Structural characteristics of aryloxybismuthanes stabilized by hypervalentbond formation. Synthesis, incorporation of 4-methoxyphenol through hydrogen bonding, and crystal supramolecularity

10-Phenoxyphenothiabismine 5,5-dioxide (2a) and related compounds 2b,c, the first example of an air-stable aryloxybismuthane whose bismuth-oxygen bond is not incorporated into a ring system, were synthesized and fully charact erized. Substitution of the OAr group in 2 by phenols in solution revealed two substitution tendencies. The substitution with 2-methoxyphenol proceede d preferentially dhe to intramolecular coordination of the 2-methoxy oxygen atom with the bismuth atom in 10-(2-methoxyphenoxy)phenothiabismine 5,5-di oxide (2b). Furthermore, the substitution is more favorable with more acidi c phenols, which is in accord with the apicophilicity observed at an apical position in hypervalent compounds. 10-(4-Methoxyphenoxy)phenothiabismine 5 ,5-dioxide (2c) was found to form 10-(4-methoxyphenoxy)phenothiabismine 5,5 -dioxide 4-methoxyphenol 1:1 complex (3) through hydrogen bonding between t he OH group of 4-methoxyphenol and the aryloxide oxygen atom of 2c. Such co mplex formation may be the initial step of the substitution reactions. Comp arison of the X-ray crystal structures of 2b, 2c, and 3 shows that these bi smuthanes adopt various association modes, which might show potential utili ty of bismuth-oxygen coordinate bonds in the construction of three-dimensio nal organometallic systems.