One Pot Reduction of Imines Generated in-situ from Aldehydes and Amines by the NaBH4-InCl3 System

A combination of sodium borohydride and a catalytic amount of indium（Ⅲ） chloride in acetonitrile reduces imines formed in-situ from aldehydes and amines to the corresponding functionalised secondary and tertiary amines in moderate to good yields. Noteworthy is that highly chemoselective reactions were achieved in the presence of other functional groups such as halogens, carbon-carbon double bonds and hydroxyl groups.     

Neue Lithiumchlorid-Suzukiphasen: Li6MCl8(M = Fe,Co, Ni)

Novel Lithium Chloride Suzuki Phases, Li₆MCl₈ (M = Fe, Co, Ni) The hitherto unknown Suzuki phases Li₆FeCl₈, Li₆CoCl₈, and Li₆NiCl₈ ( cF 60) were prepared by fusing the binary chlorides. X-ray, DTA, and conductivity data as well as the infrared and Raman spectra are presented. The unit cell dimensions of the cubic (space group Fm3 m) halides are a = 1029.3, 1027.5, and 1023.5 pm, respectively. Li₆FeCl₈ and Li₆CoCl₈ undergo a reversible phase transition to disordered LiCl solid solutions at 275 and 355°C, respectively. The metastable nickel compound can only be prepared by quenching from about 560°C. The lithium chloride Suzuki phases are fast lithium ion conductors at elevated temperatures. The specific conductivities are 1.4 × 10^?1, 1.5 × 10^?1, and 6.9 × 10^?2Ω^?1 × cm^?1 at 500°C, respectively. Whereas the i.r. spectra of the Suzuki phases only reveal a broad band, the Raman spectra exhibit the four group theoretically allowed modes as sharp scattering peaks, which are discussed in terms of the vibrational modes of this structure.     

二氯二茂钛(锆)/格氏试剂体系在有机合成中的应用

介绍近几年来二氯二茂钛 (锆 ) /格氏试剂体系在有机合成中的应用 ,特别是使用该体系发展的新反应及其机理的研究情况     

Facile Reduction of Chalcones to Dihydrochalcones with NaBH4/Ni2+ System

Chalcones have been found to undergo facile reduction on treatment with sodium borohydride-nickel chloride system in dioxan-methanol medium to afford dihydrochalcones.     

NaBH4/MCl x 体系对液体端羧基氟橡胶的还原及还原机理

以液体端羧基氟橡胶(LTCFs)为原料, 硼氢化钠与金属氯化物(NaBH₄/MCl _x )为还原体系, 采用一锅法成功将LTCFs还原为液体端羟基氟橡胶(LTHFs). 研究了多种稀土金属氯化物(LaCl₃, CeCl₃, NdCl₃和SmCl₃）和过渡金属氯化物(MnCl₂, NiCl₂, CoCl₂和CuCl₂)对LTCFs还原效果的影响及变化规律. 采用傅里叶变换红外光谱(FTIR)、 核磁共振氢谱(¹H NMR)、 核磁共振氟谱(¹⁹F NMR)和化学滴定法对原料和产物的分子链结构和官能团含量进行了表征. 结果表明, 稀土金属MCl _x 还原体系对LTCFs的还原效果均高于过渡金属MCl _x 还原体系, LTCFs中的—C=C—和—COOH均可以被还原为—C—C—和—OH, 其中NaBH₄/SmCl₃还原体系还原效率最高, 达到92%. 机理研究表明, NaBH₄/MCl _x 对—COOH的还原性能与MCl _x 中金属阳离子和羰基氧间的结合力有关, 结合力越大越有利于—COOH的还原.     

Synthesis, Characterization and Thermal Decomposition of M1[M2(C2O4)2]xH2O (x=5 for M1=Co and x=4 for M1=Cd; M2=Ni)

Cobalt bis(oxalato)nickelate pentahydrate, Co[Ni(C₂O₄)₂]5H₂O and cadmium bis(oxalato)nickelate tetrahydrate, Cd[Ni(C₂O₄)2]4H₂O have been synthesized and characterized by elemental analysis, reflectance and IR spectral studies. Thermal decomposition studies (TG, DTG and DTA ) in air showed that both the compound of cobalt and cadmium produced the oxide, MNiO_x (x=3 for M=Co; x=2 for M=Cd ) at 325 and 360°C respectively. DSC studies in nitrogen attributed only the mixture of both the metal at the end. This revised version was published online in July 2006 with corrections to the Cover Date.     

