Filled smectic A phases in binary liquid-crystalline systems of terminal-nonpolar compounds. V. Smectic A phases with unusually high ratio of the layer spacing and the average molecular length

The phase diagrams of four binary systems are presented in which one component is a bi-swallow tailed compound and the second is a nematogenic rod-like compound. In all of the phase diagrams studied an induced smectic A phase occurs. According to X-ray measurements the layer spacing d of the smectic A phase is considerably higher than the average molecular length L . Depending on the binary system and the concentration d/L ratios between 1·17 and 2·13 were found. We propose an interpretation of the results on the basis of a simple packing model.