New 2,5-di:aryl-pyrimidine derivs. - with nonlinear optical properties, useful e.g. for frequency doubling of light and in liq. crystal mixt.

摘要

Pyrimidine derivs. of formulae (I) and (IV) are new, where in formulae A-X=RaC=(-), -N=, R3-N(+)=(-)An(-) or (CN)2C(-)-N(+)=(-); Ra=NO2, R1OCO, R1COO, R2CO or R1SO2; An=anion; B=2,5-pyrimidindiyl; D=NH2, NHNH2, OR6, O(CH2)pOH, OH, NR5R6, NHR6, N=CHR4, -NH-N=CHR4 or NO2; R1,R2,R3 and R5=1-22C alkyl or CF3(CF2)m(CH2)n; m is at least 5, n=zero or integer and n+m is not over 22; R4=opt. substd. phenyl; R6 is as R1 or (CH2)pOH; p=2-5; and X1=(MeO or NO2)-C=(-) or -N=. USE/ADVANTAGE - (I), partic. in the form of supported, ordered monolayers, have non-linear optical (NLO) properties, esp. for use in frequency doubling of light. Those (I) (i.e. the pyridinium dicyanomethides) which are coloured are more useful as light modulators. Other applications are in electro-optical switches and optical parametric amplifiers, and some (I) can also be used as components of liq. crystal media. (I) have good stability (against the atmosphere, light and high temp.); high NLO activity and absorbence max. is below 400(esp. 350) nm. In an example, 5.5g (VI; Dc=NO2; An=BF4) and 4.26g 4-pyridine carbamidine hydrochloride were reacted in MeOH with NaOMe, first at room temp. then at reflux. The mixt. was cooled, diluted with water, neutralised (HCl) and the recovered pptd. recrystallised from DMF to give 4-(2-(4- pyridyl)-5-pyrimidinyl) phenol. This was O-alkylated conventionally with octadecyl bromide/K2CO3 and then N-methylated with Me2SO4 at reflux to give (II), m.pt. 126-127 deg.C; clear point 239-241 deg.C; absorbence max. in CHCl3, 376 nm.