Atomic structure, binding energy, and magnetic properties of iron atoms supported on a polyaromatic hydrocarbon

Senapati, L.; Nayak, Saroj K.; Rao, B. K.; Jena, P.

doi:10.1063/1.1568077

Cited by 26 publications

(54 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, this study has also allowed us to assess the similarities and differences between Co m ͑coronene͒ and the previously reported 16 ground state geometries of Fe m ͑coronene͒ complexes. Motivated both by this imbalance and the absence of any studies combining both experimental and theoretical efforts on these complexes, we have initiated a systematic experimental and theoretical study on Co m ͑coronene͒ ͑m =1-2͒ complexes.…”

Section: Introductionmentioning

confidence: 92%

“…15,16 In one of the earliest gas-phase experimental studies 11 on metal-coronene complexes, Dunbar and co-workers studied the interaction of metal cations such as Mg + , Al + , Si + , In + , Pb + , and Bi + with coronene molecules. However, a complementary theoretical study 16 on Fe m ͑coronene͒ ͑m =1,2͒ complexes provided a different view of the structures. It was reported that the TM-coronene cationic complexes reacted readily and formed TM͑coronene͒ 2 complexes.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Ground state structures and photoelectron spectroscopy of [Com(coronene)]− complexes

Kandalam

Kiran

Jena

et al. 2007

The Journal of Chemical Physics

View full text Add to dashboard Cite

A synergistic approach involving theory and experiment has been used to study the structure and properties of neutral and negatively charged cobalt-coronene [Com(coronene)] complexes. The calculations are based on density functional theory with generalized gradient approximation for exchange and correlation potential, while the experiments are carried out using photoelectron spectroscopy of mass selected anions. The authors show that the geometries of neutral and anionic Co(coronene) and Co2(coronene) are different from those of the corresponding iron-coronene complexes and that both the Co atom and the dimer prefer to occupy eta2-bridge binding sites. However, the magnetic coupling between the Co atoms remains ferromagnetic as it is between iron atoms supported on a coronene molecule. The accuracy of the theoretical results is established by comparing the calculated vertical detachment energies, and adiabatic electron affinities with their experimental data.

show abstract

Section: Introductionmentioning

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Ground state structures and photoelectron spectroscopy of [Com(coronene)]− complexes

Kandalam

Kiran

Jena

et al. 2007

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…For transition metal atoms, this can be more than just simple electrostatic attraction; in such complexes, the occupied metal d orbitals can donate charge to the PAH unfilled Ã orbitals, and the occupied PAH orbitals can donate charge into empty or partly occupied metal orbitals to produce a strong, pseudocovalent bond. These compounds have begun to attract increasing interest in recent years in fields such as physical and organometallic chemistry for their interesting and unique bonding characteristics (see, e.g., Buchanan et al 1998;Senapati et al 2003). Given the relative cosmic abundance of the metals iron and magnesium, complexes involving these metals or their ions might well be important in the astrophysical context (Serra et al 1992;Klotz et al 1995).…”

Section: The Effect Of Metal Complexation On the Spectrummentioning

confidence: 98%

Variations in the Peak Position of the 6.2 μm Interstellar Emission Feature: A Tracer of N in the Interstellar Polycyclic Aromatic Hydrocarbon Population

