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. 2020 Apr 30;11(23):5902–5908. doi: 10.1039/d0sc01396j

Phase transitions, lattice parameters (acub), number of molecules in the neighbouring rafts (nraft) and twist angles between the rafts (Φ/°) in the Cubbi phases of compounds 3/H and 3/na.

graphic file with name d0sc01396j-u2.jpg
3/n T/°C [ΔH kJ mol−1] a cub/nm n raft Φ L mol/nm
3/H H: Cr 126 [52.2] Iso 4.2
C: Iso 110 [27.3] Cr
3/1 H: Cr 127 [36.3] Iso 4.3
C: Iso 115 [36.4] Cr
3/2 H: Cr 120 [37.9] Iad(L) 127 [1.8] Iso1 135 [2.8] Iso 12.9 5.0 6.9 4.4
C: Iso 133 [2.7] Iso1 121 [0.2] Iso1[*] 110 [0.3] Iad(L) 105 [31.3] Cr
3/4 H: Cr 128 [53.5] Iso 18.4 4.0 7.6 4.6
C: Iso 128 [4.5] Iso1 122 [0.4] Iso1[*] 116 [0.7] I23[*] 73 [21.2] Cr
3/6 H: Cr 118 [64.6] (CrIso[*] 82 [17.3]) I23[*] 126 [2.2] Iso1 134 [5.7] Iso 18.1 3.8 7.7 4.8
C: Iso 130 [7.1] Iso1 123 [0.5] Iso1[*] 118 [1.1] I23[*] 61 [15.3] CrIso[*]
3/10 H: Cr 97 [63.2] (CrIso[*] 90 [17.6]) I23[*] 131 [2.2] Iso1 138 [5.7] Iso 18.4 3.7 7.6 5.2
C: Iso 135 [5.9] Iso1 127 [0.3] Iso1[*] 122 [0.9] I23[*] 66 [17.8] CrIso[*]
3/12 H: Cr 114 [47.0] Iad(S) 135 [3.4] Iso1 139 [6.2] Iso 11.4 3.3 7.9 5.4
C: Iso 137 [8.9] Iso1 128 [0.3] Iso1[*] 122 [0.7] Iad(S) 48 [17.9] CrIso < 20 Cr
3/14 H: Cr 108 [44.1] Iad(S) 135 [2.7] Iso1 138 [7.2] Iso 11.3 3.2 7.8 5.6
C: Iso 136 [9.2] Iso1 129 [1.4] Colhex 125 [0.5] Iad(S) 42 [16.9] CrIso < 20 Cr
3/16 H: Cr 80 [36.4] Iad(S) 133 [3.1] Iso1139 [6.1] Iso 11.5 3.2 7.8 5.8
C: Iso 136 [6.0] Iso1130 [2.3] Colhex 121 [0.5] Iad(S) 45 [25.0] Cr
a

DSC peak temperatures on heating/cooling (H/C) at 10 K min−1; nraft = ncell/(Lnet/0.45) with Lnet = 20.68aI23; and Lnet = 8.485aIa3̄d; Φ(Iad) = 70.5°/[0.354acub/0.45 nm]; Φ(I23) = 90°/[0.290acub/0.45 nm];25Lmol = maximum molecular length as determined with space filling models assuming a molecular bend of 110° and all-trans alkyl chains, see Fig. S15; abbreviations: Iso1 = achiral cybotactic isotropic liquid (see Fig. 3d), Cr = birefringent crystalline solid; CrIso = optically isotropic crystalline mesophase; CrIso[*] = mirror symmetry broken CrIso forming a conglomerate of chiral domains; Iad(S) = short pitch Iad phase with a smaller number of molecules in the unit cell/rafts and a larger twist angle Φ than in Iad(L) = long pitch Iad phase with a larger number of molecules in the unit cell/rafts and a smaller twist angle Φ; for other abbreviations, see Table 1; chiral phases are shown in bold; because the transitions Iso–Iso1 are very broad (see Table S1) it is difficult to determine precise enthalpy values; for DSC traces, see Fig. S1 and for XRD data, see Tables S1–S7 and Fig. S7 and S10–S14.