scholarly journals Lanthanum- Oligopyrrole Complexes (neutral, III) for biogas capture applications by DFT

2021 ◽  
Author(s):  
Marisol Ibarra-Rodríguez ◽  
Mario Sanchez
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Strong Interactions ◽  
Computational Studies ◽  
Functional Theory ◽  
Gas Molecules ◽  
H2 Molecule ◽  
Lanthanum Atom ◽  
Orbital Analysis

The structures and interactions of systems formed by the MPBCP (meta-Phenylene-Bridged Cyclic Oligopyrrole) functionalized with lanthanum atom were studied for investigating the abilities of MPBCP, [La-MPBCP]+3 and La-MPBCP to absorb biogas (CO2, N2, H2 and CH4) using density functional theory. The Eads calculated values for biogas molecules on [La-MPBCP]+3 and La-MPBCP showed that these gas molecules have favorable interactions with the lanthanum atom coordinated on the MPBCP. CO2 molecule shows strong interactions, with Eads values of -28.63 and -15.95 kcal/mol. In the case of H2 molecule, the Eads is lower with values of -7.51 and -5.28. It is easy to observe the CO2 molecule on the [La-MPBCP]+3 system has four times higher energy value than adsorption energy for the H2 molecule. The natural bond orbital analysis reveals that gas molecules are electron donator in the systems and the acceptor orbitals belong to lanthanum atom. Computational studies suggest that CO2, N2, CH4 and H2 molecules on [La-MPBCP]+3 and La-MPBCP present physisorption. Our findings divulge promising potential of the [La-MPBCP]+3 as an adsorber/separator CO2/H2.

scholarly journals Natural Bond Orbital Analysis of [Fe(H2O)6]2+/3+ and [Zn(H2O)6](H2O)N2+;N=0-4

2018 ◽  
Vol 22 (2) ◽  
pp. 148-155
Author(s):  
Nabaraj Pokhrel ◽  
Hari Prasad Lamichhane
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Coordination Sphere ◽  
Metal Ion ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
The Other ◽  
Strong Interactions ◽  
Functional Theory ◽  
Orbital Analysis

Nature of delocalization of the electrons from the ligands to metals in the first coordination sphere of the high-spin complexes [Fe(H2O)6]2+/3+ and [Zn(H2O)6]2+ are computationally studied using density functional theory. Among the studied complexes, natural charge transfer from H2O ligands to metal ion is found to be maximum of 1.556e in [Fe(H2O)6]3+ and minimum of 0.621e in [Zn(H\2O)6]2+. On the other hand, the interaction between the lone pairs of oxygen with metal ion was found to be stronger in [Zn(H2O)6]2+ than in the complexes with second coordination sphere. Number of such strong interactions in the first coordination sphere was found to be decreased with the addition of H2O ligands in the second coordination sphere.Journal of Institute of Science and Technology Volume 22, Issue 2, January 2018, Page: 148-155

N-Donor Competition in Iron Bis(chelate) Bis(pyrazolyl)pyridinylmethane Complexes

2014 ◽  
Vol 69 (11-12) ◽  
pp. 1206-1214 ◽  
Author(s):  
Ulrich Herber ◽  
Alexander Hoffmann ◽  
Charles Lochenie ◽  
Birgit Weber ◽  
Sonja Herres-Pawlis
Keyword(s):  
Density Functional Theory ◽  
Magnetic Susceptibility ◽  
Spin State ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Substitution Pattern ◽  
Functional Theory ◽  
Structural Characterisation ◽  
Alkyl Substitution ◽  
Orbital Analysis

Abstract We report on the synthesis and structural characterisation of the bis(chelate) bis(pyrazolyl) pyridinylmethane iron(II) complexes [Fe{HC(Pz)2(Py)}2][CF3CO2]2, [Fe{HC(3-iPrPz)(5- iPrPz)(Py)}2][CF3SO3]2 and [Fe{HC(3-iPrPz)(5-iPrPz)(Py)}2][FeBr4]Br·2C4H8O. During the synthesis of the latter ones, an isomerisation of the ligand is observed: the pyrazolyl substituent formally moves from the 3 to the 5 position. Since the donor competition between pyrazolyl and pyridinyl moieties is important for the coordination properties, we also studied the donor properties by density functional theory and natural bond orbital analysis (NBO). As a result, the pyridinyl donor is generally weaker than the pyrazolyl donor, but the pyrazolyl donor is heavily influenced by the alkyl substitution pattern. To confirm the low-spin state of the complexes, magnetic susceptibility measurements have been performed

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