柔性配体构筑的三个构象多样的镧系羧酸配位聚合物:合成,结构和荧光性质

利用2,2''-(1,4-亚苯基)二(亚苯基)二(硫基)苯二羧酸(H₂L¹)和2,2''-(2,3,5,6-四甲基-1,4-亚苯基)二(亚甲基)二(硫基)苯二甲酸(H₂L²)2个柔性二羧酸分别与镧系金属盐反应,通过溶剂热方法合成了3个配位聚合物:{[(NH₂(CH₃)₂][Nd(L¹)₂(DMF)]·2DMF}_n(1)和{[Ln(L²)_1.5(H₂O)(DMF)₂]·2DMF}_n[Ln=Ce(2),Pr(3)]。利用元素分析、红外、粉末X射线衍射、热重分析等对配合物进行了表征。X射线单晶衍射分析表明:3个配合物均为二维的层状结构,并且2个配体在配合物中表现出不同的构象。(L¹)^2-在配合物1中表现出顺式和反式2种构象,(L2²)^2-在配合物2和3中仅表现出反式构象。此外,对配合物的热稳定性和荧光性质也进行了研究。     

三个二羧酸配体配位聚合物的合成、结构表征和荧光性质

以羧酸配体2,2''-（1,4-亚苯基双（亚甲基））双（硫二基）二苯甲酸（H₂L¹）和2,2''-（2,3,5,6-四甲基-1,4-亚苯基）双（亚甲基）双（硫二基）二苯甲酸（H₂L²）分别与金属盐反应,通过溶剂热方法合成了3个配位聚合物：{[Ni（L¹）（H₂O）₄]·2H₂O}_n （1）、[Zn（L¹）（DMA）₂]_n （2）和[Co（L²）（DMF）₂]_n （3）,其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明：3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。     

三个二羧酸配体配位聚合物的合成、结构表征和荧光性质

以羧酸配体 2,2''-(1,4-亚苯基双(亚苯基))双(硫二基)二苯甲酸(H₂L¹)和 2,2''-(2,3,5,6-四甲基-1,4-亚苯基)双(亚甲基）双(硫二基)二苯甲酸(H₂L²)分别与金属盐反应,通过溶剂热方法合成了 3个配位聚合物：{[Ni(L¹)(H₂O)₄]·2H₂O}_n (1)、[Zn(L¹)(DMA)₂]_n(2)和[Co(L²)(DMF)₂]_n (3),其中DMA=N,N-二甲基乙酰胺,DMF=N,N-二甲基甲酰胺。对配合物1~3进行了单晶X射线衍射、元素分析、红外光谱、热重分析、粉末X射线衍射和固体紫外可见光谱测试和表征。单晶X射线衍射表明：3个配合物均为一维锯齿形链状结构,并通过氢键作用形成三维骨架,且配体均表现为反式构象。此外,对配合物2固态荧光性质进行了研究。     

基于5-羟甲基间苯二甲酸和咪唑衍生物的半导体型Ni-MOFs的合成、晶体结构和光催化性质

利用水热反应制备了2个配合物{[Ni （HIPA）（2,5-DPBI）_1.5（H₂O）]·2.25H₂O}_n （1）和[Ni （HIPA）（2,5-DPBMI）（H₂O）]_n （2）（H₂HIPA=5-（羟甲基）间苯二甲酸,2,5-DPBI=1,1''-（2,5-二甲基-1,4-亚苯基）双（1H-咪唑）,2,5-DPBMI=1,1''-（2,5-二甲基-1,4-亚苯基）双（4-甲基-1H-咪唑））。结构分析揭示在不同咪唑配体存在下,配合物的Ni（Ⅱ）中心具有不同的配位环境。配合物1具有拓扑符号为（4².6⁶.8²）的五连接三维框架,而配合物2则是dia型的四连接网络。粉末X射线衍射证实配合物1和2在有机溶剂和紫外可见光照射的水中均非常稳定。此外,紫外可见吸收谱、Mott-Schottky和电化学阻抗谱（EIS）测试显示配合物1和2都是典型的n型半导体材料,具有较低的电荷传输阻抗。在光催化实验中,配合物1和2对染料亚甲基蓝的降解有催化活性。     

