Patent ID: 7851505

Claim:
A compound of structural formula (I): or a solvate or hydrate thereof, wherein: R 1 (R 2 )(R 3 )(R 4 )N has the structure: R 5 , R 6 , and R 7 , and R 8 are independently hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, heteroalkyl or substituted heteroalkyl; and Y −2 is (W 2 S 12 ) −2 , (W 2 S 9 ) −2 , (W 2 S 7 ) −2 , (W 2 S 8 ) −2 , (W 2 S 11 ) −2 , (W 2 S 6 ) −2 or (W 2 S 13 ) −2 .