Volume 25, Issue 71 p. 16414-16424
Full Paper

Periodicity in Structure, Bonding, and Reactivity for p-Block Complexes of a Geometry Constraining Triamide Ligand

Katherine M. Marczenko

Katherine M. Marczenko

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

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Joseph A. Zurakowski

Joseph A. Zurakowski

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

These authors contributed equally to this work.

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Marcus B. Kindervater

Marcus B. Kindervater

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

These authors contributed equally to this work.

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Samantha Jee

Samantha Jee

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

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Toren Hynes

Toren Hynes

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

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Nicholas Roberts

Nicholas Roberts

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

These authors contributed equally to this work.

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Seoyeon Park

Seoyeon Park

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

These authors contributed equally to this work.

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Dr. Ulrike Werner-Zwanziger

Dr. Ulrike Werner-Zwanziger

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

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Dr. Michael Lumsden

Dr. Michael Lumsden

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

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Dr. David N. Langelaan

Dr. David N. Langelaan

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

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Prof. Dr. Saurabh S. Chitnis

Corresponding Author

Prof. Dr. Saurabh S. Chitnis

Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia, Canada

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First published: 01 October 2019
Citations: 45

A previous version of this manuscript has been deposited on a preprint server (https://doi.org/10.26434/chemrxiv.9750764.v1).

Graphical Abstract

A longitudinal study of strained p-block triamides: A comprehensive analysis of periodic trends in structure, bonding, and reactivity for geometry constrained triamide complexes of P, As, Sb, and Bi is reported. In this homologous series, the central element can adopt either a bent or planar geometry and the preferred orientation in the solid and solution phases (as well as computationally) have been mapped. Additionally, the influence of geometry on reactivity has been elucidated.

Abstract

The use of pincer ligands to access non-VSEPR geometries at main-group centers is an emerging strategy for eliciting new stoichiometric and catalytic reactivity. As part of this effort, several different tridentate trianionic substituents have to date been employed at a range of different central elements, providing a patchwork dataset that precludes rigorous structure–function correlation. An analysis of periodic trends in structure (solid, solution, and computation), bonding, and reactivity based on systematic variation of the central element (P, As, Sb, or Bi) with retention of a single tridentate triamide substituent is reported herein. In this homologous series, the central element can adopt either a bent or planar geometry. The tendency to adopt planar geometries increases descending the group with the phosphorus triamide (1) and its arsenic congener (2) exhibiting bent conformations, and the antimony (3) and bismuth (4) analogues exhibiting a predominantly planar structure in solution. This trend has been rationalized using an energy decomposition analysis. A rare phase-dependent dynamic covalent dimerization was observed for 3 and the associated thermodynamic parameters were established quantitatively. Planar geometries were found to engender lower LUMO energies and smaller band gaps than bent ones, resulting in different reactivity patterns. These results provide a benchmark dataset to guide further research in this rapidly emerging area.

Conflict of interest

The authors declare no conflict of interest.