Cargando…
A Xanthene‐Based Mono‐Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry
The synthesis of a novel mono‐anionic phosphino‐amide ligand based on a xanthene backbone is reported, togetherr with the corresponding Ga(I) complex, (PON)Ga (PON = 4‐(di(2,4,6‐trimethylphenyl)phosphino)‐5‐(2,6‐diisopropylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethylxanthene). The solid‐state structure o...
Autores principales: | , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2021
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7898390/ https://www.ncbi.nlm.nih.gov/pubmed/33200850 http://dx.doi.org/10.1002/chem.202004741 |
_version_ | 1783653854936563712 |
---|---|
author | Zheng, Xiongfei Heilmann, Andreas McManus, Caitilín Aldridge, Simon |
author_facet | Zheng, Xiongfei Heilmann, Andreas McManus, Caitilín Aldridge, Simon |
author_sort | Zheng, Xiongfei |
collection | PubMed |
description | The synthesis of a novel mono‐anionic phosphino‐amide ligand based on a xanthene backbone is reported, togetherr with the corresponding Ga(I) complex, (PON)Ga (PON = 4‐(di(2,4,6‐trimethylphenyl)phosphino)‐5‐(2,6‐diisopropylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethylxanthene). The solid‐state structure of (PON)Ga (obtained from X‐ray crystallography) reveals very weak O⋅⋅⋅Ga and P⋅⋅⋅Ga interactions, consistent with a R(2)NGa fragment which closely resembles those found in one‐coordinate amidogallium systems. Strong N‐to‐Ga π donation from the amido substituent is reflected in a very short N−Ga distance (1.961(2) Å), while the P⋅⋅⋅Ga contact (3.076(1) Å) is well outside the sum of the respective covalent radii. While the donor properties of the PON ligand towards Ga(I) are highly unsymmetrical, oxidation to Ga(III) leads to much stronger coordination of the pendant phosphine as shown by P−Ga distances which are up to 20 % shorter. From a steric perspective, the PON ligand is shown to be significantly bulkier than related β‐diketiminate systems, a finding consistent with reactions of (PON)Ga towards O‐atom sources that proceed without oligomerization. Despite this, the enhanced P‐donor properties brought about by oxidation at gallium are not sufficient to quench the reactivity of the highly polar Ga−O unit. Instead, intramolecular benzylic C−H activation is observed across the Ga−O bond of a transient gallanone intermediate. |
format | Online Article Text |
id | pubmed-7898390 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-78983902021-03-03 A Xanthene‐Based Mono‐Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry Zheng, Xiongfei Heilmann, Andreas McManus, Caitilín Aldridge, Simon Chemistry Full Papers The synthesis of a novel mono‐anionic phosphino‐amide ligand based on a xanthene backbone is reported, togetherr with the corresponding Ga(I) complex, (PON)Ga (PON = 4‐(di(2,4,6‐trimethylphenyl)phosphino)‐5‐(2,6‐diisopropylanilido)‐2,7‐di‐tert‐butyl‐9,9‐dimethylxanthene). The solid‐state structure of (PON)Ga (obtained from X‐ray crystallography) reveals very weak O⋅⋅⋅Ga and P⋅⋅⋅Ga interactions, consistent with a R(2)NGa fragment which closely resembles those found in one‐coordinate amidogallium systems. Strong N‐to‐Ga π donation from the amido substituent is reflected in a very short N−Ga distance (1.961(2) Å), while the P⋅⋅⋅Ga contact (3.076(1) Å) is well outside the sum of the respective covalent radii. While the donor properties of the PON ligand towards Ga(I) are highly unsymmetrical, oxidation to Ga(III) leads to much stronger coordination of the pendant phosphine as shown by P−Ga distances which are up to 20 % shorter. From a steric perspective, the PON ligand is shown to be significantly bulkier than related β‐diketiminate systems, a finding consistent with reactions of (PON)Ga towards O‐atom sources that proceed without oligomerization. Despite this, the enhanced P‐donor properties brought about by oxidation at gallium are not sufficient to quench the reactivity of the highly polar Ga−O unit. Instead, intramolecular benzylic C−H activation is observed across the Ga−O bond of a transient gallanone intermediate. John Wiley and Sons Inc. 2021-01-14 2021-02-10 /pmc/articles/PMC7898390/ /pubmed/33200850 http://dx.doi.org/10.1002/chem.202004741 Text en © 2020 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Full Papers Zheng, Xiongfei Heilmann, Andreas McManus, Caitilín Aldridge, Simon A Xanthene‐Based Mono‐Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry |
title | A Xanthene‐Based Mono‐Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry |
title_full | A Xanthene‐Based Mono‐Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry |
title_fullStr | A Xanthene‐Based Mono‐Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry |
title_full_unstemmed | A Xanthene‐Based Mono‐Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry |
title_short | A Xanthene‐Based Mono‐Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry |
title_sort | xanthene‐based mono‐anionic pon ligand: exploiting a bulky, electronically unsymmetrical donor in main group chemistry |
topic | Full Papers |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7898390/ https://www.ncbi.nlm.nih.gov/pubmed/33200850 http://dx.doi.org/10.1002/chem.202004741 |
work_keys_str_mv | AT zhengxiongfei axanthenebasedmonoanionicponligandexploitingabulkyelectronicallyunsymmetricaldonorinmaingroupchemistry AT heilmannandreas axanthenebasedmonoanionicponligandexploitingabulkyelectronicallyunsymmetricaldonorinmaingroupchemistry AT mcmanuscaitilin axanthenebasedmonoanionicponligandexploitingabulkyelectronicallyunsymmetricaldonorinmaingroupchemistry AT aldridgesimon axanthenebasedmonoanionicponligandexploitingabulkyelectronicallyunsymmetricaldonorinmaingroupchemistry AT zhengxiongfei xanthenebasedmonoanionicponligandexploitingabulkyelectronicallyunsymmetricaldonorinmaingroupchemistry AT heilmannandreas xanthenebasedmonoanionicponligandexploitingabulkyelectronicallyunsymmetricaldonorinmaingroupchemistry AT mcmanuscaitilin xanthenebasedmonoanionicponligandexploitingabulkyelectronicallyunsymmetricaldonorinmaingroupchemistry AT aldridgesimon xanthenebasedmonoanionicponligandexploitingabulkyelectronicallyunsymmetricaldonorinmaingroupchemistry |