硝酸镧联吡啶冠醚混配配合物La(NO_3)_3(bipy)(H_2O)_2(B-15-C-5)的合成及晶体结构

本文报道了La(NO_3)_3(bipy)(2H_2O)(B-15-C-5)(Mr=785.46)的合成和晶体结构。晶体属单斜晶系,空间群为P2_1/n。晶胞参数:a=11.951(6),b=18.181(7),c=14.754(5),β=96.19(3)°,V=3187.0,Z=4,D=1.637g/cm^3。晶体结构由直接法和Fourier合成解出,使用对角块矩阵和全矩阵最小二乘法对原子参数进行修正,最后偏离因子R=0.035(5261个,I>3σ(I)的衍射)。单晶结构分析表明,在该配合物中,直接参与配位的是联吡啶上的两个氮原子,三个NO_3中的六个氧原子以及两个水分子中的氧原子,La^(3+)的配位数为10。B-15-C-5是通过氢键与H_2O分子相连的。

高分子量甲基丙烯醇聚氧乙烯醚的合成工艺

通过研究甲基烯丙醇聚氧乙烯醚(M=8000)的合成工艺,探索了高分子量聚羧酸减水剂单体的合成条件。结果如下,甲基烯丙醇和环氧乙烷的摩尔比为1∶183,催化剂的用量为甲基烯丙醇摩尔数的0.014~0.015。催化剂为复配型催化剂15-冠(醚)-5与Na,摩尔比为1:1。整个合成反应分为三步进行:第一步主要是合成500分子量甲基丙烯醇聚氧乙烯醚中间体,第二步是合成1000分子量甲基丙烯醇聚氧乙烯醚中间体,第三步是合成8000分子量甲基丙烯醇聚氧乙烯醚成品。控制反应温度为120~130℃、反应压力小于0.35 MPa,能得到平均分子量为8000的甲基丙烯醇聚氧乙烯醚产品。

Studies on Electronic Structure and Chemical Bond Features of the Coordinate Compound Crystal [Mn(H_2O)_4(NCS)_2]·(18-C-6)

In this paper, the chemical bond features of the coordinate compound crystal [Mn (H2O)4 (NCS)2D·(18- C- 6) have been studied by means Mulliken's bond orders, charge distribution, and electronic density of states etc. calculated by means of CNDO/2 molecular orbital theory and based on a molecular fragment model of this compound. The results show that the main bonding fashion between the transition metal coordinate unit [Mn(H2O)4(NCS)2] and ether ring of 18-C-6 is quite highly localized hydrogen bond.

Cross-Linked Crown Ether-SE-54 as Stationary Phase for Open-Tubular Column Gas Chromatography

The cross-linking of crown ether-SE-54 in fused-silica capillary columns were initiated by dicumyl peroxide(DCUP),azo-bis-isobutyronitrile (AIBN)and ozone(O_3).Parameters of evaluation such as polarity,selectivity, phase transition temperature and thermal stability were studied and compared with those of poly(crown ether)stationary phase.

Study on the influence of crown ether on arsenic behavior during coal pyrolysis

The influence of crown ether on behaviors of arsenic at different temperatures and residence time was investigated during the pyrolysis of Tuanbo （TB） coal. The modes of occurrence of arsenic were determined by sequential chemical extraction, density fractionation and demineralization. The results indicated that at the same temperature and residence time, the arsenic removal adding dibenzo-18-crown-6 was higher than that adding 18-crown-6, and were all higher than that of TB coal during pyrolysis. When temperature was 850 ℃ and residence time was 30 min, the arsenic removal of TB coal was 30.63%; at the same condition, the arsenic removal while adding 18-crown-6 was 33.21%, higher than that of TB coal; and the arsenic removal while adding dibenzo-18-crown-6 was 67.41%, significantly higher than that of TB coal. From the results, we can see that adding crown ether can improve the arsenic removal during coal pyrolysis, and especially be conducive to the arsenic which is mainly associated with sulfates ＆ monosulfides and that in stable forms.

Density Functional Theory Study of Selectivity of Crown Ethers to Li^+ in Spent Lithium-Ion Batteries Leaching Solutions

It is a challenge to recover lithium from the leaching solution of spent lithium-ion batteries,and crown ethers are potential extractants due to their selectivity to alkali metal ions.The theoretical calculations for the selectivity of crown ethers with different structures to Li ions in aqueous solutions were carried out based on the density functional theory.The calculated results of geometries,binding energies,and thermodynamic parameters show that 15C5 has the strongest selectivity to Li ions in the three crown ethers of 12C4,15C5,and 18C6.B15C5 has a smaller binding energy but more negative free energy than 15C5 when combined with Li^+,leading to that the lithium ions in aqueous solutions will combine with B15C5 rather than 15C5.The exchange reactions between B15C5 and hydrated Li^+,Co^2+,and Ni^2+were analyzed and the results show that B15C5 is more likely to capture Li^+from the hydrated ions in an aqueous solution containing Li^+,Co^2+,and Ni^2+.This study indicates that it is feasible to extract Li ions selectively using B15C5 as an extractant from the leaching solution of spent lithium-ion batteries.

NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUPS．Ⅱ．SYNTHESIS OF NETWORK CROWN ETHER POLYMER WITH PENDANT SULFIDE SIDE CHAIN AND ITS PLATINUM COMPLEX

Network crewn ether polymer with pendant sulfide side ohain in the networkstructure units has been synthesized via ring- opening copolymerization of β-ethylthioethyl glycidyl ether and diethylene glycol bisglycidyl ether. A kind of active catalyst suitable for this reaction was suggested. The title polymer was found tobe a good ligand for platinous chloride, and the platinous complex could catalyze thehydrosilylation of olefins with triethoxysilane efficiently.

CRYSTAL AND MOLECULAR STRUCTURE OF { CNa(15-crown-5)]_n [Cd(SCN)_3]}_n

The complex [Na(15-crown-5)] [Cd(SCN)3] (15-crown-5 = C10H20 O5) crysializes in monoclinic space group P21/c with a=10. 219(2) ,b= 10. 575(2) ,c= 20. 572(2) A ,β=98. 45(1)°,V= 2198. 7A3,Mr=529. 89,Z = 4,Dx=1. 600g/cm3,F (000) -1052,μ= 15. 708cm-1. The structure was solved by direct methods with the final R=0. 064. Results of structure analysis indicate that the Na ion is bonded by 15-crown-5 to form a complex cation and the Cd(Ⅱ) is bonded by six SCN ion to form an anion chain with a distorted octahedral coordination.

CRYSTAL AND MOLECULAR STRUCTURE OF BENZO-15-CROWN-5 POTASSIUM TETRACHLOROAURATE K(C_(14)H_(20)O_5)_2-AuCl_4

The crystal and molecular structure of the title compound K(C14 H20O5)2AuCl4 has been determined by X-ray diffraction method.The crystallographic data are as follows;Mr=914.51,triclinic,space group P1,a=10.988(2),b=13.472(4),c=13.696(2)A,α=77.72(1),β=79.02(2),γ=64.92(2)°,V=1782.6(4)A3,Z=2,Dc=1.704 g.cm-3,μ=45.858 cm-1,F(000)=454,R=0.019,Rw=0.018 for 5697 observed reflections with I≥3σ(I).X-ray structure determination shows that benzo-15-crown-5(B15C5)forms a 2:1 complex with KAu-C14 in which K+is sandwiched between two crown rings.The dihedral angle between these two ether oxygen planes is 11.9°.The anion AuCl4-has a planar square configuration which is bound with the complex cation K(B15C5)2+by electrostatic force to form an ion-pair.

CRYSTAL STRUCTURE OF DISODIUM DIAZA-18-CROWN-6-N, N'-DIACETATE PENTAHYDRATE

The title compound was prepared from the reaction of diaza-18-crown-6 and sodium chloroacetate in aqueous solution and crystallized from ethanol solution by standing for a long time. The complex [Na(C16H28N2O8)·Na(H2O)5]2Cl-·2H2O+·H2O (Mr = 655. 45) crystalizes in triclinic system,space group P1 with a = 9. 623(2),b = 10. 902(3),c=15. 867(3) A ;α= 104. 63(2),β= 105. 42(2),γ=99. 88(2)°,V = 1502. 3A3,Dc=1. 09gcm-3,Z = 2,F(000) = 516,final R=0. 075 for 3218 observed reflections. The donor atoms O(4) ,O(7) ,O(13) ,O(16) ,N(1) and N(10) from the crown ether as well as the oxygen atoms O(21) and O(26) from two car boxy lato anions are coordinated cooperatively to the Na(1)+ ion to form crown ether solvated cation in a tetragonal prismatic geometry. The O(22) of one carboxylato anion, which does not coordinate the Na(1) + ion,interacts with the Na(2)+ion together with the oxygen atoms of five water molecules to form a hydrated cation having a deformed octahedral configuration.

CRYSTAL STRUCTURE OF N, N' -BIS ( 2-METHOXY-1-NAPH-THYLMETHYL)-4,13-DIAZA-18-CROWN-6 POTASSIUM IODIDE

Crystal of N , N'-bis(2-methoxy-l-naphthylmethyl)-4,13-diaza-18-crown-6 potassium iodide diethanol solvate[(C36H46N2O6)K]+I- · 2C2H5OH (Mr = 860. 47) is orthorhombic with space group Pcab, a = 17. 531(5), 6 = 21. 149(8), c = 23. 060(4)(?). F=8550. 00(?)3, Z = 8, F(000) = 3167. 64 and Dc=1. 337g/ cm3, μ = 8. 74cm-1, R = 0. 057. In the title complex, the donor atoms of the macro-ring are arranged in a twisted boat conformation. The potassium ion is octa-coordi-nated with four oxygen and two nitrogen atoms of the macro-ring and two oxygen atoms of the two side arms at the same side to form a distorted hexagonal bipyramid.

