The Crystal and Molecular Structure of l-(Diphenylmethyl)azetidin-3-ol

1-(Diphenylmethyl)azetidin-3-ol is triclinic, space group P1, with a=8.479(2), b=17.294(4),c = 10.606 (3) A, a = 118.59 (2),/~ = 100.30 (2), y = 89.63 (2) °, Z = 4. The structure was solved by multisolution methods and refined to an R of 0.044 for 2755 reflexions. The four-membered rings in the two independent molecules are puckered with dihedral angles of 156 and 153 ° . The two molecules differ in conformation with respect to rotation of the phenyl rings about the C-C bonds. The structure is stabilized by a network of O-H. • • N intermolecular hydrogen bonds.

Peptide mimics for structural features in proteins. Crystal structures of three heptapeptide helices with a C-terminal 6-->1 hydrogen bond.

The crystal structure determination of three heptapeptides containing alpha-aminoisobutyryl (Aib) residues as a means of helix stabilization provides a high-resolution characterization of 6-->1 hydrogen-bonded conformations, reminiscent of helix-terminating structural features in proteins. The crystal parameters for the three peptides, Boc-Val-Aib-X-Aib-Ala-Aib-Y-OMe, where X and Y are Phe, Leu (I), Leu, Phe (II) and Leu, Leu (III) are: (I) space group P1, Z = 1, a = 9.903 A, b = 10.709 A, c = 11.969 A, alpha = 102.94 degrees, beta = 103.41 degrees, gamma = 92.72 degrees, R = 4.55%; (II) space group P21, Z = 2, a = 10.052 A, b = 17.653 A, c = 13.510 A, beta = 108.45 degrees, R = 4.49%; (III) space group P1, Z = 2 (two independent molecules IIIa and IIIb in the asymmetric unit), a = 10.833 A, b = 13.850 A, c = 16.928 A, alpha = 99.77 degrees, beta = 105.90 degrees, gamma = 90.64 degrees, R = 8.54%. In all cases the helices form 3(10)/alpha-helical (or 3(10)helical) structures, with helical columns formed by head-to-tail hydrogen bonding. The helices assemble in an all-parallel motif in crystals I and III and in an antiparallel motif in II. In the four crystallographically characterized molecules, I, II, IIIa and IIIb, Aib(6) adopts a left-handed helical (hL) conformation with positive phi, psi values, resulting in 6-->1 hydrogen-bond formation between Aib(2) CO and Leu(7)/Phe(7) NH groups. In addition a 4-->1 hydrogen bond is seen between Aib(3) CO and Aib(6) NH groups. This pattern of hydrogen bonding is often observed at the C-terminus of helices proteins, with the terminal pi-type turn being formed by four residues adopting the hRhRhRhL conformation.

Hydration and distortion of peptide helices in crystals. α-Helical structure of a dodecapeptide, Boc-(Ala-Leu-Aib)4-OMe

The dodecapeptide Boc-(Ala-Leu-Aib)(4)-OMe crystallized with two independent helical molecules in a triclinic cell. The two molecules are very similar in conformation, with a 3(10)-helix turn at the N-terminus followed by an alpha-helix, except for an elongated N(7)...O(3) distance in both molecules. All the helices in the crystal pack in a parallel motif. Eleven water sites have been found in the head-to-tail region between the apolar helices that participate in peptide-water hydrogen bonds and a network of water-water hydrogen bonds. The crystal parameters are as follows: 2(C58H104N12O15)+ca. 10H(2)O, space group P1 with a = 12.946(2), b = 17.321(3), c = 20.465(4) Angstrom, alpha = 103.12(2), beta = 105.63(2), gamma = 107.50(2)degrees, Z = 2, R = 10.9% for 5152 data observed > 3 sigma(F), resolution 1.0 Angstrom. In contrast to the shorter sequences [Karle et al. (1988)Proc. Natl. Acad. Sci. USA 85, 299-303] and Boc-(Ala-Leu-Aib)(2)-OMe [Karle et al. (1989) Biopolymers 28, 773-781], no insertion of a water molecule into the helix is observed. However, the elongated N---O distance between Ala(7) NH and Aib(3) CO in both molecules (molecule A, 3.40 Angstrom; molecule B, 3.42 Angstrom) is indicative of an incipient break in the helices. (C) Munksgaard 1994.

