Iron Carbonyl Anions Research Articles

Infrared Photodissociation Spectroscopy of Mononuclear Iron Carbonyl Anions

The infrared photodissociation spectroscopy of mass-selected mononuclear iron carbonyl anions Fe(CO)(n)(-) (n = 2-8) were studied in the carbonyl stretching frequency region. The FeCO(-) anion does not fragment when excited with infrared light. Only a single IR active band was observed for the Fe(CO)(2)(-) and Fe(CO)(3)(-) anions, consistent with theoretical predictions that these complexes have linear D(∞h) and planar D(3h) symmetry, respectively. The Fe(CO)(4)(-) anion is the most intense peak in the mass spectra and was characterized to have a completed coordination sphere with high stability. Anion clusters larger than n = 4 were determined to involve a Fe(CO)(4)(-) core anion that is progressively solvated by external CO molecules. Three CO stretching vibrational fundamentals were observed for the Fe(CO)(4)(-) core anion, indicating that the Fe(CO)(4)(-) anion has a C(3v) structure. All the carbonyl stretching frequencies of the Fe(CO)(n)(-) anion complexes are red-shifted with respect to those of the corresponding neutrals.

Main group derivatives of a cyclometallated iron carbonyl anion. Crystal structures of Fe(CO) 2{P(OPh) 3}{(PhO) 2POC 6H 4}(SnPh 3) and two isomers of Fe(CO) 2{P(OPh) 3}{(PhO) 2POC 6H 4}(I)

The iron hydrido complex HFe(CO) 2{P(OPh) 3}{(PhO) 2POC 6H 4} ( 1), was rapidly deprotonated by DBU or [BzMe 3N][OH] in THF to afford the new carbonyl iron anion [Fe(CO) 2{P(OPh) 3}{(PhO) 2POC 6H 4}] − ([ 2] −), containing an ortho-metallated triphenyl phosphite ligand. Complex [ 2] − reacted with triorganostannyl and plumbyl salts and with halogens to give the octahedral Fe II compounds Fe(CO) 2{P(OPh) 3}{(PhO) 2POC 6H 4}(X) (X=SnPh 3, 3; SnMe 3, 4; PbPh 3, 5; PbMe 3, 6; Cl, 7; Br, 8; I, 9). The Group 14 complexes 3– 6 were obtained in one isomeric form in which the P III-donor atoms are mutually cis, the carbonyl ligands are cis and the P(OPh) 3 and MR 3 (M=Sn, Pb; R=Ph, Me) groups are trans as determined by solution-state IR, 31P and 13C NMR spectroscopic data. This geometry was confirmed for 3 by a single crystal X-ray diffraction study. The halide complexes, however, were obtained as a mixture of isomers. The major isomer ( 7, X=Cl; 8a, X=Br; 9a, X=I) has cis P atoms, trans CO groups and the halide located trans to the phosphorus atom of the ortho-metallated phosphite ligand. The structure of 9a was confirmed by an X-ray diffraction study. Two other isomers, designated 8b (X=Br) and 9b (X=I), with cis P atoms and cis CO groups were isolated from the reactions of [ 2] − with Br 2 and I 2, respectively. The structure of the latter was established by X-ray crystallography and is related to 9a by exchange of the P(OPh) 3 ligand and a carbonyl group such that the metal-bound C atom of the five-membered metallacycle is trans to CO. The stereo-geometry of 8b could not be unambiguously assigned from the spectroscopic data; however, two of the seven possible geometric isomers were suggested as plausible structures.

Synthesis, chemical characterisation and molecular structure of [Ag 3{ μ3-Fe(CO) 4}(dppm) 3][NO 3] and [Au 3{ μ-Fe(CO) 4}(dppm) 2][Cl

The reaction of Na 2[Fe(CO) 4] · xTHF with Ag 2(dppm) 2(NO 3) 2 and Au 2(dppm) 2Cl 2, respectively affords the new [Ag 3{ μ 3-Fe(CO) 4}(dppm) 3][NO 3] and [Au 3{ μ-Fe(CO) 4}(dppm) 2][Cl] derivatives in high yields. These have been crystallised either from dichloromethane or THF by precipitation with hexane and an X-ray diffraction study has unambiguously shown that the Fe(CO) 4 unit is triply bridging in [Ag 3{ μ 3-Fe(CO) 4}(dppm) 3] + and doubly bridging in [Au 3{ μ-Fe(CO) 4}(dppm) 2][Cl]. The [Ag 3{ μ 3-Fe(CO) 4}(dppm) 3] + cation has also been obtained from degradation of [Ag 13{ μ 3-Fe(CO) 4} 8] 3− with dppm. However, this preparation is less convenient owing to concomitant formation of iron carbonyl anions as side-products.

