Synthesis and Structural Characterization of a Binuclear Mixed‐Ligand (Salicylate and N,N‐diethylnicotinamide) Nickel(II) Complex,Its Magnetic Properties. [Ni2(µ‐Sal)4(Dena)2]H2O

The title complex of [Ni₂(µ‐Sal)₄(Dena)₂]H₂O, [( µ‐tetrakissalicylato‐κ‐O,O)(bis‐N,N‐diethylnicotinamide‐κ‐N)(binickel(II))]hydrate, C₄₈H₅₂Ni₂N₄O₁₆, has been synthesized and explained as structural using some elemental analysis, FT‐IR spectra, UV‐Vis reflectance, magnetic measurements, thermal analysis and x‐ray diffraction methods. The analysis results showed that the unit cell of complex includes two molecules Ni^II cation, four molecules salicylates as bridge and two molecules N,N‐diethylnicotinamide ligands, also there is one molecule hydrated aqua. The compound crystallizes in the monoclinic space group P2₁/c with the following unit‐cell parameters: a =13.6776(6) Å, b =10.5238(3) Å, c =21.8165(9), α=90.00°, β=126.546(3)°, γ=90.00º and Z=2. The compound [Ni₂(µ‐Sal)₄(Dena)₂]H₂O is a typical paddle‐wheel complex structure. Two Ni^II ions are bridged by four salicylate ligands (O2, O2ⁱ, O3, O3ⁱ, O5, O5ⁱ, O6 and O6ⁱ) using a µ‐COO^? coordination mode [symmetry code: (i) 1‐x, 1‐y, 1‐z]. Each Ni^II also coordinates to one nitrogen atom (N1 and N1ⁱ) from one N,N‐diethylnicotinamide ligand molecule in the axial position. The complex has strong paramagnetic properties.     

A candidate for a single‐chain magnet: [Mn3(OAc)6(py)2(H2O)2]n (OAc is acetate and py is pyridine)

The title complex, catena‐poly[di‐μ₃‐acetato‐κ⁶O:O:O′‐tetra‐μ₂‐acetato‐κ⁴O:O;κ⁴O:O′‐diaquabis(pyridine‐κN)trimanganese(II)], [Mn₃(CH₃COO)₆(C₆H₅N)₂(H₂O)₂]_n, is a true one‐dimensional coordination polymer, in which the Mn^II centres form a zigzag chain along [010]. The asymmetric unit contains two metal centres, one of which (Mn1) lies on an inversion centre, while the other (Mn2) is placed close to an inversion centre on a general position. Since all the acetates behave as bridging ligands, although with different μ₂‐ and μ₃‐coordination modes, a one‐dimensional polymeric structure is formed, based on trinuclear repeat units (Mn1...Mn2...Mn2′), in which the Mn2 and Mn2′ sites are related by an inversion centre. Within this monomeric block, the metal–metal separations are Mn1...Mn2 = 3.36180 (18) Å and Mn2...Mn2′ = 4.4804 (3) Å. Cation Mn1, located on an inversion centre, displays an [MnO₆] coordination sphere, while Mn2, on a general position, has a slightly stronger [MnO₅N] ligand field, as the sixth coordination site is occupied by a pyridine molecule. Both centres approximate an octahedral ligand field. The chains are parallel in the crystal structure and interact via hydrogen bonds involving coordinated water molecules. However, the shortest metal–metal separation between two chains [5.3752 (3) Å] is large compared with the intrachain interactions. These structural features are compatible with a single‐chain magnet behaviour, as confirmed by preliminary magnetic studies.     

Hybrid organic-inorganic 1D and 2D frameworks with epsilon-Keggin polyoxomolybdates as building blocks

Organic-inorganic hybrid materials based on polyoxometalate building blocks with capping La3+ ions and bidentate oxygenated ligands have been obtained by reaction at room temperature of the [epsilon-PMo12O36(OH)4[La(H2O)4]]5+ polyoxocation with glutarate (C5H6O(2)(2-)) and squarate (C4O(4)(2-)) organic ligands. [epsilon-PMo12O37(OH)3[La(H2O)4(C5H6O4)0.5]4].21 H2O (1) and [epsilon-PMo12O39(OH)[La(H2O)6]2-[La(H2O)5(C4O4)0.5]2].17 H2O (2) form unprecedented 1D chains built from alternating polyoxocations and organic ligands connected through LaO links. The structures of these materials are compared to the 2D hybrid organic-inorganic framework [NC4H12]2-[Mo22O52(OH)18[La(H2O)4]2[La(CH3CO2)2]4].8H2O (3) isolated from the hydrothermal reaction of elemental precursors (MoO(4)(2-), Mo, La3+) in acetate buffer. Compound 3 is built from previously undescribed polyoxometalate units with twenty-two MoV centers capped by six La3+ ions, four of which are bridged by acetate ligands.     

