Catalyzed by zinc bromide, tetrahydrofuran ring can be opened with acyloxyphos- phonium bromide generated in situ to afford 4-bromobutyl esters under mild conditions in good to excellent yields.
The study of interactions between surfactant and salt in aqueous solutions has attracted significant interest in recent years because of their widespread applications and relatively complex behavior.This work reports ...The study of interactions between surfactant and salt in aqueous solutions has attracted significant interest in recent years because of their widespread applications and relatively complex behavior.This work reports the systematic study of surface phenomenon and self-aggregation behavior of cationic surfactant cetyltrimethyl ammonium bromide(CTAB)with ammonium nitrate(NH_(4)NO_(3))salt.Surface and thermodynamic properties of cationic surfactant CTAB with NH_(4)NO_(3)were investigated at different temperatures using different techniques such as conductometry and surface tensiometery.The surface tension measurement was carried out to find out the critical micelle concentration,free energy of adsorption,free energy of micellization,minimum area per molecule,and surface excess concentration.The study reveals that the process of micellization is spontaneous and exothermic in nature.Conductance measurement was carried out to determine critical micelle concentration,degree of ionization and degree of counter ion binding.Addition of NH_(4)NO_(3)to the surfactant solutions increase the values of degree of ionization and degree of counter ion binding,although it lowers the values of critical micelle concentration showing that the process of micellization is more favorable and spontaneous.The study is very helpful to develop better understanding about interaction between electrolyte and surfactant,which are used in many applications and in different processes(e.g.,pharmaceutical,industrial foaming,drug solubilization,oil recovery,and medium for metal nanoparticle formation).展开更多
Compounds with visible-light-induced photoluminescence are particularly attractive in acting as the emitting components of light-emitting diodes and fluorescent probes for biological applications. A new complex [Zn(NC...Compounds with visible-light-induced photoluminescence are particularly attractive in acting as the emitting components of light-emitting diodes and fluorescent probes for biological applications. A new complex [Zn(NCS)_3(MQ)](MQ^+ = N-methyl-4,4?-bipyridinium) with an isolated molecular structure has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and solid-state photoluminescent determination. Crystal data: C_(14)H_(11)N_5S_3Zn, M_r = 410.83, monoclinic, space group P2_1/c, a = 8.809(5), b = 13.138(7), c = 15.580(9) ?, b = 104.433(10)°, V = 1746.2(17) ?~3, Z = 4, D–c = 1.563 g×cm^3, μ = 1.769 mm^(–1), F(000) = 832, the final R = 0.0376 and wR = 0.1243 for 2850 observed reflections with I > 2s(I). In the crystal structure, the zinc atom is tetrahedrally coordinated by one MQ+ ligand and three NCS– groups to yield a tetrahedral configuration. The bond length of Zn–NMQ is clearly shorter than those found in reported Zn(Ⅱ) complexes of 4,4?-bipy. The isolated units are joined by C–H···S interactions to generate a 2D hydrogen-bonding network. This compound displays visible light-induced photoluminescence, which originates from both intraligand charge-transfer of the MQ+ ligand and NCS~–→MQ^+ charge-transfer according to a density of states(DOS) calculation. Moreover, its emission band shows a clear blue shift compared with those of halide compounds.展开更多
文摘Catalyzed by zinc bromide, tetrahydrofuran ring can be opened with acyloxyphos- phonium bromide generated in situ to afford 4-bromobutyl esters under mild conditions in good to excellent yields.
文摘The study of interactions between surfactant and salt in aqueous solutions has attracted significant interest in recent years because of their widespread applications and relatively complex behavior.This work reports the systematic study of surface phenomenon and self-aggregation behavior of cationic surfactant cetyltrimethyl ammonium bromide(CTAB)with ammonium nitrate(NH_(4)NO_(3))salt.Surface and thermodynamic properties of cationic surfactant CTAB with NH_(4)NO_(3)were investigated at different temperatures using different techniques such as conductometry and surface tensiometery.The surface tension measurement was carried out to find out the critical micelle concentration,free energy of adsorption,free energy of micellization,minimum area per molecule,and surface excess concentration.The study reveals that the process of micellization is spontaneous and exothermic in nature.Conductance measurement was carried out to determine critical micelle concentration,degree of ionization and degree of counter ion binding.Addition of NH_(4)NO_(3)to the surfactant solutions increase the values of degree of ionization and degree of counter ion binding,although it lowers the values of critical micelle concentration showing that the process of micellization is more favorable and spontaneous.The study is very helpful to develop better understanding about interaction between electrolyte and surfactant,which are used in many applications and in different processes(e.g.,pharmaceutical,industrial foaming,drug solubilization,oil recovery,and medium for metal nanoparticle formation).
基金supported by the National Natural Science Foundation of China(21221001,and 21471149)Key Research Program of Frontier Science,CAS(QYZDJ-SSW-SLH028)
文摘Compounds with visible-light-induced photoluminescence are particularly attractive in acting as the emitting components of light-emitting diodes and fluorescent probes for biological applications. A new complex [Zn(NCS)_3(MQ)](MQ^+ = N-methyl-4,4?-bipyridinium) with an isolated molecular structure has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy and solid-state photoluminescent determination. Crystal data: C_(14)H_(11)N_5S_3Zn, M_r = 410.83, monoclinic, space group P2_1/c, a = 8.809(5), b = 13.138(7), c = 15.580(9) ?, b = 104.433(10)°, V = 1746.2(17) ?~3, Z = 4, D–c = 1.563 g×cm^3, μ = 1.769 mm^(–1), F(000) = 832, the final R = 0.0376 and wR = 0.1243 for 2850 observed reflections with I > 2s(I). In the crystal structure, the zinc atom is tetrahedrally coordinated by one MQ+ ligand and three NCS– groups to yield a tetrahedral configuration. The bond length of Zn–NMQ is clearly shorter than those found in reported Zn(Ⅱ) complexes of 4,4?-bipy. The isolated units are joined by C–H···S interactions to generate a 2D hydrogen-bonding network. This compound displays visible light-induced photoluminescence, which originates from both intraligand charge-transfer of the MQ+ ligand and NCS~–→MQ^+ charge-transfer according to a density of states(DOS) calculation. Moreover, its emission band shows a clear blue shift compared with those of halide compounds.