异核Ln(Na)-MOFs(Ln=Tb、Dy、Ho)的晶体结构及对乙醛、Fe3+、Cr2O72-的荧光传感和邻苯二酚的电化学传感

在溶剂热条件下合成了3个新型三维微孔同构异核金属有机骨架Ln （Na）-MOFs：{[LnNa （BDT）（H₂O）₃]·2H₂O}_n（Ln=Tb （1）、Dy （2）、Ho （3）,H₄BDT=3,5-二（3'',5''-二羧基苯基）-1H-1,2,4-三唑）,并通过单晶X射线衍射、元素分析、热重分析和粉末X射线衍射技术对其进行表征。结构分析表明,Ln （Na）-MOFs是具有相同的异核双金属单元的三维骨架结构。荧光研究表明,Tb （Na）-MOF （1）可以荧光传感检测水中Fe³⁺、Cr₂O₇^2-以及乙醛分子,具有较高的灵敏度和选择性,也可用于水中邻苯二酚的电化学检测。     

基于柔性四羧酸配体构筑的两个镉(Ⅱ)配位聚合物的晶体结构及荧光性质

通过溶剂热和水热合成的方法制备了2个Cd（Ⅱ）配位聚合物[Cd₂（L）（DMF）_1.5（H₂O）₂]_n（1）和{[Cd（L）_0.5（4,4''-bpy）（H₂O）]·2H₂O}_n（2）（H₄L=5,5''-（己烷-1,6）-双-（氧基）-二-间苯二甲酸）。结构分析表明配合物1是一个（4,4）-连接的sql拓扑网络,拓扑符号为{4⁴·6²}₂。配合物2是一个（4,4,4）-连接的三重穿插的bbf网络,拓扑符号为（6⁶）（6⁴·8²）。配合物1和2都呈现出较好的热稳定性和荧光性质。     

基于柔性四羧酸配体构筑的两个镉(Ⅱ)配位聚合物的晶体结构及荧光性质

通过溶剂热和水热合成的方法制备了2个Cd（Ⅱ）配位聚合物[Cd₂（L）（DMF）_1.5（H₂O）₂]_n（1）和{[Cd（L）_0.5（4,4''-bpy）（H₂O）]·2H₂O}_n（2）（H₄ L=5,5''-（己烷-1,6）-双-（氧基）-二-间苯二甲酸）。结构分析表明配合物1是一个（4,4）-连接的sql拓扑网络,拓扑符号为{4⁴·6²}₂。配合物2是一个（4,4,4）-连接的三重穿插的bbf网络,拓扑符号为（6⁶）（6⁴·8²）。配合物1和2都呈现出较好的热稳定性和荧光性质。     

基于2-氨基-3-羟基-吡啶Schiff碱的双核Ni(Ⅱ)和Zn(Ⅱ)配合物:合成、超分子结构和光谱性质

合成了2个2-氨基-3-羟基-吡啶Schiff碱双核Ni（Ⅱ）和Zn（Ⅱ）配合物,[Ni（L¹）（DMF）]₂（1）（H₂L¹=4-羟基-3-（（3-羟基-吡啶-2-亚氨基））-苯并吡喃-2-酮）和[Zn（L²）（H₂O）]₂·2DMF（2）（H₂L²=2-（（3,5-二溴-2-羟基）-氨基）-吡啶-3-醇）,并通过元素分析、红外光谱、紫外-可见吸收光谱、荧光光谱及X射线单晶衍射分析等手段进行了表征。X射线单晶衍射分析结果表明：配合物1和2均具有双核结构,均由2个金属离子和2个配体单元以及2个配位的溶剂分子组成,不同的是配合物2含有2个溶剂分子。配合物1和2都是单斜晶系、P2₁/c空间群,且中心金属Ni（Ⅱ）和Zn（Ⅱ）离子的空间构型均为五配位的扭曲的四方锥。此外,配合物1和2通过分子间氢键、C-H…π及π…π作用形成3D超分子结构。此外,讨论了H₂L¹,H₂L²及其相应的Ni（Ⅱ）和Zn（Ⅱ）配合物的荧光性质。配体H₂L¹和H₂L²呈现蓝色发射,最大发射波长λ_em分别为457和473 nm,而配合物1和2显示绿色发射,λ_em分别为543和538 nm。     

