Heavy-element-ligand covalence: ligand noninnocence in molybdenum and tungsten Viking-helmet Corroles

• Published in: Dalton transactions : an international journal of inorganic chemistry 2021-09, Vol.5 (37), p.12843-12849
• Main Authors: Vazquez-Lima, Hugo, Conradie, Jeanet, Johansen, Martin A. L, Martinsen, Stian Rølvaag, Alemayehu, Abraham B, Ghosh, Abhik
• Format: Article
• Language: English
• Subjects: Chemistry: 440; Clinching; Helmets; Kjemi: 440; Ligands; Matematikk og Naturvitenskap: 400; Mathematics and natural science: 400; Molybdenum; Red shift; Tungsten; VDP
• ISSN: 1477-9226; 1477-9234; 1477-9234
• DOI: 10.1039/d1dt01970h

Extensive DFT calculations with several exchange-correlation functionals indicate that molybdenum-dichlorido Viking helmet corroles are noninnocent with significant Mo IV -corrole&z.rad; 2− character. The effect is mediated by a Mo(4d)-corrole(π) orbital interaction similar to that postulated for MnCl, FeCl and FeNO corroles. The effect also appears to operate in tungsten-dichlorido corroles but is weaker relative to that for Mo. In contrast, MoO triarylcorroles do not exhibit a significant degree of corrole radical character. Furthermore, the Soret absorption maxima of a series of MoCl 2 tris( para -X-phenyl)corrole derivatives were found to redshift dramatically with increasing electron-donating character of the para substituent X, essentially clinching the case for a noninnocent macrocycle in MoCl 2 corroles. Unlike molybdenum-oxo corroles, molybdenum-dichlorido Viking helmet corroles are noninnocent, with substantial corrole radical character.