Infrared Photodissociation Spectroscopy of Heterodinuclear Iron–Zinc and Cobalt–Zinc Carbonyl Cation Complexes

Abstract

Fe-Zn and Co-Zn heteronuclear carbonyl cation complexes are produced via a laser vaporization supersonic cluster source in the gas phase. The dinuclear FeZn(CO) and CoZn(CO) cation complexes are observed to be the most intense heterodinuclear carbonyl cation species in the mass spectra. The infrared spectra are obtained via mass selection and infrared photodissociation spectroscopy in the carbonyl stretching frequency region. Their geometric and electronic structures are assigned with the support of density functional calculations. The FeZn(CO) complex is determined to have a (OC)Fe-Zn structure with a Fe-Zn half bond. The CoZn(CO) ion is established to have a staggered (OC)Co-Zn(CO) structure involving a Co-Zn σ single bond.

Ligand-Enhanced CO Activation by the Early Lanthanide–Nickel Heterodimers: Photoelectron Velocity-Map Imaging Spectroscopy of LnNi(CO)n– (Ln = La, Ce)

“…It can be seen from the above structural analysis of the heterobinuclear LnNi­(CO) n – (Ln = La, Ce) carbonyls that the number of extremely activated CO molecule is increased in the larger clusters ( n ≥ 4), evidencing the ligand-enhanced CO activation by the early lanthanide-nickel heterodimers. This is different from the structural evolutions of other homobinuclear, heterobinuclear metal–iron, and metal–nickel carbonyls. − In the Ti 2 (CO) n – ( n = 1–9) clusters, the building block of three side-on-bonded CO molecules is favored for n = 3–5, whereas the motif of two side-on-bonded CO molecules is preferred for n = 6–9, indicating that the number of extremely activated CO molecule is reduced in the larger clusters . In the MNi­(CO) n – (M = Ti, Zr, Hf) complexes, the n = 3 cluster is comprised of one terminal, one bridging, and one side-on-bonded carbonyl, whereas the binding motif of three bridging carbonyls is preferred in n = 4–7, also suggesting that the degree of CO activation is reduced in the larger clusters …”

“…Recently, the study on the reaction of CO with heteronuclear metal clusters has aroused increasing attention, which helps uncover the diverse structural features, the nature of chemical bonding, and the synergy effects of different transition metals on the catalytic performance. − In the heterobinuclear metal–iron carbonyls, PbFe­(CO) 4 – and CuFe­(CO) 4 – , the CO ligands are terminally bonded to the iron atom. , The MFe­(CO) 8 + (M = Co, Ni, Cu) cations are comprised of eclipsed (CO) 5 Fe–M­(CO) 3 + motif and MCu­(CO) 7 + (M = Co, Ni) consist of staggered (CO) 4 M–Cu­(CO) 3 + motif, where the CO molecules are terminally coordinated to the metal atoms . The ZnFe­(CO) 5 + carbonyl consists of a Zn–Fe­(CO) 5 structure with a Zn–Fe half bond and ZnCo­(CO) 7 + has a staggered Zn­(CO) 3 –Co­(CO) 4 structure involving a Zn–Co σ single bond . Interestingly, UFe­(CO) 3 – and OUFe­(CO) 3 – were determined to have triple bonds between U 6d/5f and Fe 3d orbitals, which feature one covalent σ bond and two Fe-to-U dative π bonds…”

Rhenium versus cadmium: an alternative structure for a thermally stable cadmium carbonyl compound

“…6 As such, the interaction between CO and ZnO has been investigated by a variety of techniques, which include IR spectroscopy, 7,8 solid state 13 C NMR spectroscopy, 9,10 ultraviolet photoelectron spectroscopy, 11 and scanning tunneling microscopy. 12 Zinc carbonyl compounds have also been generated under matrix isolation conditions [13][14][15] and in the gas phase, 16 but there are no reports of such compounds that have been structurally characterized by Xray diffraction. Cadmium carbonyl compounds have received even less attention than their zinc counterparts, and were rst observed by IR spectroscopic studies in an argon matrix.…”

Photoelectron Velocity Map Imaging Spectroscopic and Theoretical Study of Heteronuclear MNi(CO)7– (M = V, Nb, Ta)

“…As for MNi­(CO) 7 – (M = Ti, Zr, Hf), these structures had three bridging carbonyls, three carbonyls terminally bonded to the M (M = Ti, Zr, Hf) atom and one carbonyl terminally bonded to the Ni atom . The early transition metal–nickel carbonyls MNi­(CO) n – (M = Sc, Y, La, Ce, Ti, Zr, Hf, V) were characterized to have three different types of CO bonding configurations (side-on-bonding, bridging, and terminal carbonyls), − and the heterobinuclear noble metal–nickel carbonyls MNi­(CO) n – (M = Cu, Ag) have revealed that the carbonyls were terminally bonded to the Ni atom. , The structural information for previous studies of homobinuclear Cr 2 (CO) 7 + , Ni 2 (CO) 7 + , Pd 2 (CO) 7 + , and Fe 2 (CO) 7 – and heterobinuclear CuFe­(CO) 7 – and CoZn­(CO) 7 + have indicated that they mainly possessed terminal carbonyl coordination modes. − However, the geometric investigations indicate that our present results of the MNi­(CO) 7 – (M= V, Nb, Ta) clusters are determined to have three bridging carbonyl modes and the other carbonyls are terminally bonded to the metal atoms, which are similar to the MNi­(CO) 7 – (M= Ti, Zr, Hf) clusters . It is demonstrated that various coordination modes are adopted so as to stabilize the different binuclear carbonyl complexes, by guaranteeing that at least one of two metallic centers satisfies the 18-electron rule.…”