Synthesis, Characterization, DNA/HSA Interactions, and Anticancer Activity of Two Novel Copper(II) Complexes with 4-Chloro-3-Nitrobenzoic Acid Ligand.

The purpose of this study was to identify new metal-based anticancer drugs; to this end, we synthesized two new copper(II) complexes, namely [Cu(ncba)4(phen)] (1) and [Cu(ncba)4(bpy)] (2), comprised 4-chloro-3-nitrobenzoic acid as the main ligand. The single-crystal XRD approach was employed to determine the copper(II) complex structures. Binding between these complexes and calf thymus DNA (CT-DNA) and human serum albumin (HSA) was explored by electronic absorption, fluorescence spectroscopy, and viscometry. Both complexes intercalatively bound CT-DNA and statically and spontaneously quenched DNA/HSA fluorescence. A CCK-8 assay revealed that complex 1 and complex 2 had substantial antiproliferative influences against human cancer cell lines. Moreover, complex 1 had greater antitumor efficacy than the positive control cisplatin. Flow cytometry assessment of the cell cycle demonstrated that these complexes arrested the HepG2 cell cycle and caused the accumulation of G0/G1-phase cells. The mechanism of cell death was elucidated by flow cytometry-based apoptosis assays. Western blotting revealed that both copper(II) complexes induced apoptosis by regulating the expression of the Bcl-2(Bcl-2, B cell lymphoma 2) protein family.

Cyclometalated Ir(III)-8-oxychinolin complexes acting as red-colored probes for specific mitochondrial imaging and anticancer drugs.

A new class of luminescent IrIII antitumor agents, namely, [Ir(CP1)(PY1)2] (Ir-1), [Ir(CP1)(PY2)2] (Ir-2), [Ir(CP1)(PY4)2] (Ir-3), [Ir(CP2)(PY1)2] (Ir-4), [Ir(CP2)(PY4)2] (Ir-5), [Ir(CP3)(PY1)2]⋅CH3OH (Ir-6), [Ir(CP4)(PY4)2]⋅CH3OH (Ir-7), [Ir(CP5)(PY2)2] (Ir-8), [Ir(CP5)(PY4)2]⋅CH3OH (Ir-9), [Ir(CP6)(PY1)2] (Ir-10), [Ir(CP6)(PY2)2]⋅CH3OH (Ir-11), [Ir(CP6)(PY3)2] (Ir-12), [Ir(CP6)(PY41)2] (Ir-13), and [Ir(CP7)(PY1)2] (Ir-14), supported by 8-oxychinolin derivatives and 1-phenylpyrazole ligands was prepared. Compared with SK-OV-3/DDP and HL-7702 cells, the Ir-1-Ir-14 compounds exhibited half maximal inhibitory concentration (IC50) values within the high nanomolar range (50 nM-10.99 µM) in HeLa cells. In addition, Ir-1 and Ir-3 accumulated and stained the mitochondrial inner membrane of HeLa cells with high selectivity and exhibited a high antineoplastic activity in the entire cervical HeLa cells, with IC50 values of 1.22 ± 0.36 µM and 0.05 ± 0.04 µM, respectively. This phenomenon induced mitochondrial dysfunction, suggesting that these cyclometalated IrIII complexes can be potentially used in biomedical imaging and Ir(III)-based anticancer drugs. Furthermore, the high cytotoxicity activity of Ir-3 is correlated with the 1-phenylpyrazole (H-PY4) secondary ligands in the luminescent IrIII antitumor complex.

Mitochondria-localizing dicarbohydrazide Ln complexes and their mechanism of in vitro anticancer activity.

