scholarly journals Heterobimetallic Chromium Manganese Carbonyl Nitrosyls: Comparison with Isoelectronic Homometallic Binuclear Chromium Carbonyl Nitrosyls and Manganese Carbonyls

Inorganics ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 127
Author(s):  
Guoliang Li ◽  
Limei Wen ◽  
R. Bruce King
Keyword(s):  
Density Functional Theory ◽  
Electron Donor ◽  
Density Functional ◽  
Manganese Atom ◽  
Chromium Atom ◽  
Electron Configuration ◽  
Single Bond ◽  
Functional Theory ◽  
Chromium Carbonyl ◽  
Manganese Carbonyl

The heterometallic chromium-manganese carbonyl nitrosyls CrMn(NO)(CO)n (n = 9, 8) have been investigated by density functional theory. The lowest energy CrMn(NO)(CO)9 structures have unbridged staggered conformations with a ~2.99 Å Cr–Mn single bond similar to the experimental and lowest energy structures of the isoelectronic Mn2(CO)10 and Cr2(NO)2(CO)8. A significantly higher energy CrMn(NO)(CO)9 isomer has a nearly symmetrical bridging nitrosyl group and a very weakly semibridging carbonyl group. The two lowest energy structures of the unsaturated CrMn(NO)(CO)8 have a five-electron donor bridging η2-µ-NO nitrosyl group or a four-electron donor bridging η2-µ-CO group, as well as a Cr–Mn single bond of length ~2.94 Å. The next higher energy CrMn(NO)(CO)8 structure has exclusively terminal CO and NO ligands and a shorter Cr–Mn single bond of ~2.85 Å, suggesting an 18-electron configuration for the manganese atom and a 16-electron configuration for the chromium atom indicated by a vacant coordination site nearly perpendicular to the Cr–Mn bond.

Density Functional Theory Study of the Role of an Carbon–Oxygen Single Bond Group in the NO–Char Reaction

2018 ◽  
Vol 32 (7) ◽  
pp. 7734-7744 ◽  
Author(s):  
Tong Zhao ◽  
Wenli Song ◽  
Chuigang Fan ◽  
Songgeng Li ◽  
Peter Glarborg ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Single Bond ◽  
Density Functional Theory Study ◽  
Functional Theory

scholarly journals Unveiling the Different Reactivity of Bent and Linear Three-Atom-Components Participating in [3 + 2] Cycloaddition Reactions

Organics ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 274-286
Author(s):  
Mar Ríos-Gutiérrez ◽  
Luis R. Domingo ◽  
Fatemeh Ghodsi
Keyword(s):  
Density Functional Theory ◽  
Transition State ◽  
Electron Density ◽  
Density Functional ◽  
Geometrical Parameters ◽  
Single Bond ◽  
Conceptual Density Functional Theory ◽  
Functional Theory ◽  
Molecular Electron ◽  
Molecular Electron Density Theory

The reactivity of a series of pairs of bent and linear three-atom-component (B-TACs and L-TACs) participating in [3 + 2] cycloaddition (32CA) reactions towards ethylene and electrophilic dicyanoethylene (DCE) have been studied within the Molecular Electron Density Theory. While the pseudodiradical structure of B-TACs changes to that of pseudoradical or carbenoid L-TACs upon dehydrogenation, zwitterionic B-TACs remain unchanged. Conceptual Density Functional Theory (CDFT) indices characterize five of the nine TACs as strong nucleophiles participating in polar reactions towards electrophilic ethylenes. The activation energies of the 32CA reactions with electrophilic DCE range from 0.5 to 22.0 kcal·mol−1, being between 4.3 and 9.1 kcal·mol−1 lower than those with ethylene. In general, B-TACs are more reactive than their L-TAC counterparts. A change in the regioselectivity is found in these polar 32CA reactions; in general, while B-TACs are meta regioselective, L-TACs are ortho regioselective. The geometrical parameters of the transition state structures suggest that the formation of the single bond involving the most electrophilic carbon of DCE is more advanced. A change in the asynchronicity in the reactions involving B-TACs and L-TACs is also found.

scholarly journals Antioxidant Potential of Novel Designed Phenolic Derivatives: Computational Insights

2020 ◽  
Vol 14 (4) ◽  
pp. 448-454
Author(s):  
Dinesh R. Pandithavidana ◽  
◽  
Kushani S. K. Hewage ◽  
Keyword(s):  
Density Functional Theory ◽  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Electron Donor ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Antioxidant Action ◽  
Functional Theory ◽  
Primary Antioxidant ◽  
Phenolic Derivatives

Density functional theory calculations were applied for designed phenolic antioxidant derivatives. The reaction enthalpies related to various mechanisms of primary antioxidant action were deliberated in detail. How antioxidant activity of designed phenolic compounds has been perturbed by electron donor and withdrawing substituents present at ortho, meta and para positions, allylic conjugation and the dimerization effect were computed.

