基于多齿希夫碱配体的四核和十核锰簇合物的合成、结构和磁性

合成了一种具有{NO₄}给电子组成的多齿水杨醛希夫碱配体,3,5-二-叔丁基水杨醛-三(羟甲基)氨基甲烷(H₄L),并利用元素分析、红外光谱以及核磁共振氢谱表征其结构。Mn(ClO₄)₂或MnCl₂·4H₂O分别与该配体在溶液中反应生成了一个四核锰簇合物[Mn₄^Ⅲ(HL)₂(H₂L)₂(MeCN)₄](ClO₄)₂·2MeCN(1)和一个十核锰簇合物[Mn₆^ⅢMn₄^Ⅱ(bz)₁₀(L)₄(H₂O)₂]·10MeCN(2)。X-射线衍射分析表明化合物1的晶体结构空间群为三斜P1,而化合物2为正交Aba2。2~300K温度区间的磁性测量数据表明化合物2中存在反铁磁相互作用。     

基于季戊四胺席夫碱的Ni(Ⅱ)和Cu(Ⅱ)配合物的合成、结构及其抑菌活性

以4-甲氧基水杨醛和季戊四胺进行缩合反应得到席夫碱化合物 H₄L, 然后将配体H₄L分别与Ni(ClO₄)₂·6H₂O、Cu(ClO₄)₂在乙醇溶液中进行配位反应, 得到2个席夫碱配合物[Ni₂(L)]·DMF (1)和[Cu₄(L)₂(DMSO)₃]·2DMSO (2)。并用元素分析、FT-IR和X射线单晶衍射进行了表征。配合物1和2都属于三斜晶系, P1 空间群, 配合物1和2都为双核配合物。初步研究了配体和配合物的体外抑菌活性, 结果表明, 配体及其配合物1和2对金黄色葡萄球菌具有一定的抑菌活性。     

两个一维配位聚合物的合成、晶体结构、电化学及光学性质

合成了2个新的Robson大环配位聚合物{[Mn₂L¹(1,4-bix)₂](ClO₄)₂·5H₂O·DMF}_n(1)和{[Cu₂L²(1,4-bix)](ClO₄)₂}_n(2)(H₂L¹和H₂L²分别为1,3-丙二胺与2,6-二甲酰基-4-氟苯酚和2,6-二甲酰基-4-氯苯酚通过[2+2]缩合的产物)。2个配合物通过1,4-二(1,2,4-三唑-1-甲基)苯(1,4-bix)桥连大环单元形成一维链状结构。配合物的HOMO-LUMO能带间隙通过循环伏安法、紫外-可见漫反射光谱进行了测定,结果表明有较低的能带间隙。     

O—P—O桥联锰-席夫碱配合物的合成、结构和磁性质

采用溶液法合成了2例由O—P—O单元桥联的锰-席夫碱(SB)新型三核配合物,即[Mn₃(salen)₃(L)]ClO₄·H₂O (1)和[Mn₃(salpn)₃(L)]ClO₄(2),其中salen^2-=N,N''-乙二胺缩双水杨醛,salpn^2-=N,N''-丙二胺缩双水杨醛,H₂L=(5-(乙氧基羰基)萘-1-基)膦酸。通过单晶X射线衍射、红外光谱、粉末X射线衍射对其进行了表征。配合物1和2是同构的,均是由膦酸酯配体中的O—P—O桥联3个[Mn (SB)]+构成一个三核结构单元[Mn3(SB)3(L)]⁺,一个无序的ClO₄^-作为平衡阴离子存在。这些[Mn₃(SB)₃(L)]⁺三聚体通过π-π相互作用和相邻的分子形成超分子一维波形链。配合物1和2的磁性研究表明,不对称结构中的3个Mn(Ⅲ)离子分别是2个高自旋和1个低自旋,而Mn(Ⅲ)离子之间主要存在反铁磁相互作用。     