Family of Mixed-Valence Oxovanadium(IV/V) Dinuclear Entities Incorporating N4O3-Coordinating Heptadentate Ligands: Synthesis, Structure, and EPR Spectra

Dinuclear ((VVV)-V-IV) oxophenoxovanadates of general formula [V2O3L] have been synthesized in excellent yields by reacting bis(acetylacetonato)oxovanadium(IV) with H3L in a 2:1 ratio in acetone under an N-2 atmosphere. Here L3- is the deprotonated form of 2,6-bis[{{(2-hydroxybenzyl)(N',N'-(dimethylamino)ethyl)}amino}methyl]-4-methylphenol (H3L1), 2,6-bis[{{(5-methyl-2-hydroxybenzyl)(N',N'-(dimethylamino)ethyl)}amino}methyl]-4-methylphenol (H3L2) 2,6-bis[ {{(5-tert-butyl-2-hydroxybenzyl)(N',N'-(dimethylamino)ethyl)}amino}methyl]-4-methylphenoI (H3L3), 2,6-bis[{{(5-chloro-2-hydroxybenzyl)(N',N'-(dimethylamino)ethyl)}amino}methyl]-4-methylphenol (H3L4) , 2,6-bis[{{(5-bromo-2-hydroxybenzyl)(N',N'-(dimethylamino)ethyl)}amino}methyl]-4-methylphenol (H3L5), or 2,6-bis[{{(5-methoxy-2-hydroxybenzyl)(N',N'-(dimethylamino)ethyl)}amino}methyl]-4-methylphenol (H3L6). In [V2O3L1], both the metal atoms have distorted octahedral geometry. The relative disposition of two terminal V=O groups in the complex is essentially cis. The O=V...V=O torsion angle is 24.6(2)degrees. The V-O-oxo-V and V-O-phenoxo-V angles are 117.5(4) and 93.4(3)degrees, respectively. The V...V bond distance is 3.173(5) Angstrom. X-ray crystallography, IR, UV-vis, and H-1 and V-51 NMR measurements show that the mixed-valence complexes contain two indistinguishable vanadium atoms (type 111). The thermal ellipsoids of O2, O4, C10, C14, and C15 also suggests a type III complex in the solid state. EPR spectra of solid complexes at 77 K display a single line indicating the localization of the odd electron (3d(xy)(1)). Valence localization at 77 K is also consistent with the V-51 hyperfine structure of the axial EPR spectra (3d(xy)(1) ground state) of the complexes in frozen (77 K) dichloromethane solution: S = 1/2, g(parallel to) similar to 1.94, g(perpendicular to) similar to 1.98, A(parallel to) similar to 166 x 10(-4) cm(-1), and A(perpendicular to) similar to 68 x 10(-4) cm(-1). In contrast isotropic room-temperature solution spectra of the family have 15 hyperfine lines (g(iso) similar to 1.974 and A(iso) similar to 50 x 10(-4) cm(-1)) revealing that the unpaired electron is delocalized between the metal centers. Crystal data for the [V2O3L1].CH2Cl2 complex are as follows: chemical formula, C32H43O6N4C12V2; crystal system, monoclinic; space group, C2/c; a = 18.461(4), b = 17.230(3), c = 13.700(3) Angstrom; beta = 117.88(3)degrees; Z = 8.

X-ray studies on crystalline complexes involving amino acids and peptides. XXV. Structures of DL-proline hemisuccinic acid and glycyl-L-histidinium semisuccinate monohydrate and a comparative study of amino-acid and peptide complexes of succinic acid

