Synthesis and characterization of amine complexes of the cyclopentadienyliron dicarbonyl complex cation, [Cp(CO)2Fe]+

Abstract

[{CpFe(CO) 2 } 2 l-(NH 2 (CH 2 ) n NH 2 )](BF 4 ) 2 (n = 2-4) (3), respectively. These complexes have been fully characterized and the mass spectral patterns of complexes 2 are reported. The structures of compounds 2a (n = 2) and 2b (n = 3) have been confirmed by single crystal X-ray crystallography. The single crystal X-ray diffraction data show that complex 2a, [CpFe(CO) 2 NH 2 (CH 2 ) 2 CH 3 ]BF 4 , crystallizes in a triclinic P 1 space group while 2b, [CpFe(CO) 2 NH 2 (CH 2 ) 3 CH 3 ]BF 4 , crystallizes in an orthorhombic Pca2 1 space group with two crystallographically independent molecular cations in the asymmetric unit. Furthermore, the reaction of 1 with 1-alkenes gives the g 2 -alkene complexes in high yield.

Reactions of N-heterocyclic ligands with substitutionally labile organometallic complexes, [(η5-C5R5)Fe(CO)2E]BF4

“…The two {Cp(CO) 2 Fe} units are linked by the HMTA ligand through the nitrogen atoms in which the coordination geometry around Fe can be described as distorted octahedral with three sites occupied by a cyclopentadienyl ligand, while the two carbonyls and the HMTA ligand occupy the remaining three sites. The Fe-N bond distances were found to be 2.0817(17) and 2.0858(18) Å, which are comparable to the 2.092(4) Å in [(CO) 4 Fe(DABCO) [30], but longer than the Fe-N bond lengths previously reported for cyclopentadienylirondicarbonyl amine complexes [44,48,50]. The three carbon atoms adjacent to the iron centre form a base with a distorted tetragonal geometry about nitrogen with N-C bonds in the range 1.514 ± 0.010 Å. Valence angles are: Fe-N-C, 111.89 ± 1.51°and C-N-C, 106.94 ± 0.84°.…”

“…The IR spectra of compounds 3a-4b show two strong absorption bands in the range 2058-1982 cm À1 assignable to the two terminal carbonyls as expected for cationic amine complexes [44,[48][49][50]. The IR spectra of 4a and 4b exhibited characteristic v(CO) stretching vibrations at wavenumbers lower than those of 3a and 3b by ca.…”

“…Iron is also found in the blood of both vertebrates and invertebrates in which it forms Fe-N bonds in the heme group of hemoglobin or myoglobin. To the best of our knowledge HMTA, DABCO and 1-meIm complexes with the {(g 5 4 (R = H, CH 3 ; 1-meIm = 1-methylimidazole), which is a part of an on-going study on functionalized transition metal alkyl complexes [41][42][43][44][45][46][47][48].…”

Regioselective reactions of electrophilic iron dicarbonyl cations, [(η5-C5R5)(CO)2Fe]+ (R = H, CH3) with heterofunctional amine ligands

“…In the IR spectra of compounds 3e9, the n(CO) bands are in the expected range for terminal carbonyl groups of amine-coordinated iron dicarbonyl complexes [20,22]. The infrared spectra of the Cp* complexes 4 and 6 show the n(CO) bands at lower frequencies than their Cp counterparts due to the electron releasing ability of the pentamethylcyclopentadienyl ligand which consequently increases the metal / carbon back donation.…”

(μ-Ethane-1,2-diamine-κ2N:N′)bis[dicarbonyl(η5-cyclopentadienyl)iron(II)] bis(tetrafluoridoborate)

“…The title compound is a water-soluble organometallic compound which was prepared as part of our ongoing study on functionalized alkyl transition metal complexes (M'thiruaine et al, 2011;Changamu & Friedrich 2008;Friedrich et al, 2005;Changamu, Friedrich, Howie, & Rademeyer, 2007;Changamu et al, 2009). The asymmetric unit ( (Table 1).…”