Gallagher T, Taylor M J, Ernst S R, Hackert M L, Poonia N S
Chemistry Department, University of Texas, Austin 78712.
Acta Crystallogr B. 1991 Jun 1;47 ( Pt 3):362-8. doi: 10.1107/s0108768190013544.
The crystal structures of the dipotassium and the mixed sodium/potassium picrate complexes with the crown ether dibenzo-24-crown-8 (DB24C8) were solved and found to be nearly identical. (I): NaK-pic2(DB24C8), [NaK(C6H2N3O7)2(C24H32O8)]. Mr = 966.8, triclinic, P1, a = 8.164 (2), b = 9.960 (2), c = 13.368 (3) A, alpha = 103.92 (3), beta = 108.03 (2), gamma = 93.23 (2) degrees, V = 993.0 (7) A3, Z = 1, Dm = 1.54 (T = 298 K). Dx = 1.62 (1) g cm-3, lambda = (Mo K alpha) 0.71069 A, mu = 2.37 cm-1, F(000) = 500, T = 103 K, R = 0.086 for 2904 unique reflections. (II): K2pic2(DB24C8), [K2(C6H2N3O7)2(C24H32O8)]. Mr = 982.9, triclinic, P1, a = 8.231 (4), b = 9.850 (2), c = 13.346 (4) A, alpha = 103.91 (2), beta = 106.82 (3), gamma = 93.37 (2) degrees, V = 995.7 (9) A3, Z = 1, Dm = 1.59 (T = 298 K), Dx = 1.638 (8) g cm-3, lambda (Mo K alpha) = 0.71069 A, mu = 3.30 cm-1, F(000) = 508, T = 163 K, R = 0.042 for 4835 unique reflections. Both structures feature eight-coordinated cations between alternating layers of relatively flat crown ligands and paired picrates. In the mixed-metal system the two cations are disordered between two P1-related sites; these metal sites have a coordination environment only slightly different from that in the dipotassium structure. Na+ is able to occupy an environment similar to that of K+ under the conditions of these crystals, a situation not previously observed in the chemistry of crown ethers or macrocylic multidentates.
已解析出苦味酸二钾和苦味酸钠/钾与冠醚二苯并 - 24 - 冠 - 8（DB24C8）形成的混合配合物的晶体结构，发现它们几乎相同。（I）：NaK - pic2(DB24C8)，[NaK(C6H2N3O7)2(C24H32O8)]。Mr = 966.8，三斜晶系，P1，a = 8.164(2)，b = 9.960(2)，c = 13.368(3) Å，α = 103.92(3)，β = 108.03(2)，γ = 93.23(2)°，V = 993.0(7) ų，Z = 1，Dm = 1.54（T = 298 K）。Dx = 1.62(1) g cm⁻³，λ = (Mo Kα) 0.71069 Å，μ = 2.37 cm⁻¹，F(000) = 500，T = 103 K，对2904个独立反射，R = 0.086。（II）：K2pic2(DB24C8)，[K2(C6H2N3O7)2(C24H32O8)]。Mr = 982.9，三斜晶系，P1，a = 8.231(4)，b = 9.850(2)，c = 13.346(4) Å，α = 103.91(2)，β = 106.82(3)，γ = 93.37(2)°，V = 995.7(9) ų，Z = 1，Dm = 1.59（T = 298 K），Dx = 1.638(8) g cm⁻³，λ(Mo Kα) = 0.71069 Å，μ = 3.30 cm⁻¹，F(000) = 508，T = 163 K，对4835个独立反射，R = 0.042。两种结构的特征都是在相对扁平的冠醚配体和成对苦味酸盐的交替层之间有八配位阳离子。在混合金属体系中，两种阳离子在两个与P1相关的位置之间无序分布；这些金属位点的配位环境与二钾结构中的仅略有不同。在这些晶体的条件下，Na⁺能够占据与K⁺相似的环境，这种情况以前在冠醚或大环多齿配体的化学中未曾观察到。
