Macrocyclic phosphorus-containing

Although most of the macrocycles that contain phosphorus or arsenic which have thus far been prepared, are primarily transition metals binders, two compounds have been prepared which are essentially crown ethers containing phosphorus. Kudrya, Shtepanek and Kirsanovhave prepared two compounds which are essentially polyoxygen macrocycles but which contain one or two methylphosphonic acid esters as part of the ring. These two macrocycles are shown below as 7d and 17 and are both prepared by the reaction of 2,2 [oxybis(ethyleneoxy)] bisphenolate with methylphosphonic dichloride in a mixture of acetonitrile and benzene. The crystalline monomer 16) and dimer 17) were isolated in 17% and 11% yields respectively as indicated in Eq. (6.13). 

Kyba and his coworkers have made numerous phosphorus-containing macrocycles and many of these are recorded in the tables at the end of this chapter. In addition, this group has prepared and reported quite a number of arsinocycles. The observations concerning phosphorus macrocycles apply in general to the arsinocycles as well, but the inversion barrier is even higher for the latter than the former. ... 

From Phosphorus-Containing Macrocycles to Phosphorus-Containing... 

In view of the widespread use of tertiary phosphines in coordination chemistry, it is somewhat surprising that phosphorus-containing macrocycles have not evoked more interest. In part this is undoubtedly due to experimental difficulties. The synthesis of P macrocycles is doubly difficult, since the usual difficulties and hazards of phosphorus(III) chemistry are compounded by the complexities and low yields of multistage heterocyclic macrocyclic syntheses. Because of these difficulties, the development of synthetic methods has been slow. Mann s survey73 of the heterocyclic derivatives of P, As, Sb and Bi did not mention phosphorus macrocycles and recent textbooks74,75 give them only cursory mention. 

A number of macrocycles containing only one phosphorus atom have been prepared, and they are usually referred to as phosphorus-containing crown ethers rather than as P macrocycles. The 18-crown, or [18]anePOs, was prepared by van Zon (equation 28).82 This cyclic phosphine is stable in air, even in solution (cf. Ph3P). However, when the non-macrocyclic substituent is Bul the phosphorus is oxidized in solution by air in the presence of alumina. This unwelcome discovery was made by van Zon when purifying the material by chromatography on an alumina column. 

Russian workers83 84 have synthesized a series of phosphorus-containing crowns utilizing O—P—O bonds in the macrocycle, i.e. cyclic phosphonate esters (7). One of these is claimed to have been prepared in 40% yield (equation 29). 

Phosphorus-containing macrocycles, 990, 996, 998 macrocychc effect, 1002 ring size, 1003 stereochemistry, 1003 Phosphorus heterocycles transition metal complexes, 1041 Phosphorus ligands, 989-1061 ir-acid series, 1033 bonding, 1030-1041 cone angle concept, 1012 trigonal bipyramidal complexes, 1036 Phosphorus oxychloride metal complexes, 500 Phosphorus ylides transition metal complexes, 1056 Phosphorylation biological, 978 Phosvitin, 975 Photochromism... 

Phosphorus-containing macrocycles have not proved to be popnlar ligands owing, in part, to their difficult multistage synthesis. We arbitrarily define phosphorus macrocycles as those with 10 or more ring members, at least one of which is phosphorus. It should be noted that the usual purpose of... 

Phosphorus-containing macrocycles, synthesis and complexing ability of 88UK1353. 

There are four comprehensive reference texts on phosphine coordination chem-istry. Two are somewhat out-of-date, but the article by Levason is more recent. However, all four give much useful information on synthetic procedures for the preparation of primary, secondary and tertiary phosphines diphosphines multidentate and macrocyclic phosphines mixed Group 15 donor and mixed Group 15/16 donor systems and phosphorus-containing heterocycles. The coordination chemistry of phosphorus has expanded to include P4 fragments, Pg rings, and even naked phosphorus atoms, for example, nine-coordinate P and -Pg systems. ... 

The next two articles cover the chemistry of phosphorus containing macrocycles. The phosphorus containing cahxarenes have attracted much attention in recent years due to their various functions such as metal cations binding, catalysis, molecular recogination, and bioactivity. Likewise, other phosphorus-containing macrocycles, cryptands, and dendrimers find various uses in analytical chemistry and biochemistry. 

Thus, we first discuss thermodynamics, paying attention to features that are important for polymer synthesis (e.g., dependence of equilibrium monomer concentration on polymerization variables) then we describe kinetics and thermodynamics of macrocyclization, trying to combine these two related problems, usually discussed separately. In particular we present the new theory of kinetic enhancement and kinetic reduction in macrocyclics. Thereafter, we describe the polymerization of several groups of monomers, namely cyclic ethers (oxiranes, oxetanes, oxolanes, acetals, and bicyclic compounds) lactones, cyclic sulfides, cyclic amines, lactams, cyclic iminoethers, siloxanes, and cyclic phosphorus-containing compounds, in this order. We attempted to treat the chapters uniformly we discuss practical methods of synthesis of the corresponding polymers (monomer syntheses and polymer properties are added), and conditions of reaching systems state and reasons of deviations. However, for various groups of monomers the quality of the available information differ so much, that this attempt of uniformity can not be fulfilled. 

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