Spectrum analysis of monophosphates SrMN(PO4)2, where M=Co,Ni

The infrared and Raman spectra of triclinic phosphates SrM2(PO4)2 where M = Co, Ni have been reported and analysed. The results of a force field calculation for SrNi2(PO4)2 are presented.     

Cyano-bridged hexanuclear Fe4M2 (M = Ni, Co, Mn) clusters: spin-canted antiferromagnetic ordering of Fe4Ni2 cluster

Heterobimetallic hexanuclear cyano-bridged complexes, [{Fe(Tp)(CN)3}4{M(MeCN)(H2O)2}(2)].10H2O.2MeCN [M = Ni (1), Co (2), Mn (3); Tp = hydrotris(1-pyrazolyl)borate], have been synthesized in H2O-MeCN solution. Complexes 1-3 are isostructural and hexanuclear with [{Fe(Tp)(CN)3}4{M(MeCN)(H2O)2}2] units linked by hydrogen bonds to form a 2D-structure in the solid state. Complex 1 is a canted antiferromagnet that undergoes a field-induced spin-flop-like transition at approximately 1 T and 2 K. At 4.45 K 1 has a transition to paramagnetic state of noninteracting S = 4 magnetic clusters. However, 2 and 3 show antiferromagnetic intracluster coupling. Facile loss of solvent from 2 alters the local symmetry resulting in changing the intracluster interaction from antiferro- to ferromagnetic.     

Coordination frameworks constructed from bipyridyl piperazine and MCl2 (M = Co, Ni, Zn): structural characterization and optical properties

Three metal-organic polymers, [CoCl2(bpfp)]n 1, {[NiCl2(bpfp)2](H2O)3}n 2 and [ZnCl2(bpfp)]n 3 (bpfp = N,N'-bis(3-pyridylformyl)piperazine), are formed by the self-assembly of the flexible bpfp with MCl2 (M = Co, Ni, Zn), respectively. X-Ray single-crystal structural analysis reveals that polymer 1 exhibits a novel grid network, in which the grid is composed of segments of bpfp and cobalt ions. Polymer 2 consists of 2D rhombohedral grids, the dimensions of the grid are 15.782 x 12.434 A2 and the diagonal-to-diagonal distances are 13.186 x 25.169 A2. In polymer 3, infinite wavelike chains are extended to 2D supramolecular arrays via C-H...Cl hydrogen bonds. The third-order nonlinear optical (NLO) behaviors of 1-3 and bpfp were investigated in dilute DMF solution by Z-scan measurement. The results show that 1, 2 and 3 exhibit good third-order NLO properties, which are quite different from bpfp that shows weak NLO behavior. This paper demonstrates that metal ions can strongly influence the crystal structures and third-order NLO properties of polymers.     

Mcore-Ptshell(M=Fe、Co、Ni)纳米粒子电催化氧还原的对比研究

纳米Pt具有较高的氧还原催化活性,但抗甲醇性不足,对直接甲醇燃料电池的性能产生影响。本文采用胶体模板法制备Mcore-Ptshell(M=Fe、Co、Ni)核壳型纳米粒子,用XRD和TEM表征纳米粒子的微观形貌和结构,动电位法和交流阻抗考察电催化活性和抗甲醇性。结果显示,Mcore-Ptshell纳米粒子的平均粒径约为10 nm,壳层厚度约为2~3 nm,3种催化材料的氧还原活性均高于碳载纳米Pt,抗甲醇性也有明显提高,其中Fecore,1-Ptshell,1/C的活性最高,峰电流密度达到0.5833 mA.cm-2,Cocore,1-Ptshell,1/C次之,Nicore,1-Ptshell,1/C最低;Fecore,1-Ptshell,1/C与Nicore,1-Ptshell,1/C的抗甲醇性相当,略好于Cocore,1-Ptshell,1/C。     

