STUDY ON POLYMER-Ru-Co BIMETALLIC COMPLEXES CATALYSTS Ⅱ.X-RAY PHOTOELECTRON SPECTROSCOPIC ANALYSIS

Polymer Ru-Co bimetallic complexes have been examined by X-ray photoelectron spectroscopy.The catalyst is highly active only when the mole ratio of Co/Ru is 4: 3. The activity of catalysts does not depend on the total Co/Ru ratio, but on the surface stoichiometry of Co and Ru. When the relative intensities of Co_2_p and Ru_(3d) of XPS peaks are close to each other and both are high,the catalyst exhibits its maximum activity The mechanism ofcatalytic hydroformylation has been discussed.

STUDY ON POLYMER—Ru-Co—BIMETALLIC COMPLEXES CATALYSTS Ⅰ. SYNTHESIS OF CATALYSTS AND THEIR USE FOR THE HYDROFORMYLATION

Six kinds of polymer ligands, supported on SiO_2, containing coordinating atoms P, S and N respectively, have been synthesized. The Ru(Ⅲ)-Co(Ⅱ) bimetallic complexes of these polymer ligands have been obtained and examined as catalysts for the hydroformylation of cyclohexene. The effects of reaction temperature, pressure and Co/Ru ratio etc. on the activities of catalysts were investigated in detail. The catalysts are all polymer-noncarbonyl-metal complexes, easily to be prepared, active and stable. From the experimental results it can be suggested that under reaction conditions such polymer-noncarbonyl-metal complexes convert 'in situ' to polymer-carbonyl-metal complexes, thus become active catalysts. The course of this conversion is supposed as a preliminary approach.

Syntheses and Crystal Structures of Two Cyano-bridged Bimetallic Complexes [Ce(DMSO)_4(H_2O)_3Fe(CN)_6]·H_2O and [La(DMSO)_4(H_2O)_3Co(CN)_6]·H_2O(DMSO = Dimethylsulfoxide)

Two new bimetallic cyano-bridged complexes [Ce（DMSO）4（H2O）3Fe（CN）6]·H2O 1 and [La（DMSO）4（H20）3Co（CN）6].H20 2 have been prepared by the ball milling reaction method and structurally characterized by X-ray single-crystal structure analyses. Crystallographic data for 1： C14H32CeFeN6O8S4, Mr= 736.67, monoclinic, space group P2 1/n, a = 14.952（1）, b = 13.7276（9）, c = 15.392（1） A, β= 108.288（1）°, V = 2999.6（4） A3, Z = 4, Dc= 1.631 g/cm^3, g = 2.304 mm^-1, F（000） = 1480, R = 0.0593 and wR = 0.1611; and those for 2： C14H32CoLaN6O8S4, Mr=738.54, monoclinic, space group P21/n, a = 14.945（3）, b = 13.731（3）, c = 15.300（3） A, β= 107.806（1）°, V= 2989.3（11） A^3, Z= 4, Dc = 1.641 g/cm^3, μ = 2.288 mm^-1, F（000） = 1480, R = 0.0383 and wR = 0.1132. In both complexes the lanthanide ion is eight-coordinated in a square antiprism arrangement, and the Fe（Ⅲ） or Co（Ⅲ） ion in a nearly regular octahedral environment The [LnM（CN）6（DMSO）4（H2O）3]·H2O （Ln = Ce and M = Fe for 1; Ln = La and M = Co for 2） species are held together via hydrogen bonds by coordinated water molecules, lattice water molecules and nitrogen atoms of cyanide groups to form a three-dimensional framework.

Syntheses and Crystal Structures of Two Cyano-bridged Bimetallic Complexes [Ln(DMSO)_2(H_2O)(μ-CN)_4Fe(CN)_2] (Ln = Ce and Eu, DMSO = Dimethylsulfoxide) with Layered Structure

