Carbon—arsenic bonds reactions with

Attempts to prepare arsolyl anions by reductive cleavage of s-chloro-2,3,4,5-tetramethylarsole or reductive cleavage of the permethylated l,l -biarsole result in erratic yields of the anion (153) and are contaminated by elemental arsenic. A superior procedure calls for reduction of the. 45-phenyl derivative (Scheme 35). With this procedure, analytically pure anion (153) is prepared in near quantitative yield by extracting the byproduct PhLi with ether after the reaction has finished. Reaction of this anion with 2.0 equivalents of TMEDA allows the preparation of crystals of its TMEDA adduct (68) that are suitable for x-ray analysis. This shows the nearly planar arsole ring to be rj-5 coordinated, the arsenic-carbon bonds to be intermediate between single and double bond... 

Only a few reports deal with reactions of arsenic and antimony compounds with HFA. Several reports describe insertion of HFA into As—H bonds 43, 72, 155). In contrast to the heavier group IV elements, insertion leads to the formation of 2-arsanoperfluoropropanols 87. This difference can be explained by assuming nucleophilic attack by the arsenic lone pair on the highly electrophilic carbonyl carbon. 

A particularly interesting class of S02-bridged polynuclear complexes is exemplified by the A-frame complex [PdCl(dpm)]2(S02), which results from addition of SO2 to the metal-metal bonded dimer [PdCl(dpm)]2 (Fig. 31). A unique feature of this complex is the reversibility of the SO2 binding across the metal-metal bond. Carbon monoxide effects a similar reaction with [PdQ(dpm)]2. X-ray photoelectron spectra have been reported for the SO2 complex and its arsenic analogue [PdQ(dam)]2(S02). Insertion... 

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