Interactions between Ultrastable Na4Ag44(SR)30 Nanoclusters and Coordinating Solvents: Uncovering the Atomic-scale Mechanism

We report the mechanism on the ultrahigh stability of Na<sub>4</sub>Ag<sub>44</sub>(SR)<sub>30</sub> by uncovering how coordinating solvents interact with the Na<sub>4</sub>Ag<sub>44</sub>(SR)<sub>30</sub> nanocluster at the atomic scale. Through synchrotron X-ray experiments and theoretical calculations, it was found that strongly coordinating aprotic solvents interact with surface Ag atoms, particularly between ligand bundles, which compresses the Ag core and relaxes surface metal-ligand interactions. Furthermore, water was used as a cosolvent to demonstrate that semi-aqueous conditions play an important role in protecting exposed surface regions and can further influence the local structure of the silver nanocluster itself. Notably, under semi-aqueous conditions, aprotic coordinating solvent molecules preferentially remain on the metal surface while water molecules interact with ligands, and ligand bundling persisted across the varied solvation conditions.

Download Full-text

Multishell EXAFS Fitting Analysis of a Compositionally Precise Thiolate-Gold Nanocluster

MRS Proceedings ◽

10.1557/opl.2014.409 ◽

2014 ◽

Vol 1655 ◽

Author(s):

Daniel M. Chevrier ◽

Amares Chatt ◽

Peng Zhang ◽

Chenjie Zeng ◽

Rongchao Jin

Keyword(s):

Structural Information ◽

Gold Nanoclusters ◽

Gold Nanocluster ◽

Experimental Conditions ◽

X Ray ◽

Metal Metal ◽

Ligand Interactions ◽

Novel Applications ◽

X Ray Absorption ◽

Metal Ligand

ABSTRACTThiolate-gold nanoclusters exhibit unique optical, magnetic and chiral properties, which are attractive for novel applications in nanotechnology. A fundamental challenge facing these nanomaterials is being able to study and understand their physical properties in various experimental conditions. To overcome this, extended X-ray absorption fine structure (EXAFS) spectroscopy can be employed to probe the Au local structure of thiolate-gold nanoclusters in a variety of conditions, providing valuable structural information from multiple bonding environments (i.e. metal-metal and metal-ligand interactions). This study discusses a methodology for conducting a multishell EXAFS fitting analysis that can be implemented for thiolate-gold nanocluster systems. Specifically, experimental and simulated EXAFS data for Au36(SR)24 nanoclusters are examined with a total of 5 scattering paths fitted to the experimental data.

Download Full-text

Achtfachkoordination von Cadmium(II) und sekundäre Metall—Ligand-Bindungen in [Cd(NO3)2(C12H22N6)] und [Cd(C12H22N6)2(BF4)2 / Eight-Coordination of Cadmium(II) and Secondary Metal —Ligand Bonds in [Cd(NO3) 2(C12H22N6)] and [Cd(C12H22N6) 2(BF4)2

Zeitschrift für Naturforschung B ◽

10.1515/znb-1988-1210 ◽

1988 ◽

Vol 43 (12) ◽

pp. 1579-1588 ◽

Cited By ~ 8

Author(s):

Henry Strasdeit ◽

Siegfried Pohl

Keyword(s):