DL-Proline hemisuccinic acid, C5H9NO2.1/2C4H6O4, M(r) = 174.2, P2(1/c) a = 5.254 (1), b = 17.480 (1), c = 10.230 (i) angstrom, beta = 119.60 (6)-degrees Z = 4, D(m) = 1.41 (4), D(x) = 1.42 g cm-3, R = 0.045 for 973 observed reflections. Glycyl-L-histidinium semisuccinate monohydrate, C8H13N4O3+.C4H5O4-.H2O, M(r) = 348.4, P2(1), a = 4.864 (1), b = 17.071 (2), c = 9.397 (1) angstrom, beta = 90.58-degrees, Z = 2, D(m) = 1.45 (1), D(x) = 1.48 g cm-3, R = 0.027 for 1610 observed reflections. Normal amino-acid and dipeptide aggregation patterns are preserved in the structures in spite of the presence of succinic acid/semisuccinate ions. In both the structures, the amino-acid/dipeptide layers stack in such a way that the succinic acid molecules/semisuccinate ions are enclosed in voids created during stacking. Substantial variability in the ionization state and the stoichiometry is observed in amino-acid and peptide complexes of succinic acid. Succinic acid molecules and succinate ions appear to prefer a planar centro-symmetric conformation with the two carboxyl (carboxylate) groups trans with respect to the central C=C bond. Considerable variation is seen in the departure from and modification of normal amino-acid aggregation patterns produced by the presence of succinic acid. Some of the complexes can be described as inclusion compounds with the amino acid/dipeptide as the 'host' and succinic acid/semisuccinate/succinate as the 'guest'. The effects of change in chirality, though very substantial, are not the same in different pairs of complexes involving DL and L isomers of the same amino acid.

Systematic crystallographic investigation of hydrogen-bonded networks involving monohydrogen tartrate-amine complexes: Potential materials for nonlinear optics

Crystal structures of six binary salts involving aromatic amines as cations and hydrogen tartrates as anions are presented. The materials are 2,6-xylidinium-L-monohydrogen tartrate monohydrate, C12H18O6.5N, P22(1)2(1), a = 7.283(2) Angstrom, b = 17.030(2) Angstrom, c = 22.196(2) Angstrom, Z = 8; 2,6-xylidinium-D-dibenzoyl monohydrogen tartrate, C26H25O8N, P2(1), a = 7.906(1) Angstrom, b = 24.757(1) Angstrom, c = 13.166(1) Angstrom, beta = 105.01(1)degrees, Z = 4; 2,3-xylidinium-D-dibenzoyl monohydrogen tartrate monohydrate, C26H26O8.5N, P2(1), a = 7.837(1) Angstrom, b = 24.488(1) Angstrom, c = 13.763(1) Angstrom, beta = 105.69(1)degrees, Z = 4; 2-toluidinium-D-dibenzoyl monohydrogen tartrate, C25H23O8N, P2(1)2(1)2(1), a = 13.553(2) Angstrom, b = 15.869(3) Angstrom, c = 22.123(2) Angstrom, Z = 8; 3-toluidinium-D-dibenzoyl monohydrogen tartrate (1:1), C25H23O8N, P1, a = 7.916(3) Angstrom, b = 11.467(6) Angstrom, c = 14.203(8) Angstrom, alpha = 96.44(4)degrees, beta = 98.20(5)degrees, = 110.55(5)degrees, Z = 2; 3-toluidinium-D-dibenzoyl tartrate dihydrate (1:2), C32H36O10N, P1, a = 7.828(3) Angstrom, b = 8.233(1) Angstrom, c = 24.888(8) Angstrom, alpha = 93.98 degrees, beta = 94.58(3)degrees, = 89.99(2)degrees, Z = 2. An analysis of the hydrogen-bonding schemes in terms of crystal packing, stoichiometric variations, and substitutional variations in these materials provides insights to design hydrogen-bonded networks directed toward the engineering of crystalline nonlinear optical materials.

Synthesis, properties and crystal structures of diastereomeric areneruthenium(II) chiral Schiff-base complexes

