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The chemistry of cationic polyphosphorus cages--syntheses, structure and reactivity.

Holthausen MH, Weigand JJ - Chem Soc Rev (2014)

Bottom Line: The aim of this review is to provide a comprehensive view of the chemistry of cationic polyphosphorus cages.The synthetic protocols established for their preparation, which are all based on the functionalization of P4, and their intriguing follow-up chemistry are highlighted.In addition, this review intends to foster the interest of the inorganic, organic, catalytic and material oriented chemical communities in the versatile field of polyphosphorus cage compounds.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Toronto, Toronto, Canada. m.holthausen@utoronto.ca.

ABSTRACT
The aim of this review is to provide a comprehensive view of the chemistry of cationic polyphosphorus cages. The synthetic protocols established for their preparation, which are all based on the functionalization of P4, and their intriguing follow-up chemistry are highlighted. In addition, this review intends to foster the interest of the inorganic, organic, catalytic and material oriented chemical communities in the versatile field of polyphosphorus cage compounds. In the long term, this is envisioned to contribute to the development of new synthetic procedures for the functionalization of P4 and its transformation into (organo-)phosphorus compounds and materials of added value.

No MeSH data available.


Related in: MedlinePlus

Oxidation of Ag(i) complex 25[A] with I2 at low temperatures giving intermediary P5I2+-cage 26a+ (top), targeted syntheses of P5X2+-cages 26a–c+ (X = I, Br, Cl) by the reaction of P4, PX3 and Ag(CH2Cl2)[A] and molecular structure of 26b[A] (bottom); A = Al(OC(CF3)3)4.
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sch7: Oxidation of Ag(i) complex 25[A] with I2 at low temperatures giving intermediary P5I2+-cage 26a+ (top), targeted syntheses of P5X2+-cages 26a–c+ (X = I, Br, Cl) by the reaction of P4, PX3 and Ag(CH2Cl2)[A] and molecular structure of 26b[A] (bottom); A = Al(OC(CF3)3)4.

Mentions: The oxidation of Ag(i) complex 25[A] (A = Al(OC(CF3)3)4) featuring two intact P4 ligands with elemental iodine at low temperatures gives rise to interesting binary PI cations. The P5I2+-cage 26a+ was observed in the reaction mixture at –78 °C together with PI3 and P4 (Scheme 7).36 However, on raising the temperature above –40 °C, decomposition of 26a+ was observed, leading to the formation of P3I6+ (23+) and unidentified by-products. A proposed reaction mechanism indicates the partial oxidation of the P4 ligands in 25+ by I2 to give PI3.36 The latter reacts with Ag[A] (A = Al(OC(CF3)3)4) via halide abstraction to give AgI and formally the phosphenium ion PI2+. This highly reactive, predominantly electrophilic ambiphile reacts with white phosphorus via insertion in one of the P–P bonds of the P4 tetrahedron yielding the P5I2+-cage 26a+. Likewise, according to the observations described in Section 3, a mechanism involving the formation of phosphanylphosphonium ion P2I5+ can also be considered. Here, P2I5+ is assumed to transfer a PI2+ phosphenium ion to P4 and, thus, serves as a phosphenium ion source. Upon warming the reaction mixture, the excess of PI3 reacts with P4 to yield diphosphane P2I4 in a conproportionation reaction. The diphosphane reacts with 26a+via transfer of the phosphenium ion PI2+. This gives P4 and the P3I6+ cation 23+ which is formed upon insertion of the PI2+ ion into the P–P bond of P2I4. On the basis of these observations, a synthetic protocol for the targeted preparation of P5X2+-cages was developed (Scheme 7).36,37 Thus, white phosphorus reacts with PX3 (X = I, Br) in the presence of Ag(CH2Cl2)[A] as a halide abstracting agent and salts of cage cations 26a+ and 26b+ can be isolated in good yield. However, utilizing PCl3, the formation of the respective cation 26c+ was observed only in trace amounts since it readily decomposes in the reaction mixture.38 The molecular structure of 26b+ is shown in Scheme 7. The structural motif of the P5-core of the P5X2+-cage was unprecedented and was not previously observed as part of the many known polyphosphides and organo-polyphosphanes.


