Liquid 2-Pyridinium Styryl Dyes having Oxaalkyl Units

2-{4-[Bis(2,5-dioxa-7-heptanyl)amino]styryl}-1-(2,5,8-trioxa-10-octadecanyl)- and 1-(2,5,8-trioxa-10-octadecanyl)-2-{4-[bis(2,5,8- trioxa-10-octadecanyl)-amino]styryl}pyridinium bis(perfluorobutylsulfonyl)imide are liquid compounds at room temperature. The fluorescence intensity of these liquid derivatives in liquid nitrogen was enhanced ca. six-times compared with that at room temperature.