Diastereomers (SRu,Sc)-1a and (RRu,Sc)-1b, in a ratio of 85: 15 and formulated as [Ru(η-MeC6H4Pri-p)Cl(L*)], have been prepared by treating [{Ru(η-MeC6H4Pri-p)Cl2}2] with the sodium salt of (S)-α-methylbenzylsalicylaldimine (HL*) in tetrahydrofuran at –70 °C. The reaction of 1(1a+1b) with AgClO4 in acetone followed by an addition of PPh3 or 4-methylpyridine (4Me-py) leads to the formation of adducts [Ru(η-MeC6H4Pri-p)(PPh3)(L*)]ClO42[(SRu,Sc)2a, (FRu,Sc)2b] and [Ru(η-MeC6H4Pri-p)(4Me-py)(L*)]ClO43[(SRu,Sc)3a, (RRu,Sc)3b] in the diastereomeric ratios (SRu,Sc) : (RRu,Sc) of 2 : 98 and 76 : 24, respectively. Complex 1 crystallises with equal numbers of 1a and 1b molecules in an asymmetric unit of monoclinic space group P21 with a= 10.854(1), b= 17.090(1), c= 12.808(4)Å, β= 110.51(1)°, and Z= 4. The structure was refined to R= 0.0552 and R′= 0.0530 with 2893 reflections having I[gt-or-equal] 1.5σ(I). The absolute configurations of the chiral centres in the optically pure single crystal of the PPh3 adduct have been obtained from an X-ray study. Crystals of formulation [Ru(η-MeC6H4Pri-p)-(PPh3)(L*)]2[ClO4][PF6]·1.5 CHCl3, obtained in presence of both ClO4 and PF6 anions, belong to the non-centric triclinic space group P1 with a= 10.852(2), b= 14.028(1), c= 15.950(2)Å, α= 91.51(1), β= 105.97(1), γ= 106.11(1)°, and Z= 2. The final residuals were R= 0.0713, R′= 0.0752 with 7283 reflections having I[gt-or-equal] 2.5σ(I). The crystal structures of 1a,1b, and the PPh3 adduct (2b,2b′) consist of a ruthenium(II) centre bonded to a η-p-cymene, a bidentate chelating Schiff base, and a unidentate ligand (Cl or PPh3). The chirooptical properties of the complexes have been studied using 1H NMR and CD spectral data. The presence of a low-energy barrier for the intermediate involved in these reactions, showing both retention as well as inversion of the metal configuration, is discussed.

Dynamics of pulsed flow in an elastic tube

Internal haemorrhage, often leading to cardio-vascular arrest happens to be one of the prime sources of high fatality rates in mammals. We propose a simplistic model of fluid flow in our attempt to specify the location of the haemorrhagic spot, which, if located accurately, could possibly be operated leading to an instant cure. The model we employ for the purpose is basically fluid mechanical in origin and consists of a viscous fluid, pumped by a periodic force and flowing through an elastic tube. The analogy is with that of blood, pumped from the heart and flowing through an artery or vein. Our results, aided by graphical illustrations, match reasonably well with experimental observations.

Thermodynamic study of Fe2O3 Fe2(SO4)3 equilibrium using an oxyanionic electrolyte (Na2SO4 I)

The emf of the cell, Pt, Ar + O2 + SO2 + SO3/Na2SO4-I/Fe2O2 + Fe2(SO4)3, Pt, has been measured in the temperature range 800 to 1000 K, using a gas mixture of known input composition as the reference electrode. The equilibrium composition of the reference gas at the measuring temperatures was computed using the thermodynamic data on the gaseous species reported in the literature. A mixture of ferric oxide and sulfate was kept in a closed system to ensure establishment of equilibrium partial pressure at the electrode. The cell was designed to avoid physical contact between Fe2(SO4)3 and Na2SO4 electrolyte. Uncertainties arising from the formation of sulfate solid solution were thus eliminated. The Gibbs’ energy of formation of ferric sulfate calculated from the emf is discussed in comparison with data reported in the literature. There is no evidence for the formation of oxysulfates in the Fe-S-0 system. Based on the results obtained in the present study for Fe2(SO4)3 and literature data for other phases, chemical potential diagrams have been constructed for the Fe-S-O system at 900 and 1100 K.