Crystal Structure of[La(NO_3)_3(12-crown-4)-(H_2O)](12-crown-4)

The crystal structure of crown ether-hydrogen bonded complex,[La(NO3)3 (12-crown-4) ( H2O)] (12-crown-4) has been determined by X-ray method. The title complex C16H34LaN3O18 (Mr=695. 5) crystallized in orthorhombic Pnma with a=23. 495(8), b=13. 603(5),c=8. 474(3); V=2706(1); Z=4 ; Dc=1. 71 g/cm3; F(000)=1408, μ=17. 0 cm-1 (MOKα). The final R=0. 052 and Rw= 0. 054(unit weight) for 1367 observed reflections. The La( Ⅲ) ion is 11-coordinated by three nitrale anions, four oxygen atoms from a crown ligand and one O atom of a water molecule. The other crown molecule is hydrogen bonded wilh the coordinated water molecule. The imposed mirror plane in the structure made both crown ligands and one of nitrate groups severely disordered.

Synthesis and Crystal Structure of 13-Phenyl-1,10-dithia-4,7-dioxa-13-aza-15-Crown-5

Crystal structure of the title compound C 16 H 25 O 2NS 2 has been determined by X-ray diffraction method. Its crystallographic data were as follows: M r=327.51, triclinic, space group P1, a=8.864(3), b=10.127(4), c=10.390(3) , α=105.94(3), β=103.10(2), γ=90.96(3)°, V=870.3(7) 3, Z=2, D c=1.250g.cm -3 , μ(MoKα)=2.966cm -1 , F(000)=176, a total of 3275 reflections measured (2θ max =50°), 2246[I5σ(I)] used in the refinement, R=0.067, R w=0.082. The result shows that the distances of N(1)-C(2) and N(1)-C(3) are longer than that of N(1)-C(11), which indicates that the interaction of C Ar -N sp 2 is stronger than that of C sp 3 -N sp 2 . Oxygen, nitrogen and sulfur atoms of the ring in the same plane was deduced from the least\|squares planes and the dihedral angles.

Sevoflurane Versus Propofol for Myocardial Protection in Patients Undergoing Coronary Artery Bypass Grafting Surgery: a Meta-analysis of Randomized Controlled Trials

Objective To systematically review randomized controlled trials to compare myocardial protection profiles of sevoflurane with propofol in patients undergoing coronary artery bypass grafting （CABG） surgery. Methods Electronic databases were searched to identify all randomized controlled trials comparing sevoflurane with propofol for protecting myocardium in adult patients undergoing CABG surgery. Two authors independently extracted patients＇ perioperative data, including patients＇ baseline characteristics, surgical variables, and outcome data. For continuous variables, treatment effects were calculated as weighted mean difference （WMD） and 95% confidential interval （C/）. For dichotomous data, treatment effects were calculated as odds ratio （OR） and 95% CI. Each outcome was tested for heterogeneity, and randomized-effects or fixed-effects model was used in the presence or absence of significant heterogeneity （Q test P〈0.05）. Sensitivity analyses were done by examining the influence of statistical model on estimated treatment effects. Publication bias was explored through visual inspection of funnel plots of the outcomes. Statistical significance was defined as P〈0.05. Results Our search yielded 13 studies including 696 patients, and 402 patients were allocated into sevoflurane group and 294 into propofol group. There was no significant difference in postoperative mechanical ventilation time, inotropic support, mortality, myocardial infarction, and atrial fibrillation between the two groups （all P〉0.05）. Patients randomized into sevoflurane group had higher post-bypass cardiac index （WMD=0.39, 95% CI： 0.18 to 0.60, P=0.0003）, lower troponin I level （WMD=-0.82, 95% CI：-0.87 to -0.85, P=0.0002）, lower incidence of myocardial ischemia （OR=0.37, 95% CI： 0.16 to 0.83, P=0.02）, shorter ICU and hospital stay length （WMD=-10.99, 95% CI： -12.97 to -9.01, P〈0.00001; WMD=-0.78, 95% CI： -1.00 to -0.56, P〈0.00001, respectively）. Conclusion This meta-analysis has found some evidence showing that sevoflurane has better myocardial protection than propofol in CABG surgery.

