1
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Inoue T, Ina T, Masai H, Kondo N, Matsui F, Kinoshita T, Nakajima A. Extended X-ray Absorption Fine Structure (EXAFS) Measurements on Alkali Metal Superatoms of Ta-Atom-Encapsulated Si 16 Cage. J Phys Chem Lett 2024; 15:5376-5381. [PMID: 38738993 DOI: 10.1021/acs.jpclett.4c00492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
The silicon cage nanoclusters encapsulating a tantalum atom, termed Ta@Si16, exhibit characteristics of alkali metal "superatoms (SAs)". Despite this conceptual framework, the precise structures of Ta@Si16 and Ta@Si16+ remain unclear in quantum calculations due to three energetically close structural isomers: C3v, Td, and D4d structures. To identify the geometrical structure of Ta@Si16 SAs, structural analysis was conducted using extended X-ray absorption fine structure (EXAFS) with a high-intensity monochromatic X-ray source, keeping anaerobic conditions. Focusing on "superordered" films, which constitute amorphous thin films composed solely of Ta@Si16 SAs, this analysis preserved locally ordered structures. Spectral comparisons between experimental and simulated Ta L3-edge EXAFS unveil that Ta@Si16 SAs on a substrate adopt a C3v-derived structure, while Si K-edge EXAFS introduces spectral ambiguity in structural identifications, attributed to both intracluster and intercluster scatterings. These findings underscore the significance of locally ordered structure analyses in understanding and characterizing novel nanoscale materials.
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Affiliation(s)
- Tomoya Inoue
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Toshiaki Ina
- Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan
| | - Hirokazu Masai
- National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577, Japan
| | - Naonori Kondo
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
| | - Fumihiko Matsui
- Institute for Molecular Science, Myodaiji, Okazaki 444-8585, Japan
- SOKENDAI (The Graduate University for Advanced Studies), Myodaiji, Okazaki 444-8585, Japan
| | - Toyohiko Kinoshita
- Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan
| | - Atsushi Nakajima
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
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2
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Rivic F, Schäfer R. Magnetism of single-doped paramagnetic tin clusters studied using temperature-dependent Stern-Gerlach experiments with enhanced sensitivity: impact of the diamagnetic ligand field and paramagnetic dopant. Phys Chem Chem Phys 2024; 26:12982-12992. [PMID: 38639064 DOI: 10.1039/d4cp00890a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
In this work, the magnetic properties of tetrel clusters SnNTM, which are singly doped with transition metals (TM), are investigated. On the one hand, the number of tetrel atoms (N = 11, 12, 14 and 17 with TM = Mn) is varied; on the other hand, different transition metals (N = 14, TM = Cr, Mn, Fe) are studied. Magnetic deflection experiments under cryogenic conditions show that the variation of the number of tetrel atoms strongly changes the magnetic properties of the Mn-doped clusters. It is observed that Sn12Mn, Sn11Mn and Sn14Mn partially show super-atomic behaviour, while spin relaxation occurs in Sn17Mn. Magnetic deflection experiments at higher nozzle temperatures were carried out for the first time enhanced by a second parallel-aligned Stern-Gerlach magnet to achieve larger deflections. The resulting temperature-dependent one-sided deflections are quantitatively analysed using Curie's law and show that Sn17Mn possesses the highest magnetic moment of these clusters, followed by Sn12Mn and Sn11Mn. Sn14Mn shows the lowest magnetic moment. The replacement of Mn by Cr in Sn14Mn leads to a diamagnetic singlet, i.e., the magnetic moment of Cr in Sn14Cr is completely quenched. The replacement of Mn by Fe in turn leads to a paramagnetic species, whereby Sn14Fe is most likely present as a triplet. On this basis, the geometrical and electronic structures are analysed using quantum chemical calculations, indicating an arachno-type structure for Sn14Cr, Sn14Mn and Sn14Fe, which has already been predicted in the literature for Si14Cr. This is experimentally confirmed by deflection of molecular beams with an electric field under cryogenic conditions, suggesting that the arachno-type geometry is crucial for the overall stability of the transition-metal-doped tetrel clusters Sn14TM with TM = Cr, Mn, Fe.
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Affiliation(s)
- Filip Rivic
- Technical University of Darmstadt, Eduard-Zintl-Institute, Peter-Grünberg-Straße 8, 64287 Darmstadt, Germany.
| | - Rolf Schäfer
- Technical University of Darmstadt, Eduard-Zintl-Institute, Peter-Grünberg-Straße 8, 64287 Darmstadt, Germany.