Solubility and activity of oxygen in liquid nickel in equilibrium with -Al2O3 and NiO.(1+x)Al2O3

The limiting solubility of oxygen in liquid nickel in equilibrium withα-alumina and nickel aluminate has been measured by inert gas fusion analysis of suction samples in the temperature range 1730 to 1975 K. The corresponding oxygen potential has been monitored by a solid electrolyte cell consisting of calcia stabilized zirconia as the electrolyte and Mo + MoO2 as the reference electrode. The results can be summarized by the following equations: log(at. pct O) = \frac - 10,005T + 4.944 ( ±0.015)log(atpctO)=T−10005+4944(0015) % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn DmO2 /4.606RT = log P O2 1/2 = \frac - 13,550T + 4.411 ( ±0.009)O24606RT=logPO212=T−13550+4411(0009) From simultaneous measurements of the potential and concentration of oxygen in melts, not in thermodynamic equilibrium with alumina and aluminate phases, information on the composition dependence of the activity coefficient and the standard free energy of solution of oxygen is obtained. For the reaction, $\frac{1}{2} O_2 \to \underset{\raise0.3em\hbox{$Missing close brace ΔG o = -72,930 - 7.11T (±840) J gr.at.–1 = + 0.216 at. pct OlogfO=T−500+0216atpctO where the standard state for dissolved oxygen is that which makes the value of activity equal to the concentration (in at. pct) in the limit as concentration approaches zero. The oxygen solubility in liquid nickel in equilibrium with solid NiO, evaluated from thermodynamic data, is compared with information reported in the literature. Implications of the results to the deoxidation equilibria of aluminum in nickel are discussed.

Iso-specific Ziegler-Natta polymerization of α-olefins with a single-component organoyttrium catalyst

The synthesis of a sterically tailored ligand array (M)_2((C_5H_2-2-Si(CH_3)_3-4-C(CH_3)_3)S_2i(CH_3)_2]("M_2Bp") (M = Li, 16; K, 19) is described. Transmetallation of Li_2Bp with YCl_3(THF)_3 affords exclusively the C_2 symmetric product rac-[BpY(µ_2-Cl)_2Li(THF)_2], 20. A X-ray crystal structure of 20 has been determined; triclinic, P1, a= 13.110 (8), b = 17.163 (15), c = 20.623 (14) Å, α = 104.02 (7), β = 99.38 (5), γ = 100.24 (6)° , Z = 4, R = 0.056. Transmetallation of K_2Bp with YCl_3(THF)_3 affords the halide free complex rac-BpYCl, 23. The corresponding rac-BpLaCl, 28, is prepared in an anlogous manner. In all cases the achiral meso isomer is not obtained since only for the racemic isomers are the unfavorable steric interactions between the Si(CH3)_3 groups in the narrow portion of the [Cp-M'-Cp] wedge avoided. Alkylation of 20 or 23 with LiCH(Si(CH_3)_3)_2 affords rac-BpYCH(Si(CH_3)_3)_2, 26 in good yield. Alkylation of 28 with LiCH(Si(CH_3)_3)_2 affords rac-BpLaCH(Si(CH_3)_3)_2 29. Hydrogenation of 26 cleanly affords the bridging hydride species [BpY(µ_2-H)]_2, 27, as the homochiral (R,R) and (S,S) dimeric pairs. 26 is an efficient initiator for the polymerization of ethylene to high molecular weight linear polyethylene. 27 catalyzes the polymerization of propylene (25% v/v in methylcyclohexane) and neat samples of 1-butene, 1-pentene, 1-hexene to moderately high molecular weight polymers: polypropylene (M_n = 4,200, PDI 2.32, T_m 157 °C); poly-1-butene (M_n = 8,500, PDI 3.44, T_m 105 °C); poly-1-pentene (M_n = 20,000, PDI 1.99, T_m 73 °C); poly-1-hexene (M_n = 24,000, PDI 1.75, T_m < 25 °C). ^(13)C NMR spectra at the pentad analysis level indicates that the degree of isotacticity is 99% mmmm for all polymer samples. 27 is the first single component iso-specific α-olefin polymerization catalyst. The presumed origins of the high isospecificity are presented.

