Two Novel Complexes Based on N-N Bridged Ligand:Syntheses,Crystal Structures,Fluorescence and Magnetic Property

Two novel coordination compounds,1[Zn4（L1）4（NO3）2（H2O）2]（NO3）2·2H2O and 2[Mn2（L2）2（DMF）（H2O）3]（ClO4）2·DMF（HL1 = N＇-[（1E）-pyridine-2-ylmethylidene]pyrazine-2-carbohydrazide,H2L2 = 2-hydroxy-3-methoxybenzaldehyde（pyrazin-2-ylcarbonyl）hydrazone）,based on the N-N bridged ligands were prepared and structurally characterized.Compound 1represents the[2＊2]molecular squares,in which both N atoms belonging to the N-N bridged ligands are connected to the Zn centers.The emission of compound 1 exhibits a blue shift,which can be assigned to strong electrostatic interaction between Zn^Ⅱ ions and the L1^-1.Compound 2represents a rare phenol-O bridged Mn2^Ⅱ complex.The magnetic investigation indicates weak antiferromagnetic interactions between the Mn^Ⅱ centers.

Synthesis and Crystal Structure of a Three-dimensional Mn(Ⅱ) Coordination Polymer with 3-(Pyrazin-2-yloxy)-pyridine and Azide Anion as Mixed Bridge Ligand

A three-dimensional coordination polymer [Mn2（μ1.3-N3）4（μ-PP）2]n （PP = 3-（pyrazin-2-yloxy）-pyridine） has been synthesized with 3-（pyrazin-2-yloxy）-pyridine and azide anion as mixed bridge ligand, and its crystal structure was determined by X-ray crystallography. The crystal data： triclinic system, space group P1, with a = 6.794（4）, b = 9.885（6）, c = 9.947（6） A, α = 64.170（6）, β= 84.190（8）, γ= 85.319（8）°, V = 597.7（6）A^3, Z = 1, C18H14Mn2N18O2, Mr = 624.35, Dc = 1.735 g/cm^3, F（000） = 314 and μ = 1.117 mm^-1. In the crystal, the azide anion acts as a bridge ligand and makes adjacent Mn（Ⅱ） ions connect into a two-dimensional sheet on the ab plane, then 3-（pyrazin-2-yloxy）-pyridine serves as a bidentate bridge ligand to connect neighboring sheets along

Organic ligand nanoarchitectonics for BiVO_(4) photoanodes surface passivation and cocatalyst grafting

Bismuth vanadate(BiVO_(4))is a promising photoanode material for efficient photoelectrochemical(PEC)water splitting,whereas its performance is inhibited by detrimental surface states.To solve the problem,herein,a low-cost organic molecule 1,3,5-benzenetricarboxylic acid(BTC)is selected for surface passivation of BiVO_(4) photoanodes(BVOs),which also provides bonding sites for Co^(2+)to anchor,resulting in a Co-BTC-BVO photoanode.Owing to its strong coordination with metal ions,BTC not only passivates surface states of BVO,but also provides bonding between BVO and catalytic active sites(Co^(2+))to form a molecular cocatalyst.Computational study and interfacial charge kinetic investigation reveal that chemical bonding formed at the interface greatly suppresses charge recombination and accelerates charge transfer.The obtained Co-BTC-BVO photoanode exhibits a photocurrent density of 4.82 mA/cm^(2) at 1.23 V vs.reversible hydrogen electrode(RHE)and a low onset potential of 0.22 VRHE under AM 1.5 G illumination,which ranks among the best photoanodes coupled with Co-based cocatalysts.This work presents a novel selection of passivation layers and emphasizes the significance of interfacial chemical bonding for the construction of efficient photoanodes.