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3
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Beuthert K, Weinert B, Wilson RJ, Weigend F, Dehnen S. [M@Sn 14-xSb x] q- (M = La, Ce, or U; x = 6-8; q = 3, 4): Interaction of 4f or 5f Metal Ions with 5p Metal Atoms in Intermetalloid Clusters. Inorg Chem 2023; 62:1885-1890. [PMID: 35639728 DOI: 10.1021/acs.inorgchem.2c01298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The impact of 4f metal ions Ln3+ (Ln = La or Ce) versus 5f metal ions Un+ (n = 3 or 4) on the compositions and distribution of 5p metal atoms in the cluster shells of endohedral species [M@Sn14-xSbx]q- (M = La, Ce, or U; x = 6-8; q = 3, 4) was studied by means of combined experimental and quantum chemical investigations. While all known f-block metal ion-centered endohedral clusters possessed combinations of larger main group metal atoms so far (Sn/Bi or Pb/Bi), resulting in mixtures of 13- and 14-atom cages, the 14-atom cages reported herein comprise exclusively Sn and Sb atoms and therefore are challenged in accommodating the large 4f and 5f ions. We show that the clusters form in reactions of (Sn2Sb2)2- anions with [Ln(C5Me4H)3] or [U(C5Me4H)3Cl], and that salts of [La@Sn6Sb8]3-, [La@Sn7Sb7]4-, [U@Sn8Sb6]4-, and [U@Sn7Sb7]3- can be isolated from them. The assignment of Sn versus Sb in the encapsulating cage follows a simple rule. Different central atoms cause only slight differences in this regard and with respect to distortions of the cluster shells. The reactions also yielded the salt of the new binary anion (Sn4Sb4)2- that was recently predicted by quantum chemical studies.
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Affiliation(s)
- Katrin Beuthert
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Bastian Weinert
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Robert J Wilson
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Florian Weigend
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
| | - Stefanie Dehnen
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35043 Marburg, Germany
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4
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Trivalent Polyhedra as Duals of Borane Deltahedra: From Molecular Endohedral Germanium Clusters to the Smallest Fullerenes. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28020496. [PMID: 36677561 PMCID: PMC9865895 DOI: 10.3390/molecules28020496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/20/2022] [Accepted: 12/27/2022] [Indexed: 01/06/2023]
Abstract
The duals of the most spherical closo borane deltahedra having from 6 to 16 vertices form a series of homologous spherical trivalent polyhedra with even numbers of vertices from 8 to 28. This series of homologous polyhedra is found in endohedral clusters of the group 14 atoms such as the endohedral germanium cluster anions [M@Ge10]3- (M = Co, Fe) and [Ru@Ge12]3- The next members of this series have been predicted to be the lowest energy structures of the endohedral silicon clusters Cr@Si14 and M@Si16 (M = Zr, Hf). The largest members of this series correspond to the smallest fullerene polyhedra found in the endohedral fullerenes M@C28 (M = Zr, Hf, Th, U). The duals of the oblate (flattened) ellipsoidal deltahedra found in the dirhenaboranes Cp*2Re2Bn-2Hn-2 (Cp* = η5-Me5C5; 8 ≤ n ≤ 12) are prolate (elongated) trivalent polyhedra as exemplified experimentally by the germanium cluster [Co2@Ge16]4- containing an endohedral Co2 unit.