Structural and magnetic properties of MCl2 (M = Fe, Mn, Co): acetonitrile solvates

MIICl2 (M = Mn, Fe, Co) as their acetonitrile solvates were isolated, and their structural, spectroscopic, and magnetic properties were studied. MCl2(NCMe)2 (M = Fe, Mn) form 1-D chains of octahedral MII ions with four bridging chlorides and two axial MeCN's. The presence of an axial distortion for MFe causes a significant magnetic anisotropy that increases significantly below 150 K; however, chiav [=(chi parallel + 2chi perpendicular)/3] almost coincides with the value obtained on a polycrystalline sample. MnCl2(NCMe)2 is a paramagnet with a weak antiferromagnetic coupling. Annealing FeCl2(NCMe)2 at 55 degrees C forms the monosolvate of FeCl2(NCMe) composition in which two chains collapse into a double chain with formation of Fe-Cl bonding such that half of the mu-Cl's becomes mu3-Cl's. This material orders magnetically below Tc = 4.3 K. For M = Co, paramagnetic tetrahedral [CoCl3(NCMe)]- anions are isolated.     

Synthesis,Crystal Structures and Electrochemical Properties of Complexes [M(ImH)4(tfbdc)(H2O)] (M=Co,Ni)

The title complexes [M(ImH)₄(tfbdc)(H₂O)] ( 1 : M=Co; 2 : M=Ni) (ImH=imidazole, tfbdc=2,3,5,6‐tetrafluoroterephthalate) were synthesized by the reaction of M(OAc)₂·4H₂O, H₂tfbdc and ImH in water solution. The complexes were characterized by elemental analysis, IR spectra, thermogravimetric analysis, cyclic voltammetry and X‐ray single crystal structure analysis. Structural analysis reveals that 1 and 2 possess isostructure: monoclinic, P2₁/c, Z=4. M(II) ion in complexes 1 and 2 has a distorted octahedral geometry coordinated by one oxygen atom from water, one oxygen atom from tfbdc^2? and four nitrogen atoms from ImHs. They are discrete zero‐dimensional molecular complexes. And the adjacent monomeric components are connected by hydrogen bonds to form a supramolecule. Electrochemical properties of the complexes 1 and 2 show that electron transfer of M(II) between M(III) in electrolysis is a quasi‐reversible process.     

Stability and nature of complexes of the type MCl+ in aqueous solution (M=Mn,Co, Ni,and Zn)

Equilibrium constants have been determined both potentiometrically and spectrophotometrically for reactions of the type M²⁺+Cl^??MCl⁺ using aqueous solutions of the corresponding metal perchlorates as the reaction media (M=Mn, Co, Ni, and Zn). The variation in the quotient of the activity coefficients of these reactions with increasing molality of the reaction medium has been found to be approximately the same for the CuCl⁺ (previously studied), MnCl⁺, and ZnCl⁺ complexes, while a different dependence is observed for the CoCl⁺ and NiCl⁺ complexes. The results are interpreted as indicating equilibrium coexistence of the [MCl(OH₂)₅]⁺ and {[M(OH₂)₆]Cl}⁺ species in the latter two cases. Approximate values of the corresponding equilibrium constants are estimated in addition to the derived overall thermodynamic stability constants of the MCl⁺ formal complexes. The latter are found to follow a partly inverted Irving-Williams series, the fact being accountable in terms of the ligand field stabilization energy.     

类晶加合物(M=Co,Cu, Ni)的晶体结构及分子间相互作用的理论研究

合成了3种化合物 [2-ClPyH]2CoCl4(1), [2-ClPyH]2NiCl4(2)和[2-ClPyH]2CuCl4(3), 单晶X射线衍射法晶体结构测定结果表明, 这3种化合物是同形加合物, 在它们的结构中, [2-ClPyH]+离子呈平面状, 而[MCl4]2-离子为变形的四面体. 晶体结构分析发现晶体中存在N—H…Cl和C—H…Cl氢键, 以及Cl…Cl分子间相互作用和π-π堆积作用. 对自由状态下独立的配位离子进行的几何构型优化, 以及三维周期性条件下几何结构优化的量子化学计算结果表明, 标题化合物中具有方向性和选择性的氢键决定延伸性结构的方向, 而相对较弱的卤素…卤素作用在最终晶体结构的确定中扮演很重要的角色.     