Hudgins

Bauschlicher

Allamandola

2005

ApJ

289

304

View full text Add to dashboard Cite

This paper presents the results of an investigation of the molecular characteristics that underlie the observed peak position and profile of the nominal 6.2 m interstellar emission band generally attributed to the CC stretching vibrations of polycyclic aromatic hydrocarbons (PAHs). It begins with a summary of recent experimental and theoretical studies of the spectroscopic properties of large (>30 carbon atoms) PAH cations as they relate to this aspect of the astrophysical problem. It then continues with an examination of the spectroscopic properties of a number of PAH variants within the context of the interstellar 6.2 m emission, beginning with a class of compounds known as polycyclic aromatic nitrogen heterocycles (PANHs; PAHs with one or more nitrogen atoms substituted into their carbon skeleton). In this regard, we summarize the results of recent relevant experimental studies involving a limited set of small PANHs and their cations and then report the results of a comprehensive computational study that extends that work to larger PANH cations including many nitrogen-substituted variants of coronene + (C 24 H þ 12 ), ovalene + (C 32 H þ 14 ), circumcoronene + (C 54 H þ 18 ), and circum-circumcoronene + (C 96 H þ 24 ). Finally, we report the results of more focused computational studies of selected representatives from a number of other classes of PAH variants that share one or more of the key attributes of the PANH species studied. These alternative classes of PAH variants include (1) oxygen-and silicon-substituted PAH cations; (2) PAH-metal ion complexes (metallocenes) involving the cosmically abundant elements magnesium and iron; and (3) large, asymmetric PAH cations.Overall, the studies reported here demonstrate that increasing PAH size alone is insufficient to account for the position of the shortest wavelength interstellar 6.2 m emission bands, as had been suggested by earlier studies. On the other hand, this work reveals that substitution of one or more nitrogen atoms within the interior of the carbon skeleton of a PAH cation induces a significant blueshift in the position of the dominant CC stretching feature of these compounds that is sufficient to account for the position of the interstellar bands. Subsequent studies of the effects of substitution by other heteroatoms (O and Si), metal ion complexation ( Fe + , Mg + , and Mg 2+ ), and molecular symmetry variation-all of which fail to reproduce the blueshift observed in the PANH cations-indicate that N appears to be unique in its ability to accommodate the position of the interstellar 6.2 m bands while simultaneously satisfying the other constraints of the astrophysical problem. This result implies that the peak position of the interstellar feature near 6.2 m traces the degree of nitrogen substitution in the population, that most of the PAHs responsible for the interstellar IR emission features incorporate nitrogen within their aromatic networks, and that a lower limit of 1%-2% of the cosmic nitrogen is sequestered within the interstellar PAH populati...

show abstract

“…We use this molecular system as a prototype for a graphene sheet, where on the hollow site of the central ring, a cobalt atom is introduced as a local defect. Metal-coronene complexes are currently of experimental [61][62][63][64] and theoretical [65,66] interest, because the delocalised π electrons in coronene make it a suitable model system for studying the interaction of metals with extended systems. These papers show that many different metals (TMs and otherwise) can form bound ionic and neutral complexes with coronene.…”

Section: Cobalt On Coronenementioning

confidence: 99%

Computational study of adsorption of cobalt on benzene and coronene

2015

View full text Add to dashboard Cite

We investigate the binding of the cobalt atom on small aromatic model systems as a proxy for interaction with graphene, using density functional theory, coupled-cluster theory, and combinations of them using projector-based quantum embedding. We set out in some detail the electronic structure of the cobalt atom alone, because some nuances of atomic structure appear to have been overlooked in previous studies. Two states of the complex in particular are studied: those formed from the a 4 F ground state of the atom; and from c 2 D, the lowest doublet state with configuration 3d 9 4s 0 . We highlight the difficulties in extracting reliable results from typical approximate density functionals, and demonstrate that embedding calculations using the coupled-cluster theory in an active subsystem greatly reduce functional dependence, and produce a picture more consistent with the available experimental information. Our results cast doubt on previous calculations that have predicted strong chemisorptive binding between graphene and the c 2 D state of cobalt.

show abstract

Atomic structure, binding energy, and magnetic properties of iron atoms supported on a polyaromatic hydrocarbon

Cited by 26 publications

References 22 publications

Ground state structures and photoelectron spectroscopy of [Com(coronene)]− complexes

Ground state structures and photoelectron spectroscopy of [Com(coronene)]− complexes

Variations in the Peak Position of the 6.2 μm Interstellar Emission Feature: A Tracer of N in the Interstellar Polycyclic Aromatic Hydrocarbon Population

Computational study of adsorption of cobalt on benzene and coronene

Contact Info

Product

Resources

About