Dimethyl Sulfoxide ◽

Monoclinic Space Group ◽

Tetradentate Ligand ◽

Neutral Complex ◽

Space Group ◽

X Ray ◽

Nmr Data ◽

Symmetrical Configuration ◽

Solvent Molecules ◽

Metal Ligand

Abstract [Cd(NO3)2(C12H22N6)] (1), [Cd(C12H22N6)2](BF4)2 (2), and [Cd(C12H22N6)2](ClO4)2 (3) are obtained from methanolic solutions by reaction of 2,5,8,10,13,16-Hexaazapentacyclo[ 8.6.1.125.0918.0l3,7]octadecane (C12H22N6) with Cd(NO3)2-4H2O, Cd(BF4)2, and Cd(ClO4)2 · 6H2O, respectively. 1 crystallizes in the monoclinic space group C2/c with a = 10.346(1), b =18.162(1), c - 10.462(1) Å, β = 112.95(1)°, and Z = 4. 2 is monoclinic, space group P21/n, a = 16.958(1), b = 10.653(1), c = 18.747(1) Å, β= 112,66(1)°, and Z = 4. The X-ray structures of 1 and 2 were refined to R(Rw) = 0.028 (0.029) and 0.060 (0.057), respectively. The compounds contain discrete [Cd(NO3)2(C12H22N6)] and [Cd(C12H22N6)2]2+ complexes, respectively. The Cd atoms are eight-coordinated with four primary and four longer, secondary metal -ligand bonds. In both complexes the hexaamine has an axially symmetrical configuration and acts as a tetradentate ligand. The N03 ligands are aniso-bidentate. Mean bond lengths are (Cd -N)prim 2.308(3), (Cd-N)sec 2.676(3), (Cd-0)prim 2.331(2), (Cd-0)sec 2.593(3) Å for 1, and (Cd-N)prim 2.374 (ligand 1), 2.438 (ligand 2), (Cd-N)sec 2.746 (ligand 1), 2.702 Å (ligand 2) for2. In water the neutral complex 1 dissociates and behaves as an 1:2 electrolyte. 13C and 113Cd NMR data and the conductivity of solutions of 2 or 3 in dimethyl sulfoxide indicate a fast but incomplete exchange of the ligands in [Cd(C12H22N6)2]2+ by solvent molecules

Download Full-text

Crystal and molecular structures of 3-acetyl-5-[2-(3-ethyl-2-benzothiazolidene)]ethylidenerhodanine and its lithium and sodium salts. Layered organic–inorganic structures

Acta Crystallographica Section B Structural Science ◽

10.1107/s0108768195008263 ◽

1996 ◽

Vol 52 (2) ◽

pp. 277-286 ◽

Cited By ~ 7

Author(s):

F. Nüesch ◽

M. Grätzel ◽

R. Nesper ◽

V. Shklover

Keyword(s):

Molecular Structures ◽

Water Molecules ◽

Crystal Data ◽

X Ray Diffraction ◽

Space Group ◽

X Ray ◽

Oriented Molecules ◽

Internal Surfaces ◽

Solvent Molecules ◽

Inorganic Layers

An X-ray diffraction study of the crystals of 5-[2-(3-ethyl-2-benzothiazolidene)]ethylidenerhodanine N-acetic acid (1, solvate with dimethylsulfoxide), lithium 5-[2-(3-ethyl-2-benzothiazolidene)]ethylidenerhodanine N-acetate (2, solvate with water and dimethylformamide) and sodium 5-[2-(3-ethyl-2-benzothiazolidene]ethylidenerhodanine N-acetate (3, octahydrate) have been carried out at 295 K. Crystal data for (1): C16H14N2O3S3.C2H6OS, Mr = 456.6, triclinic, a = 7.664 (6), b = 9.874 (8), c = 14.851 (8) Å, α = 101.71 (5), β = 90.45 (5), γ = 102.27 (5)°, V = 1074 (1) Å3, space group P{\bar 1}, Z = 2, F(000) = 476, Dx = 1.412 g cm−3, μ(MoKα) = 0.469 mm−1, R = 0.0698 for 1688 reflections with F > 6σ(F); for (2): Li+.C16H13N2O3S− 3.2H2O.1.5C3H7NO, Mr = 530.1, triclinic, a = 7.249 (5), b = 10.773 (6), c = 16.433 (13) Å, α = 87.66 (6), β = 85.22 (6), γ = 77.04 (6)°, V = 1246 (1) Å3, space group P1, Z = 2, F(000) = 556, Dx = 1.413 g cm−3, μ(Mo Kα) = 0.342 mm−1, R = 0.0551 for 2360 reflections with F > 6σ(F); for (3): Na+.C16H13N2O3S− 3.8H2O, Mr = 544.6, monoclinic, a = 46.209 (12), b = 7.005 (3), c = 16.583 (8) Å, β = 109.45 (4)°, V = 5061 (6) Å3, space group C2/c, Z = 8, F(000) = 2288, Dx = 1.429 Mg m−3, μ(Mo Kα) = 0.365 mm−1, R = 0.0440 for 2680 reflections with F > 6σ(F). Crystals (1) and (2) are built up of stacks of head-to-tail oriented molecules and anions, respectively, which have alternating interplanar separations of 3.41 (1) and 3.46 (1) Å for (1), and 3.38 (1) and 3.45 (1) Å, for (2) (so-called H aggregation of dye). The Li+ cations and solvent molecules form the cationic layers in crystal (2), alternating with the anionic layers along the c direction. The shifted head-to-head oriented anions in crystal (3) form uniform stacks along the b axis at the interplanar separation of 3.39 (1) Å (so called J aggregation of dye). The stacks are arranged in bilayers with the O atoms on the outer surfaces of the bilayers. The inorganic layers situated between the anionic organic bilayers consist of extended chains of distorted edge-shared polyhedra of Na+ cations and water molecules. The O atoms on the outer surfaces of the bilayers do not participate in the direct ionic interactions with the Na+ cations. The structure and stability of layered organic inorganic structures with internal surfaces are discussed by means of the crystal structures of (1)–(3) and literature data.