基于2-氨基-3-羟基-吡啶Schiff碱的双核Ni(Ⅱ)和Zn(Ⅱ)配合物:合成、超分子结构和光谱性质

合成了2个2-氨基-3-羟基-吡啶Schiff碱双核Ni（Ⅱ）和Zn（Ⅱ）配合物,[Ni（L¹）（DMF）]₂（1）（H₂L¹=4-羟基-3-（（3-羟基-吡啶-2-亚氨基））-苯并吡喃-2-酮）和[Zn（L²）（H₂O）]2·2DMF（2）（H₂L²=2-（（3,5-二溴-2-羟基）-氨基）-吡啶-3-醇）,并通过元素分析、红外光谱、紫外-可见吸收光谱、荧光光谱及X射线单晶衍射分析等手段进行了表征。X射线单晶衍射分析结果表明：配合物1和2均具有双核结构,均由2个金属离子和2个配体单元以及2个配位的溶剂分子组成,不同的是配合物2含有2个溶剂分子。配合物1和2都是单斜晶系、P2₁/c空间群,且中心金属Ni（Ⅱ）和Zn（Ⅱ）离子的空间构型均为五配位的扭曲的四方锥。此外,配合物1和2通过分子间氢键、C-H…π及π…π作用形成3D超分子结构。此外,讨论了H₂L¹,H₂L²及其相应的Ni（Ⅱ）和Zn（Ⅱ）配合物的荧光性质。配体H₂L¹和H₂L²呈现蓝色发射,最大发射波长λ_em分别为457和473 nm,而配合物1和2显示绿色发射,λ_em分别为543和538 nm。     

基于3，4'，5-联苯三羧酸构筑的钕配合物的合成、结构、荧光、光催化及磁性质

采用NdCl₃·6H₂O和3,4'',5-联苯三羧酸（H₃bpt）为原料在DMF/H₂O混合溶剂热条件下合成得到一个三维钕配合物{[Nd （bpt）（DMF）（H₂O）]·2H₂O}_n（1）,并通过红外光谱、元素分析、单晶及粉末X射线衍射表征了配合物1的结构。单晶衍射结果表明,配合物1具有（5,5）-连接的三维结构,拓扑符号为（4⁴·6³·8³）（4⁸ 6²）。此外,对配合物1的热稳定性、荧光性质、光催化降解染料及磁性质进行了详细研究。     

A one‐dimensional cadmium metal–organic chain based on a [Cd4(COO)4] secondary building unit and a flexible dicarboxylic acid ligand

An infinite one‐dimensional cadmium metal–organic chain, namely catena‐poly[aquabis(μ₃‐2,2′‐{[1,2‐phenylenebis(methylene)]bis(sulfanediyl)}dibenzoato)dicadmium(II)], [Cd₂(C₂₂H₁₆O₄S₂)₂(H₂O)]_n, was synthesized by solvothermal reaction of Cd(NO₃)₂·4H₂O and 2,2′‐{[1,2‐phenylenebis(methylene)]bis(sulfanediyl)}dibenzoic acid (H₂L). The Cd^II centres have six‐coordinate CdS₂O₄ and CdSO₅ geometries. Due to the flexible –CH₂–S– arms, the L²⁻ ligand adopts both syn and anti conformations. Four Cd^II cations are linked by two syn L²⁻ ligands to form a centrosymmetric planar tetranuclear Cd^II core, which is further extended through bonding to the anti L²⁻ ligands to form a one‐dimensional metal–organic chain. Adjacent one‐dimensional chains are connected by C—H...π interactions and nonclassical C—H...O hydrogen bonds to form the resultant three‐dimensional supramolecular framework.     