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5
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Huang Y, Xue Y, Muñoz‐Castro A, Popov IA, Sun Z. [Nb@Ge
13/14
]
3−
: New Family Members of Ge‐Based Intermetalloid Clusters. Chemistry 2022; 28:e202202192. [DOI: 10.1002/chem.202202192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Ya‐Shan Huang
- State Key Laboratory of Elemento-Organic Chemistry Tianjin Key Lab for Rare Earth Materials and Applications School of Materials Science and Engineering Nankai University Tianjin 300350 P.R. China
| | - Yuan Xue
- Department of Chemistry The University of Akron Akron OH 44325–3601 USA
| | - Alvaro Muñoz‐Castro
- Facultad de Ingeniería Arquitectura y Diseño Universidad San Sebastián Bellavista 7 Santiago 8420524 Chile
| | - Ivan A. Popov
- Department of Chemistry The University of Akron Akron OH 44325–3601 USA
| | - Zhong‐Ming Sun
- State Key Laboratory of Elemento-Organic Chemistry Tianjin Key Lab for Rare Earth Materials and Applications School of Materials Science and Engineering Nankai University Tianjin 300350 P.R. China
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6
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Wang K, Yin GJ, Jia ZZ, Miao L, Moro R, von Issendorff B, Ma L. Anion photoelectron spectroscopy and density functional theory study of TM 2Si n- (TM = V, Cr; n = 14-20) clusters. Phys Chem Chem Phys 2022; 24:18321-18330. [PMID: 35880636 DOI: 10.1039/d2cp01649d] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We investigated the structural evolution and electronic properties of medium-sized silicon cluster anions doped with two transition metal atoms, TM2Sin- (TM = V, Cr; n = 14-20), by using mass-selective anion photoelectron spectroscopy combined with density functional theory (DFT) calculations. Putative ground state structures of these clusters were obtained by using a genetic algorithm coupled with the DFT calculations. It was found that the two TM atoms tend to form a TM-TM bond, which - except for V2Si19- - is shorter than the nearest neighbour distance in the crystalline state of the respective metals. The V2Sin- clusters with n = 14 to 17 exhibit structures based on a silicon hexagonal antiprism, while the larger ones exhibit more fullerene-like cage structures. Cr2Sin- clusters follow the same trend, although with a silicon hexagonal prism structure for n = 14 and 15, and the transition to fullerene-like structures occurring at n = 17. Among these clusters, TM2Si18- have the largest average binding energy and second order differences in energy, therefore the highest relative stability. All of the clusters possess total magnetic moment of 1 μB, but with very different contributions from the doped TM atoms. Especially in the Cr doped clusters there is a tendency towards an anitiferromagnetic arrangement of the magnetic moments of the two Cr atoms.
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Affiliation(s)
- Kai Wang
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Guang-Jia Yin
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Ze-Zhao Jia
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Lin Miao
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Ramiro Moro
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Bernd von Issendorff
- Fakultät für Physik, Universität Freiburg, H. Herderstr. 3, D-79104 Freiburg, Germany
| | - Lei Ma
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
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7
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Wang K, Jia ZZ, Fan Z, Zhao HY, Yin GJ, Moro R, von Issendorff B, Ma L. Structures and electronic properties of VSi n- ( n = 14-20) clusters: a combined experimental and density functional theory study. Phys Chem Chem Phys 2022; 24:8839-8845. [PMID: 35355038 DOI: 10.1039/d2cp00619g] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We present a systematic study of the structures and electronic properties of vanadium-doped silicon cluster anions, VSin- (n = 14-20), by combining photoelectron spectroscopy (PES) measurements and density functional theory (DFT) based theoretical calculations. High resolution PES of low temperature (10 K) clusters are acquired at a photon wavelength of 248 nm. Low-lying structures of VSi14-20- are obtained by a genetic algorithm based global minimum search code combined with DFT calculations. Excellent agreement is found between the measured PES and the simulated electron density of states of the putative ground-state structures. We conclude that clusters with sizes n = 14 and n = 15 prefer cage-like structures, with the encapsulated vanadium atom bonding with all silicon atoms, while a fullerene-like motif is more favorable for n ≥ 16. For the sizes n = 16 to 19, the structures consist of a V@Si14 with two, three, four, and five Si atoms on the surface of the cage. For n = 20 the structure consists of a V@Si15 with five Si atoms on the surface of the cage. VSi14- has the highest stability and stands out as a simultaneous closing of electronic and geometrical shells.
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Affiliation(s)
- Kai Wang
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Ze-Zhao Jia
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Zheng Fan
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Hong-Yuan Zhao
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Guang-Jia Yin
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Ramiro Moro
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
| | - Bernd von Issendorff
- Fakultät für Physik, Universität Freiburg, H. Herderstr. 3, D-79104 Freiburg, Germany
| | - Lei Ma
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China.
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8
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Khanna V, Singh R, Claes P, Nguyen MT, Fielicke A, Janssens E, Lievens P, McGrady JE. Evolution of Vibrational Spectra in the Manganese-Silicon Clusters Mn 2Si n, n = 10, 12, and 13, and Cationic [Mn 2Si 13] . J Phys Chem A 2022; 126:1617-1626. [PMID: 35238570 PMCID: PMC9084549 DOI: 10.1021/acs.jpca.1c10027] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
A comparison
of DFT-computed and measured infrared spectra reveals
the ground state structures of a series of gas-phase silicon clusters
containing a common Mn2 unit. Mn2Si12 and [Mn2Si13]+ are both axially
symmetric, allowing for a clean separation of the vibrational modes
into parallel (a1) and perpendicular (e1) components.