Two new bimetallic cyano-bridged complexes [Ln（DMSO）2（H2O）（μ-CN）4Fe（CN）2] （Ln = Ce 1, Eu 2） have been prepared by the grinding reaction method and structurally characterized by X-ray single-crystal structure analysis. Crystallographic data for 1： C10H14CeFeN6O3S2, Mr = 526.36, monoclinic, P2/n, a = 7.852（4）, b = 10.729（5）, c = 11.181（5）A,β = 96.992（8）°, V = 935.0（7） A^3, Z = 2, Dc = 1.870 g/cm^3,/1 = 3.421 mm^-1, F（000） = 512, R = 0.0363 and wR = 0.0971; and those for 2： C10H14EuFeN6O3S2, Mr = 538.20, monoclinic, P21n, a = 7.739（5）, b = 10.668（7）, c = 11.008（7） A,β = 96.943（3）°, V = 902.1（11） A^3, Z = 2, Dc = 1.981 g/cm^3,/1 = 4.499 mm^-1, F（000） = 522, R = 0.0345 and wR = 0.0855. In each complex the lanthanide ion is seven-coordinated in a pentagonal bipyramidal arrangement, and the Fe（Ⅲ） ion is in a nearly regular octahedral environment. The title complexes can be described as two- dimensional （2-D） stair-like structures, which are further connected by hydrogen bonds to form three-dimensional （3-D） frameworks.

CATALYTIC BEHAVIOR OF SILICA-SUPPORTED POLY-γ- AMINOPROPYL- SILOXANE-Co-Ru BIMETALLIC COMPLEX FOR THE HYDROFORMYLATION OF CYCLOHEXENE

The cobalt and ruthenium bimetallic complex of poly-γ-amino-propylsiloxane( abbr. as Si-CH_2-Co-Ru) was prepared, and it was found that it can catalyze the hydroformylation of cyclobexene effectively with the conversion amounting to over 90%. Cyclohexanecarboxaldehyde was first formed in the hydroformylation, and then further hydrogenated to form cylcohexanemethanol. The coversion was affected obviously by the Co/Ru ratio.When Co/Ru molar ratio was 100-150, i.e. in the very low content of noble metal Ru, the catalytic activity of Si-NH_2 -Co-Ru was also very high. The product composition was affected by CO/H_2 ratio in the reaction gas. Aldehyde can be got high selectively by controlling CO/H_2 ratio. Compared with other catalyst system, the Si-NH_2-Co-Ru catalyst has higher catalytic activity and efficiency with very low Ru/Co ratio. The total turnover number was more than 28,800 (based on the amount of ruthenium used).

Syntheses and Structural Characterizations of η~5-2,4-Cyclopentadien-1-yl Di-carbonyliron Heteronuclear Bi-Metallic Complexes

The novel complexes, Cp(CO) 2FeTiCp 2Cl(1) and Cp(CO) 2FeSn(CH 2CMe 2Ph) 3(2), were synthesized and characterized by means of elemental analyses and IR spectra, Cp(CO) 2FeSn· (CH 2CMe 2Ph) 3 was additionally characterized by X ray crystal structure analysis. The results of the elemental analyses are in good agreement with the theoretical values. The IR spectra show the existence of η 5 2,4 cyclopentadien 1 yl, carbonyl and methyl groups in the title complexes. The above experimental results show that the M-M bond exists in Cp(CO) 2FeSn· (CH 2Me 2Ph) 3, while the existence of the M-M bond in Cp(CO) 2FeTiCp 2Cl is highly possible, too. Both the two complexes are rather stable towards air and moisture, easily soluble in tetrahydrofuran and toluene, while their solubilities are greatly different in n hexane.

Synthesis and Molecular Structure of A Bimetallic Salen Complex Containing Zn and La: A Disordered Nitrate Group Dancing between Two Metal Centers

A new bimetallic complex containing Zn and La was prepared from a salen ligand possessing methoxyl groups at the 3, 3′-positions. The structural feature is that one of nitrate groups is disordered and displaced between two metal centers. Crystal system: Triclinic space group:P-1, Z=2. a=0.82714(17) nm, b=1.3484(3) (1) nm, and c=1 3898(3) (1) nm, α=79.89(3)°, β=76.67(3)°, and γ=72.43(3)°. V=1 428 6(5) nm3, Dx=1.812 g·cm-3. (Δρ)max=1 510×10-3 enm3, (Δρ)min=-1.503×10-3 enm3. Accordingly, two water molecules occupy the metal centers in the apical positions via the syn-geometry.

HYDROFORMYLATION OF MMA CATALYZED BY SILICA-SUPPORTED POLY-γ-AMINO PROPYLSILOXANE-Rh-Co BIMETALLIC COMPLEX

A silica-supported poly-γ- aminopropylsiloxane-rhodium-cobalt bimetallic complex(abbreviated as SiO_2-NH_2-Rh-Co)has been prepared and used as catalyst for hydroformylationof methyl methacrylate. The results showed that the catalyst could catalyze the reaction in95.6% conversion with 92.8% selectivity for the normal aldehyde, methyl β-formylisobu-tyrate. Such catalyst also showed high stability during the reaction and could be used repeat-edly.