Synthesis of a one-dimensional metal-dimer assembled system with interdimer interaction, M2(dtp)4 (M = Ni, Pd; dtp = dithiopropionato)

A metal-dimer assembled system, M(2)(dtp)(4) (M = Ni, Pd; dtp = dithiopropionate, C(2)H(5)CS(2-)), was synthesized and analyzed by the X-ray single-crystal diffraction method, UV-vis-near-IR spectra of solutions, solid-state diffuse reflectance spectroscopies, and electrical conductivity measurements. The structures exhibit one-dimensional metal-dimer chains of M(2)(dtp)(4) with moderate interdimer contact. These complexes are semiconducting or insulating, which is consistent with the fully filled d(z)2 band of M(II)(d(8)). Interdimer metal-metal distances were 3.644(2) Angstroms in Ni(2)(dtp)(4) and 3.428(2) Angstroms in Pd(2)(dtp)(4), each of which is marginally longer than twice the van der Waals radius of the metal. Interdimer charge-transfer transitions were nevertheless observed in diffuse reflectance spectra. The origin of this transition is considered to be due to an overlap of two adjacent d(sigma) orbitals, which spread out more than the d(z)2 orbital because of the antibonding d(sigma) character of the M(d(z)2)-M(d(z)2). The Ni(2)(dtp)(4) exhibited an interdimer charge-transfer band at a relatively low energy region, which is derived from the Coulomb repulsion of the 3d(sigma) orbital of Ni.     

Vibrational Spectroscopic Investigation of the Hofmann-type Clathrates: M(piperidine)2Ni(CN4. G (M=Co, Ni or Cu; G = benzene derivatives)

Infrared spectra of M(piperidine)₂Ni(CN)₄.0.5G (M=Co, Ni or Cu;G= chlorobenzene, 1,2-dichlorobenzene or 1,3-dichlorobenzene; M=Co or Ni;G=1,4-dichlorobenzene) compounds are reported. The piperidine molecules inthe host permit the inclusion of bulky guest molecules. The spectral featuressuggest that the compounds are similar in structure to the Hofmann-type clathrates.     

Die Systeme des Typs MCl/AlCl3/SO2 (M = Li,Na, K,NH4)

The MCl/AlCl₃/SO₂ Systems (M = Li, Na, K, NH₄) Phase diagrams of the ternary systems of the type MCl/AlCl₃/SO₂ were determined by measurement of SO₂ pressure, solubilities, and by thermal analysis. The complete phase diagram in the range from ?30 to +50°C is given for the case M = Na, partial diagrams for M = Li, K, NH₄. There exist solid compounds of the type MAlCl₄ · nSO₂ (M = Li, Na; n = 1.5 and 3) (M = K; n = 1.5 and 5) (M = NH₄; n = 5). Liquid phases can be obtained at room temperature and atmospheric pressure in the NaCl or LiCl containing systems.     

[MPy4(NCO)2]-2Py clathrates (M = M(II) = Mn,Fe, Co,Ni, Cu,Zn, Cd; Py = pyridine)

