(μ-Formato-κ 2 O:O′)bis­[dicarbon­yl(η 5-cyclo­penta­dien­yl)iron(II)] tetra­fluoridoborate

In the structure of the title compound [Fe2(C5H5)2(CHO2)(CO)4]BF4, each FeII atom is coordinated in a pseudo-octa­hedral three-legged piano-stool fashion. The cyclo­penta­dienyl ligand occupies three fac coordination sites while the two carbonyl ligands and formate O atom occupy the remaining three sites

(μ-Ethane-1,2-diamine-κ2 N:N′)bis­[dicarbon­yl(η5-cyclo­penta­dien­yl)iron(II)] bis­(tetra­fluorido­borate)

The asymmetric unit of the title compound, [Fe2(C5H5)2(C2H8N2)(CO)4](BF4)2, contains two half-cations, each located on a center of symmetry, and two tetra­fluorido­borate anions. The iron atoms adopt a three-legged piano-stool geometry. All amine H atoms are involved in N—H⋯F hydrogen bonds, which consolidate the crystal packing along with weak C—H⋯O and C—H⋯F inter­actions

Synthesis and characterization of iron amine complexes.

Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.The organometallic Lewis acid [(η5-C5H5)(CO)2Fe]BF4 reacts with excess dry diethyl ether at low temperatures to form the novel labile complex [(η5-C5H5)(CO)2Fe(OEt2)]BF4 which in turn serves as a precursor in the syntheses of various cationic dicarbonylcyclopentadienyliron complexes. The reactions of [(η5-C5H5)(CO)2Fe(OEt2)]BF4 with various 1-alkylamines, α,ω-diaminoalkanes, N-heterocyclics and heterofunctional amine ligands, as well as olefins, have been investigated. Reactions with 1-alkylamines and α,ω-diaminoalkane ligands lead to a series of novel monuclear and dinuclear complexes of the types [(η5-C5H5)(CO)2FeL]BF4 and [{(η5-C5H5)(CO)2Fe}2(μ-L)](BF4)2, respectively. The reaction of [(η5-C5H5)(CO)2Fe(OEt2)]BF4 with N-heterocyclic ligands such as 1,3,5,7-tetraazaadamantane (HMTA) and 1,4-diazabicyclo[2.2.2]octane (DABCO) give dinuclear complexes [{(η5-C5H5)(CO)2Fe}2(μ-L)](BF4)2 and monuclear complexes [(η5-C5H5)(CO)2FeL]BF4 (L = HMTA, DABCO). Its reaction with 1-methylimidazole (1-meIm) affords only the monuclear complex [(η5-C5H5)(CO)2Fe(1-meIm)]BF4 in which the coordination of 1-methylimidazole is via the sp2-N. The reaction with heterofunctional amine ligands is highly regioselective with the cation [(η5-C5H5)(CO)2Fe]+ showing higher affinity for NH2 than π-bonded, O or CN functionalities. Besides amines, [(η5-C5H5)(CO)2Fe(OEt2)]BF4 reacts with olefins and HCOOH to form complexes of the type [(η5-C5H5)(CO)2Fe(η2-olefin)]BF4 and [{(η5-C5H5)Fe(CO)2}2(μ-OCHO)]BF4, respectively. For comparison of steric and electronic effects, analogous pentamethylcyclopentadienyl amine complexes were synthesized from the THF complex [{η5-C5(CH3)5}(CO)2Fe(THF)]BF4. The reaction of 3-aminoprop-1-ene with the etherate complexes [(η5-C5R5)(CO)2Fe(E)]BF4 (R = H: E= Et2O; R = CH3: E = THF) led to air stable complexes [(η5-C5R5)(CO)2Fe(NH2CH2CHCH2)]BF4 (R = H, CH3), which in turn react with a mole equivalent of the etherate complexes to give dinuclear complexes of the type, [(η5-C5R5)(CO)2Fe(NH2CH2CHCH2)Fe(CO)2(η5-C5R'5)](BF4)2 (R not necessarily equal to R'). They also undergo halogenation to give the chiral dihalopropylamino complexes [(η5-C5R5)(CO)2Fe(NH2CH2CH(X)CH2(X))]BF4 (R=H, CH3; X = Cl, Br). The reaction of the dinuclear complex [{(η5-C5H5)(CO)2Fe}2(NH2CH2CHCH2](BF4)2 with NaI in acetone gives [(η5-C5H5)(CO)2Fe(NH2CH2CHCH2)]I and [(η5-C5H5)Fe(CO)2I]. All these complexes have been fully characterized by 1H NMR, 13C NMR, IR spectroscopy and elemental analysis. The mass spectra of 1-aminoalkane and diaminoalkane complexes have also been recorded and are discussed. The structures of 16 synthesized compounds have been confirmed by single crystal X-ray crystallography. Most of the amine complexes are water-soluble and some undergo counteranion exchange with sodium tetraphenylborate in both aqueous and organic media to give BPh4- salts

