VARIABLE ASSEMBLY OF IMIDAZOLE INTO ALPHA-VOPO4-CENTER-DOT-2H(2)O

alpha-VOPO4 ..2H(2)O reacts with imidazole (Im) in anhydrous ethanol to give a layered composite with d(00l)=10.3 Angstrom, whereas in 95% ethanol it gives a phase with d(00l)=8.8 Angstrom; both have formula VOPO4(Im)1.0 . nH(2)O (8.8 Angstrom phase, n=0.2; 10.3 Angstrom phase, n=0.6). The 8.8 Angstrom phase slowly changes to a third phase with d(00l)=9.63 Angstrom. Indirect evidence suggests that the 10.3 Angstrom phase contains Im coordinated to intralayer vanadium and oriented vertically to the planes, whereas in the 8.8 Angstrom phase the Im lies almost flat between the layers and is not coordinated, i.e., the materials may be considered 'intercalation isomers'.