Strong Antiferromagnetic Exchange-Coupling Observed in Hydride-Bridged Dimeric Dysprosium(Ⅲ)Single-Molecule Magnet

One dihydride-bridged dimeric Dy(Ⅲ)guanidinate complex,formulated as[{(Me_(3)Si)_(2)NC(NiPr)_(2)}_(2)Dy(μ-H)]_(2)(1Dy),was successfully isolated and the introduction of hydride bridges significantly reduces the intramolecular Dy(Ⅲ)…Dy(Ⅲ)distance to only 3.688(1)Å.To investigate the effect of such a short Dy(Ⅲ)…Dy(Ⅲ)distance on magnetism,we also prepared its dibromide-bridged analogue[{(Me_(3)Si)_(2)NC(NiPr)_(2)}_(2)Dy(μ-Br)]_(2)(2Dy),which has a much longer Dy(Ⅲ)…Dy(Ⅲ)distance of 4.605(4)Å.Surprisingly,2Dy demonstrates much larger effective energy barrier for magnetization reversal(U_(eff))and higher blocking temperature(T_(B)).The worse performance of 1Dy is attributed to the concerted effect of strong antiferromagnetic interactions between Dy(Ⅲ)ions(J_(total)=–2.683 cm^(–1))and the unparallel arrangement of magnetic principle axes of the Dy(Ⅲ)ions for 1Dy.

二炔基桥联双核钌配合物的电喷雾质谱研究

A rapid method is applied to analyze conjugated organic ligands bridged binuclear ruthenium complexes by electrospray ionization-tandem mass spectrometry (ESI MSn).Fragmentation pattern be discussed.

Structure of the Manganese (V) Complex-Mn·3/2(μ-DHBQ)·4H_2O·2Cl

The novel complex of Mn(V): Mn·3/2(μ -DHBQ)·4H2O·2Cl (where, H2DHBQ =2,5-dihydroxyl- 1,4-benzoquinone) was synthesized and its crystal structure has been determined by X-ray diffraction. The complex belongs to trigonal system with space group P3(# 147), a= 1 .415(2)nm, c=0.6552(4) nm, V=1 .1371(7) nm-3, Z=2, Dx=1.183 g/cm3, μ=7.37 cm-1, F(000)=408.00,R=0.041, Rw=0.046.

Synthesis and Crystal Structure of Rare Earth Metal Chlorides Bearing Bridged-lndenyl Ancillary Ligand

Two new rare earth metal chloride complexes supported by a bridged-indenyl ancillary ligand, [C9H6SiMe2- （CH2）2SiMeEC9H6]Ln（u-Cl）2Li（TMEDA） [Ln=Y （1）, Lu （2）], were synthesized via salt metathesis reaction. Reaction of C9H7SiMeE（CH2）ESiMeEC9H7 with 2 equiv, of n-butyllithium in hexane at room temperature afforded [C9H6SiMe2- （CHE）2SiMeEC9H6]Li2 as white powder in 95% isolated yield. Further treatment of [C9H6SiMe2（CHE）2SiMeE- C9H6]Li2 with anhydrous LnCl3 in 1 ： 1 molar ratio in THF/TMEDA at room temperature provided the bridged-indenyl rare earth metal chlorides 1 and 2 in 86%--89% isolated yields. Both complexes were characterized by FT-IR spectroscopy, NMR spectroscopy, elemental analysis, and X-ray single crystal structure analysis. The central metals in both complexes are eight-coordinated by two indenyl ligands in η^5-fashion, and two chlorine atoms to adopt a distorted tetrahedral geometry.

Synthesis and Characterization of A Dinuclear Europium Complex

A dinuclear Eu(Ⅲ) complex Eu2(DBM)6TPPD (Hexa(dibenzoyl-methanido)-(N, N, N, N-tetra(2-pyridyl)-1, 4-phenylenediamine)-dieuropium(Ⅲ)) was synthesized by employing DBM (dibenzoylmethane) and TPPD (N, N, N, N-Tetra(2-pyridyl)-1, 4-phenyl-enediamine) as sensitizing ligands for the Eu(Ⅲ) ion and a bridging ligand, respectively. The analysis of the absorption, excitation, and emission spectra of the dinuclear complex along with a comparison with analogous mononuclear complex containing the same β-diketone ligands and 1, 10-phenanthroline (phen) suggests that the dinuclear complex follows the luminescence mechanism of general Ln(Ⅲ) complexes.

