Synthesis and characterization of antiapicophilic arsoranes and related compounds.

Utilizing bulky bidentate ligand systems with C(2)F(5) and n-C(3)F(7) groups, antiapicophilic arsoranes (5b and 5c, respectively) were synthesized. A kinetic study on the isomerization of these arsoranes to their more stable isomers showed that the barriers increased in the order of CF(3) < C(2)F(5) < n-C(3)F(7) in accord with their steric bulk. It was also revealed that the degree of freezing isomerization was larger for the change from CF(3) to C(2)F(5) than from C(2)F(5) to n-C(3)F(7), obvious from the differences in activation free energy at 363 K of 1.6 and 0.3 kcal mol(-1), respectively. X-ray structural analysis of several precursors of these two systems disclosed the unique structures of these compounds.