Download Full-text

Manganese Kβ X-ray Emission Spectroscopy As a Probe of Metal–Ligand Interactions

Inorganic Chemistry ◽

10.1021/ic200970t ◽

2011 ◽

Vol 50 (17) ◽

pp. 8397-8409 ◽

Cited By ~ 93

Author(s):

Martha A. Beckwith ◽

Michael Roemelt ◽

Marie-Noëlle Collomb ◽

Carole DuBoc ◽

Tsu-Chien Weng ◽

...

Keyword(s):

Emission Spectroscopy ◽

X Ray ◽

Ligand Interactions ◽

Metal Ligand

Download Full-text

Comparative Study of Complexes of Rare Earths and Actinides with 2,6-Bis(1,2,4-triazin-3-yl)pyridine

Inorganics ◽

10.3390/inorganics7030026 ◽

2019 ◽

Vol 7 (3) ◽

pp. 26 ◽

Cited By ~ 4

Author(s):

Attila Kovács ◽

Christos Apostolidis ◽

Olaf Walter

Keyword(s):

Blue Shift ◽

X Ray Diffraction ◽

Covalent Character ◽

Ionic Radii ◽

X Ray ◽

Group Iii ◽

Exchange Correlation ◽

Ligand Interactions ◽

Ft Ir ◽

Metal Ligand

Complexes of group III metals (rare earth and actinides) with 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine (BTP) have been investigated by computational (DFT) and, in limited cases, by experimental (FT-IR, X-ray) techniques with the goal of determining the characteristics of metal–ligand interactions. The DFT calculations using the M062X exchange-correlation functional revealed that metal–ligand distances correlate with the ionic radii of the metals, in agreement with available X-ray diffraction results on the Sc, Y, La, U, and Pu complexes. A related blue-shift trend could be observed in seven characteristic bands in the IR spectra associated with metal–ligand vibrations. The computations uncovered considerable charge transfer interactions, particularly in the actinide complexes, as important covalent contributions to the metal–ligand bonding. The covalent character of the metal–ligand bonds decreases in the actinides, from U to Cm.

Download Full-text

The Intercalation of CORM-2 with Pharmaceutical Clay Montmorillonite (MMT) Aids for Therapeutic Carbon Monoxide Release

International Journal of Molecular Sciences ◽

10.3390/ijms20143453 ◽

2019 ◽

Vol 20 (14) ◽

pp. 3453 ◽

Cited By ~ 2

Author(s):

Muhammad Faizan ◽

Kifayat Ullah Khan Niazi ◽

Niaz Muhammad ◽

Yongxia Hu ◽

Yanyan Wang ◽

...

