) – X-ray Crystal Structures of Fe(CO)3[MeNC(Ph)C(Ph)=O] and Fe2(CO)4[tBuNC(H)(Me)C(O)(O)C(Me)C(H)=NtBu]

Siebenlist¹,

Frühauf²,

Vrieze³

et al. 2000

Eur. J. Inorg. Chem.

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The reaction of Fe2(CO)9 at room temperature in THF or toluene with the α‐imino ketones R1N=C(R2)–C(R3)=O (L) (R1 = alkyl, R2 = H, Me, Ph, R3 = Me, Ph) (a–k), initially results in the formation of the mononuclear chelate Fe(CO)3(α‐imino ketone) complexes 6 which can be isolated in moderate (6h) to high (6e–g) yield. Under these reaction conditions, complexes 6 subsequently react with [Fe(CO)4] fragments or dimerise, to form the dinuclear complexes Fe2(CO)6(α‐imino ketone) (7a–j) or Fe2(CO)4(L–L) (8a,b,k), respectively. The complexes 8 contain two α‐imino ketone ligands C–C coupled at the ketone carbon atoms. Complexes 8a,b react with CO at elevated temperatures to quantitatively yield Fe(CO)3(α‐imino ketone) (6a,b). This reaction can be reversed photochemically. Irradiation of a solution of 6a,b in the low‐energy band results in the reformation of 8a,b in almost quantitative yield. The extremely air‐sensitive complexes 6 and the dinuclear complexes 7 and 8 have been characterised spectroscopically (IR, UV/Vis, 1H and 13C NMR) and by elemental analysis. The solid state structures of complexes 6g and 8a have been determined by single‐crystal X‐ray diffraction. The molecular structure of 6g confirms the flat σ‐O,σ‐N chelate coordination of the α‐imino ketone. The structure of 8a consists of two metal–metal‐bonded Fe(CO)2 units, bridged by a formally 10e‐donating dianionic C–C coupled (tBu‐ADO) ligand. A mechanism for the formation of complexes 8 is discussed.

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Section: Ir Uv/vis Spectroscopy and Elemental Analysissupporting

confidence: 65%

Preparation and Properties of Carbonyliron Complexes of 1-Aza-4-oxa-1,3-butadiene (α-Imino Ketone) – X-ray Crystal Structures of Fe(CO)3[MeNC(Ph)C(Ph)=O] and Fe2(CO)4[tBuNC(H)(Me)C(O)(O)C(Me)C(H)=NtBu]

Siebenlist¹,

Frühauf²,

Vrieze³

et al. 2000

Eur. J. Inorg. Chem.

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“…The recent discovery by Brookhart and co-workers of Ni(II) and Pd(II) α-olefin polymerization catalysts containing bulky diimine ligands − has stimulated renewed interest in the chemistry of 1,4-diazabutadiene (DAB) ligands and their complexes. − Ligands of this type have been studied extensively in several different contexts. First, DAB ligands possess different possible modes of coordination as 2-, 4-, 6-, and even 8-electron donors in terminal, chelating, and bridging arrangements. − These different modes of coordination in turn confer different reactivities on the complexed metal ions, as detailed in the review by van Koten and Vrieze . Second, as α-diimine ligands, DAB ligands have electronic structural similarities to the more extensively studied heteroaromatic chelating agents 2,2‘-bipyridine and 1,10-phenanthroline. , In 1973, for example, Miller and Dance showed that square-planar Ni(II) diimine dithiolate complexes containing 1,10-phenanthroline and the DAB ligand biactetyl bis(anil) (R = Ph; R‘ = Me) were spectroscopically similar with a common low-energy charge transfer-to-diimine absorption.…”

Section: Introductionmentioning

confidence: 99%

Unsymmetrical 1,4-Diazabutadiene Complexes of Platinum(II)

1997

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The new unsymmetrical 1,4-diazabutadiene ligand glyoxal bis(2-(methoxymethyl)-4,6-di-tert-butylphenyl)diimine (L) and its reduced analog (LH 4 ) were synthesized. The reactions of both ligands with bis(benzonitrile) complexes of palladium and platinum, MCl2(PhCN)2, were investigated. Two isomers of formula MCl2 L were isolated from the reaction of L with MCl2(PhCN)2 (1a and 1b for Pd, 2a and 2b for Pt), while only a single product, MCl2(LH 4 ), formed in the reaction with LH 4 (3 for M = Pd, 4 for M = Pt). All new compounds were characterized by elemental analyses and IR and NMR spectroscopies. The molecular structures for L, LH 4 , 2b, 3, and 4 were determined by single-crystal X-ray diffraction. The metal complexes exhibit distorted square-planar geometry. The aryl groups of the L and LH 4 ligands lie out of the coordination plane in a manner that blocks potential axial ligation sites. Ligand L crystallizes in the triclinic space group P1̄ with a = 5.760(1) Å, b = 9.383(2) Å, c = 14.954(3) Å, α = 89.38(2)°, β = 79.67(2)°, γ = 88.14(2)°, and Z = 1. The reduced ligand LH 4 crystallizes in the monoclinic space group P21 with a = 5.9758(1) Å, b = 17.4272(2) Å, c = 15.6222(1) Å, β = 99.063(1)°, and Z = 2. Complex 2b crystallizes in the monoclinic space group P21/c with a = 16.9599(2) Å, b = 18.4985(2) Å, c = 12.4976(0) Å, β = 100.945(0)°, and Z = 4. Complex 3 crystallizes in the monoclinic space group C2/c with a = 36.1506(8) Å, b = 8.0994 (2) Å, c = 15.5671(1) Å, β = 113.988(1)°, and Z = 4. Complex 4 crystallizes in the monoclinic space group C2/c with a = 36.0649(3) Å, b = 8.1787(2) Å, c = 15.7585(3) Å, β = 112.610(1)°, and Z = 4.