Information about the Mn–Mn and Mn–Si bonding can be
extracted by tracing the evolution of these modes as the cluster increases
in size. In [Mn2Si13]+, where the
antiprismatic core is capped on both hexagonal faces, a relatively
simple spectrum emerges that reflects a pseudo-D6d geometry. In cases where the cluster is
more polar, either because there is no capping atom in the lower face
(Mn2Si12) or the capping atom is present but
displaced off the principal axis (Mn2Si13),
the spectra include additional features derived from vibrational modes
that are forbidden in the parent antiprism.
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Affiliation(s)
- Vaibhav Khanna
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
| | - Roshan Singh
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
| | - Pieterjan Claes
- Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200 D, B-3001 Leuven, Belgium
| | - Minh Tho Nguyen
- Institute for Computational Science and Technology (ICST), Quang Trung Software City, Ho Chi Minh City 53151, Vietnam
| | - André Fielicke
- Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany.,Institut für Optik und Atomare Physik, Technische Universität Berlin, Hardenbergstrasse 36, 10623, Berlin, Germany
| | - Ewald Janssens
- Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200 D, B-3001 Leuven, Belgium
| | - Peter Lievens
- Quantum Solid-State Physics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200 D, B-3001 Leuven, Belgium
| | - John E McGrady
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
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9
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Wang K, Zhao HY, Miao L, Jia ZZ, Yin GJ, Zhu XD, Moro R, von Issendorff B, Ma L. Photoelectron Spectroscopy and Density Functional Investigation of the Structural Evolution, Electronic, and Magnetic Properties of CrSi n- ( n = 14-18) Clusters. J Phys Chem A 2022; 126:1329-1335. [PMID: 35175756 DOI: 10.1021/acs.jpca.1c09557] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
CrSin- (n = 14-18) cluster anions have been investigated by a combination of photoelectron spectroscopy (PES) and first-principles calculations. The lowest-lying structures of the clusters have been determined by a global minimum search based on the genetic algorithm, combined with density functional theory (DFT) calculations. The simulated PES spectra of the lowest-energy isomers are in agreement with the experimental results, which gives strong evidence that the correct structures have been found. While sizes n = 14 and n = 15 prefer cage-like structures based on multi-center bonding within the cage, the larger sizes adopt structures based on fullerene-type cages around the Cr atom, with the additional atoms attached to the cage surface. A Hirshfeld analysis shows that the Cr atoms act as electron donors in all clusters, thus enhancing the electron count in the cage. It also reveals that the magnetic moment of 1μB shown by all clusters is mainly contributed by the Cr atom. One interesting exception is size 17, where the Cr atom contributes a small moment antiparallel to that of the silicon cage.
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Affiliation(s)
- Kai Wang
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Hong-Yuan Zhao
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Lin Miao
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Ze-Zhao Jia
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Guang-Jia Yin
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Xiao-Dong Zhu
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Ramiro Moro
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
| | - Bernd von Issendorff
- Fakultät für Physik, Universität Freiburg, H. Herderstr. 3. D-79104 Freiburg, Germany
| | - Lei Ma
- Tianjin International Center for Nanoparticles and Nanosystems, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, China
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10
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McGrady JE, Weigend F, Dehnen S. Electronic structure and bonding in endohedral Zintl clusters. Chem Soc Rev 2021; 51:628-649. [PMID: 34931207 DOI: 10.1039/d1cs00775k] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Endohedral Zintl clusters-multi-metallic anionic molecules in which a d-block or f-block metal atom is enclosed by p-block (semi)metal atoms-are very topical in contemporary inorganic chemistry. Not only do they provide insight into the embryonic states of intermetallic compounds and show promise in catalytic applications, they also shed light on the nature of chemical bonding between metal atoms. Over the past two decades, a plethora of endohedral Zintl clusters have been synthesized, revealing a fascinating diversity of molecular architectures. Many different perspectives on the bonding in them have emerged in the literature, sometimes complementary and sometimes conflicting, and there has been no concerted effort to classify the entire family based on a small number of unifying principles. A closer look, however, reveals distinct patterns in structure and bonding that reflect the extent to which valence electrons are shared between the endohedral atom and the cluster shell. We show that there is a much more uniform relationship between the total valence electron count and the structure and bonding patterns of these clusters than previously anticipated. All of the p-block (semi)metal shells can be placed on a ladder of total valence electron count that ranges between 4n+2 (closo deltahedra), 5n (closed, three-bonded polyhedra) and 6n (crown-like structures). Although some structural isomerism can occur for a given electron count, the presence of a central metal cation imposes a preference for rather regular and approximately spherical structures which maximise electrostatic interactions between the metal and the shell. In cases where the endohedral metal has relatively accessible valence electrons (from the d or f shells), it can also contribute its valence electrons to the total electron count of the cluster shell, raising the effective electron count and often altering the structural preferences. The electronic situation in any given cluster is considered from different perspectives, some more physical and some more chemical, in a way that highlights the important point that, in the end, they explain the same situation. This article provides a unifying perspective of bonding that captures the structural diversity across this diverse family of multimetallic clusters.