The title compounds form an iso structural series and are isomorphic with other [MPy₄X₂]-2Py clathrates (XRD, KM4 diffractometer, cell parameters and space group Ccca from 17–80 reflections). In the clathrate [NiPy₄(NCO)₂]-2Py studied in detail (XRD, CAD-4 diffractom eter, λCuK_α, Ω/2θ scan mode, θ_max = 78‡, 990 strong reflections, 104 parameters, R = 0.053), the host molecule has 222 symmetry, and the twofold axes run along the coordination bonds. The transoctahedral environment of nickel consists of six nitrogen atoms of four pyridine and two isocyanate ligands. The coordination polyhedron is slightly distorted due to changes in the bond lengths. The molecule has a propeller conformation. The guest molecules lie in the cavities of the crystal structure in conformity with the van der Waals type of packing. The host complex [NiPy₄(NCO)₂] (XRD, CAD-4 diffractometer, 4615 strong reflections, 560 parameters, R-0.037) crystallizes in the triclinic crystal system (space group P1) with two independent asymmetric molecules in the unit cell. The molecular structure is analogous to that in the ciathrate phase, but the coordination angles are severely distorted; one of the molecules acquires a distorted propeller conformation, and the other, a centrosvmmetric conformation, which is less favorable. While being structurally identical, the [MPy₄(NCO)₂]-2Py clathrates differ heavily in the properties. The first four complexes dissociate to host complexes, and their thermal stability changes in the sequence Mn< Fe< Co< Ni; the Cu and Zn clathrates decompose in one step to dipyridine complexes with decomposition of host complexes. Decomposition of the Cd ciathrate follows one of these patterns depending on conditions. The results are compared with those for other known systems. Synthetic procedures are given. Translated fromZhurnal Strukturnoi Khimii, Vol. 40, No. 5, pp. 935–953, September–October, 1999.     

Synthesis and characterization of (smif)2M(n) (n = 0, M = V, Cr, Mn, Fe, Co, Ni, Ru; n = +1, M = Cr, Mn, Co, Rh, Ir; smif =1,3-di-(2-pyridyl)-2-azaallyl)

A series of Werner complexes featuring the tridentate ligand smif, that is, 1,3-di-(2-pyridyl)-2-azaallyl, have been prepared. Syntheses of (smif)(2)M (1-M; M = Cr, Fe) were accomplished via treatment of M(NSiMe(3))(2)(THF)(n) (M = Cr, n = 2; Fe, n = 1) with 2 equiv of (smif)H (1,3-di-(2-pyridyl)-2-azapropene); ortho-methylated ((o)Mesmif)(2)Fe (2-Fe) and ((o)Me(2)smif)(2)Fe (3-Fe) were similarly prepared. Metatheses of MX(2) variants with 2 equiv of Li(smif) or Na(smif) generated 1-M (M = Cr, Mn, Fe, Co, Ni, Zn, Ru). Metathesis of VCl(3)(THF)(3) with 2 Li(smif) with a reducing equiv of Na/Hg present afforded 1-V, while 2 Na(smif) and IrCl(3)(THF)(3) in the presence of NaBPh(4) gave [(smif)(2)Ir]BPh(4) (1(+)-Ir). Electrochemical experiments led to the oxidation of 1-M (M = Cr, Mn, Co) by AgOTf to produce [(smif)(2)M]OTf (1(+)-M), and treatment of Rh(2)(O(2)CCF(3))(4) with 4 equiv Na(smif) and 2 AgOTf gave 1(+)-Rh. Characterizations by NMR, EPR, and UV-vis spectroscopies, SQUID magnetometry, X-ray crystallography, and DFT calculations are presented. Intraligand (IL) transitions derived from promotion of electrons from the unique CNC(nb) (nonbonding) orbitals of the smif backbone to ligand π*-type orbitals are intense (ε ≈ 10,000-60,000 M(-1)cm(-1)), dominate the UV-visible spectra, and give crystals a metallic-looking appearance. High energy K-edge spectroscopy was used to show that the smif in 1-Cr is redox noninnocent, and its electron configuration is best described as (smif(-))(smif(2-))Cr(III); an unusual S = 1 EPR spectrum (X-band) was obtained for 1-Cr.     

NaBH4-I2还原法制备N,N'-二甲基间苯二胺

以间苯二胺为原料, 与酰化剂甲酸反应制得中间体N,N'-二甲酰基间苯二胺, 再以NABH4-I2为还原剂合成得到产品N,N'-二甲基间苯二胺, 对合成工艺进行了优化, 并分析了还原机理, 化合物的结构经IR, 1H NMR和MS分析确定. 该法原料易得, 反应条件要求低, 收率高且成本更低.