In this study, two novel organic ligands, bis(salicylaldehyde)pyrazino-1,10-phenanthroline-7,10-dicarbohydrazide (L) and bis(salicylaldehyde)-1,10-phenanthroline-7,10-dicarbohydrazide (L1), were synthesized. These ligands were used to react with lanthanide(iii) acetate to obtain complexes 1-6, namely, [Dy5(L)2(CH3COO)5(CH3OH)(µ3-OH)(µ2-OH)(H2O)]·2CH3OH (1), [Tb5(L)2(CH3COO)5(CH3OH)(µ3-OH)(µ2-OH)(H2O)]·3CH3OH (2), [Gd5(L)2(CH3COO)5(CH3OH)(µ3-OH)(µ2-OH)(H2O)]·3CH3OH (3), [Dy5(L1)2(µ2-OH)(µ3-OH)(CH3COO)5(CH3OH)(H2O)2]·2H2O (4), [Dy5(L1)2(µ3-OH)(CH3COO)6(CH3OH)3]·CH3OH (5), and [Dy5(L1)2(µ2-OH)2(µ3-OH)(CH3COO)4(CH3OH)(H2O)2]·CH3OH (6). Fluorescence studies demonstrated that complexes 1-6 show appreciable fluorescence in the yellow-green region. In vitro antitumor screening revealed that complex 1 exhibits better inhibitory activities than the commercial anticancer drug cisplatin against SK-OV-3 and A549 tumor cell lines, with IC50 values of 8.09 ± 1.25 and 13.26 ± 0.39 µM, respectively. All six complexes showed low cytotoxicity toward normal human liver HL-7702 cells compared with cisplatin. Complexes 1 and 3 induced the highest apoptosis rate of SK-OV-3/DDP cells. They also bind to DNA via an intercalative mode with the binding constant Kq values of 1.6 × 104 and 1.19 × 104 L mol-1, respectively. Confocal fluorescence imaging ascertained that complexes 1 and 3 are primarily localized in the mitochondria. Further studies revealed that these complexes trigger SK-OV-3/DDP cell apoptosis via a mitochondrial dysfunction pathway, which is probably caused by the reduction of the mitochondrial membrane potential and the induction of reactive oxygen species production.

Triethylamine-templated nanocalix Ln12 clusters of diacylhydrazone: crystal structures and magnetic properties.

Three {Ln12} (Ln = Gd (1), Tb (2), Dy (3)) nanocalix clusters with a novel ligand of N,N'-bis(o-vanillidene)-1H-imidazole-4,5-dicarbohydrazide (H5ovih) were synthesized via the amine-templating strategy. The skeletal structures of these clusters were constructed from three symmetric {Ln4} units via the linkage of three V-type ligands, with a calix shape, which has not been reported previously. Complex 1 exhibited a clear magnetocaloric effect (MCE), whose maximum -ΔSm value reached 36.77 J kg-1 K-1 at 70 kOe and 2.0 K.

Discovery of high in vitro and in vivo antitumor activities of organometallic ruthenium(ii)-arene complexes with 5,7-dihalogenated-2-methyl-8-quinolinol.

