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971.
Novel HPLC methods were developed for the analytical and semipreparative resolution of new antidepressant drug mirtazapine enantiomers. At analytical scale, the separation of the mirtazapine enantiomers was investigated using both cellulose and amylose tris(3,5-dimethylphenylcarbamate) (CDMPC and ADMPC) chiral stationary phases under normal-phases and polar organic modes. Good baseline enantioseparation was achieved using cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phases under both normal-phases and polar organic modes. Furthermore, the elution order of mirtazapine enantiomic pairs was found reversed by changing the stationary phase from the amylose-based ADMPC–CSPs to its cellulose-based counterpart, CDMPC–CSPs. The validation of the analytical methods including linearity, limit of detection (LOD), limit of quantification (LOQ), recovery and precision, together with the semipreparative resolution of mirtazapine racemate were carried out using cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phases and methanol as mobile phase without any basic additives under polar organic mode. At analytical scale, the elution times of both enantiomers were less than 6 min at normal temperature and 1.0 ml/min, with the separation factor () 1.99 and the resolution factor (Rs) 3.56. Then, the analytical methods were scaled up to semipreparative loading to obtain small quantities of both mirtazapine enantiomers. At semipreparative scale, about 16 mg/h enantiomers could be isolated and elution times of both enantiomers were less than 10 min at 2.0 ml/min. To increase the throughput, the technique of boxcar injections was used. One enantiomer ((−)-(R)-mirtazapine) was isolated with purity of >99.9% e.e. and >98.0% yield and another ((+)-(S)-mirtazapine) was isolated with purity of >97.0% e.e. and >99.0% yield. In addition, optical rotation and circular dichroism (CD) spectroscopy of both mirtazapine enantiomers isolated were also investigated. 相似文献
972.
One linear template 13 and one cyclophane template 15, both incorporating two electron rich 1,4‐dialkoxybenzene units and one diamide unit, have been synthesized. By utilizing donor‐acceptor interaction and/or intermolecular hydrogen bonding assembling principles, one novel hetero[3]rotazane 22·4Cl, possessing one neutral and one tetracationic ring components, has been synthesized from 13, through neutral [2]rotaxane 21 as intermediate. With 15 as template, tetracationic [2]catenane 23·4PF6 was assembled by using donor‐acceptor interaction, but no neutral [2]rotaxane could be obtained under the typical conditions of hydrogen bonding assembling principle. The interlocked supramolecular compounds have been characterized and their spectral properties are investigated. 相似文献
973.
运用三足四齿配体三(2-甲基吡啶)胺(TPA)或三(2-甲基苯丙咪唑)胺(TBA),得到两个双核铁(III)配合物,[Fe2L2(μ2-O)(μ2-p-NH2-C6H4COO)]3+
(L = TPA, 1 和 L = TBA,
2)。两个配合物均为单斜晶系,空间群为P2(1)/c.晶胞参数 1: a =
1.4529(4), b = 1.6622(5), c = 2.0625(6) nm, β= 100.327(5)º,
V = 4.900(3) nm3, z = 4, F(000) = 2344, 分子量Mr = 1142.91, Dc
= 1.549 g/cm3, R1 = 0.0544,
R2 = 0.0962. 2: a = 1.3378(4), b = 2.1174(7), c =
2.4351(7) nm, β= 97.315(6)º, V = 6.842(4) nm3,
z = 4, F (000) = 3116, 分子量Mr = 1505.08, Dc
= 1.444 g/cm3, R1 = 0.0793, R2 = 0.1623. 在两个双核铁(III)配合物中,中心的三价铁和配体TPA或TBA上的四个氮原子和两个氧原子通过不同的桥形成一个畸变的八面体构型。 相似文献
974.
Si-Tai Zheng Huan-Huan Yin Zhao-Guang Ma Nan-Li Sheng Tian-Guang Zhan Xiao-Yang Yan Jiecheng Cui Li-Juan Liu Kang-Da Zhang 《中国化学快报》2019,30(3):707-709
Photoresponsive supramolecular hydrogel was fabricated from a small azobenzene-bridged dicationic pyridinium salt in the aqueous solution. The UV-vis light triggered reversible gel-sol transformation of such low-molecular-weight supramolecular hydrogel was systematically investigated through various analytical techniques. 相似文献
975.
