ARSA

When immediately followed by -in or -ine, phospha- should be replaced by phosphor-, arsa- by arsen-, and stiba-by antimon-. The saturated six-membered rings corresponding to phosphorin and arsenin are named phosphorinane and arsenane. A further exception is the replacement of borin by borinane. 

In order to avoid ambiguity, it was previously recommended that these prefixes be modified when names already preempted for noncyclic compounds would otherwise be generated. The recommendation was that when immediately followed by -in or -ine, phospha- be changed to phosphora , arsa- to arsen- and stiba- to antimon-. This recommendation has been superseded by a suitable change in the stem suffix (see ahead), but is mentioned here because it is still substantially used in modern literature, including other chapters of this present work. 

The first such compound to be prepared was the deep-yellow unstable compound 9-arsa-anthracene but the thermally stable colourless arsabenzene (arsenin) can now conveniently be made by a general route from l,4-pentadiyne ... 

Walmsley AR, T Zhou, Ml Boirges-Walmsley, BP Rosen (1999) The ATPase mechanism of ArsA, the catalytic subunit of the arsenite pump. J Biol Chem 274 16153-16161. 

A further related class of 7r complexes is that where the 5-membered ring is provided by the CB4, C2B3 or CP (or As) B3 face of a widoundecacarborane or heterocarborane. Examples are found with Ge—R or with an outward-pointing lone pair. While there has been no crystal structure report, the structure with the Ge completing the closo-dodecacarborane structure is compatible with B11 and other NMR data. 2-carba, 2,3-dicarba, 2,4-dicarba, 2,3-phospha(or arsa)carba and 2,4-phosphacarba skeletons are all represented. 

Titanacydobutenes are useful intermediates for the synthesis of various organic compounds. The titanium atom in titanacydobutane can be replaced by phosphorus [70,71] or arsenic [71] to form phospha- 68 and arsa-cyclobutanes 69, respectively (Scheme 14.30). 

Scheme 14.30. Transformation of titanacydobutenes into phospha- and arsa-cyclobu-tenes.

LSR measurements are generally performed at room temperature. A detailed study of the influence of temperature on the magnitude of ArsAS has shown that the use of chiral LSR at low temperatures offers important advantages for the enantiomer analysis of weakly coordinat-... 

Sample formula11 AAg ARSa Theoretical formulab AAg ARSa... 

The calcium silylamide Ca N(SiMe3)2 2, or its ether adducts, has been used as a synthon to generate numerous other related derivatives. These include phosphanides, arsa-nides," thiolates, " selenolates and tellurolates, as well as a variety of diaza-substimted complexes, some of which were discussed above (see also Ref. 11). 

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