由芳香羧酸和1,3,5-三咪唑基苯为配体构筑的锌、镉配合物的合成、结构和荧光性质

通过水热法得到了2个配位聚合物{[Zn(timb)(BTEC)_0.5]·H₂O}_n(1)和{[Cd(timb)(DPA)]·H₂O}_n(2)(timb=1,3,5-三咪唑基苯,H₄BTEC=均苯四甲酸,H₂DPA=2,2-联苯二甲酸),对它们进行了元素分析、红外光谱分析,并利用X射线衍射测定了它们的单晶结构。 配合物1属于三斜晶系,P1空间群。配合物2属于单斜晶系,C2/c空间群。配合物1拥有一个不寻常的三维框架结构,其拓扑为(4.6³·8⁶)₂(4²·8⁴)(6³)₂;而配合物2具有一维单层纳米管结构。结果说明了金属离子和有机羧酸配体在配合物组装过程中起着非常重要的作用。此外,在室温下对2个配合物进行了荧光性质分析。     

基于2-甲基-8-羟基喹啉的镝单分子磁体的晶体结构及磁性

以2-甲基-8-羟基喹啉(HL)为配体合成了2个含有镝离子的配位化合物[Dy₂L₄(HL)₄(H₂O)₂](ClO₄)₂·2H₂O(1)和[Dy₂L₆(C₂H₅OH)]·H₂O(2)。虽然在这两个配位化合物中配体都是2-甲基-8-羟基喹啉,但其参与配位的方式不同。这导致2个化合物中镝离子所处的配位环境不同,进而对化合物的磁性产生了影响。     

2-吡啶甲醇和1,1,1-三羟甲基乙烷混合配体七核锰配合物的合成、晶体结构与磁性

四水合氯化锰、2-吡啶甲醇和1,1,1-三羟甲基乙烷在乙腈里反应合成出一个七核Mn簇合物[Mn₃^ⅡMn₄^Ⅲ(Cl)₆(hmp)₆(thme)₂]·H₂O·3CH₃CN(1·H₂O·3CH₃CN,hmpH为2-吡啶甲醇, thmeH3为三羟甲基乙烷),并对该化合物进行X射线衍射单晶结构分析、元素分析、红外光谱和磁性研究。1·H₂O·3CH₃CN属于单斜晶系I2/a空间群,配合物核骨架可看成由交替的Mn^Ⅱ和Mn^Ⅲ离子形成一个六边形,而这个六边形又围绕在1个Mn^Ⅲ离子的周围,这种结构类型的配合物以前并没有报道过。磁性研究表明,化合物1·H₂O中Mn^Ⅲ与Mn^Ⅱ或Mn^Ⅲ与Mn^Ⅲ离子之间总体是铁磁性耦合的,交流磁化率研究发现该化合物有弱的频率依赖现象。     

由芳香羧酸和1,3,5-三咪唑基苯为配体构筑的锌、镉配合物的合成、结构和荧光性质

通过水热法得到了2个配位聚合物{[Zn(timb)(BTEC)_0.5]·H₂O}_n(1)和{[Cd(timb)(DPA)]·H₂O}_n(2)(timb=1,3,5-三咪唑基苯,H₄BTEC=均苯四甲酸,H₂DPA=2,2-联苯二甲酸),对它们进行了元素分析、红外光谱分析,并利用X射线衍射测定了它们的单晶结构。 配合物1属于三斜晶系,P1空间群。配合物2属于单斜晶系,C2/c空间群。配合物1拥有一个不寻常的三维框架结构,其拓扑为(4.6³·8⁶)₂(4²·8⁴)(6³)₂;而配合物2具有一维单层纳米管结构。结果说明了金属离子和有机羧酸配体在配合物组装过程中起着非常重要的作用。此外,在室温下对2个配合物进行了荧光性质分析。     

Co(Ⅱ)与甜菜碱类衍生物形成的两种配合物的结构和磁性特征

合成了2种新的Co(Ⅱ)的配合物{[Co(L1)₂(H₂O)₂](ClO₄)₂·4H₂O}_n(1)和{[Co(L2)₂(H₂O)₄](ClO₄)₂·8H₂O·L2}_n(2)(L1=1,1'-(4,4'-二亚甲基联苯)二(1-吡啶鎓-3-羧酸盐),L2=1,1'-(4,4'-二亚甲基联苯)二(1-吡啶鎓-4-羧酸盐)),并且分别用红外光谱、热差分析、X射线粉末衍射和X射线单晶衍射表征了这两种化合物。晶体结构分析表明L1,L2,1和2分别属于P2₁/c,P2₁/c,P1和P1空间群。化合物1为二维的配位聚合物,2为单核配合物。二者的晶体结构都含有大量的氢键作用或者配位键形成的孔状结构。此外,磁性研究表明,1和2中都存在反铁磁性相互作用。     

