Patent ID: 7910754

Claim:
A compound of the formula wherein R 1 , R 2 , R 3 , and R 4 each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group, wherein R 1 and R 2 can be joined together to form a ring, wherein R 3 and R 4 can be joined together to form a ring, and wherein R 1 , R 2 , R 3 , and R 4 can each be joined to a phenyl ring in the central structure; wherein a and b each, independently of the others, is an integer which is 0, 1, 2, or 3; wherein R 5 and R 6 are each optionally present and wherein each of R 5 and R 6 independently of the other, if present, are independently selected from (i) an alkyl group, (ii) an aryl group, (iii) an arylalkyl group, (iv) an alkylaryl group, (v) a halogen atom, (vi) an ester group, (vii) an amide group, (viii) a sulfone group, (ix) an amine group or ammonium group, (x) a nitrile group, (xi) a nitro group, (xii) a hydroxy group, (xiii) a pyridine or pyridinium group, (xiv) an ether group, (xv) a ketone group, (xvi) a carbonyl group, (xvii) a thiocarbonyl group, (xviii) a sulfate group, (xix) a sulfide group, (xx) a sulfoxide group, (xxi) a phosphine or phosphonium group, (xxii) a phosphate group, (xxiii) a mercapto group, (xxiv) a urethane group, or (xxv) a urea group, wherein R 5 and R 6 can each be joined to a phenyl ring in the central structure, wherein R 8 , R 9 , and R 10 each, independently of the other, is optionally present and wherein each of R 8 , R 9 , and R 10 , if present, is independently selected from (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group; wherein R″ is optionally present and wherein R′ and R″, if present, are each independently selected from (i) an alkyl group, (ii) an aryl group, (iii) an arylalkyl group, or (iv) an alkylaryl group; wherein at least one of R′ or R″ contains at least about 5 carbon atoms; wherein CA is a hydrogen atom or a cation; and wherein A is an anion.