New Insights into the Chemistry of Imidodiphosphinates from Investigations of Tellurium-Centered Systems

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• 作者：Tristram Chivers ; Jamie S. Ritch ; Stuart D. Robertson ; Jari Konu ; Heikki M. Tuononen
• 刊名：Accounts of Chemical Research
• 出版年：2010
• 出版时间：August 17, 2010
• 年：2010
• 卷：43
• 期：8
• 页码：1053-1062
• 全文大小：346K
• 年卷期：v.43,no.8(August 17, 2010)
• ISSN：1520-4898

文摘

Dichalcogenido-imidodiphosphinates, [N(PR₂E)₂]⁻ (R = alkyl, aryl), are chelating ligands that readily form cyclic complexes with main group metals, transition metals, lanthanides, and actinides. Since their discovery in the early 1960s, researchers have studied the structural chemistry of the resulting metal complexes (where E = O, S, Se) extensively and identified a variety of potential applications, including as NMR shift reagents, luminescent complexes in photonic devices, or single-source precursors for metal sulfides or selenides. In 2002, a suitable synthesis of the tellurium analogs [N(PR₂Te)₂]⁻ was developed. In this Account, we describe comprehensive investigations of the chemistry of these tellurium-centered anions, and related mixed chalcogen systems, which have revealed unanticipated features of their fundamental structure and reactivity.

An exhaustive examination of previously unrecognized redox behavior has uncovered a variety of novel dimeric arrangements of these ligands, as well as an extensive series of cyclic cations. In combination with calculations using density functional theory, these new structural frameworks have provided new insights into the nature of chalcogen-chalcogen bonding. Studies of metal complexes of the ditellurido ligands [N(PR₂Te)₂]⁻ have revealed unprecedented structural and reaction chemistry. The large tellurium donor sites confer greater flexibility, which can lead to unique structures in which the tellurium-centered ligand bridges two metal centers. The relatively weak P−Te bonds facilitate metal-insertion reactions (intramolecular oxidative-addition) to give new metal−tellurium ring systems for some group 11 and 13 metals.

Metal tellurides have potential applications as low band gap semiconductor materials in solar cells, thermoelectric devices, and in telecommunications. Practically, some of these telluride ligands could be applied in these industries. For example, certain metal complexes of the isopropyl-substituted anion [N(PⁱPr₂Te)₂]⁻ serve as suitable single-source precursors for pure metal telluride thin films or novel nanomaterials, for example, CdTe, PbTe, In₂Te₃, and Sb₂Te₃.