Density functional theory study of interactions between carbon monoxide and iron tetraaza macrocyclic complexes, FeTXTAA (X = −Cl, −OH, −OCH₃, −NH₂, and –NO₂)

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• 作者：Isaias de Matos Mourão Neto ; Adilson Luís Pereira Silva…
• 关键词：Iron complexes ; Carbon monoxide ; Density functional theory ; Back bonding
• 刊名：Journal of Molecular Modeling
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：23
• 期：2
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Computer Applications in Chemistry; Molecular Medicine; Computer Appl. in Life Sciences; Characterization and Evaluation of Materials; Theoretical and Computational Chemistry;
• 出版者：Springer Berlin Heidelberg
• ISSN：0948-5023
• 卷排序：23

文摘

This work describes a DFT level theoretical quantum study using the B3LYP functional with the Lanl2TZ(f)/6-31G* basis set to calculate parameters including the bond distances and angles, electronic configurations, interaction energies, and vibrational frequencies of FeTClTAA (iron-tetrachloro-tetraaza[14]annulene), FeTOHTAA (iron-tetrahydroxy-tetraaza[14]annulene), FeTOCH₃TAA (iron- tetramethoxy-tetraaza[14]annulene), FeTNH₂TAA (iron-tetraamino-tetraaza[14]annulene), and FeTNO₂TAA (iron-tetranitro-tetraaza[14]annulene) complexes, as well as their different spin multiplicities. The calculations showed that the complexes were most stable in the triplet spin state (S = 1), while, after interaction with carbon monoxide, the singlet state was most stable. The reactivity of the complexes was evaluated using HOMO–LUMO gap calculations. Parameter correlations were performed in order to identify the best complex for back bonding (3d_xzFe → 2p_xC and 3d_yzFe → 2p_zC) with carbon monoxide, and the degree of back bonding increased in the order: FeTNO₂TAA < FeTClTAA < FeTOHTAA < FeTOCH₃TAA < FeTNH₂TAA.