1.Mixed Micellization of Dimeric (Gemini) Surfactants and Conventional Surfactants. I. Mixtures of an Anionic Dimeric Surfactant and of the Nonionic Surfactants C12E5 and C12E8
Zana R1, Lévy H, Kwetkat K. J Colloid Interface Sci. 1998 Jan 15;197(2):370-6.
The mixed micellization between the anionic dimeric surfactant Dim1 (disodium 1,11-didecyl-3,6,9-trioxaundecane 1,11-disulfate) and the two nonionic surfactants C12E5 and C12E8 (penta- and octaoxyethylene monododecyl ethers, respectively) has been investigated. The cmc of the mixtures has been measured by fluorescence probing, using the fluorescent probe pyrene. Its variation with composition revealed synergism in micelle formation. The micelle aggregation (N) numbers have been measured using time-resolved fluorescence quenching at a total surfactant concentration of about 70 mM and at 25, 40, and 55°C. The differences in total aggregation number of the mixed micelles in the two systems reflect (i) the higher aggregation number of C12E5 micelles with respect to C12E8 and Dim1 micelles; (ii) the higher cloud temperature of C12E8 with respect to C12E5; and (iii) the opposite temperature dependences of N for Dim1 and nonionic surfactants micelles.
Kim JS1, Lee WK, Rim JA, Jensen WP, Lee JH, Kim MJ, Kim JG, Suh IH. Acta Crystallogr C. 2000 Nov;56 Pt 11:1369-71.
A new calix-crowned azacrown ether, C(51)H(59)NO(11)S, consisting of four phenyl rings in a 1,3-alternate conformation was synthesized from the reaction of 25, 27-bis(5-chloro-3-oxapentyloxy)calixcrown-5 and p-toluenesulfonamide in the presence of Cs(2)CO(3). A crown-5 loop was attached on the two facing lower rims of the calixarene and the N-tosyl azacrown group was attached on the other set of lower rims of the calixarene backbone. This molecule seems to offer an inside cavity for the formation of a host-guest complex.
3.X-ray and neutron structure of 1,8-(3,6,9-trioxaundecane-1,11-diyldioxy)-9,10-dihydro-10,10-dimethylanthracene-9-ol (P326); some pitfalls of automatic data collection.
Palmer RA1, Potter BS, Lisgarten JN, Fenn RH, Mason SA, Mills OS, Robinson PM, Watt CI. Acta Crystallogr B. 2001 Jun;57(Pt 3):339-45. Epub 2001 Jun 1.
The structure of the crown ether 1,8-(3,6,9-trioxaundecane-1,11-diyldioxy)-9,10-dihydro-10,10-dimethylanthracene-9-ol, C(24)H(30)O(6).H(2)O (1), code name P326, the parent compound for a series of derivatives, has been determined by both X-ray diffraction at room temperature and neutron diffraction at very low temperature. The unit cells are very similar at both temperatures and in both cases the crystals exhibit P2(1) symmetry with Z = 4 (two molecules, A and B, respectively, per asymmetric unit) and pseudosymmetry P2(1)/c. The higher symmetry is broken mainly by the two independent water molecules in the unit cell, some reflections which would be absent in P2(1)/c having strong intensities in both the X-ray and neutron data. In both molecules A and B hydrogen bonds involving the water molecule stabilize the macrocyclic ring structure, one involving the macrocyclic O(9) as a donor. Close contacts between the water and macrocyclic O atoms in each molecule also suggest the presence of two bifurcated hydrogen bonds, involving water HW2 to both O(16) and O(18), and water HW1 to both O(18) and O(20), respectively, with considerable variation in the geometry being present.
Hou RB, Li B, Yin BZ, Wu LX. Acta Crystallogr Sect E Struct Rep Online. 2009 Apr 18;65(Pt 5):o1057. doi: 10.1107/S1600536809013154.
In the title mol-ecule, C(16)H(20)O(5)S(6), the two five-membered rings form a dihedral angle of 4.7 (3)°. The crystal packing exhibits weak inter-molecular C-H⋯O hydrogen bonds, which link the mol-ecules into chains propagating in , and π-π inter-actions, indicated by the short distances [3.756 (5) Å] between the centroids of five-membered rings from mol-ecules related by translation along the b axis.