Structures of dimetallocenes M2(C5H5)2 (M = Zn, Cu, Ni, Co, Fe) and their perfluorinated derivatives

2017 ◽  
Vol 41 (13) ◽  
pp. 5924-5933 ◽  
Author(s):  
Jing Li ◽  
Guoliang Li ◽  
Yaoming Xie ◽  
R. Bruce King ◽  
Henry F. Schaefer
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Low Energy ◽  
Single Bond ◽  
Functional Theory

Density functional theory shows that the dizincocenes Zn2(C5X5)2 (X = H, F) have singlet coaxial structures with two (η5-C5X5)Zn units linked by a Zn–Zn single bond. However, the low-energy M2(C5H5)2 (M = Cu–Fe) structures have perpendicular configurations with bridging C5H5 ligands.

The diversity of iron−sulfur bonding in binuclear iron carbonyl sulfides

2014 ◽  
Vol 92 (8) ◽  
pp. 750-757
Author(s):  
Liqing Zhou ◽  
Guoliang Li ◽  
Qian-Shu Li ◽  
Yaoming Xie ◽  
R. Bruce King
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Iron Carbonyl ◽  
Low Energy ◽  
Single Bond ◽  
Functional Theory ◽  
Iron Sulfur ◽  
Co Dissociation ◽  
Similar Density ◽  
Binuclear Iron

The potential accessibility of Fe2S(CO)n derivatives with 1:2 sulfur to iron ratios by the decarboxylation of iron carbonyl thionyls has led to their investigation using density functional theory. The lowest energy Fe2S(CO)n (n = 8, 7, 6) structures are predicted to be singlet structures with all terminal CO groups, a bridging sulfur atom, and a formal Fe–Fe single bond of length ∼2.5 Å. The Fe−S distances in these structures shorten from ∼2.3 to ∼2.1 Å as CO groups are lost, suggesting an increase in the formal Fe−S bond orders. The thermochemistry of CO dissociation suggests that both Fe2S(CO)8 and Fe2S(CO)7 are viable synthetic objectives. A similar density functional theory study of Fe2S2(CO)n derivatives (n = 7, 6, 5) finds the experimentally known Fe2S2(CO)7 structure with a bridging S2CO group and the Fe2S2(CO)6 structure with a bridging disulfide ligand to be the lowest energy structures by substantial margins of ∼17 and ∼21 kcal/mol, respectively. The low-energy structures for the unsaturated Fe2S2(CO)5 are derived from the low-energy Fe2S2(CO)6 structures by loss of a CO group in various ways with relatively little change in the underlying Fe2S2 framework.

scholarly journals Electron Donor and Acceptor Influence on the Nonlinear Optical Response of Diacetylene-Functionalized Organic Materials (DFOMs): Density Functional Theory Calculations

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2096 ◽  
Author(s):  
Muhammad Khalid ◽  
Riaz Hussain ◽  
Ajaz Hussain ◽  
Bakhat Ali ◽  
Farrukh Jaleel ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Electron Donor ◽  
Density Functional ◽  
Nbo Analysis ◽  
Basis Set ◽  
First Hyperpolarizability ◽  
Functional Theory ◽  
Parent Molecule ◽  
Donor And Acceptor

Herein, we report the quantum chemical results based on density functional theory for the polarizability (α) and first hyperpolarizability (β) values of diacetylene-functionalized organic molecules (DFOM) containing an electron acceptor (A) unit in the form of nitro group and electron donor (D) unit in the form of amino group. Six DFOM 1–6 have been designed by structural tailoring of the synthesized chromophore 4,4′-(buta-1,3-diyne-1,4-diyl) dianiline (R) and the influence of the D and A moieties on α and β was explored. Ground state geometries, HOMO-LUMO energies, and natural bond orbital (NBO) analysis of all DFOM (R and 1–6) were explored through B3LYP level of DFT and 6-31G(d,p) basis set. The polarizability (α), first hyperpolarizability (β) values were computed using B3LYP (gas phase), CAM-B3LYP (gas phase), CAM-B3LYP (solvent DMSO) methods and 6-31G(d,p) basis set combination. UV-Visible analysis was performed at CAM-B3LYP/6-31G(d,p) level of theory. Results illustrated that much reduced energy gap in the range of 2.212–2.809 eV was observed in designed DFOM 1–6 as compared to parent molecule R (4.405 eV). Designed DFOM (except for 2 and 4) were found red shifted compared to parent molecule R. An absorption at longer wavelength was observed for 6 with 371.46 nm. NBO analysis confirmed the involvement of extended conjugation and as well as charge transfer character towards the promising NLO response and red shift of molecules under study. Overall, compound 6 displayed large <α> and βtot, computed to be 333.40 (a.u.) (B3LYP gas), 302.38 (a.u.) (CAM-B3LYP gas), 380.46 (a.u.) (CAM-B3LYP solvent) and 24708.79 (a.u.), 11841.93 (a.u.), 25053.32 (a.u.) measured from B3LYP (gas), CAM-B3LYP (gas) and CAM-B3LYP (DMSO) methods respectively. This investigation provides a theoretical framework for conversion of centrosymmetric molecules into non-centrosymmetric architectures to discover NLO candidates for modern hi-tech applications.

