Phosphaethyne complexes

Reaction of (diisopropylamino)phosphaethyne P=CN(Pr )2 with [Ni(CO)3(P C6Hn 3)] affords the planar 16-electron Ni° complex (1056) with -bound phosphaethyne.2540 Upon coordination, the P=C triple bond distance increases to 1.665(2) A, which is typical for phosphaalkenes. Upon... 

In the following, three comparisons of isoelectronic systems are presented. The first consists of a comparison of the isoelectronic ligands ethyne (HCCH) and phosphaethyne (HCP) for different transition metals and in different states of aggregation. The second compares cyclopenta-dienyl and pentadienyl complexes, while the third relates complexes of benzene and hexaphosphabenzene. Although narrow in terms of breadth of compounds, we hope there is sufficient detail in these systems to convey some appreciation of the systematic variation possible with isoelectronic substitution. 

Co-condensation of indium vapor and tert-butyl-phosphaethyne at 77 K yields the volatile ln(l) complexes [In(jj -P3C2Bu2)] and 1,3-diphosphacyclopentadienyl complex [In(j7 -P2C3Bu3)]. Single-crystal x-ray diffraction studies for [In(jj -P3C2Bu9] reveals a discrete molecular stmcture, involving half-sandwich coordination of the... 

A theoretical study of the intermediates involved in the formation of phospha-propyne from pyrolysis of vinylphosphirane has led to a new route to phospha-alkynes. Thus, pyrolysis of trimethylsilyl(l-phosphiranyl)diazomethane has yielded MeaSiC = P, via an intermediate 1-phosphiranylmethylene . Regioselec-tivity in the [3 + 2] cycloaddition reaction between phosphaethyne and diazomethane has been studied by theoretical techniques , and further examples of reactions of this type described . Cycloaddition of phospha-alkynes with silylenes has also been reported. The primary phosphine 324 has been isolated from the addition of diethylphosphite to t-butylphosphaethyne. The chemistry of phospha-alkyne cyclotetramer systems has been reviewed and the first examples of platinum(II) complexes of such cage systems described. Aspects of the reactivity of coordinated phospha-alkynes have received further study, and a remarkable metal-mediated double reduction of t-butylphosphaethyne to the complexed fluorophosphine 325 described Phosphorus-carbon-aluminium cage structures have been isolated from the reactions of kinetically stable phospha-alkynes with trialkylaluminium compounds and new phosphaborane systems have been obtained from the reactions of phospha-alkynes with polyhedral boranes . Further studies of wo-phospha-alkyne coordination chemistry have appeared . The reactivity of the ion 326 has been explored. ... 

Diphosphacyclobutene derivatives are synthesized from mesilylene-substituted phosphaethyne by treatment with i -BuLi (eq 44). The product 28 forms carbonyl complexes with transition metals such as chromium and tungsten. 

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