稀土铁双核配合物的合成

本文通过LnCl_3·nTHF和[C_5H_4(SiMe_3)]Na反应得到了两类配合物[C_5H_4(SiMe_3)] LnCl_2·nTHF (Ln = Nd，Sm，Gd；n = 0，1，2)、[C_5H_4(SiMe_3)] LnCl_2·HCl·nTHF (Ln = Nd，Sm，Gd；n = 1，2)。通过元素分析、红外分析、质谱、核磁共振和热重分析确定了配合物的分子组成，特别是带氯化氢的产品在红外光谱中有1250 cm~(-1)，835 cm~(-1)，748 cm~(-1)自的三甲基硅基特征吸收峰。对氯化稀上进行了结构分析，结果发现LnCl_3·4THF (Ln = Sm，Gd)是与NdCl_3·4THF之间存在着变态关系。GdCl_3·4THF。晶体属单斜晶系，空间群为P21/C，晶胞参数为a = 30.765(7)，b = 8.219(3)，C = 17.534(3)A~·，β = 93.71(2)°；SmCl_3·4THF。晶体属单斜晶系，空间群为P21/C，晶胞参数为a = 30.921(13)，b = 8.287(7)，C = 17.665(8)，β = 94.17(4)°。LnCl_3·4THF的单位晶胞中存在着八个分子，每对分子互相等同，但每对分子内部两个分子之间互不等同。SmCl_3·2THF·DME晶体属单斜晶系，空间群为P21/a，晶胞参数为a = 13.547(8)，b = 8.607(4)，C = 16.029(9)A°，β = 90.53(5)°。铲原子与三个氯原子。两个四氢呋喃中的氧原子以及DME中的两个氧原子键合，形成七配位的配合物，但是配位多面体不是理想的五角双锥，而是形成了比五角双锥(D_(5h))对称性更低的多面体(C_(3v))。它能看作是在正八面体的一个面的中心加上第七个原子的结果，而且这八面体主要受到决定上述那个面的三个原子伸展开的畸变。在制备C_5H_5SiMe_3时，如果不用减压蒸馏，而在常压下直接蒸馏，则得到的不是C_5H_5SiMe_3而是它的二聚体(C_5H_5SiMe_3)_2。用红外光谱和核磁共振确定了它的组成和结构，特别是在1650 cm~(-1)处出现(C_5H_5SiMe_3)_2的孤立双键吸收峰。用C_5H_5SiMe_3和Ee(CO)_5回流反应制得了[C_5H_4(SiMe_3) Ee(CO)_2]_2。经过元素分析，红外光谱，质谱，顺磁共振确定了配合物的组成，红外光谱中有桥羰基的吸收峰，质谱图中498的离子峰的出现标志着上述二聚体的存在。用[C_5H_5Fe(CO)_2]_2作为制备双金属配合物的原料，用Na/Hg并还原[C_5H_5Fe(CO)_2]_2。反应时间为6-7小时得到中间体[C_5H_5Fe(CO)_2]_2Na·4THF的深紫红色晶体。反应时间加长，中间体被破坏，反应到15小时时生成了[C_5H_5Fe(CO)_2]Na·TMEDA的黄色晶体，特别是中间体的获得及晶体结构的测定对我们解释反应的机理非常重要。[C_5H_5Fe(CO)_2]_2Na·4THF为单斜晶系，空间群为P21/n，晶胞参数为a = 10.155(5)，b = 17.121(4)，C = 18.667(6)A°，β = 97.61(3)°，V = 3216.9A°~3， 2 = 4。铁的配位数为七，钠的配位数为六，钠离子和桥连羰基氧以配位键结合，每个钠离子连结着两个[C_5H_5Fe(CO)_2]_2~-，而每个[C_5H_5Fe(CO)_2]_2~-又连结着两个钠离子，组成一个无限链状分子，键状分子间以Van de W力结合。[C_5H_5Fe(CO)_2]Na·TMEDA正交晶系，空间群为P_(2,2,2,)。晶胞参数为a = 6.001(4)，b = 10.644(6)，C = 24.214(11)A~·。α = β = r = 90°。z = 4 V = 1546·7A°~3，铁的配位数为五。钠的配位数为四，钠离子和羰基氧以配位键结合，每个钠离子连结着两个[C_5H_5Fe(CO)_2]~-，每个[C_5H_5Fe(CO)_2]~-又连结着两个钠离子，体系就是以这种连结方式或正负电荷交替的形式无限螺旋分子，每个链节存在着两个[C_5H_5Fe(CO)_2]Na·TMEDA分子，链节的长度为a轴的轴长，说明螺旋分子以a轴轴长向上平移。用LnCl_3·nTHF和[C_5H_5Fe(CO)_2]Na反应制得了[C_5H_5Fe(CO)_2] LnCl_2·nTHF (Ln = Nd, Sm, Gd; n = 1, 2)，用[C_5H_5Fe(CO)_2] LnCl_2和[C_5H_4(SiMe_3)]Na或用[C_5H-4(SiMe_3)] LnCl_2和[C_5H_5Fe(CO)_2]Na得到[C_5H_5Fe(CO)_2] [C_5H_4(SiMe_3)] LnCl·nTHF (Ln = Nd, Sm, Gd; n = 0, 1, 3)，配合物[C_5H_5Fe(CO)_2] LnCl_2·nTHF及[C_5H_5Fe(CO)_2] [C_5H_4(SiMe_3)] LnCl·nTHF中存在着2000 cm~(-1)左右的终端羰基吸收峰及1766 cm~(-1)左右的桥连羰基吸收峰。说明稀土和铁之间是以羰基相连的。在TOTOE质谱仪上，配合物[C_5H_5Fe(CO)_2]Gd~·Cl·THF出现[C_5H_5Fe(CO)]GdCl_2、[Fe(CO)_2] Gd~+Cl_2的离子峰，配合物[C_5H_5Fe(CO)_2]-[C_5H_4(SiMe_3)] GdCl·THF出现[C_5H_5Fe(CO)_2] [C_5H_4]Gd~+Cl、[C_5H_5Fe(CO)_2]Gd~+Cl·[C_5H_4C(SiMe_3)] Gd~+Cl等离子峰。所有稀土有机配合物都溶于四氢呋喃、苯，对空气和水敏感。