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Affiliation(s)
- John E McGrady
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, OX1 3QZ, UK.
| | - Florian Weigend
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften, Philipps University Marburg, Hans-Meerwein-Straße 4, 35043 Marburg, Germany.
| | - Stefanie Dehnen
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften, Philipps University Marburg, Hans-Meerwein-Straße 4, 35043 Marburg, Germany.
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11
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Morgan HWT, Csizi KS, Huang YS, Sun ZM, McGrady JE. Open Shells in Endohedral Clusters: Structure and Bonding in the [Fe 2@Ge 16] 4- Anion and Comparison to Isostructural [Co 2@Ge 16] 4. J Phys Chem A 2021; 125:4578-4588. [PMID: 34014678 DOI: 10.1021/acs.jpca.1c02837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The anionic cluster [Fe2@Ge16]4- has been characterized and shown to be isostructural to the known D2h-symmetric α isomer of the cobalt analogue [Co2@Ge16]4-. Together with the known pair of compounds [Co@Ge10]3- and [Fe@Ge10]3-, the title compound completes a set of four closely related germanium clusters that allow us to explore how the metal-metal and metal-cage interactions evolve as a function of size and of the identity of the metal. The results of spin-unrestricted density functional theory (DFT) and multiconfigurational self-consistent field (MC-SCF) calculations present a consistent picture of the electronic structure where transfer of electron density from the metal to the cage is significant, particularly in the Fe clusters where the exchange stabilization of unpaired spin density is an important driving force.
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Affiliation(s)
- Harry W T Morgan
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
| | - Katja-Sophia Csizi
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
| | - Ya-Shan Huang
- Tianjin Key Lab of Rare Earth Materials and Applications, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China
| | - Zhong-Ming Sun
- Tianjin Key Lab of Rare Earth Materials and Applications, School of Materials Science and Engineering, Nankai University, Tianjin 300350, China
| | - John E McGrady
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, U.K
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12
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Affiliation(s)
- Jijun Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
| | - Qiuying Du
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
| | - Si Zhou
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024, China
| | - Vijay Kumar
- Center for Informatics, School of Natural Sciences, Shiv Nadar University, NH-91, Tehsil Dadri, Gautam Buddha Nagar 201314, U. P., India
- Dr. Vijay Kumar Foundation, 1969 Sector 4, Gurgaon 122001, Haryana, India
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13
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Peters B, Lichtenberger N, Dornsiepen E, Dehnen S. Current advances in tin cluster chemistry. Chem Sci 2020; 11:16-26. [PMID: 32110355 PMCID: PMC7012043 DOI: 10.1039/c9sc04363b] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 10/19/2019] [Indexed: 11/21/2022] Open
Abstract
This perspective summarizes highlights and most recent advances in tin cluster chemistry, thereby addressing the whole diversity of (mostly) discrete units containing tin atoms. Although being a (semi-)metallic element, tin is in the position to occur both in formally positive or negative oxidation states in these molecules, which causes a broad range of fundamentally different properties of the corresponding compounds. Tin(iv) compounds are not as oxophilic and not as prone to hydrolysis as related Si or Ge compounds, hence allowing for easier handling and potential application. Nevertheless, their reactivity is high due to an overall reduction of bond energies, which makes tin clusters interesting candidates for functional compounds. Beside aspects that point towards bioactivity or even medical applications, materials composed of naked or ligand-protected tin clusters, with or without bridging ligands, show interesting optical, and ion/molecule-trapping properties.
