Document Type
Article
Publication Date
2018
Publication Title
Acta Crystallographica Section C: Structural Chemistry
Volume
C
Issue
74
Pages
1641-1649
Publisher Name
Wiley Periodicals LLC
Abstract
Treatment of the ortho-triazacyclophane 1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-triene [(C6H5)3(NH)(NCH3)2, L1] with Fe[N(SiMe3)2]2 yields the dimeric iron(II) complex bis(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido)bis[(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido)iron(II)], [Fe(C20H18N3)4] or Fe2(L1)4 (9). Dissolution of 9 in tetrahydrofuran (THF) results in solvation by two THF ligands and the formation of a simpler monoiron complex, namely bis(μ-1,4-dimethyltribenzo[b,e,h][1,4,7]triazacyclonona-2,5,8-trien-7-ido-κN7)bis(tetrahydrofuran-κO)iron(II), [Fe(C20H18N3)2(C4H8O)2] or (L1)2Fe(THF)2 (10). The reaction is reversible and 10 reverts in vacuo to diiron complex 9. In the structures of both 9 and 10, the monoanionic triazacyclophane ligand L1− is observed in only the less-symmetric saddle conformation. No bowl-shaped crown conformers are observed in the solid state, thus preventing chelating κ3-coordination to the metal as had been proposed earlier based on density functional theory (DFT) calculations. Instead, the L1− ligands are bound in either a η2-chelating fashion through the amide and one amine donor (for one of the four ligands of 9), or solely through their amide N atoms in an even simpler monodentate η1-coordination mode. Density functional calculations on dimer 9 revealed nearly full cationic charges on each Fe atom and no bonding interaction between the two metal centers, consistent with the relatively long FeFe distance of 2.912 (1) Å observed in the solid state.
Recommended Citation
Less, Wei-Tsung; Zeller, Matthias; Upp, David; Politanska, Yuliya; Steinman, Doug; Al-Assil, Talal; and Becker, Daniel P. Ph.D.. Iron(II) Complexes of Dimethyltriazacyclophane. Acta Crystallographica Section C: Structural Chemistry, C, 74: 1641-1649, 2018. Retrieved from Loyola eCommons, Chemistry: Faculty Publications and Other Works, http://dx.doi.org/10.1107/S2053229618015255
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.
Copyright Statement
© International Union of Crystallography 2018
Comments
Author Posting. © International Union of Crystallography 2018. This article is posted here by permission of the International Union of Crystallography for personal use, not for redistribution. The article was published in Acta Crystallographica Section C, 2018, https://doi.org/10.1107/S2053229618015255.