取代环戊二烯基稀土有机氯化物的合成及其反应

本文通过无水LnCl_3(Ln = Pr.Nd.Gd)与两倍摩尔的叔丁基环戊二烯基碱金属盐在THF中60－80℃反应，分离到一类新的二（叔丁基环戊二烯基）稀土氯化物（T-DuCp）_2 2net.nTHF (Ln = Pr,Nd,n = 2 Ln = Gd,n = 1)，对它们进行了元素分析。红外光谱及水鲜色质谱的表征。对于配合物（t-BuCp）_2PrCl·2THF的单晶，测定了它的晶体结构，晶体层单斜晶系P21/C空间群，晶胞参数为：a = 15.080 b = 8.855 c = 21.196A, β = 110.34°V = 2653.9A~3 δ = 4，结构分析表明此配合物是一中性的单分子配合物。最后的R = Rw = 0.058平均Pr-C.2.81 Pr-Cent 2.53A, Pr-Cl及Rr-O键长分别为2.72与2.62A。本文通过Lnel_3(Ln = Nd.Pr.Ga)与等摩尔的叔丁基环戊二烯基碱金属盐在THF中60－80℃反应，分离到一类中性的单(叔丁基环戊二烯基)稀土二氯化物，并对它们进行了元素分析，红外光谱及水鲜色质谱的表征。本文通过轻稀土元素La,Pr的三氯化物与带基钠以1:2摩尔比在THF中70－80℃反应，分离到了二带基轻稀土氯化物（CaH_7）_2LaCl.2THF及[(CqH_7)_2PrCl.THF]_2。并且对此二配合物进行了元素分析。红外光谱及水鲜色质谱的表征。对于[(CuH_7)_2PrCl.TH]_2配合物，测定了它的晶体结构，这是第一个得到结构表征的茚基稀土氯化物，晶体层于单斜晶系，P_(21)/C空间群，晶胞参数为a = 7.808 b = 17.796 c = 14.070A β = 93.97°v = 1950.31A. E = 2最后的R = 0.045. Rw = 0.039结构分析表明此配合物以中性的二聚体形式存在。平均的Pr-C.2.81 Pr-Cent 2.53. Pr-Cl.2.84H Pr-O钻长2.54A。为了进一步研究不同配体对配合物结构的影响，我们还研究了Gael_3与Nae_5Mes以1:1摩尔比在THF中的反应，分离到了两种配合物[(NaTHF)(C_5MesGd.THF)_2Cl_5]_2.6THF(I)及L_5Me_5GdCl2.3THF(II)并且对配合物（I），测定了它的晶体结构，晶体层于三斜晶系。Pi空间群。晶胞参数a = 12.183 b = 13.638 c = 17.883A, α = 110.38 β = 94.04 γ = 99.44°, V = 2721.20A, E = 1。结构分析表明，此配合物是一种以两个Na原子通过THF中的O原子而桥联的金层有机配合物，在结构上有十分新颖的特点。在此配合物分子中含有四个Gd原子及二个Na原子，Na及Gd间以Cl桥键相联结，Gd-Gd_2 = 4.033 Gdll-Na = 2.818A。最后的R = 0.04M Rw = 0.042。本文还对（t-BuCp）_2P_2Cl.2THF与NaH及LiAlH4的反应进行了初步的研究，分离到（t-Bucp）_2PrH.2THF及(t-Bucp)_2P_2RIH_4.3THF两种新的氢化物，并且对它们进行了元素分析，红外光谱的表征，对于它们水鲜产物的气相分中的H_2，用气相色谱法进行了定性表征。