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“…Actually, we have found that reaction of I with C O resulted in the formation of Ru,(CO),(R-DAB), where the R-DAB is now a a-N, p2-N', r12-CN' 6e donor, and only terminal carbonyls are present.2g As yet, no crystal structure of this compound has been obtained but we can assume the presence of a "normal" metalmetal internuclear distance, making reference to X-ray crystal structures of the isoelectronic home and heterodinuclear analogues [Fez( CO),( c-Hex-DAB) 34 and FeRu( CO),( i-Pr-DAB) 35] where the metal-metal distances are 2.597 and 2.660 A, respectively. This is in agreement with the LUMO (30 a') nature of I (see Figure 1 l), which is Ru-Ru' bonding but strongly antibonding between metals and the bridging CO and R-DAB ligands.…”

Section: Discussionmentioning

confidence: 99%

Ruthenium carbonyl 1,4-diaza-1,3-butadiene (R-DAB) complexes. A theoretical and experimental investigation of the electronic structure of Ru2(CO)4(R-DAB)(.mu.-CO) and Ru2(CO)4(R-DAB)(.mu.-HC.tplbond.CH)

Casarin¹,

Vittadini²,

Vrieze³

et al. 1988

J. Am. Chem. Soc.

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The electronic structure of two binuclear ruthenium clusters containing the 8e donor 1,4-diaza-l,3-butadiene (R-DAB) ligand [Ru,(CO),(R-DAB)(p-CO) and Ru,(CO),(R-DAB)(pHC=CH)] is for the first time discussed by using SCF first principle discrete variational (DV) X a calculations and gas-phase UV photoelectron (PE) spectroscopy. Despite the short metal-metal interatomic distance, the bonding scheme of both molecules is dominated by the absence of any direct metal-metal bond. On the contrary, the importance of a strong multicentered interaction involving the p-bridged ligands has been emphasized. As far as the R-DAB moiety is concerned, theoretical results indicated a poorer involvement of n+ and nlinear combinations of nitrogen lone pairs than rj* and r2 levels in metals-R-DAB interactions. Looking into the nature of such a r interaction it has been found that the Ru atom of the metallacycle fragment is mostly involved in M -r3* back-bonding while r2 -

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Neue Verbindungen aus 1,4‐Diaza‐1,3‐dienen und Eisencarbonylen: Hexacarbonyl(1,4‐diazadien)dieisen und substituierte 2(3H)‐Imidazolone

Abstract: Neuartige zweikernige Eisenkomplexe mit unsymmetrisch gebundenen 1,4‐Diaza‐1,3‐dienen (dad) entstehen auf den unten skizzierten Wegen. In Konkurrenz zur Bildung von (dad)Fe‐(CO)3 werden einige dad‐Liganden durch CO‐Insertion in Imidazolone umgewandelt.

Cited by 58 publications

References 5 publications

Preparation and Properties of Carbonyliron Complexes of 1-Aza-4-oxa-1,3-butadiene (α-Imino Ketone) – X-ray Crystal Structures of Fe(CO)3[MeNC(Ph)C(Ph)=O] and Fe2(CO)4[tBuNC(H)(Me)C(O)(O)C(Me)C(H)=NtBu]

Preparation and Properties of Carbonyliron Complexes of 1-Aza-4-oxa-1,3-butadiene (α-Imino Ketone) – X-ray Crystal Structures of Fe(CO)3[MeNC(Ph)C(Ph)=O] and Fe2(CO)4[tBuNC(H)(Me)C(O)(O)C(Me)C(H)=NtBu]

Unsymmetrical 1,4-Diazabutadiene Complexes of Platinum(II)

Ruthenium carbonyl 1,4-diaza-1,3-butadiene (R-DAB) complexes. A theoretical and experimental investigation of the electronic structure of Ru2(CO)4(R-DAB)(.mu.-CO) and Ru2(CO)4(R-DAB)(.mu.-HC.tplbond.CH)

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