Treatment activity of 0D/2D coordination complexes on gastric carcinoma by inhibiting the cancer cell viability

In the present study, via reaction of Ni(NO₃)₂·6H₂O with two flexible dicarboxylic ligands under the solvothermal reaction conditions, two new Ni(II)-containing coordination complexes with the chemical formulae of [Ni4(L1)₄(DMF)₄·2DMF]_n (1) and [Ni(L2)(DMF)]_n (2) (H2L1= 2,2'-(1,4-phenylenebis(methylene))bis(sulfanediyl)dinicotinic acid and H2L2 ?= ?2,2'-(1,2-phenylenebis(methylene))bis(sulfanediyl)dinicotinic acid) have been prepared. For the treatment of the gastric carcinoma, the Cell Counting Kit-8 kit was carried out for the detection of the gastric carcinoma cells viability after compound treatment. Additionally, the Annexin V-FITC/PI apoptosis assay was also conducted and the apoptosis levels of the gastric carcinoma cells were determined after compound exposure.     

Bent and linear trinuclear nickel complexes with ligands derived from N -acylsalicylhydrazide ligands: structural characterization and bioactivity

Two trinuclear Ni(II) complexes Ni₃(L₁)₂(py)₂(DMF)(H₂O) (1) and Ni₃(L₂)₂(py)₂(DMF)₂ (2) with two new trianionic pentadentate ligands N-(3,5-dimethylbenzoyl)-salicylhydrazide (H₃L₁) and N-(phenylacetyl)-5-nitrosalicylhydrazide (H₃L₂) have been synthesized and characterized by X-ray crystallography. Nickel ions in the two complexes have square-planar/octahedral/square-planar coordination. Central metal ion and two terminal metal ions in the two complexes are combined by two bridging deprotonated ligands, forming a trinuclear structural unit with an M–N–N–M–N–N–M core. Studies on the trinuclear Ni(II) complexes show that the β-branched N-acylsalicylhydrazide ligands with sterically flexible Cα methylene groups yield linear trinuclear Ni(II) complexes, while α-branched N-acylsalicylhydrazide ligands tend to form bent trinuclear Ni(II) complexes. Antibacterial screening data in a previous study indicates that bent trinuclear Ni(II) compound 1 is more active than linear compound 2 and less active than a tetranuclear nickel compound.     

Solvent-modulated zincII networks with different stacking arrangements

Two Zn^II complexes, [Zn₂(L)₂(DMF)(H₂O)₂]·DMF (1) and [Zn(L)(DEF)]·DEF (2), were synthesized by solvothermal reactions using 4,4′-(2,3,5,6-tetramethylbenzene1,4-diyl)dibenzoic acid (H₂L) and Zn(NO₃)₂·6H₂O in different solvents of DMF, ethanol, and water for 1 and N,N-diethylformamide (DEF) for 2. The L^2? with different coordination modes connect [Zn₂(COO)₂] secondary building units (SBUs) to generate a wavy 2-D (4,4) network of 1 while in 2 there are paddlewheel [Zn₂(COO)₄] SBUs which are connected by L^2? to form a planar 2-D (4,4) network. The 2-D layered structures show different stacking arrangements and are further linked by hydrogen bonding or C–H?π interactions to give 3-D architectures. The different structures and stacking arrangements of 1 and 2 result from different reaction solvents. Photoluminescence properties of the complexes were investigated.     

