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Updated: Oct 23, 2025

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Di-tert-butyldiphosphatetrahedrane as a Source of 1,2-Diphosphacyclobutadiene Ligands
Gabriele Hierlmeier1, Peter Coburger1,2, Daniel J Scott1
1Institut für Anorganische Chemie, Universität Regensburg, 93040, Regensburg, Germany.
Abstract:
Reactions of di-tert-butyldiphosphatetrahedrane (1) with cycloocta-1,5-diene- or anthracene-stabilised metalate anions of iron and cobalt consistently afford complexes of the rarely encountered 1,2-diphosphacyclobutadiene ligand, which have previously been very challenging synthetic targets. The subsequent reactivity of 1,2-diphosphacyclobutadiene cobaltates toward various electrophiles has also been investigated and is compared to reactions of related 1,3-diphosphacyclobutadiene complexes. The results highlight the distinct reactivity of such isomeric species, showing that the 1,2-isomers can act as precursors for previously unknown triphospholium ligands. The electronic structures of the new complexes were investigated by several methods, including NMR, EPR and Mößbauer spectroscopies as well as quantum chemical calculations.
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