1,3-Bis(4-dibutylamino-2-hydroxyphenyl)-2,4-dihydroxycyclobutenediylium 1,3-Cyclobutanedione, 2,4-bis(4-(dibutylamino)-2-hydroxyphenyl)- 121289-36-9 2,4-Bis(4-(dibutylamino)-2-hydroxyphenyl)-1,3-cyclobutanedione Tetrabutyl squarate