Transformations of high spin MnII and FeII polymeric pivalates in reactions with pivalic acid and o-phenylenediamines

The thermolysis and reactions of the polymeric high spin Mn^II and Fe^II complexes [Mn(μ-OOCBu^t)₂(HOEt)]_n (1) and [Fe(μ-OOCBu^t)₂]_n (3) with pivalic acid and o-phenylenediamines 1,2-(NH₂)₂C₆H₂R₂ (R = H or Me) were studied. The synthesis of compound 1 performed with a deficiency of pivalate anions affords the antiferromagnetic chloropivalate polymer { (MeCN)(HOOCBu^t)(H₂O)Mn₅Cl(OH)(OOCBu^t)₈·MeCN}_n. The reaction of 1 with an excess of pivalic acid produces the antiferromagnetic polymer [Mn₄(OOCBu^t)₈(HOOCBu^t)₂]_n. The analogous reaction of pivalic acid with polymer 3 gives the mononuclear complex Fe(η ¹-OOCBu^t)₂(η¹-HOOCBu^t)₄ containing the high spin iron(II) atom as the major product. Study of the reactions of 3 with a deficiency (<1: 1) and an excess (>1: 1) of diamines demonstrated that the polymer {[(η²-(NH₂)₂C₆H₄)₂Fe(μ-OOCBu^t)₂][Fe₂(μ-OOCBu^t)₄] · · 2MeCN}_n is generated as the major product in the former case, whereas the mononuclear complexes Fe(η¹-OOCBu^t)₂[η¹-(NH₂)₂C₆H₄]₄ and Fe(η¹-OOCBu^t)₂[η²-(NH₂)₂C₆H₂Me₂][η¹-(NH₂)₂C₆H₂Me₂]₂ are predominantly obtained in the latter case. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 779–792, May, 2006.     

New members of the [Mn6/oxime] family and analogues with converging [Mn3] planes

The synthesis, structural, and magnetic characterization of five new members of the hexanuclear oximate [Mn^III₆] family are reported. All five clusters can be described with the general formula [Mn^III₆O₂(R-sao)₆(R′-CO₂)₂(sol)_x(H₂O)_y] (where R-saoH₂ = salicylaldoxime substituted at the oxime carbon with R = H, Me and Et; R′ = 1-naphthalene, 2-naphthalene, and 1-pyrene; sol = MeOH, EtOH, or MeCN; x = 0–4 and y = 0–4). More specifically, the reaction of Mn(ClO₄)₂·6H₂O with salicylaldoxime-like ligands and the appropriate carboxylic acid in alcoholic or MeCN solutions in the presence of base afforded complexes 1–5: [Mn₆O₂(Me-sao)₆(1-naphth-CO₂)₂(H₂O)(MeCN)]·4MeCN (1·4MeCN); [Mn₆O₂(Me-sao)₆(2-naphth-CO₂)₂(H₂O)(MeCN)]·3MeCN·0.1H₂O (2·3MeCN·0.1H₂O); [Mn₆O₂(Et-sao)₆(2-naphth-CO₂)₂(EtOH)₄(H₂O)₂] (3); [Mn₆O₂(Et-sao)₆(2-naphth-CO₂)₂(MeOH)₆] (4) and [Mn₆O₂(sao)₆(1-pyrene-CO₂)₂(H₂O)₂(EtOH)₂]·6EtOH (5·6EtOH). Clusters 3, 4, and 5 display the usual [Mn₆/oximate] structural motif consisting of two [Mn₃O] subunits bridged by two O_oximate atoms from two R-sao^2? ligands to form the hexanuclear complex in which the two triangular [Mn₃] units are parallel to each other. On the contrary, clusters 1 and 2 display a highly distorted stacking arrangement of the two [Mn₃] subunits resulting in two converging planes, forming a novel motif in the [Mn₆] family. Investigation of the magnetic properties for all complexes reveal dominant antiferromagnetic interactions for 1, 2, and 5, while 3 and 4 display dominant ferromagnetic interactions with a ground state of S = 12 for both clusters. Finally, 3 and 4 display single-molecule magnet behavior with U_eff = 63 and 36 K, respectively.     

