UV spectra of iron-doped carbon clusters FeCn n=3–6

Abstract

Electronic transitions of jet-cooled FeC n clusters (n = 3 − 6) were measured between 230 and 300 nm by a mass-resolved 1+1 resonant two-photon ionization technique. Rotational profiles were simulated based on previous calculations of ground state geometries and compared to experimental observations. Reasonable agreement is found for the planar fan-like structure of FeC 3 . The FeC 4 data indicate a shorter distance between the Fe atom and the bent C 4 unit of the fan. The transitions are suggested to be 3 A 2 ← 3 B 1 for FeC 3 and 5 A 1 ← 5 A 1 for FeC 4 . In contrast to the predicted C ∞v geometry, non-linear FeC 5 is apparently observed. Line width broadening prevents analysis of the FeC 6 spectrum.

Characterization of Magnetic Series of Iron–Carbon Clusters FenC0,±1 (n ≤ 13)

“…Independently of the number of carbon atoms bonded to iron, FeC 1–3 clusters are found with triplet and quintet multiplicities and, consequently, magnetic moment comparable to that found for iron in its atomic ground state . Similarly, electronic transitions observed by Steglitch and co-workers suggest the same behavior in the range FeC 3–6 . Moreover, quasi-linear chains and cyclic and fanlike structures for FeC 1–10 0,± clusters were analyzed by Zhu and Li, obtaining high-spin species as well .…”

“…22 Similarly, electronic transitions observed by Steglitch and co-workers suggest the same behavior in the range FeC 3−6 . 28 Moreover, quasi-linear chains and cyclic and fanlike structures for FeC 1−10 0,± clusters were analyzed by Zhu and Li, obtaining high-spin species as well. 27 More authors reported similar conclusions on carbon clusters interacting with a single iron atom.…”

“…The theoretical characterization of the interaction among a few carbon and iron atoms has been approached in several manners. − One of them deals with a single iron atom interacting with a small amount of carbon atoms. Reports on the dimer FeC − and FeC n ( n = 2–10) − clusters are a few examples of this category. Another point of view treats with interactions among a few iron and carbon atoms that are structurally mixed.…”

Small binary iron‐carbon clusters with persistent high magnetic moments. A theoretical characterization

“…Other studies reported the vertical detachment energy and vibrational frequencies for FeC 3 as well as adiabatic EA (AEA) for FeC 4 . More recently, Steglich et al, based on studies carried out by means of resonant two‐photon ionization experiments and theoretical calculations, suggested that in the structure of FeC 6 , carbon atoms are disposed in a curved chain centered at the iron atom . Previously, Helden and coworkers found evidence, obtained by means of gas phase ion chromatography, that small mixed iron‐carbon clusters anions Fe n C m − (n = 1, 2, 3, m = 2‐8) have two competitive structures; one with the carbon atoms in linear chain, and the other with monocyclic rings including the iron atoms .…”

“…[29] More recently, Steglich et al, based on studies carried out by means of resonant twophoton ionization experiments and theoretical calculations, suggested that in the structure of FeC 6 , carbon atoms are disposed in a curved chain centered at the iron atom. [30] Previously, Helden and coworkers found evidence, obtained by means of gas phase ion chromatography, that small mixed iron-carbon clusters anions Fe n C m − (n = 1, 2, 3, m = 2-8) have two competitive structures; one with the carbon atoms in linear chain, and the other with monocyclic rings including the iron atoms. [31] Duncan and Pilgrim also reported the formation of several Fe x C y + cationic iron-carbon clusters produced by laser vaporization of iron targets.…”