The effect of temperature on yields and product ratios during the synthesis of cryptands containing the ferrocene unit

The condensation of 1,1-bis(chlorocarbonyl)ferrocene with diaza-18-crown-6 gives 1,1′-(1,4,10,13-tetraoxa-7,16-diazacyclo-octadecane-7,16-diyldicarbonly)ferrocene (3) and its dimer 1,1″; 1′, 1‴-bis (1,4,10,13-tetraoxa-7,16-diaza-cyclo-octadecane-7,16-diyldicarbonyl) bisferrocene (4); the overall yields of (3) and (4) and the product ratios are dependent upon the reaction temperature.