Cathodic carbonylation. Synthesis of aliphatic aldehydes using an electroreductively generated iron-carbonyl anion

Alkyl halides are electroreductively coupled with pentacarbonyliron to generate the acyliron complexes. After hydrolytic work-up, these anionic acyl compounds produce aldehydes in good yields. The best results were obtained with the bromide as starting halide. The first step in the formation of acyliron complexes is the direct cathodic reduction of [Fe(CO)5] to the anionic species. Synthetic and mechanistic aspects of the reaction are discussed.

Novel C-alkylation of a CO-bridged dinuclear iron carbonyl anion: a new synthesis of Fe2(CO)6 complexes containing a bridging acyl ligand

Preparation de complexes (μ-RCO) (μ-R'S) Fe 2 (CO) 6 . Etude de leurs reactions conduisant a (μ-EtOC)(μ-R'S)Fe 2 (CO) 6

Alkylation and acylation of the iron carbonyl anion [(CO)4FeSi(CH3)3]-. Evidence for 1,3-silatropic shifts from iron to acyl oxygen

Les reactions de l'anion du titre avec CH 3 OSO 2 F, CH 3 OSO 2 CF 3 et CH 3 CH 2 OSO 2 F et par C 6 H 5 CH 2 Br et H 2 C=CHCH 2 Br donnent cis-(CO) 4 Fe(R)Si(CH 3 ) 3 . Avec les agents acylants on obtient H 2 C=CHOSi(CH 3 ) 3 , CH 3 CH=CHOSi(CH 3 ) 3 ou C 6 H 5 CH=CHOSi(CH 3 ) 3 . Synthese et transposition de (CO) 4 Fe=C(CH 3 )OSi(CH 3 ) 3

ChemInform Abstract: MONO‐SUBSTITUTION OF IRON PENTACARBONYL CATALYZED BY POLYNUCLEAR IRON CARBONYL ANIONS

Chemischer InformationsdienstVolume 10, Issue 28 Organoelement Compounds ChemInform Abstract: MONO-SUBSTITUTION OF IRON PENTACARBONYL CATALYZED BY POLYNUCLEAR IRON CARBONYL ANIONS S. B. BUTTS, S. B. BUTTSSearch for more papers by this authorD. F. SHRIVER, D. F. SHRIVERSearch for more papers by this author S. B. BUTTS, S. B. BUTTSSearch for more papers by this authorD. F. SHRIVER, D. F. SHRIVERSearch for more papers by this author First published: July 10, 1979 https://doi.org/10.1002/chin.197928294Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue28July 10, 1979 RelatedInformation

Chemistry of iron carbonyl anions: Selective reduction of nitroarenes and α, β-unsaturated carbonyl compounds, and reductive dehalogenation of organic halides by (C 2H 5) 4N + HFe 3(CO) 11−

The tetraethylammonium undecacarbonylhydridotriferrate [(C 2H 5) 4N + HFe 3(CO) 11 −] (I): which can be easily prepared in a two-step sequence from iron pentacarbonyl, triethylamine and tetraethylammonium chloride, selectively reduces nitroarenes to amines and α, β-unsaturated carbonyl compounds to the corresponding saturated compounds both in good yield. I reacts with some organic halides to give dehalogenated products.

Mono-Substitution of iron pentacarbonyl catalyzed by polynuclear iron carbonyl anions

The specific formation of LFe(CO) 4 (L = PPh 3, P(OPh) 3, P(OMe) 3 can be achieved by the reaction of Fe(CO) 5 with L in the presence of a catalytic amount of iron carbonyl anion. A convenient synthetic procedure was developed in which the iron carbonyl anion catalyst is generated in situ. It is shown that the mechanism does not proceed by the simple cleavage of the Fe 2(CO) 8 2− or Fe 3(CO) 11 2− anions, because triphenylphosphine reacts with these anions in the absence of Fe(CO) 5 to produce (PPh 3) 2Fe(CO) 3.

Structural studies of the carbonylate and carbonyl hydride anions of iron

The Mössbauer and i.r. spectra of the mono-, di-, tri-, and tetra-nuclear iron carbonyl anions and carbonyl hydride anions are reported. Structures for the eight ions are suggested, and systematic variations in chemical isomer shift and quadrupole splitting discussed. New interconversions of the ions in aqueous solution are reported.

Mössbauer spectra, structure, and bonding in iron carbonyl derivatives

The Mössbauer spectra of the mono-, di-, tri- and tetra-nuclear iron carbonyl anions and carbonyl hydride anions are reported and compared with the known spectra of the neutral binary carbonyls. Increase in anionic charge in the sequence 0, –1, –2 results in progressively lower values of chemical isomer shift δ for each series. In addition, there is a systematic increase in δ as the co-ordination number of iron increases from 4 to 7. These trends are interpreted in terms of changes in the bonding in these compounds. Systematic variations in the quadrupole splitting Δ are also discussed.

Preparation of a technetium iron carbonyl anion

Preparation of a technetium iron carbonyl anion