A new proposal for the electronic structure of carbon monoxide

2021 ◽  
Vol 34 (2) ◽  
pp. 193-200
Author(s):  
Stephan J. G. Gift

A new proposal for the electronic structure of carbon monoxide CO is presented. The approach involves the creation of an additional half-filled 2p orbital in the oxygen atom by the transfer of an electron from the filled 2p orbital to one of two half-filled hybridized <mml:math display="inline"> <mml:mrow> <mml:mn>2</mml:mn> <mml:mi>s</mml:mi> <mml:msub> <mml:mi>p</mml:mi> <mml:mi>z</mml:mi> </mml:msub> </mml:mrow> </mml:math> orbitals in the carbon atom. The result is a triple bond comprising one sigma bond and two pi bonds between C and O strengthened by an ionic bond contribution. The proposed structure accounts for many unusual features of the molecule CO including the observed direction of the dipole moment, which is considered anomalous based on the concept of electronegativity of the constituent atoms as well as the increased bond dissociation energy compared with isoelectronic nitrogen <mml:math display="inline"> <mml:mrow> <mml:msub> <mml:mi>N</mml:mi> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> . It also provides a basis for the CO molecule being a stable ligand combining with transition metals using the lone electron pair in the filled <mml:math display="inline"> <mml:mrow> <mml:mn>2</mml:mn> <mml:mi>s</mml:mi> <mml:msub> <mml:mi>p</mml:mi> <mml:mi>z</mml:mi> </mml:msub> </mml:mrow> </mml:math> orbital of the carbon atom. The electron transfer mechanism is effectively applied to the isoelectronic compound boron monofluoride BF and predicts properties of the undetected isoelectronic molecule BeNe. Finally, the method proposes new electronic structures for the cyanide ion <mml:math display="inline"> <mml:mrow> <mml:mi>C</mml:mi> <mml:msup> <mml:mi>N</mml:mi> <mml:mo>−</mml:mo> </mml:msup> </mml:mrow> </mml:math> which resolves the long-standing puzzle of “charge reversal” on the molecule and the carbon monofluoride ion <mml:math display="inline"> <mml:mrow> <mml:mi>C</mml:mi> <mml:msup> <mml:mi>F</mml:mi> <mml:mo>+</mml:mo> </mml:msup> </mml:mrow> </mml:math> .

2008 ◽  
Vol 73 (1) ◽  
pp. 59-72 ◽  
Author(s):  
Stanislava Šoralová ◽  
Martin Breza

Optimal geometries and corresponding electronic structures of various [Pb(OH)3]- and [Pb(OH)4]2- conformational isomers are investigated by the B3LYP and MP2 treatments. Unlike highly symmetric [Pb(OH)3]- structure (C3 symmetry), the most stable [Pb(OH)4]2- conformational isomer has only C2 symmetry. Hydrogen bonds exhibit a lower influence on the stereochemistry of lead(II) hydroxocomplexes in comparison with the steric effect of the Pb(II) lone electron pair. The picture of the Pb(II) lone electron pair cannot explain the lowered symmetry of isolated [Pb(OH)4]2- complexes with four equivalent hydrogen bonds.


Author(s):  
Kaname Kanai ◽  
Takuya Inoue ◽  
Takaya Furuichi ◽  
Kaito Shinoda ◽  
Takashi Iwahashi ◽  
...  

A series of n-cycloparaphenylenes ([n]CPP) were studied by ultraviolet photoemission, inverse photoemission, ultraviolet-visible absorption, and X-ray photoemission spectroscopy to detect their unique electronic structures. [n]CPP has a cyclic structure in...


2019 ◽  
Vol 7 (33) ◽  
pp. 19531-19538 ◽  
Author(s):  
Qi Hu ◽  
Guomin Li ◽  
Xiaowan Huang ◽  
Ziyu Wang ◽  
Hengpan Yang ◽  
...  

The electronic structures of single atomic Ru (SA-Ru) were suitably optimized by nearby Ru NPs for boosting the hydrogen evolution reaction (HER) over SA-Ru.


2021 ◽  
Author(s):  
Stephen Sproules

The electronic structures of homovalent [V2(μ-S2)2(R2dtc)4] (R = Et, iBu) and mixed-valent [V2(μ-S2)2(R2dtc)4]+ are reported here. The soft-donor, eight-coordinate ligand shell combined with the fully delocalised ground state provides a...


1966 ◽  
Vol 19 (9) ◽  
pp. 1567 ◽  
Author(s):  
RD Brown ◽  
EK Nunn

A VESCF molecular-orbital study of the electronic structure of the triiodide anion in its crystalline environment in caesium triiodide and in tetraphenylarsonium triiodide reveals the effect of the lattices upon the electronic structures. The calculated total valence-electron energy as a function of the position of the central iodine nucleus provides an understanding of the observed geometries of the anion in the two crystals. The energy plot also implies that the asymmetric stretch of the triiodide is strongly anharmonic in the crystal. A satisfactory correlation exists between observed iodine : iodine bond lengths and computed bond orders.