Keyword(s):

Carbon Monoxide ◽

Layer Structure ◽

Xrd Analysis ◽

Water Molecules ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Ruthenium Carbonyl ◽

Solvent Molecules ◽

First Time

The pharmaceutical clay montmorillonite (MMT) is, for the first time, explored as a carbon monoxide-releasing material (CORMat). MMT consists of silicate double layered structure; its exfoliation feature intercalate the CORM-2 [RuCl(μ-Cl)(CO)3]2 inside the layers to suppress the toxicity of organometallic segment. The infrared spectroscopy (IR) confirmed the existence of ruthenium coordinated carbonyl ligand in MMT layers. The energy-dispersive X-ray spectroscopy (EDX) analysis showed that ruthenium element in this material was about 5%. The scanning electron microscopy (SEM) and transmission electron microscope (TEM) images showed that the layer-structure of MMT has been maintained after loading the ruthenium carbonyl segment. Moreover, the layers have been stretched out, which was confirmed by X-ray diffraction (XRD) analysis. Thermogravimetric (TG) curves with huge weight loss around 100–200 °C were attributed to the CO hot-release of ruthenium carbonyl as well as the loss of the adsorbed solvent molecules and the water molecules between the layers. The CO-liberating properties have been assessed through myoglobin assay. The horse myoglobin test showed that the material could be hydrolyzed to slowly release carbon monoxide in physiological environments. The half-life of CO release was much longer than that of CORM-3, and it has an excellent environmental tolerance and slow release effect.

Download Full-text

Multiwavelets Applied to Metal-Ligand Interactions: Energies Free from Basis Set Errors

10.26434/chemrxiv.13669951.v1 ◽

2021 ◽

Author(s):

Anders Brakestad ◽

Peter Wind ◽

Stig Rune Jensen ◽

Luca Frediani ◽

Kathrin Hopmann

Keyword(s):

Transition Metal ◽

Basis Set ◽

Basis Sets ◽

Electronic Interaction ◽

Promising Alternative ◽

Ligand Interactions ◽

Counterpoise Corrections ◽

Solvent Molecules ◽

Catalyzed Reactions ◽

Metal Ligand

The following article will be submitted to the Journal of Chemical Physics. It is thus not a peer-reviewed manuscript. After it is hopefully accepted for publication, it will be found (in revised form) at https://aip.scitation.org/journal/jcp<div><br></div><div>Transition metal-catalyzed reactions invariably include steps, where ligands associate or dissociate. In order to obtain reliable energies for such reactions, sufficiently large basis sets need to be employed. In this paper, we have used high-precision Multiwavelet calculations to compute the metal-ligand association energies for 27 transition metal complexes with common ligands such as H2, CO, olefins and solvent molecules. By comparing our Multiwavelet results to a variety of frequently used Gaussian-type basis sets, we show that counterpoise corrections, which are widely employed to correct for basis set superposition errors, often lead to underbinding. Additionally, counterpoise corrections are difficult to employ, when the association step also involves a chemical transformation. Multiwavelets, which can be conveniently applied to all types of reactions, provide a promising alternative for computing electronic interaction energies free from any basis set errors. <br></div>

Download Full-text

Multiwavelets Applied to Metal-Ligand Interactions: Energies Free from Basis Set Errors

10.26434/chemrxiv.13669951 ◽

2021 ◽

Author(s):

Anders Brakestad ◽

Peter Wind ◽

Stig Rune Jensen ◽

Luca Frediani ◽

Kathrin Hopmann

Keyword(s):

