by n(CO)m+ (n=7-16, m=0-8) after Nb< Los grupos sub>n+ react with the reactant CO. (Right) A composition of 1S and 1Pz superatomic orbitals, with 2S and 2Pz orbitals in Nb12+ contributed by the s and d orbitals respectively. Also shown are the NICS scan related to the aromaticity of the Nb group cage12+ and the localized orbital locator (LOL) projected onto the XY plane. The inserts are the flux traces of the induced ring current of Nb12+ When an external magnetic field is applied to the [0, 0, 1] address. Credit: Science China Press” width=”800″ height=”530″/> (Left) Typical mass spectra of cationic niobium clusters produced by a home magnetron sputtering (MagS) source and collected by a custom triple quadrupole mass spectrometer (TQMS), and after reacting with different doses of reagents (3% CO in He). The inset shows the intensity of Nbnorth(CO)meter+ (n=7-16, m=0-8) after Nbnorth+ The groups react with the reactant CO. (Right) A composition of 1S and 1Pz superatomic orbitals, with 2S and 2Pz orbitals in Nb12+ contributed by the s and d orbitals respectively. Also shown are the NICS-scans belonging to the aromaticity of the Nb cage.12+ cluster, and the localized orbital locator (LOL) projected onto the XY plane. Insertions are the flux traces of the induced ring current of Nb12+ When an external magnetic field is applied to the [0, 0, 1] address. Credit: Science China Press
In an article published in National Journal of Sciencea group of niobium tolerant to CO Nb12+ was discovered by reacting Nbnorth+ with CO in a well designed flow tube reactor.
The origin of the chemical inertness of Nb12+, called “niobespherene”, is revealed by unique superatomic states that are contributed by the 5s and 4d electrons of niobium. Energy-decreasing 2S and 2P superatomic orbitals composed of d-electrons delocalize along Nb12+ and balance the cluster structure, leading to cage aromaticity and greater stability.
This study was led by Dr. Zhixun Luo (State Key Laboratory of Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences).
Transition metal particles are widely applied in a wide range of fields. However, the precise micromechanisms involving the universal scale relationship between intermediates, metal-metal bond formation, and crystal field collapse are largely unclear. A wave of progress in recent years has facilitated highly detailed new studies of groups of metals.
Reactions of metal groups in the gas phase allow fully revealing the structure-property relationship of nanomaterials and the microscopic mechanisms of nanocatalysts with atomic precision. However, it is challenging to prepare pure metal clusters in view of their high activity, thus it is challenging to experimentally explore their stability and relative properties.
Beyond this, it is not always easy to understand why one chemical is more stable than another. A unified answer for metal groups has led to the establishment of the super atom concept that rationalizes electron delocalization; however, group stability based on superatom theory has not been unambiguously confirmed for any metal other than the s and p blocks of the periodic table of elements.
Recently, researchers in Dr. Luo’s group have made great progress in preparing pure metal niobium clusters. They find a group of hollow cage metal Nb12+ which appears in prominent abundance in mass spectra after reacting with CO under sufficient gas collision conditions. For the first time, they fully elucidated the superatomic stability of this niobesphere, revealed the novelty of d-orbital hybridization to form superatomic orbitals, and illustrated the potential of this compound as a new CO-tolerant material.
Synthesizing a Super Atom: Opening Doors to Their Use as Substitutes for Elementary Atoms
Benben Huang et al., Nb12+——Niobespherene: a full metal hollow cage group with superatomic stability and resistance to CO attack, National Journal of Science (2022). DOI: 10.1093/nsr/nwac197
Provided by Science China Press
Citation: Niobespherene: A Full Metal Hollow Cage Group With Superatomic Stability And Resistant To Attack By CO (Oct 25, 2022) Retrieved Oct 25, 2022 from https://phys.org/news/2022-10-niobespherene -full-metal-hollow-cage-cluster.html
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