Bis‐aroylhydrazone based on 2,2′‐bis substituted diphenylamine for synthesis of new binuclear organotin (IV) complexes: Spectroscopic characterization,crystal structures,in vitro DNA‐binding,plasmid DNA cleavage,PCR and cytotoxicity against MCF7 cell line

New dinuclear organotin (IV) complexes, Me₄Sn₂L, Ph₄Sn₂L and Bu₄Sn₂L, have been synthesized from reaction of R₂SnCl₂ (R = Me, Ph and Bu) with a 2,2′‐bis‐substituted diphenylamine arοylidene hydrazone, H₄L. The synthesized compounds were investigated by elemental analysis and infrared, ¹H‐NMR and ¹¹⁹Sn‐NMR spectroscopy. The structures of H₄L, Me₄Sn₂L and Bu₄Sn₂L were also confirmed by X‐ray crystallography. H₄L molecules adopt (E)‐configuration and keto‐tautomeric form in the solid state. In all complexes, the bis‐hydrazone acts as a tetra‐anionic ligand with two contiguous ONO tridentate domains that coordinate the two R₂Sn moieties in the enolate form. The coordination environments of both tin centers are five‐coordinate. DNA‐binding studies were performed by UV–Vis spectroscopy, and the results indicate that the synthesized compounds significantly interact with calf thymus‐DNA in the intercalative mode. The results of polymerase chain reaction assay show that all the compounds affect on amplification of DNA, and complexes are more effective than ligands. The in vitro cytotoxicity against the human breast cancer line (MCF7) was determined using the MTT assay, and H₄L and the dibutytin complex showed higher activity.     

Synthesis,structural characterization and cytotoxic activity of triorganotin 5‐(salicylideneamino)salicylates

Six new triorganotin complexes ( 1a – 1c and 2a – 2c ) of 5‐(salicylideneamino)salicylic acid, [5‐(3‐X‐2‐HOC₆H₃CH═N)‐2‐HOC₆H₃COO]SnR₃ (X = H, 1 ; CH₃O, 2 ; R = Ph, a ; Cy, b ; CH₂C(CH₃)₂Ph, c ), have been synthesized by one‐pot reaction of 5‐aminosalicylic acid, salicylaldehyde and triorganotin hydroxide and characterized using elemental analysis and infrared and NMR (¹H, ¹³C and ¹¹⁹Sn) spectra. The crystal structures of 1a , 1b , 2a ·CH₃OH, 2b ·CH₃OH and 2c ·CHCl₃ have been determined using single‐crystal X‐ray diffraction. In non‐coordinated solvent CDCl₃, the tin atoms in the complexes are all four‐coordinated. In the crystalline state, these compounds adopt a four‐ or five‐coordination mode. Complex 1a exhibits a 44‐membered macrocyclic tetrameric structure with trigonal bipyramidal geometry around the tin atoms in which the axial positions are occupied by the oxygen atom of carboxylate group of the ligand and the phenolic oxygen atom from the adjacent ligand. The coordination geometry of tin atom in 1b and 2c ·CHCl₃ is a distorted tetrahedron shaped by three carbon atoms of alkyl groups and a carboxylate oxygen atom of the ligand. In 2a ·CH₃OH and 2b ·CH₃OH, the tin atom has a distorted trans‐C₃SnO₂ trigonal bipyramidal geometry formed by three alkyl groups, a monodentate carboxylate group and a coordinated methanol molecule. The molecules of 2a ·CH₃OH and 2b ·CH₃OH are linked via O─H···O hydrogen bonds into a one‐dimensional supramolecular chain and a centrosymmetric R₄⁴(22) macrocycle, respectively. Bioassay results against two human tumor cell types (A549 and HeLa) show the complexes are efficient cytostatic agents and may be explored as potential antitumor drugs.     

