The failure of 4 and 6 was surprising given their symmetrical design was anticipated to bind the symmetrical pocket of A108G TTR■. The behaviour of 5 and 3 was equally surprising: (i) with 5 displaying selective binding of the symmetric binding pocket of A108G TTR■, (ii) while 3 displayed no binding preference for TTR (Fig. ). Inspired by the unsymmetrical nature of 5 and 3, however, we were curious if these compounds might display greater affinity for an unsymmetrical binding pocket (Fig. )-where a higher affinity was anticipated to lead to an even greater turn-on in keto emission.