Photoelectron spectroscopic study of the anionic transition metalorganic complexes [Fe1,2(COT)]− and [Co(COT)]−

Abstract

The gas-phase, iron and cobalt cyclooctatetraene cluster anions, [Fe(1,2)(COT)](-) and [Co(COT)](-), were generated using a laser vaporization source and studied using mass spectrometry and anion photoelectron spectroscopy. Density functional theory was employed to compute the structures and spin multiplicities of these cluster anions as well as those of their corresponding neutrals. Both experimental and theoretically predicted electron affinities and photodetachment transition energies are in good agreement, authenticating the structures and spin multiplicities predicted by theory. The implied spin magnetic moments of these systems suggest that [Fe(COT)], [Fe(2)(COT)], and [Co(COT)] retain the magnetic moments of the Fe atom, the Fe(2) dimer, and the Co atom, respectively. Thus, the interaction of these transition metal, atomic and dimeric moieties with a COT molecule does not quench their magnetic moments, leading to the possibility that these combinations may be useful in forming novel magnetic materials.

Electronic, Magnetic, and Transport Properties of Fe-COT Clusters: A Theoretical Study

“…First, we test the reliability of these adopting computational parameters for Fe-COT clusters by calculating the adiabatic electron affinity (EA) value of half-sandwich Fe-COT cluster: one Fe atom locates above the center of a COT ring. The calculated EA is ∼0.95 eV, which is close to the experimental measurement (1.18 eV) and previous theoretical result (1.04 eV) . Before building the Fe-COT junctions, we optimize the geometric structures of Fe-COT clusters .…”

“…The calculated EA is ∼0.95 eV, which is close to the experimental measurement (1.18 eV) and previous theoretical result (1.04 eV). 21 Before building the Fe-COT junctions, we optimize the geometric structures of Fe-COT clusters. 29 The stable structures of Fe n COT n+1 (n ) 1-4) clusters are shown in Figure 1a-d…”

“…Many lanthanide complexes (Ln = Ce, Nd, Eu, Tb, Ho, Tm, and Yb) and transition-metal complexes (TM = V, Fe, Ni, and Ag) sandwiched between COT rings have been successfully produced by using laser vaporization and molecular beam methods in the past few years. − Using molecular beam magnetic deflection technique, Nakajima et al investigated the electronic and magnetic properties of Eu-COT clusters and found that Eu-COT has large magnetic moment (MM) and the total MM linearly increases with the number of Eu atoms. Jaeger et al and Kandalam et al performed photodissociation and anion photoelectron spectroscopy studies on Fe-COT clusters, respectively. For Ln-COT clusters, these experimental and theoretical investigations mainly focus on the stability, charge transfer, electronic structure, and magnetic properties; only few attempt to explore the electron transport property of Ln-COT clusters .…”

Photoelectron spectroscopy and theoretical studies of [Com(pyrene)n]− (m=1,2 and n=1,2) complexes

“…11 Fe-PAH complexes were studied theoretically by Senapati et al, 61 Wang et al, 50 and Simon and Joblin. 47 Our group studied several TM-organic complexes using mass spectrometry and negative ion photoelectron spectroscopy, including benzene, 15,54,55 pyridine, 12 coronene, 23,69 pyrene, 70 and cyclooctatetraene 71 as organic ligands. Based on joint experimental and theoretical efforts, we have recently reported the geometric and electronic structure and magnetic properties of anionic and neutral TM-PAH complexes, such as Co m ͑coronene͒ n , 23 Fe m ͑coronene͒ n , 69 and Fe m ͑pyrene͒ n .…”

Photoelectron spectroscopic study of iron-pyrene cluster anions

“…Transition metal-organic molecular complexes play an important role in the field of organometallic chemistry because of their unique structural, electronic and magnetic properties. Many experimental and theoretical studies have provided information regarding the interactions between various transition metals and organic ligands, such as benzene, pyridine, 22 fullerene (C 60 ), 6,15,[23][24][25][26][27][28][29][30][31] coronene, 15,[32][33][34][35][36][37][38][39][40][41][42] cyclooctatetrene (COT), 6,43,44 and pyrene. 37,45,46,49 Most of these studies have focused on characterizing the bonding between the d-electrons in the subject transition metals and the πelectrons of the organic ligands.…”