93972-02-2Relevant articles and documents
Catalytic activity of 1-methylimidazole-based phosphine ligands in the palladium-catalyzed Suzuki coupling reaction
Guan, Jin Tao,Song, Xiao Ming,Zhang, Zhi Yong,Wei, Ben Mei,Dai, Zhi Qun
, p. 87 - 89 (2015/01/30)
The catalytic activities of three N-methylimidazole-based phosphine ligands in the Suzuki coupling reaction were tested using PdCl2 as the catalyst. The results showed all three phosphine ligands exhibited excellent activity towards the Suzuki reaction, and the catalytic activity decreased with increasing number of imidazole groups.
Structural Characterization of Crystalline Ternary Inclusion Compounds at the Air-Water Interface
Plaut, David J.,Martin, Stephen M.,Kjaer, Kristian,Weygand, Markus J.,Lahav, Meir,Leiserowitz, Leslie,Weissbuch, Isabelle,Ward, Michael D.
, p. 15922 - 15934 (2007/10/03)
Crystalline ternary inclusion monolayers consisting of a two-dimensional hydrogen-bonded host network of guanidinium (G) ions and organosulfonate (S) amphiphiles, and biphenylalkane guests, can be generated at the air-water interface through synergistic structural enforcement by hydrogen bonding and host-guest packing. Surface pressure-area isotherms of the 4′ -hexadecylbiphenyl-4-sulfonate (C16BPS) amphiphile in the presence of G, with or without guest, are characterized by lift-off molecular areas expected for the GS sheet based on single-crystal X-ray structures of homologous bulk crystals. Intercalation of biphenylalkane guests (4-CnH 2n+1-C6H4-C6H5, n = 1, 4, 6, 10, 16; denoted CnBP) between organosulfonate hydrophobes, which define pocketlike cavities in the GS monolayer host, afford ternary inclusion monolayers with a 1:1 host-guest stoichiometry. These inclusion monolayers are less compressible than the guest-free host, consistent with dense packing of the biphenylalkane moieties of the host and the biphenylalkane guests. The inclusion monolayers are distinguished from the amorphous guest-free host and from selected guanidinium-free mixed monolayers by structural characterization with grazing-angle incidence X-ray diffraction (GIXD). The GIXD data for the ternary (G)C16BPS:C16BP and (G)C16BPS:C6BP inclusion monolayers obtained upon compression are consistent with a rectangular unit cell. The dimensions of these unit cells and refinement of the GIXD data suggest a "rotated shifted ribbon" GS hydrogen-bonding motif similar to that observed in some bulk GS crystals, including (G) (ethylbiphenylsulfonate). GIXD reveals that (G)C16BPS:C16BP and (G)C16BPS:C6BP are more crystalline than the corresponding guanidinium-free mixed monolayers. The (G)C16BPS:C6BP inclusion monolayer is stable upon compression, even though the alkyl-alkyl host-guest interactions are reduced due to the shorter hexyl substituents of the guest, demonstrating an important reinforcing role for the hydrogen-bonded GS sheet. The structure of a C16BPS: tetracosane (C24) mixed monolayer is independent of G; the unit cell symmetry and dimensions suggest a structure governed by alkyl-alkane interactions that prohibit formation of a GS network. These results illustrate that the existence of ternary inclusion monolayers with an intact GS network requires guest molecules that are structurally homologous with the hydrophobes of the host, in this case biphenylalkanes. The observation of these inclusion compounds suggests an approach for introducing functional nonamphiphilic molecules to an air-water interface through inclusion in a well-defined host.
SYNTHESIS OF 4-ALKYL-4'-CYANOBIPHENYLS
Ruolene, Yu. I.,Adomenas, P. V.,Sirutkaitis, R. A.,Denis, G. I.
, p. 1187 - 1191 (2007/10/02)
Liquid crystals of the 4-alkyl-4'-cyanobiphenyl group were synthesized without the use of copper cyanide. 4-Alkyl-4'-formylbiphenyls and the 4-formyloximes of 4'-alkylbiphenyl, which possess a liquid-crystalline state, were isolated.Beginning with the pentyl homolog, they form an enantiotropic nematic phase, and beginning with octyl homolog they also form a smectic meso phase.