A Structural Investigation of the D2O Solvated, Acetone Solvated and Nonsolvated 1,4-Diazabicyclo[2.2.2]octane Complexes of the Half Sandwich Moiety [(η 5-C5H5)(CO)2Fe]

Two new solvates of the dinuclear salt {(η 5-C5H5)(CO)2Fe}2(μ-DABCO)](BF4)2 (DABCO = 1,4-diazabicyclo[2.2.2]octane); 1 (D2O solvate) and 2 (acetone solvate), and the mononuclear salt [(η 5-C5H5)(CO)2Fe(DABCO)]BF4, 3, have been synthesized and structurally characterized. The D2O solvate, 1 forms crystals in the triclinic space group P1, the acetone solvate forms crystals in the monoclinic P21/c space group, while the unsolvated mononuclear salt, 3, forms crystals in the orthorhombic P212121 space group. The respective unit cell parameters are: Compound 1, a = 7.66300(10) Å, b = 12.3133(2) Å, c = 13.9629(2) Å, α = 69.179(1) °, β= 77.114(1) ° and γ = 84.282(1) °; Compound 2, a = 17.3633(3) Å, b = 14.1688(3) Å, c = 11.3542(2) Å, β = 99.344(1) °; Compound 3, a=8.9936(2) Å, b=10.8949(3) Å, c=15.3417(4) Å. The DABCO ligand adopts a twisted conformation with N-C-C-N torsion angles ranging between –21.05(12) to –19.31(12) ° and 15.3(2) –15.7(2) ° in 1 and 2, respectively, whereas in 3, the CH2 groups of each NCH2CH2N moiety are almost eclipsed, the torsion angles ranging from –2.89(18) to –1.50(16) °.KEYWORDS Cyclopentadienyliron dicarbonyl complex, 1,4-diazabicyclo[2.2.2]octane (DABCO), X-ray crystallography

Dicarbonyl(η5-cyclopentadienyl)(hexamethylenetetramine-κN1)iron(II) tetrafluoridoborate

In the structure of the title compound, [Fe(C5H5)(C6H12N4)(CO)2]BF4, the arrangement around the FeII atom corresponds to that of a three-legged piano stool. The cyclopentadienyl ligand occupies three coordination sites of the apical position in a η5 fashion, while two CO ligands and one N atom of the hexamethylenetetramine ligand occupy the remaining coordination sites to complete a distorted octahedral geometry. The asymmetric unit consists of two sets of crystallographically independent cations and anions with the r.m.s. deviations of the overlay of non-H atoms of each pair being 0.081 and 0.120 Å, respectively. The Fe—N bond lengths are 2.0459 (15) and 2.0490 (14) Å, while the Fe—Cp(centroid) distances are 1.7257 (3) and 1.7246 (3) Å. One of the anions displays disorder, with the F atoms having occupancies of 0.58 (4) and 0.42 (4)

Dicarbonyl(hexamethylene-1,3,5,7-tetramine-κN1)(η5-pentamethylcyclopentadienyl)iron(II) tetrafluoridoborate

In the title compound, [Fe(C10H15)(C6H12N4)(CO)2]BF4, the arrangement around the FeII atom corresponds to a three-legged piano stool. The pentamethylcyclopentadienyl (Cp*) ligand occupies three coordination sites, while two CO ligands and one N atom of the hexamethylenetetramine ligand occupy the remaining coordination sites, completing a pseudo-octahedral geometry. Both the complex cation and the BF4− anion reside on crystallographic mirror planes. The Fe—N bond length is 2.069 (2) and the Fe—Cp*(centroid) distance is 1.7452 (3) Å

Iron-Catalyzed Ferrocenylmethanol OH Substitution by S, N, P, and C Nucleophiles

The iron complex [Fp][OTf] {Fp(+) = [Fe(CO)(2)(Cp)](+), OTf- = SO3CF3-} is an efficient catalyst for the direct substitution of the OH group in ferrocenylmethanol [Fc-CH2OH] by thiols, aromatic amines, diphenylphosphane, and carbon nucleophiles (furan, pyrrole, and indole). This approach offers a convenient route to ferrocenes containing side chains with different functional groups. The advantages of the method are associated with the use of a catalyst based on iron, which is a nontoxic and readily available transition metal, and in the direct OH substitution, which produces water as the only byproduct