Syntheses of bimetallic lanthanide bis(amido) complexes stabilized by bridged bis(guanidinate) ligands and their catalytic activity toward the hydrophosphonylation reaction of aldehydes and ketones

A series of bimetallic lanthanide bis(amido) complexes stabilized by bridged bis(guanidinate) ligands {[(Me3Si)2N]2Ln[(RN)2-CN(CH2)2]}2 [R=iPr, Ln=Sm(1), Yb(2), Y(3); R=cyclohexyl(Cy), Ln=Sm(4), and Yb(5)] were synthesized through the metathesis reactions of {Ln(μ-Cl)[N(Si Me3)2]2(THF)}2(Ln=Sm, Yb, Y) with lithium guanidinate {Li[(RN)2CN(CH2)2]}2(R=iPr, Cy), the latter of which was generated in situ by the reaction of carbodiimides with lithium amides. Complexes 1–5 were well characterized by elemental analyses, IR spectra, and(for Complex 3) NMR spectroscopy. The solid-state molecular structures of all of the complexes were determined by single-crystal X-ray analyses with the exception of Complex 3, which showed similar unsolvated centrosymmetric dinuclear structures. Each of the lanthanide centers is four-coordinated with two nitrogen atoms from a guanidinate ligand and two nitrogen atoms from two amido groups. The piperazidine rings adopt chair conformations in all cases. These organolanthanide complexes were found to be efficient catalysts for the hydrophosphonylation reaction of various aldehydes and unactivated ketones and to afford ?-hydroxyphosphonates in high yields under low catalyst loading(0.1 mol%) in a short reaction time.

A Corrugated 2D Mn(Ⅱ) Network:[Mn_3(μ-oxalate)_3(μ-4,4'-bpy)_2(4,4'-bpy)_2]_n

The title complex, [Mn3（μ-oxalate）3（μ-4,4′-bpy）2（4,4′-bpy）2]n, was synthesized and structurally characterized by X-ray crystallography. It crystallizes in the monoclinic, space group P2 1/c with a = 16.3222（6）, b = 16.2594（5）, c = 16.4885（5） A, β = 94.9900（10）°, V= 4359.3（2） A^3, Z = 4, Mn3C46N8O12H32, Mr = 1053.62, Dc = 1.605 g/cm^3, F（000） = 2140 and μ（MoKa） = 0.932 mm^-1. The structure was refined to R = 0.0578 and wR = 0.1061 for 4795 observed reflections （I 〉 2σ（I））. The oxalate anions behave as the bridging ligand and link two manganese atoms repeatedly to form infinite one-dimensional chains which further extend into a two-dimensional network by bridging 4,4′-bpy ligands.

Syntheses and Characterizations of Novel One-dimensional Coordination Polymers Self-assembled from Co(NCS)_2 and Flexible Diester-bridged Pyridine-based Ligands

The self-assembly reactions of Co(NCS) 2 with diester-bridged pyridine-based ligands pyCO 2-(CH 2) m-O 2Cpy (py=4-pyridyl; m=2, 3, 4) have been studied. Interestingly, while Co^(NCS) 2 reacted with pyCO 2-(CH 2) 2-O 2Cpy (La) in MeOH/H 2O or THF/MeCN to yield two coordination polymers [Co^(NCS) 2(La) 2] n(1) and [Co(NCS) 2(La) 2·2THF] n(2), reactions of Co(NCS) 2 with pyCO 2-(CH 2) 3-O 2Cpy (Lb) in MeOH/MeCN and Co(NCS) 2 with pyCO 2-(CH 2) 4-O 2Cpy (Lc) in EtOH/H 2O afforded [Co(NCS) 2(Lb) 2· 0.5MeOH] n(3) and [Co(NCS) 2(Lc) 2·2H 2O] n(4), respectively. The X-ray diffraction analyses indicated that polymers 1-4 consist of a one-dimensional Co(II) chain in which each of the two adjacent Co(II) ions is bridged by two pyCO 2-(CH 2) m-O 2Cpy ligands to form a macrocycle. In addition, the structures of polymers 1-4 were also characterized by infrared spectroscopy, thermogravimetry and elemental analysis.

Synthesis of Benzoxazine Functionalized Amine-Bridged Bis(phenolato) Rare Earth Complexes and Their Application in Ring-Opening Polymerization of rac-Lactide

The reactivities of benzoxazine functionalized amine bridged bis(phenol)s LnH_(2)(n=1—3)with rare earth metal complexes were explored,founding that both the aryl substituents of the ligand and the rare earth metals have profound influences on reaction outcomes.

