Table 1. Phase Sequences and Transition Temperatures (°C)a,b of Tris(keto-hydrazone)s Belonging to THN(6)n and THN(9)n Seriesf.
| phase
sequence |
||
|---|---|---|
| compound | heating | cooling |
| THN(6)6 | Cr 119.6 (25.5) Colh/p6mm 125.3 (1.4) I | I 120 (1.4) Colh/p6mmc |
| THN(6)7 | Cr 105 (30.7) Colh/p6mm 152 (1.7) I | I 149 (1.6) Colh/p6mmc |
| THN(6)8 | Cr 96.7 (50.4) Colh/p6mm 152.9 (2.2) I | I 150.8 (1.8) Colh/p6mm 45.7 (24.1) Cr |
| THN(6)9 | Cr 91.2 (34) Colh/p6mm 154.3 (2.1) I | I 153.8 (2) Colh/p6mm 52.1 (32.4) Cr |
| THN(6)10 | Cr 94.4 (56.7) Colh/p6mm 149.2 (2.4) I | I 146.3 (2.2) Colh/p6mm 56.8 (7.8) Cr |
| THN(6)11 | Cr 98.7 (47) Colh/p6mm 161.6 (2.9) I | I 159.5 (2.8) Colh/p6mm 62.6 (46) Cr |
| THN(6)12 | Cr 92.5 (19.2) Colh/p6mm 156.8 (2.6) I | I 155.5 (2.5) Colh/p6mm 62.2 (18.1) |
| THN(6)10B | Colh/p6mm 131.2 (1.8) I | I 126.6 (1.8) Colh/p6mme |
| THN(9)6 | Colh/p6mm 225 Id | I 218d Colh/p6mme |
| THN(9)7 | Col 215 Id | I 211.7d Colr/p2mme |
| THN(9)8 | Colr/p2mm 210 Id | I 205dColr/p2mme |
| THN(9)9 | Colr/p2mm 200 Id | I 195d Colr/p2mme |
| THN(9)10 | Colr/p2mm 190 Id | I 183d Colr/p2mme |
| THN(9)11 | Colr/p2mm 190 Id | I 184d Colr/p2mme |
| THN(9)12 | Colr/p2mm 180 Id | I 176d Colr/p2mme |
| THN(9)10B | Colr/p2mm 154 Id | I 142d Colr/p2mme |
For compounds belonging to THN(6)n series, peak temperatures in the DSC traces obtained during the first heating–cooling cycles at 5 °C min–1 are given along with the enthalpies (kJ mol–1) of transitions.
The temperature of the phase transitions of tris(hydrazone)s belonging to the THN(9)n (trialkoxy) series could be determined with the aid of POM only as no events were seen in the DSC traces.
This phase (supercools) exists until the limitation (−50 °C) of the DSC instrument; however, the fluidity of the phase decreases in the temperature range of 40–65 °C, but the texture of the Col phase remains unaltered, implying freezing of the phase in the glassy state.
The phase transition was observed under POM and too weak to get detected in DSC.
This phase (supercools) exists until the limitation (−50 °C) of the DSC instrument.
I, isotropic liquid; Colh/p6mm, hexagonal columnar phase with the p6mm lattice; Colr/p2mm, columnar rectangular phase with the p2mm lattice; Cr, crystal.