The chemistry of cationic polyphosphorus cages--syntheses, structure and reactivity.

Holthausen MH, Weigand JJ - Chem Soc Rev (2014)

Oxidation of Ag(i) complex 25[A] with I2 at low temperatures giving intermediary P5I2+-cage 26a+ (top), targeted syntheses of P5X2+-cages 26a–c+ (X = I, Br, Cl) by the reaction of P4, PX3 and Ag(CH2Cl2)[A] and molecular structure of 26b[A] (bottom); A = Al(OC(CF3)3)4.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4288811&req=5

sch7: Oxidation of Ag(i) complex 25[A] with I2 at low temperatures giving intermediary P5I2+-cage 26a+ (top), targeted syntheses of P5X2+-cages 26a–c+ (X = I, Br, Cl) by the reaction of P4, PX3 and Ag(CH2Cl2)[A] and molecular structure of 26b[A] (bottom); A = Al(OC(CF3)3)4.
Mentions: The oxidation of Ag(i) complex 25[A] (A = Al(OC(CF3)3)4) featuring two intact P4 ligands with elemental iodine at low temperatures gives rise to interesting binary PI cations. The P5I2+-cage 26a+ was observed in the reaction mixture at –78 °C together with PI3 and P4 (Scheme 7).36 However, on raising the temperature above –40 °C, decomposition of 26a+ was observed, leading to the formation of P3I6+ (23+) and unidentified by-products. A proposed reaction mechanism indicates the partial oxidation of the P4 ligands in 25+ by I2 to give PI3.36 The latter reacts with Ag[A] (A = Al(OC(CF3)3)4) via halide abstraction to give AgI and formally the phosphenium ion PI2+. This highly reactive, predominantly electrophilic ambiphile reacts with white phosphorus via insertion in one of the P–P bonds of the P4 tetrahedron yielding the P5I2+-cage 26a+. Likewise, according to the observations described in Section 3, a mechanism involving the formation of phosphanylphosphonium ion P2I5+ can also be considered. Here, P2I5+ is assumed to transfer a PI2+ phosphenium ion to P4 and, thus, serves as a phosphenium ion source. Upon warming the reaction mixture, the excess of PI3 reacts with P4 to yield diphosphane P2I4 in a conproportionation reaction. The diphosphane reacts with 26a+via transfer of the phosphenium ion PI2+. This gives P4 and the P3I6+ cation 23+ which is formed upon insertion of the PI2+ ion into the P–P bond of P2I4. On the basis of these observations, a synthetic protocol for the targeted preparation of P5X2+-cages was developed (Scheme 7).36,37 Thus, white phosphorus reacts with PX3 (X = I, Br) in the presence of Ag(CH2Cl2)[A] as a halide abstracting agent and salts of cage cations 26a+ and 26b+ can be isolated in good yield. However, utilizing PCl3, the formation of the respective cation 26c+ was observed only in trace amounts since it readily decomposes in the reaction mixture.38 The molecular structure of 26b+ is shown in Scheme 7. The structural motif of the P5-core of the P5X2+-cage was unprecedented and was not previously observed as part of the many known polyphosphides and organo-polyphosphanes.

Bottom Line: The aim of this review is to provide a comprehensive view of the chemistry of cationic polyphosphorus cages.The synthetic protocols established for their preparation, which are all based on the functionalization of P4, and their intriguing follow-up chemistry are highlighted.In addition, this review intends to foster the interest of the inorganic, organic, catalytic and material oriented chemical communities in the versatile field of polyphosphorus cage compounds.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Toronto, Toronto, Canada. m.holthausen@utoronto.ca.

ABSTRACT
The aim of this review is to provide a comprehensive view of the chemistry of cationic polyphosphorus cages. The synthetic protocols established for their preparation, which are all based on the functionalization of P4, and their intriguing follow-up chemistry are highlighted. In addition, this review intends to foster the interest of the inorganic, organic, catalytic and material oriented chemical communities in the versatile field of polyphosphorus cage compounds. In the long term, this is envisioned to contribute to the development of new synthetic procedures for the functionalization of P4 and its transformation into (organo-)phosphorus compounds and materials of added value.

No MeSH data available.


Related in: MedlinePlus