Transition Metal ◽

Basis Set ◽

Basis Sets ◽

Electronic Interaction ◽

Promising Alternative ◽

Ligand Interactions ◽

Counterpoise Corrections ◽

Solvent Molecules ◽

Catalyzed Reactions ◽

Metal Ligand

The following article will be submitted to the Journal of Chemical Physics. It is thus not a peer-reviewed manuscript. After it is hopefully accepted for publication, it will be found (in revised form) at https://aip.scitation.org/journal/jcp<div><br></div><div>Transition metal-catalyzed reactions invariably include steps, where ligands associate or dissociate. In order to obtain reliable energies for such reactions, sufficiently large basis sets need to be employed. In this paper, we have used high-precision Multiwavelet calculations to compute the metal-ligand association energies for 27 transition metal complexes with common ligands such as H2, CO, olefins and solvent molecules. By comparing our Multiwavelet results to a variety of frequently used Gaussian-type basis sets, we show that counterpoise corrections, which are widely employed to correct for basis set superposition errors, often lead to underbinding. Additionally, counterpoise corrections are difficult to employ, when the association step also involves a chemical transformation. Multiwavelets, which can be conveniently applied to all types of reactions, provide a promising alternative for computing electronic interaction energies free from any basis set errors. <br></div>

Download Full-text

SYNTHESIS AND STRUCTURE OF 4-(9-HYDROXY-1,4,7-TRIOXYNONYL)PHTHALONITRILE

IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA ◽

10.6060/tcct.2017603.5494 ◽

2017 ◽

Vol 60 (3) ◽

pp. 15

Author(s):

Alexandra S. Kuznetsova ◽

Maksim V. Dmitriev ◽

Alexander V. Zav’yalov ◽

Oscar I. Koifman ◽

Mikhail K. Islyaikin

Keyword(s):

Water Molecule ◽

Ethyl Acetate ◽

Theoretical Calculations ◽

Triethylene Glycol ◽

Solvent Evaporation ◽

Water Molecules ◽

X Ray Diffraction ◽

Intermolecular Hydrogen Bonds ◽

Reduced Pressure ◽

X Ray

4-(9-Hydroxy-1,4,7-trioxynonyl)phthalonitrile was prepared by reaction of 4-nitrophthalonitrile with triethylene glycol in dry DMSO in the presence of fresh-calcined fine milled K2CO3 at 60 °C for 12 hours. The reaction mixture was poured into cold distilled water and extracted by CH2Cl2. Then the crude product obtained after solvent evaporation was purified by column chromatography on silica gel using elution mixture of ethyl acetate : hexane (1:3) and after that end product was dried at reduced pressure at 80 oC for 4 h. The product was characterized by IR and 1Н NMR spectroscopies, mass-spectrometry, elemental analysis and X-ray diffraction data. In MALDI-TOF spectrum, two signals located at 299 [M+Na]+ and 315 [M+К]+ Da were detected. Conformity between the calculated isotopic distributions and those derived from experimental data proves these assignments. A colorless monocrystal suitable for X-Ray measurements was grown up by low temperature solvent evaporation from a solution of 4-(9-hydroxy-1,4,7-trioxynonyl)phthalonitrile in ethyl acetate. X-ray studying showed that this compound is a monohydrate of 4-(9-hydroxy-1,4,7-trioxynonil)phthalonitrile with a water molecule located in lateral chain. Four molecules of 4-(9-hydroxy-1,4,7-trioxynonil)phthalonitrile and four water molecules were founded to be located in one unit cell with formatting eight intermolecular hydrogen bonds. Hence triethylene glycol fragment forms a chelate-like cavity which is able to hold a water molecule or a cation of alkali metal. It was found that its structure is very similar to that optimized at DFT/B3LYP/6-31G(d,p) level. The some bond lengths of theoretical calculations are found to be greater than experiment data because of close intermolecular interactions in solid state.Forcitation:Kuznetsova A.S., Dmitriev M.V., Zav’yalov A.V., Koifman O.I., Islyaikin M.K. Synthesis and structure of 4-(9-hydroxy-1,4,7-trioxynonyl)phthalonitrile. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 3. P. 15-21.

Download Full-text