Unsaturation in binuclear heterometallic carbonyls: the cyclopentadienyliron manganese carbonyl CpFeMn(CO)n system as a hybrid of the Cp2Fe2(CO)n and Mn2(CO)n systems

2016 ◽  
Vol 40 (9) ◽  
pp. 7482-7492 ◽  
Author(s):  
Xiuli Feng ◽  
Nan Li ◽  
Liqiang Lv ◽  
R. Bruce King
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Manganese Carbonyl

The structures and energetics of the CpFeMn(CO)n (n = 7, 6, 5) have been examined by density functional theory.

Interaction of Phosphorus with Impurity Atoms in BCC Iron

2018 ◽  
Vol 284 ◽  
pp. 627-633
Author(s):  
A.V. Verkhovykh ◽  
A.A. Mirzoev ◽  
D.A. Mirzaev
Keyword(s):  
Density Functional Theory ◽  
Magnetic Moment ◽  
Phosphorus Atom ◽  
Density Functional ◽  
Abrupt Change ◽  
Manganese Atom ◽  
Functional Theory ◽  
Impurity Atoms ◽  
Solution Energy ◽  
Bcc Iron

The paper presents the results of modelling of phosphorus interaction with substitutional (Cr, Mn, P) and interstitial (C) impurity atoms in bcc iron in the framework of density functional theory using WIEN2k software. It is found that a repulsion exists of a phosphorus atom in the three first spheres of coordination of carbon, chromium and phosphorus atoms, while for manganese such repulsion of phosphorus takes place only in the second sphere. This repulsion is a consequence of an abrupt change of magnetic moment of manganese atom, so the solution energy of phosphorus almost does not change. On the contrary, chromium decreases phosphorus solubility in iron, in agreement with other data.

Major Differences Between Mononuclear and Binuclear Manganese Carbonyl Cyanides and Isoelectronic Binary Chromium Carbonyls Arising from Basicity of the Cyanide Nitrogen Atom

2014 ◽  
Vol 67 (9) ◽  
pp. 1318 ◽  
Author(s):  
Ruixue Jia ◽  
Chaoyang Wang ◽  
Luo Qiong ◽  
Qian-Shu Li ◽  
Yaoming Xie ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Nitrogen Atom ◽  
Density Functional ◽  
Low Energy ◽  
Energy Structure ◽  
Functional Theory ◽  
End To End ◽  
Manganese Carbonyl

The manganese carbonyl cyanides Mn(CO)n(CN) and Mn2(CO)n(CN)2 have been investigated by density functional theory. The lowest energy structure for Mn(CO)5(CN) is found to be the experimentally known C-bonded cyanide. The experimentally unknown N-bonded Mn(CO)5(NC) lies ~60 kJ mol–1 above its cyanide isomer. The Mn(CO)4(CN) isomers are obtained by removal of a CO group in various ways from Mn(CO)5(CN) or Mn(CO)5(NC). Three structures, cyanide Mn(CO)3(CN), isocyanide Mn(CO)3(NC), and Mn(CO)3(η2-CN), are found for the tricarbonyl. All low-energy binuclear Mn2(CO)n(CN)2 structures have two end-to-end bridging CN groups. These two η2-CN bridges can be oriented in the same or opposite directions. The Mn2(CO)7(CN)2 structures of this type can be derived from these Mn2(CO)8(CN)2 structures by removal of a CO group with relatively little change in the remainder of the structure. These low-energy Mn2(CO)n(CN)2 structures (n = 8, 7) are very different from the previously studied isoelectronic Cr2(CO)n+2 structures in which low-energy end-to-end CO bridged structures are not found.

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