Synthesis and Crystal Structure of a Cyano-bridged Bimetallic Complex[La(betaine)_2(H_2O)_6Fe(CN)_6]·2H_2O

The title complex [La(betaine)2(H2O)6Fe(CN)6]?2H2O (betaine = (CH3)3NCH2CO2) has been synthesized and characterized by X-ray single-crystal structure analysis. The crystal crystallizes in monoclinic, space group P21/n with a = 15.793(5), b = 8.927(3), c = 22.257(7) ?, β = 110.147(5)o, C16H38FeLaN8O12, Mr = 729.31, Z = 4, V = 2946.0(15) ?3, Dc = 1.640 g/m3, μ(MoKα) = 1.988 mm-1, F(000) =1476, R = 0.0388 and wR = 0.0827 for 4237 observed reflections (I > 2σ(I)). The La3+ ion is nine-coordinated by one cyano nitrogen atom and eight oxygen atoms of two betaine and six water molecules. Each complex molecule is connected to form a 3D network structure by some O–H…O and O–H…N hydrogen bonds.

SPECTROPHOTOMETRIC STUDY OF BIMETALLIC TERNARY COMPLEX OF LANTHANUM——COPPER WITH ALIZARIN FLUORINE BLUE

The bimetallic ternary complex formation in the aqueous solution of La and Cu with alizarin fluorine blue (AFB) was studied by spectrophotometry.The ternary complex LaCu3(AFB)3 has maximum light absorption at 550nm.The colour reaction selectivity is fairly good and the method can be applied to the direct photometric determination of copper in lanthanum or some pure metals.A new mathematical approach to the treatment of spectrophotometric data for differentiation between mononuclear and polynuclear in solution is presented.The improvable fixed logarithm method is for complexes of the type MmBn(m=n) or MmBn(m=n).We report that La(Ⅲ) combines with AFB at pH 4.5 to form a single complex,withm=n=2,La2(AFB)2.

Synthesis and Crystal Structure of Tetra((8-quinolyl)-amido-N)ytterbium Bi(tetrahydrofuran-O)lithium

The treatment of the mixture of n-BuLi with 1 equiv.8-aminoquinoline in THF in situ,which reacted further with 1/3 equiv.of YbCl3 in THF,to give the homoleptic lanthanide amide ate complex Yb（NH-C9H6N）4Li（C4H8O）2（1）.The crystal structure was determined by X-ray diffraction and the following crystallographic data were obtained：C44H44N8O2YbLi,Mr = 896.85,monoclinic,space group C2/c,a = 7.8384（16）,b = 22.294（5）,c = 22.668（5）,β = 97.614（5）°,V = 3926.3（14）3,Z = 4,Dc = 1.517 g/cm3,F（000）= 1812,μ（MoKα）= 2.431 mm-1,R = 0.0542 and wR = 0.1523 for 3372 observed reflections with I 2σ（I）.The structure of molecule 1 consists of one ytterbium atom,one lithium atom,four 8-aminoquinoline ligands and two THF molecules.The ytterbium atom is coordinated by eight nitrogen atoms of four 8-aminoquinoline ligands,forming a distorted dodecahedral geometry.

Diatomic Pd catalyst with conjugated backbone for synergistic electrochemical CO_(2)reduction

Double-site catalysts have attracted widespread attention in the field of electrocatalysis due to their high metal loading,adjustable active centres,and electronic valence states.However,the development of bimetallic sites catalysts that coordinate with definite atoms is still in the exploratory stage.Here,we designed and synthesized a bimetallic palladium complex(BPB-Pd_(2))with conjugated backbone.The supported BPB-Pd_(2)was applied to electrochemical CO_(2)reduction reaction(CO_(2)RR)for the first time.The as-obtained BPB-Pd_(2)gives an exceptional Faradaic efficiency of CO(FECO)of 94.4%at−0.80 V vs.reversible hydrogen electrode(RHE),which is significantly superior to monoatomic palladium catalyst(BPB-Pd1).The density functional theory(DFT)calculations revealed that the essential reason for the outstanding activity of BPB-Pd_(2)toward CO_(2)RR was that the electronic effect between diatomic palladium reduces the free energy change for CO_(2)RR process.Thus,BPB-Pd_(2)exhibits moderate free energy change to form COOH*intermediate,which was beneficial for the generation of CO in CO_(2)RR.