Electronic structure and bonding analysis of transition metal sandwich and half-sandwich complexes of the triphenylene ligand

Full geometry optimization using the BP86 and B3LYP methods has been carried out for all of the low-energy isomers of half-sandwich L3M(Tphn) (Tphn = triphenylene, M = Ti–Ni, and L3 = (CO)3, Cp–) and sandwich M(Tphn)2 (Tphn = triphenylene and M = Ti, Cr, Fe, Ni) structures. Depending on the electron richness of the molecule and the nature of the metal, a complete rationalization of the bonding in triphenylene complexes has been provided. The triphenylene adopts various hapticities from η2 to η6, some of them involving full or partial coordination of the C6 ring and shown to be quite flexible with respect to the ground spin state. The triphenylene behavior remains dependent on the electron-withdrawing and electron-donor properties of the (CO)3M and CpM fragments, respectively. For the sandwich complexes, both triphenylene ligands prefer to behave differently depending on the coordination mode to satisfy the metal electron demand.

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Hydrogen Insertion Effects on the Electronic Structure of Equiatomic MgNi Traced by ab initio Calculations

Zeitschrift für Naturforschung B ◽

10.5560/znb.2013-2282 ◽

2013 ◽

Vol 68 (1) ◽

pp. 44-50 ◽

Cited By ~ 2

Author(s):

Samir F. Matar ◽

Adel F. Al Alam ◽

Naim Ouaini

Keyword(s):

Hydrogen Absorption ◽

Geometry Optimization ◽

Low Energy ◽

Experimental Limit ◽

Covalent Character ◽

Full Geometry Optimization ◽

Density Analysis ◽

Cohesive Energies ◽

Model Structures ◽

Hydrogen Insertion

For equiatomic MgNi which can be hydrogenated up to the composition MgNiH1.6 at an absorption/ desorption temperature of 200 °C, the effects of hydrogen absorption are approached with the model structures MgNiH, MgNiH2 and MgNiH3. From full geometry optimization and calculated cohesive energies obtained within DFT, the MgNiH2 composition close to the experimental limit is identified as most stable. Charge density analysis shows an increasingly covalent character of hydrogen: MgNiH (H-0.67) → MgNiH2 (H-0.63) ! MgNiH3 (H-0.55). While Mg-Ni bonding prevails in MgNi and hydrogenated model phases, extra itinerant low-energy Ni states appear when hydrogen is introduced signaling Ni-H bonding which prevails over Mg-H as evidenced from total energy calculations and chemical bonding analyses.

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Ruthenium Azocarboxamide Half-Sandwich Complexes: Influence of the Coordination Mode on the Electronic Structure and Activity in Base-Free Transfer Hydrogenation Catalysis

Organometallics ◽

10.1021/acs.organomet.6b00424 ◽

2016 ◽

Vol 35 (17) ◽

pp. 2840-2849 ◽

Cited By ~ 15

Author(s):

Michael G. Sommer ◽

Sofiya Marinova ◽

Michael J. Krafft ◽

Damijana Urankar ◽

David Schweinfurth ◽

...

Keyword(s):

Electronic Structure ◽

Coordination Mode ◽

Transfer Hydrogenation ◽

Sandwich Complexes ◽

Hydrogenation Catalysis ◽

Structure And Activity ◽

Half Sandwich

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ß-Cyclodextrin Inclusion Complexes with Catechol-Containing Antioxidants Protocatechuic Aldehyde and Protocatechuic Acid—An Atomistic Perspective on Structural and Thermodynamic Stabilities

Molecules ◽

10.3390/molecules26123574 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3574

Author(s):

Thammarat Aree

Keyword(s):