环戊二烯基轻稀土烷基配合物的合成、表征和反应性能的研究

本文通过LnCl_3·2LiCl (Ln=La, Nd)和等摩尔的CH_3C_5H_4Na在四氢呋喃中于室温反应，得到了一种新的阴离子型配合物[Li(THF)_2]_2 (M-Cl)_4[(η~5-CH_3C_5H_4)Ln·THF] (Ln=La, Nd)，对其进行了元素分析，红外光谱和核磁谱的鉴定，并测得了[Li(THF)_2]_2 (M-Cl)_4[(η~5-CH_3C_5H_4)Nd·THF]的X-光晶体结构。晶体属单斜晶系，空间群为P_(21/n)，晶脆参数为a=12.130(5)，b=17.343(5)，c=17.016(5)A，β=108.54(3)°，V=3393.87A~3，E=4，R=0.0505，中心钕原子分别与CH_3Cp~-。THF和四个桥氯配位，形成稳定的八配位的八面体结构。通过[Li(THF)_2]_2(M-Cl)_4[(η~5-CH_3C_5H_4)Nd·THF]与2摩尔的t-BuLi在四氢呋喃和戊烷的混和溶液中反应，分离得到一种新的阴离子型配合物晶体，经元素分析，红外光谱，核磁和水解色质谱的鉴定，证明为[Li(DME)_3][(η~5-CH_3C_5H_4)Nd(t-Bu)_3]，此配合物不仅对空气和水汽极为敏感，而且对温度也很敏感，即使在-5 ℃下放置也会逐渐分解，发生β-H消除。我们进一步研究了LnCl_3·2LiCl与2摩尔的C_5H_5Na的四氢呋喃反应液在低温下与等摩尔的CH_3Li乙醚溶液反应，从中分离得到一种新的阴离子型烷基配合物晶体[Li(DME)_3][(η~5-C_5H_5)_3LnCH_3] (Ln=La, Nd)对其进行了元素分析，红外光谱，核磁和水解色质谱的鉴定。此外，从这一反应中还得到另一种副产物，经X-光结构鉴定为[Li(DME)_3]~+{[(η~5-C_5H_5)Nd(M-Cl)_2Nd(η~5-C_5H_5)](M-Cl)_4(M_4-D)[(η~5-C_5H_5)Nd(M-CH_3)_2Nd(η~5-C_5H_5)]}~(2-)[Li(DME)_3]~+。本文还研究了NdCl_3·2LiCl与2倍摩尔的CH_3C_5H_4Na的四氢呋喃反应液和等摩CH_3Li乙醚溶液于-78 ℃下反应，从中分离得到另一种新的阴离子型配合物[Li(DME)_3][(η~5-CH_3C_5H_4)_3NdCH_3]并对其进行了元素分析，红外光谱的鉴定。我们还研究了配合物[Li(DME)_3][(η~5-CH_3C_5H_4)Nd(t-Bu)_3]对苯乙烯的催化聚合活性，发现它可以单独引发苯乙烯聚合，得无规聚苯乙烯。