Inorganics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 28
Author(s):  
Kriti Pathak ◽  
Chandan Nandi ◽  
Jean-François Halet ◽  
Sundargopal Ghosh

Synthesis, isolation, and structural characterization of unique metal rich diamagnetic cobaltaborane clusters are reported. They were obtained from reactions of monoborane as well as modified borohydride reagents with cobalt sources. For example, the reaction of [Cp*CoCl]2 with [LiBH4·THF] and subsequent photolysis with excess [BH3·THF] (THF = tetrahydrofuran) at room temperature afforded the 11-vertex tricobaltaborane nido-[(Cp*Co)3B8H10] (1, Cp* = η5-C5Me5). The reaction of Li[BH2S3] with the dicobaltaoctaborane(12) [(Cp*Co)2B6H10] yielded the 10-vertex nido-2,4-[(Cp*Co)2B8H12] cluster (2), extending the library of dicobaltadecaborane(14) analogues. Although cluster 1 adopts a classical 11-vertex-nido-geometry with one cobalt center and four boron atoms forming the open pentagonal face, it disobeys the Polyhedral Skeletal Electron Pair Theory (PSEPT). Compound 2 adopts a perfectly symmetrical 10-vertex-nido framework with a plane of symmetry bisecting the basal boron plane resulting in two {CoB3} units bridged at the base by two boron atoms and possesses the expected electron count. Both compounds were characterized in solution by multinuclear NMR and IR spectroscopies and by mass spectrometry. Single-crystal X-ray diffraction analyses confirmed the structures of the compounds. Additionally, density functional theory (DFT) calculations were performed in order to study and interpret the nature of bonding and electronic structures of these complexes.


Author(s):  
Yanrong Jiang ◽  
Qinqin Yuan ◽  
Wenjin Cao ◽  
Markus Rohdenburg ◽  
Marc C. Nierstenhöfer ◽  
...  

A fundamental understanding of cyclodextrin-closo-dodecaborate inclusion complexes has become of great interest in supramolecular chemistry. Herein, we report a systematic investigation on the electronic structure and intramolecular interactions of perhalogenated...


2021 ◽  
Author(s):  
Xiu-Yuan Li ◽  
Wang Ying-Bo ◽  
Song Yan ◽  
Xiang Dan ◽  
Chaozheng He

Abstract A new porous metal-organic framework, [Pb5(Ac)7(nIm)3]n (1), has been successfully synthesized by employing 2-nitroimidazole ligand and Pb2+ ion. 1 contains novel the ribbon-shaped Pb-O SBU and reveals a 2D porous framework with a 1D tubular channel. Moreover, 1 shows moderate adsorption uptake towards CO2 and luminescence properties from intraligand charge transfer. We further confirmed nitro group and metal ion are important adsorption sites by GCMC simulations, and the electronic structures of 1 was investigated.


2021 ◽  
Vol 25 ◽  
Author(s):  
Evgenia S. Veligina ◽  
Nataliya V. Obernikhina ◽  
Stepan G. Pilyo ◽  
Oleksiy D. Kachkovsky ◽  
Volodymyr S. Brovarets

: Background: Synthesis of a series of 2-(dichloromethyl)pyrazolo[1,5- a][1,3,5]triazines was carried out and evaluated in vitro for their anticancer activity against a panel of 60 cell lines derived from nine cancer types. The joint quantum-chemical and experimental study of the influence of the extended πconjugated phenyl substituents on the electron structure of the pyrazolo[1,5-a][1,3,5]triazines as Pharmacophores were performed. It is shown that the decrease in the barriers to the rotation of phenyl substituents in compounds 1-7 possibly leads to an increase in the anti-cancer activity, which is in agreement with the change in the parameter biological affinity ϕ0. Analysis of the S0 → S1 electronic transitions (π→π*) of the pyrazolo[1,5-a][1,3,5]triazines shows that an increase in their intensity correlates with anti-cancer activity. Thus, the introduction of phenyl substituents increases the likelihood of investigated pyrazolo[1,5-a][1,3,5]triazines interacting with protein molecules (Biomolecule) by the π stacking mechanism. In both methyl and phenyl derivatives of pyrazolo[1,5-a][1,3,5]triazines, the second electronic transition includes the n-MO (the level of the lone electron pair in two-coordinated nitrogen atoms). The highest intensity of the η→π* electronic transition is observed in pyrazolo[1,5-a][1,3,5]triazine with pyridine residue, which does not exhibit anti-cancer activity, but exhibits antiviral activity [13]. It can be assumed that the possibility of the formation of [Pharmacophore-Biomolecule] complex by hydrogen bonding ([H-B]) mechanism with protein molecules increases.


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