Two new clusters with MnII-MnIV magnetic exchange from the use of polyalcohol ligands

Two mixed-valence Mn(II,IV) complexes, [Mn^II₄Mn^IV₃(teaH)₃(tea)(thmeH)₃(thme)](ClO₄)₂·3MeCN (1) and [Mn^II₂Mn^IV₂(edteH)₂(peolH)₂]·4MeOH (2), where H₄edte = N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine, teaH₃ = tris(2-hydroxyethyl)amine, H₄peol = pentaerythritol, and H₃thme = 1,1,1-tris(hydroxymethyl)ethane, were prepared from the corresponding manganese salts and mixed ligands with polyalcohols. The two clusters consist of a trapped-valence polynuclear core comprising 4Mn^II and 3Mn^IV for 1, 2Mn^II and 2Mn^IV ions for 2. Complex 1 crystallizes in the rhombohedral space group R3c, while 2 crystallizes in the monoclinic space group P2₁/c. Complex 1 consists of a near-planar Mn₇ unit that comprises a Mn₆ hexagon of alternating Mn^II and Mn^IV ions surrounding a central Mn^II ion. The remaining coordinated sites are occupied by eight different deprotonation degrees of H₃tea or H₃thme. The tetranuclear cluster of 2 consists of a fused defective dicubane Mn₄O₆ core, and the four Mn ions are coordinated by oxygens from edteH^3? and peolH^3? into an unusual butterfly-like [Mn^II₂Mn^IV₂] topology. The two clusters are also characterized by mass spectra and X-ray photoelectron spectroscopy. Direct current magnetization studies reveal ferromagnetic interactions within both Mn clusters.     

基于季戊四胺席夫碱的Ni(Ⅱ)和Cu(Ⅱ)配合物的合成、结构及其抑菌活性

以4-甲氧基水杨醛和季戊四胺进行缩合反应得到席夫碱化合物H_4L,然后将配体H_4L分别与Ni(Cl O_4)_2·6H_2O、Cu(Cl O_4)_2在乙醇溶液中进行配位反应,得到2个席夫碱配合物[Ni_2(L)]·DMF(1)和[Cu_4(L)_2(DMSO)_3]·2DMSO(2)。并用元素分析、FT-IR和X射线单晶衍射进行了表征。配合物1和2都属于三斜晶系,P1空间群,配合物1和2都为双核配合物。初步研究了配体和配合物的体外抑菌活性,结果表明,配体及其配合物1和2对金黄色葡萄球菌具有一定的抑菌活性。     

Mn4 single-molecule magnets with a planar diamond core and S=9

The syntheses and magnetic properties are reported for three Mn₄ single-molecule magnets (SMMs): [Mn₄(hmp)₆(NO₃)₂(MeCN)₂](ClO₄)₂·2MeCN (3), [Mn₄(hmp)₆(NO₃)₄]·(MeCN) (4), and [Mn₄(hmp)₄(acac)₂(MeO)₂](ClO₄)₂·2MeOH (5). In each complex there is a planar diamond core of Mn^III ₂Mn^II ₂ ions. An analysis of the variable-temperature and variable-field magnetization data indicate that all three molecules have intramolecular ferromagnetic coupling and a S=9 ground state. The presence of a frequency-dependent alternating current susceptibility signal indicates a significant energy barrier between the spin-up and spin-down states for each of these three Mn^III ₂Mn^II ₂ complexes. The fact that these complexes are SMMs has been confirmed by the observation of hysteresis in the plot of magnetization versus magnetic field measured for single crystals of complexes 3 and 4. The hysteresis loops for both of these complexes exhibit steps characteristic of quantum tunneling of magnetization. Complex 4 shows its first step at zero field, whereas the first step for complex 3 is shifted to −0.10 T. This shift is attributable to weak intermolecular antiferromagnetic exchange interactions present for complex 3.     