Synthesis and Characterization of Cobalt（Ⅱ） and Copper（Ⅱ） Tricyanomethanide （tcm） Complexes with 2,2＇-Dipyridyl N,N＇-Dioxide （dpdo） as Co-ligands： [Co（dpdo）（tcm）2], [Cu（dpdo）（tcm）2] and Cu（dpdo）2（tcm）2

Three new transition metal tricyanomethanide complexes [Co（dpdo）（tcm）2] （1）, [Cu（dpdo）（tcm）2] （2） and Cu（dpdo）2（tcm）2 （3） were synthesized and structurally characterized. In compound 1 each Co（II） ion is coordinated to four disorder tcm anions and one dpdo molecule to give a distorted octahedral geometry. In compound 2 each Cu（II） ion is surrounded by four tcm anions and one dpdo ligand to form a square bipyramidal geometry. Both compounds 1 and 2 display a μ1,5-tcm bridged infinite chain structure. Interestingly, in compound 3 coordination geometry around the central ion is square-planar, each Cu（II） ion is coordinated by two dpdo molecules to form a cationic part, the cationic parts is linked with the free tcm anionic parts via electrostatic attraction, leading to the formation of a mononuclear structure. Magnetic susceptibility measurement in the range 2--300 K indicates that there are antiferromagnetic couplings between adjacent metal ions in 1 （0=--2.33 K, C=2.13 cm3-mol 1oK） and 2 （J= --0.30, g = 2.20） respectively.

Binuclear Ruthenium Complexes with Benzo[1,2-b;4,5-b＇]- dithiophene Analogues as Bridge Ligands： Syntheses, Characterization and Notable Difference on Electronic Coupling

Diruthenium ethynyl complexes 1--3 （1： 1,5-dithia-s-indacene-4,8-dione; 2： 4,8-diethoxybenzo[1,2-b：4,5- b＇]dithiophene; 3： 4,8-didodecyloxybenzo[1,2-b：4,5-b＇]dithiophene） have been synthesized by incorporating the re- spective conjugated heterocyclic spacer and characterized by NMR and elemental analysis. The effects of bridge ligands＇ properties on electronic coupling between redox-active ruthenium terminal groups were investigated by electrochemistry, UV/vis/near-IR and IR spectroelectrochemistry combined with density functional theory （DFT） and time-dependent DFT calculations. Electrochemistry results indicated that complexes 1--3 exhibit two fully re- versible oxidation waves, and complexes 2 and 3 with electron-rich and π-conjuagted bridge ligands are character- ized by excellent electrochemical properties. Furthermore, the larger v（C≡C） separation from the IR spectroelec- trochemical results of 2 and 3 and the intense NIR absorption features of singly oxidized species 2＋ and 3＋ re- vealed that their molecular skeletons have superior abilities to delocalize the positive charge. The spin density dis- tribution from DFT calculations proved the conclusions of this study.

Synthesis and magnetic properties of μ-phenolato copper (Ⅱ) binuclear complexes with different exogenous bridges

The syntheses and magnetic properties are reported for a series of copper(Ⅱ) complexes prepared from a pentadentate binucleating ligand 2,6-diformyl-4-methylphenol di(benzoyl-hydrazone) (H3L). These complexes incorporate different exogenous ions (X-) into a bridging position to form copper(Ⅱ) binuclear complexes of the formula [Cu2(H2L)X]2+, where X-= Br-(1), Cl-(2), HO-(3), C2H5O-(4) and C3H3N2- (5). The complexes have been characterized with variable temperature magnetic susceptibility (4.2-300 K) and the observed data were fit to those from a modified Bleaney-Bowers equation by least-squares method, giving the exchange integral 2J = -6.2 cm-1 for 1, -76.4 cm-1 for 2, -241.9 cm-1 for 3, -231.1 cm-1 for 4 and -343.8 cm-1 for 5. This suggested that there is an antiferromagnetic interaction between the Cu(Ⅱ) ions and the sequence of the effect of some exogenous bridging ligands on magnetic coupling is corresponding to that in spectrochemical series.

Synthesis, Structure and Reactivity of Lanthanocene Complexes

A variety of lanthanocene complexes, e.g. chlorides, hydrocarbyls, amides, hydrides and divalent derivatives, were synthesized by using a series of designed cyclopentadienyl, indenyl and fluorenyl ligands with ring bridges or dornor functionalized sidearms. X Ray crystallographic analyses reveal the formation of intramolecular coordination bonds between central metals and heteroatoms (O, N) in sidearms or bridging chains. Some applications of these complexes are also discussed in this account.