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Affiliation(s)
- Bertram Peters
- Fachbereich Chemie , Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) , Philipps-Universität Marburg , Hans-Meerwein-Straße 4 , D-35043 Marburg , Germany .
| | - Niels Lichtenberger
- Fachbereich Chemie , Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) , Philipps-Universität Marburg , Hans-Meerwein-Straße 4 , D-35043 Marburg , Germany .
| | - Eike Dornsiepen
- Fachbereich Chemie , Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) , Philipps-Universität Marburg , Hans-Meerwein-Straße 4 , D-35043 Marburg , Germany .
| | - Stefanie Dehnen
- Fachbereich Chemie , Wissenschaftliches Zentrum für Materialwissenschaften (WZMW) , Philipps-Universität Marburg , Hans-Meerwein-Straße 4 , D-35043 Marburg , Germany .
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Wilson RJ, Lichtenberger N, Weinert B, Dehnen S. Intermetalloid and Heterometallic Clusters Combining p-Block (Semi)Metals with d- or f-Block Metals. Chem Rev 2019; 119:8506-8554. [DOI: 10.1021/acs.chemrev.8b00658] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Robert J. Wilson
- Fachbereich Chemie und Wissenschaftliches Zentrum für Materialwissenschaften, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043 Marburg, Germany
| | - Niels Lichtenberger
- Fachbereich Chemie und Wissenschaftliches Zentrum für Materialwissenschaften, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043 Marburg, Germany
| | - Bastian Weinert
- Fachbereich Chemie und Wissenschaftliches Zentrum für Materialwissenschaften, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043 Marburg, Germany
| | - Stefanie Dehnen
- Fachbereich Chemie und Wissenschaftliches Zentrum für Materialwissenschaften, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043 Marburg, Germany
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Prabha S, Reber AC, Khanna SN. The structure and stability of CrnTem (1 ≤ n ≤ 6, 1 ≤ m ≤ 8) clusters. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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16
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Structure and bonding in endohedral transition metal clusters. ADVANCES IN INORGANIC CHEMISTRY 2019. [DOI: 10.1016/bs.adioch.2018.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Jin X, Arcisauskaite V, McGrady JE. Quantum chemical models for the absorption of endohedral clusters on Si(111)-(7 × 7): a subtle balance between W–Si and Si–Si bonding. Phys Chem Chem Phys 2019; 21:13686-13695. [DOI: 10.1039/c9cp01841g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The absorption of endohedral clusters on Si(111)-7 × 7 generates a new bond between W and a surface silicon adatom.
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Affiliation(s)
- Xiao Jin
- Department of Chemistry
- University of Oxford
- UK
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Chauhan V, Reber AC, Khanna SN. Strong lowering of ionization energy of metallic clusters by organic ligands without changing shell filling. Nat Commun 2018; 9:2357. [PMID: 29907744 PMCID: PMC6003947 DOI: 10.1038/s41467-018-04799-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/08/2018] [Indexed: 11/09/2022] Open
Abstract
Alkali atoms have unusually low ionization energies because their electronic structures have an excess electron beyond that of a filled electronic shell. Quantum states in metallic clusters are grouped into shells similar to those in atoms, and clusters with an excess electron beyond a closed electronic may also exhibit alkali character. This approach based on shell-filling is the way alkali species are formed as explained by the periodic table. We demonstrate that the ionization energy of metallic clusters with both filled and unfilled electronic shells can be substantially lowered by attaching ligands. The ligands form charge transfer complexes where the electronic spectrum is lifted via crystal field like effect. We demonstrate that the effect works for the weakly bound ligand, N-ethyl-2-pyrrolidone (EP = C6H11NO), and that the effect leads to a dramatic lowering of the ionization energy independent of the shell occupancy of the cluster.
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Affiliation(s)
- Vikas Chauhan
- Department of Physics, Virginia Commonwealth University, Richmond, VA, 23284-2000, USA
| | - Arthur C Reber
- Department of Physics, Virginia Commonwealth University, Richmond, VA, 23284-2000, USA
| | - Shiv N Khanna
- Department of Physics, Virginia Commonwealth University, Richmond, VA, 23284-2000, USA.
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