Crystal Structures of Ln(NO_3)_3(Ln=La,Yb) Complexes with 12-crown-4

The synthesis and crystal structures of Ln(NO3)3(Ln=La,Yb) complexes with 12-crown-4 are reported. La (NO3 )3 (12-crown-4) (H2O)x(Ln=La,x=1; Ln=Yb, x=0), Mr=519. 2(535.3), space group P21/n(P21/c)with α =7. 612(2)(12. 116(3)), b=13. 932(6) (8. 544(3)),c= 16. 179(6) (15.241 (3));β=101.40 (2)( 91.82 (2))°; V=1682 (1) (1577(1)); Z=4 (4);μ(MoKα)=26.7(63.2) cm -1; F(000) =1024 (1036) ; R=0. 035 (0. 034) ; Rw= 0. 028 (0.036) for 1665 (1594) observed reflections with Ⅰ>3σ(Ⅰ). The La(Ⅲ) ion in La (NO3)3 (12-crown-4) (H2O) is 11-coordinated, being bonded to three bidentate nitrate ions , four oxygen atoms of the crown molecule and one oxygen atom of a water molecule. Yb(NO3)3 (12-crown-4) is a 10-coordinated complex, in which the metal ion bonds with three bidentate nitrate ions and four oxygen atoms of a crown ether.

Synthesis and Crystal Structure of Potassium Crown Ether Tetrathiosquarate

Slow diffusion of diethylether into a concentrated solution of K2C454.H20 and two equivalents of 18-crown-6 in pyridine affords dark orange crystals of bis（potassium{18-crown-6}）（3-cyclobutene-1,2-dithione-3,4-dithiolate） [K（C12H2406）]2（CnS4）. The crystal structure determination （monoclinic, P 2t/n, a = 12.2095（8） A, b = 11.3263（8） A, c = 14.0552（7） A, fl = 101.032（3）~, Z = 2） shows the presence of C4S42 - ions with almost undistorted D4h symmetry having C-C bond lengths of 1.442（10） A and 1.478（8） A and C-S bond lengths of 1.651（8） A and 1.664（7） A. Since the K＋ ions are shielded in a half-spherical way by the crown ether ligands, the crystal structures is built of centrosymmetric molecular entities [（18-crown-6）K（C4S4）K（18-crown-6）]. The K＋ ions have eight of coordination number, C4S42- acts as a chelating and bridging ligand towards two K＋ with K-S distances of 3.434（2） A and 3.380（2） A.

SYNTHESIS OF LINEAR POLYSILOXANE WITH PENDANT BENZO－15－C－5 MOIETIES AND ITS TRANPORT PROPERTIES IN BULK LIQUID MEMBRANE SYSTEM

Linear polysiloxanes with pendant benzo-15-crown-5 moieties have been synthesized from 3'--or 4'--allylbenzo--15--C--5 via hydrosilylation of methyldichlorosilane, followed by polycondensation with silanol--terminated polydimethylsiloxane. It was found that the polysiloxanes could be used as carriers in bulk liquid membrane to transport ions. Factors influencing transport rate have been investigated.

Synthesis and Crystal Structure of［Na（DB18C6）（H_2O）_2］_2Mo_6O_（19）·3DMF·2CH_3OH

The title complex [Na (DB_18C_6) (H_2O)_2]_2Mo_6O_19·3DMF · 2CH_3OH (Ⅰ) , a new type of crown hexamolybdate supermolecule, has been synthesized. Its crystal structure has been determined by X-ray diffraction analysis. The crystal C_49H_32 Mo_6N_2Na_2O_40 is tetragonal, space group P4/mbm, a= 17.108(2), c= 28. 285 (6) A ,V=8279(2) A￣ 3, Z=4 , M_r= 1960. 8 , D_x=1. 573 g/cm￣3 , P=9. 51cm￣(-1). F(000)=3936. The final agreement factors R=0. 058 and R_w= 0. 062 for 1777 independent reflections with F>4σ(F). In contrast to what we have reported about [Na(DB_18C_6)(CH_3OH)]_2Mo_6O_19(Ⅱ) where the whole complex was linked together, the cation [Na (DB_18C_6 ) (H_2O)_2]￣ + , that has crystallographic D_2h symmetry, combines with the anion with the symmetry O_h by electronic interaction.

Crystal Structure of Calix［4］（dioxo） crown－6 Acetonitrile（1：3） Inclusion Complex

The X-ray crystal structure of the inclusion complex of p-tert-butylcalix [4] crown-6 with actonitrile is reported. C54H70O10·3CH3CN, Mr=1002. 3 ,monoclinic, space group C2/c with cell dimensions of a=23.587(7),b=21.153(6),c=15.608(8) A,β=116.99(3)°,V=6939.2 A3,Z=4, F(000)=2160,Dc=0.959 g/cm3,μ=1.114 cm-1; R=0.088 for 2066 reflections with I>3σ(I).The calixarene subunit exists in a distorted cone conformation. One of the three acetonitrile molecules is located in the intracavity of the calixarene subunit and the other two in the intermolecular channels.