The compounds Ce(10)Cl(4)Ga(5) and Ln(3)ClGa(4) (Ln = La, Ce) were synthesized from stoichiometric mixtures of Ln, LnCl(3), and Ga under Ar atmosphere in sealed Ta ampules at 910-1020 degrees C for 25-26 days. Ce(10)Cl(4)Ga(5) is isostructural to La(10)Cl(4)Ga(5) (space group I4/mcm, No. 140) with lattice constants a = 7.9546(11) A, c = 31.793(6) A. Ln(3)ClGa(4) represents a new structural type, also in the space group I4/mcm, with a = 8.1955(8) and 8.1123(11) A, c = 11.363(2) and 11.229(2) A, respectively, for Ln = La and Ce. Ce(10)Cl(4)Ga(5) features building blocks of Ga-centered Ce(6) trigonal prisms and distinctive two-dimensional intermetallic CuAl(2) and U(3)Si(2) type nets. Its electronic structure falls within the realm of reduced rare-earth halides. Ln(3)ClGa(4) also contains the intermetallic CuAl(2) type nets, but the interstitials are inverted: The building blocks are Cl-centered Ln(6) octahedra. Its electronic structure is characterized by strong peripheral Ln-Ga bonding stabilizing the Ln(6)Cl octahedron which normally would have its Ln-Ln antibonding orbitals filled with electrons from interstitials beyond chalcogen. Magnetic susceptibility and conductivity measurements confirm the metallic nature of all three compounds. 相似文献
976.
977.
Eight tris(organotin)-substituted Keggin tungstosilicate heteropolyanions have been synthesized and characterized by elemental analysis, infrared and M?ssbauer spectroscopy, multinuclear NMR, and X-ray crystallography. The new anions contain alpha- or beta-SiW(9)O(34)(10)(-) moieties and are of two structural types, [(RSn)(3)(SiW(9)O(37))](7)(-) (R, isomer: Ph, alpha-, 1; n-Bu, alpha-, 2; Ph, beta-, 3; n-Bu, beta-, 4) and [(RSnOH)(3)(SiW(9)O(34))(2)](14)(-) (Ph, alpha-, 5; n-Bu, alpha-, 6; Ph, beta-, 7; n-Bu, beta-, 8). Crystals of Cs(4)H(3)[(PhSn)(3)(SiW(9)O(37))].8H(2)O (anion 3) are monoclinic, space group C2/c, with lattice constants a = 48.91(2) ?, b = 12.111(3) ?, c = 20.334(9) ?, beta = 102.30 degrees, and Z = 8. The anion has nominal C(3)(v)() symmetry and has a structure with three corner-shared WO(6) octahedra of the beta-Keggin anion replaced by three PhSnO(5) groups. Crystals of Cs(9)H(5)[(BuSnOH)(3)(SiW(9)O(34))(2)].36H(2)O (anion 6) are tetragonal, space group P&fourmacr;2(1)m, with lattice constants a = b = 29.005(4) ?, c = 13.412(4) ?, and Z = 4. The anion has the anticipated D(3)(h)() symmetry and contains three BuSnOH groups sandwiched between A,alpha-SiW(9)O(34)(10)(-) anions. 相似文献
978.
Tongbu Lu Xin Wang Minyu Tan Yu Liu Yoshihisa Inoue Tadao Hakushi 《Helvetica chimica acta》1993,76(1):241-247
The lanthanide nitrate complexes with 13-crown-4(13-C-4) have been prepared in AcOEt. These new complexes with the general formula Ln(NO3)3.(13-c-4) (Ln = La–Nd, Sm–Lu) have been characterized by means of elemental analysis, IR and 1H-NMR spectra, conductivity measurements, and TG-DTA techniques. The crystal and molecular structure of Nd(No3)3. (13-c-4) has been determined by single crystal X-ray diffraction. It crystallizes in the monoclinic space group P21/a with Z = 8. Lattice parameters are a = 15.393(1), b = 12.578(1), c = 19.279(2) Å, β = 113.05(1)°, V = 3435 Å3, Dc = 2.01 g cm?3, μ = 31.0 cm?1 (Mok2), F(000) = 2056. The structure was solved by Patterson and Fourier techniques and refined by least-squares to a final conventional R value of 0.032 for 5218 independent reflections with I ? 3σ(I). There are two independent Nd(No3)3 · (13-C-4) monomers in one asymmetrical unit. The coordination numbers are ten in these two independent monomers. 相似文献
979.
The Bose-Einstein condensation of free relativistic particles [=(M
2
c
4
+c
2
p
2
)
1/2
–Mc
2
] is studied rigorously. For massless bosons (=cp), the condensation transition of third (second) order occurs in2 (3) dimensions (D). The molar heat capacity follows the T
2
(T
3
) law below the condensation temperature Tc [k
B
Tc=(2
2
c
2
n/1.645)
1/2
[(
2
3
c
3
n/1.202)
1/3
], reaches4.38 (10.8) R at T=Tc, and approaches the high-temperature-limit value2 (3) R with no jump (a jump equal to6.75R) in2 (3)D. For finite-mass (M) bosons, the phase transition occurs only in3D with the condensation temperature Tc always smaller than that of the corresponding nonrelativistic bosons [=(2M)
–1
p
2
]. If the mass M is reduced to zero, the condensation temperature Tc grows monotonically and reaches eventually that of massless relativistic bosons. This mass-dependence of Tc is therefore distinct from the case of nonrelativistic bosons, where Tc grows to infinity as M 0. A brief discussion is given for a possible connection with the normal-to-super transition of the independently moving Cooper pairs (bosons). 相似文献
980.