Synthesis,crystal structure and magnetic properties of new MnIII–CuII heterometallic aggregates based on multidentate Schiff-base ligands

Reaction of copper powder, manganese(II) nitrates and multidentate Schiff-base ligands in hot methanol solution led to the isolation of two new Mn^III–Cu^II heterometallic aggregates, [Mn₂ ^IIICu₂ ^II(H₂L)₄] · (NO₃)₂ · 2CH₃OH (1) (H₄L=2-[(2-hydroxy-benzylidene)-amino]-2-hydroxymethyl-proane-1,3-diol) and [Mn^IIICu^II ₃(sae)₄(MeOH)(H₂O)₃] · NO₃ · MeOH (2) (H₂sae = salicylidene-2-ethanolamine). Both compounds were characterized by elemental analysis, IR, XPS, EPR, XRPD and single crystal X-ray diffraction. Compound 1 crystallizes in the triclinic space group P 1 with a = 11.1268(4) Å, b = 11.6153(4) Å, c = 11.8129(5) Å, α = 88.435(10)°, β = 80.203(10)°, γ = 77.572(10)°, V = 1469.13(10) ų, Z = 1, R1(wR2) =0.0300(0.0771). Compound 2 crystallizes in the monoclinic space group P2₁/n with a = 18.1715(7), b = 12.9931(5), c = 19.5903(8) Å, β = 97.1980(10)°, V = 4588.9(3) ų, Z = 4, R1(wR2) = 0.0667 (0.1998). The magnetic susceptibilities of 1 and 2 display the antiferromagnetic interactions in both compounds.     

Syntheses,structural determination,and binding studies of binuclear eight-coordinate (enH2)[GdIII 2(pdta)2(H2O)2] · 8H2O and mononuclear nine-coordinate (enH2)[GdIII(egta)(H2O)]2 · 6H2O

The (enH₂)[Gd^III ₂(pdta)₂(H₂O)₂]?·?8H₂O (1) (en?=?ethylenediamine and H₄pdta?=?propylenediamine-N,?N,?N′,?N′-tetraacetic acid) and (enH₂)[Gd^III(egta)(H₂O)]₂?·?6H₂O (2) (H₄egta?=?ethyleneglycol-bis-(2-aminoethylether)-N,?N,?N′,?N′-tetraacetic acid) complexes were synthesized and characterized by infrared spectrum, thermal analysis, and single-crystal X-ray diffraction. The complex (enH₂)[Gd^III ₂(pdta)₂(H₂O)₂]?·?8H₂O has a binuclear eight-coordinate structure with pseudo square antiprism and crystallizes in the monoclinic crystal system with C2/c space group. Through a carboxylate bridge, an infinite 1-D zigzag polymeric binuclear [Gd^III ₂(pdta)₂(H₂O)₂]^2? complex anion is formed. All infinite zigzag polymeric complex anions link through hydrogen bonds, yielding a layer structure. (enH₂)[Gd^III(egta)(H₂O)]₂?·?6H₂O has a mononuclear nine-coordinate structure with pseudo monocapped square antiprism and crystallizes in the monoclinic crystal system with P2₁/n space group. Each enH₂ ²⁺ cation, through hydrogen bonds, connects two adjacent [Gd^III(egta)(H₂O)]^? complex anions.     

Synthesis and structural characterization of centrosymmetric multinuclear nickel(II) complexes with neutral tetradentate N6-ligand

A neutral tetradentate ligand L1 [L1?=?3,6-bis(pyrazol-1-yl)-pyridazine] reacts with Ni(ClO₄)₂·6H₂O and undergoes counterion exchange with PF ^?₆ to give di- and tetranuclear complexes [Ni₂(L1)₂(CH₃CN)₄](PF₆)₄·4H₂O (1) and [Ni₄(L1)₄(µ-OH)₄](ClO₄)₄·2H₂O (2), respectively. The presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as base controls the nuclearity of the complex formation. Both complexes were structurally characterized by physicochemical and spectroscopic techniques. Their crystal structures revealed that both complexes are centrosymmetric and adopt slightly distorted octahedral geometry. Complex 1 crystallizes in monoclinic space group C2/c as the Ni(II) center is octahedrally bound to L1 in a trans-isomer arrangement. Complex 2 crystallizes in tetragonal space group I4₁/amd with four L1 and four hydroxy bridging ligands linked to Ni(II) center in cis-isomer arrangement. Cyclic voltammograms of complexes 1 and 2 were measured under Ar and CO₂. Under CO₂, the quasireversible peaks of both complexes become irreversible and a current enhancement occurs under reduction.