Structurally diverse coordination compounds of zinc as effective precursors of zinc oxide nanoparticles with various morphologies

The structurally diverse coordination compounds of zinc were designed and synthesized using two types of building blocks: short‐chain carboxylate ions and hexamethylenetetraamine. They were characterized by X‐ray crystallography, infrared spectroscopy and thermal analysis. The studied compounds were used as precursors for production (via controlled thermal conversion) of zinc oxide nanoparticles. The conversion process was optimized in terms of two parameters (heating rate and maximum temperature). Such an approach, combined with proper design of the precursor structure, allows fabrication of various zinc oxide micro‐ and nanoparticles. The influence of a precursor structure and modifications of conversion parameters on size and morphology of ZnO particles were studied and discussed.     

首例含4, 4'-联吡啶和乙酸锌的光致变色化合物

采用一种新方法得到一维配位聚合物[Zn(CH₃COO)₂(4,4'-bipy)]_n(1)。配合物1的晶体结构和荧光性质已经有详细报道,但光致变色性质还没有相关的研究工作发表。通过研究化合物1在光照前后的紫外吸收光谱和顺磁共振谱,表明化合物1具有电子转移光致变色性能。实验结果验证了我们提出的利用非光致变色单元设计电子转移光致变色材料的新方法是有效可行的。     

三环己基锡吡啶-4-甲酸酯聚合物的合成、结构和量子化学研究

双齿配体吡啶-4-甲酸与三环己基氢氧化锡反应,合成了三环己基锡吡啶-4-甲酸酯聚合物[Cy3Sn(O2CC5H4N)]n(Cy为环己基)。经IR、1H NMR、元素分析和X射线衍射表征结构,晶体结构属单斜晶系,空间群P21/c,晶体学参数:a=1.222 4(4)nm,b=0.980 9(5)nm,c=2.089 9(9)nm,β=107.238(3)°,Z=4,V=2.393 6(4)nm3,Dc=1.360 g.cm-3,μ(Mo Kα)=1.085 mm-1,F(000)=1 016,R1=0.028 2,wR2=0.068 4。中心锡原子为五配位三角双锥构型,通过吡啶-4-甲酸的1个氧和吡啶氮原子配位成链。两条相邻的链之间经氢键(C-H…O)作用组成"双链"结构,"双链"之间通过环己基H与另链的吡啶环发生σ→π作用形成二维结构。利用量子化学G98W软件,在lan12dz基组对配合物的稳定性、前沿分子轨道组成及能量进行研究。     

离子型化合物{[Ph2Sn]2[2,6-Py(CO2)2]3H2O}2-[HNEt3]+2 的合成及晶体结构研究

在三乙胺作碱的条件下 ,用三苯基氯化锡和 2 ,6 -吡啶二甲酸以 1∶ 1摩尔比反应 ,合成了离子型有机锡化合物 { [Ph2 Sn]2 [2 ,6 -Py( CO2 ) 2 ]3 H2 O} 2 - [HNEt3 ]+2 。用 X-射线单晶衍射测定了该化合物的晶体结构。化合物为单斜晶系 ,空间群 P2 1 /n,a=1 .70 73( 7) nm,b=1 .74 47( 7) nm,c=2 .4 333( 1 0 ) nm,β=1 0 9.6 94 ( 7)°,Z=4 ,V=6 .82 4 ( 5 ) nm3 ,Dx=1 .2 82 g/cm3 ,μ=0 .793mm- 1 ,F( 0 0 0 ) =2 6 96 ,R1 =0 .0 5 6 3,WR2 =0 .1 5 39。化合物中两个锡原子呈七配位畸变五角双锥构型     

基于邻香草醛缩2-氨基-4-硝基苯酚的Schiff碱有机锡配合物的合成、晶体结构及生物活性

邻香草醛缩2-氨基4-硝基苯酚(H₂L)分别与二丁基氧化锡、二苄基二氯化锡反应, 合成了二丁基锡Schiff碱配合物(1)和单苄基Schiff碱配合物(2)。配合物经元素分析、¹H NMR、¹³C NMR、IR、UV-Vis表征, 并用X-射线单晶衍射测定了分子结构。研究了配体H₂L及配合物1、2对癌细胞Hela、MCF7、HepG2、Colo205、NCI-H460的抑制活性, 结果表明配合物1对这5种癌细胞的抑制效果优于现有抗癌药物卡铂, 可作为抗癌药物的候选化合物。在Tris缓冲溶液中, 以EB做为荧光探针, 用荧光光谱法研究了配体H₂L及配合物2与鲱鱼精DNA的相互作用, 结果表明配合物与DNA作用主要是由于Schiff碱配体协同效应所致。