From discrete dinuclear to 1-D and 2-D structures: nickel dipicolinate complexes with flexible bis(imidazole) ligands

Three new complexes, [Ni₂(dpc)₂(L₁)₂(H₂O)₂]?·?4H₂O (1), [Ni(dpc)(L₂)_1.5] _n (2), and {[Ni(dpc)(L₃)_1.5]?·?2H₂O} _n (3), where H₂dpc?=?dipicolinic acid, L₁?=?1,4-bis(2-methylimidazol-1-yl)butane, L₂?=?4,4′-bis(2-methylimidazol-1-ylmethyl)biphenyl, and L₃?=?1,4-bis(benzimidazol-1-yl)-2-butylene, have been synthesized by hydrothermal methods and characterized by elemental analyses, infrared spectra, thermogravimetric analysis, and X-ray crystallography. The common structural characteristic of the three complexes is that the Ni²⁺ is coordinated by tridentate dipicolinate through nitrogen of pyridine and oxygen of carboxylate, serving as a terminal ligand. In 1, two L₁ link two [Ni(dpc)(H₂O)] units to a discrete binuclear metallomacrocycle with a 22-membered ring, which is assembled through multiple O–H?···?O hydrogen bonds to form a 3-D supramolecular framework. Complex 2 exhibits a 1-D ladder-like chain structure constructed by cis/trans-conformation L₂ linking metal centers; 3 displays a 2-D (6,3) topology, being constructed from the linking of [Ni(pdc)] by L₃. These results indicate the merits of flexible bis(imidazole) ligands as building blocks with dipicolinate for the construction of complexes with diverse structural motifs.     

Ligand Recognition Processes in the Formation of Homochiral C3‐Symmetric LnL3 Complexes of a Chiral Alkoxide

The reaction of a chiral racemic bidentate ligand HL¹ (tBu₂P(O)CH₂CH(tBu)OH) with mid to late trivalent lanthanide cations affords predominantly homochiral lanthanide complexes (RRR)‐[Ln(L¹)₃] and (SSS)‐[Ln(L¹)₃]. A series of reactions are reported that demonstrate that the syntheses are under thermodynamic control, and driven by a ligand ‘self‐recognition’ process, in which the large asymmetric bidentate L¹ ligands pack most favourably in a C₃ geometry around the lanthanide cation. The synthesis of bis(L¹) adducts [Ln(L¹)₂X] (X=N(SiMe₃)₂, OC₆H₃tBu‐2,6) is also reported. Analysis of the diastereomer mixtures shows that homochiral (L¹)₂ complexes are favoured but to a lesser extent. The complexes Ln(L¹)₃ and [Ln(L¹)₂(OC₆H₃tBu‐2,6)] have been studied as initiators for the polymerization of ε‐caprolactone and its copolymer with lactide, glycolide and its copolymer with lactide, and ε‐caprolactam.     

Synthesis and crystal structure of yttrium(III) and lanthanide(III) complexes with a new terpyridine-like ligand 2,4-bis(3,5-dimethylpyrazol-1-yl)- 6-diethylamino-1,3,5-triazine

A new planar aromatic tridentate terpyridine-like ligand, 2,4-bis(3,5-dimethylpyrazol-1-yl)-6-diethylamino-1,3,5-triazine (L), has been synthesized and the structures of its complexes [YL(NO₃)₃] (1) and [LnL(NO₃)₃(H₂O)]L [Ln?=?La (2), Ce (3), Pr (4), Nd (5), Eu (6)] have been determined by X-ray crystal structural analysis. The structures of the five lanthanoid complexes are isomorphous and isostructural but different from the crystal structure of the yttrium complex [YL(NO₃)₃]. The latter shows a nine-coordinate metal center whereas the crystal structure of the lanthanoid complexes [LnL(NO₃)₃(H₂O)]L show a 10-coordinate metal center. The?π–π?stacking and hydrogen bonding between the coordinated and uncoordinated L molecules sensitized the Ln luminescence. The thermal behavior of the ligand and its complexes is discussed.