Inclusion Complexes ◽

Protocatechuic Acid ◽

Inclusion Complexation ◽

Geometry Optimization ◽

Therapeutic Effects ◽

Full Geometry Optimization ◽

Oh Groups ◽

X Ray ◽

Protocatechuic Aldehyde ◽

Crystal Contacts

Protocatechuic aldehyde (PCAL) and protocatechuic acid (PCAC) are catechol derivatives and have broad therapeutic effects associated with their antiradical activity. Their pharmacological and physicochemical properties have been improved via the cyclodextrin (CD) encapsulation. Because the characteristics of b-CD inclusion complexes with PCAL (1) and PCAC (2) are still equivocal, we get to the bottom of the inclusion complexation by an integrated study of single-crystal X-ray diffraction and DFT full-geometry optimization. X-ray analysis unveiled that PCAL and PCAC are nearly totally shielded in the b-CD wall. Their aromatic rings are vertically aligned in the b-CD cavity such that the functional groups on the opposite side of the ring (3,4-di(OH) and 1-CHO/1-COOH groups) are placed nearby the O6–H and O2–H/O3–H rims, respectively. The preferred inclusion modes in 1 and 2 help to establish crystal contacts of OH×××O H-bonds with the adjacent b-CD OH groups and water molecules. By contrast, the DFT-optimized structures of both complexes in the gas phase are thermodynamically stable via the four newly formed host–guest OH⋯O H-bonds. The intermolecular OH×××O H-bonds between PCAL/PCAC 3,4-di(OH) and b-CD O6–H groups, and the shielding of OH groups in the b-CD wall help to stabilize these antioxidants in the b-CD cavity, as observed in our earlier studies. Moreover, PCAL and PCAC in distinct lattice environments are compared for insights into their structural flexibility.

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Half-sandwich complexes of Group 9 metals with N,Nʹ-ligands for CF3-carbenoid alkylation of N-(pyrimidin-2-yl)indole

Journal of Organometallic Chemistry ◽

10.1016/j.jorganchem.2021.121899 ◽

2021 ◽

pp. 121899

Author(s):

Sofya S. Kuvshinova ◽

Yulia V. Nelyubina ◽

Vladimir A. Larionov ◽

Daria V. Vorobyeva ◽

Sergey N. Osipov ◽

...

Keyword(s):

Sandwich Complexes ◽

Half Sandwich

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Uranium(iv) cyclobutadienyl sandwich compounds: synthesis, structure and chemical bonding

Chemical Communications ◽

10.1039/c9cc09018e ◽

2020 ◽

Vol 56 (6) ◽

pp. 944-947 ◽

Cited By ~ 7

Author(s):

Nikolaos Tsoureas ◽

Akseli Mansikkamäki ◽

Richard A. Layfield

Keyword(s):

Chemical Bonding ◽

Molecular Structures ◽

Sandwich Complexes ◽

Sandwich Complex ◽

Sandwich Compounds ◽

Bonding Properties ◽

Half Sandwich

The synthesis, molecular structures and bonding properties of two uranium(iv) cyclobutadienyl half-sandwich complexes and a doubly activated cyclobutadienyl sandwich complex are described.

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Theoretical Investigation of the Size Effect on the Oxygen Adsorption Energy of Coinage Metal Nanoparticles

Catalysis Letters ◽

10.1007/s10562-021-03567-y ◽

2021 ◽

Author(s):

Amir H. Hakimioun ◽

Elisabeth M. Dietze ◽

Bart D. Vandegehuchte ◽

Daniel Curulla-Ferre ◽

Lennart Joos ◽

...

Keyword(s):

Particle Size ◽

Size Effect ◽

Adsorption Energy ◽

Single Point ◽

Finite Size ◽

Geometry Optimization ◽

Oxygen Adsorption ◽

Finite Size Effect ◽

Full Geometry Optimization ◽

Coinage Metal

AbstractThis study evaluates the finite size effect on the oxygen adsorption energy of coinage metal (Cu, Ag and Au) cuboctahedral nanoparticles in the size range of 13 to 1415 atoms (0.7–3.5 nm in diameter). Trends in particle size effects are well described with single point calculations, in which the metal atoms are frozen in their bulk position and the oxygen atom is added in a location determined from periodic surface calculations. This is shown explicitly for Cu nanoparticles, for which full geometry optimization only leads to a constant offset between relaxed and unrelaxed adsorption energies that is independent of particle size. With increasing cluster size, the adsorption energy converges systematically to the limit of the (211) extended surface. The 55-atomic cluster is an outlier for all of the coinage metals and all three materials show similar behavior with respect to particle size. Graphic Abstract

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The synthesis and unexpected solution chemistry of thermochromic carborane-containing osmium half-sandwich complexes

Dalton Transactions ◽

10.1039/c5dt04398k ◽

2016 ◽

Vol 45 (4) ◽

pp. 1763-1768 ◽

Cited By ~ 6

Author(s):

Anaïs Pitto-Barry ◽

Amy South ◽

Alison Rodger ◽

Nicolas P. E. Barry

Keyword(s):

Solution Chemistry ◽

Sandwich Complexes ◽

Lewis Bases ◽

Half Sandwich

The functionalisation of the 16-electron complex [Os(η6-p-cymene)(1,2-dicarba-closo-dodecarborane-1,2-dithiolato)] (1) with a series of Lewis bases to give the corresponding 18-electron complexes is reported.

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