Bridge compound with N,N-dialkylamino group and application thereof

A bridge compound with an N,N-dialkylamino group of the following formula (I),

• wherein,
• R and R′each independently are selected from the group consisting of hydrogen, halogen, hydroxyl, carboxyl, sulfo, nitro, cyano, C1-4 alkyl, C1-4 alkoxy, ureido and amido;
• R1 and R2 each independently are hydrogen, or C1-4 alkyl;
• R″ is hydrogen, C1-4 alkylcarbonyl, phenyl, C1-4 alkyl, or C1-4 alkyl substituted by halogen, hydroxyl, carboxyl or sulfo;
• B and B′ each independently are selected from the group consisting of —SO2— and —CONH—(CH2)n—SO2—;
• i and j are integers independent of one another between 0 to 3;
• and
• m and n are integers independent of one another between 2 to 4.