This paper reports the synthesis, structure characterization, and anticancer properties of 13 organometallic Ru(ii)-arene complexes: [Ru(η6-p-cymene)Cl-(L1)] (1), [Ru(η6-p-cymene)Cl-(L2)] (2), [Ru(η6-p-cymene)Cl-(L3)] (3), [Ru(η6-p-cymene)Cl-(L4)] (4), [Ru(η6-p-cymene)Cl-(L5)] (5), [Ru(η6-p-cymene)I-(L1)] (6), [Ru(η6-p-cymene)I-(L2)] (7), [Ru(η6-p-cymene)I-(L3)] (8), [Ru(η6-p-cymene)I-(L4)] (9), [Ru(η6-p-cymene)I-(L5)] (10), [Ru(η6-p-cymene)I-(L6)] (11), [Ru(η6-p-cymene)I-(L7)] (12), and [Ru(η6-p-cymene)Cl-(L8)] (13) respectively containing deprotonated 5,7-dichloro-2-methyl-8-quinolinol (H-L1), 5,7-dibromo-2-methyl-8-quinolinol (H-L2), 5-chloro-7-iodo-8-hydroxy-quinoline (H-L3), 5,7-dibromo-8-quinolinol (H-L4), 5,7-diiodo-8-hydroxyquinoline (H-L5), 8-hydroxy-2-methylquinoline (H-L6), 2,8-quinolinediol (H-L7), or 6,7-dichloro-5,8-quinolinedione (H-L8). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay showed that 13 organometallic Ru(ii)-arene complexes 1-13 are more selective for HeLa cells than normal HL-7702 cells. In addition, 1, 2, 5, and 6, which contain the active ligands H-L1 and H-L2, showed remarkable cell cytotoxicity, giving the respective IC50 values of 2.00 ± 0.20 nM, 0.89 ± 0.62 µM, 25.00 ± 0.30 nM, and 2.18 ± 0.35 µM on HeLa cancer cells. These values indicated higher activity than 6,7-dichloro-5,8-quinolinedione and other 8-hydroxyquinoline derivative Ru(ii)-arene complexes. Interestingly, all these Ru(ii)-arene complexes 1-13 were significantly less toxic to human hepatic (HL-7702) cells. Moreover, 1- and 2-induced HeLa cell apoptosis was mediated by the inhibition of telomerase activity and dysfunction of mitochondria, and resulted in DNA damage and increased anti-migration activity on HeLa cells. The organometallic Ru(ii)-arene complex 1 exhibited evident priority to the antitumor activity compared to 2, which should be highly associated with the key roles of the 5,7-dichloro substituted groups in the L1 ligand of organometallic Ru(ii)-arene complexes 1. Remarkably, 1 showed higher inhibitory activity against the xenograft tumor growth of human cervical cells (HeLa) in vivo (tumor growth inhibition rate (TGIR) = 58.5%) than cisplatin. This study was the first to show that the 5,7-dihalogenated-2-methyl-8-quinolinol organometallic Ru(ii)-arene complexes 1 and 2 are novel Ru(ii) anticancer drug candidates.

High in vitro and in vivo antitumor activities of Ln(III) complexes with mixed 5,7-dichloro-2-methyl-8-quinolinol and 4,4'-dimethyl-2,2'-bipyridyl chelating ligands.

Three novel Ln(III) complexes, namely, [Pm(dmbpy)(ClQ)2NO3] (1), [Yb(dmbpy)(ClQ)2NO3] (2), and [Lu(dmbpy)(ClQ)2NO3] (3), with mixed 5,7-dichloro-2-methyl-8-quinolinol (H-ClQ) and 4,4'-dimethyl-2,2'-bipyridyl (dmbpy) chelating ligands were first synthesized. The cytotoxic activity of Ln(III) complexes 1-3, H-ClQ, and dmbpy against a panel of human normal and cancer cell lines, namely, human non-small cell lung cancer cells (NCI-H460), human cervical adenocarcinoma cancer cells, human ovarian cancer cells, and human normal hepatocyte cells, were evaluated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The three novel Ln(III) complexes showed a high in vitro antitumor activity toward the NCI-H460 with IC50 of 1.00 ±â€¯0.25 nM for 1, 5.13 ±â€¯0.44 µM for 2, and 11.87 ±â€¯0.79 µM for 3, respectively. In addition, Ln(III) complexes 1 and 2 exerted their in vitro antitumor activity/mechanism mainly via the mitochondrial death pathway and caused a G2/M phase arrest in the following order: 1 > 2. An NCI-H460 tumor xenograft mouse model was used to evaluate the Pm(III) complex 1in vivo antitumor activity. Pm(III) complex 1 showed a high in vivo antitumor activity, and the tumor growth inhibition rate (IR) was 56.0% (p < 0.05). In summary, our study on Pm(III) complex 1 revealed promising results in in vitro and in vivo antitumor activity assays.

Bifunctional Mononuclear Dysprosium Complexes: Single-Ion Magnet Behaviors and Antitumor Activities.

Two mononuclear dysprosium complexes (Et3NH)[Dy(BrMQ)4]·H2O·DMF(BrMQ-Dy) and (Et3NH)[Dy(ClMQ)4]·H2O·DMF (ClMQ-Dy) (H-BrMQ = 5,7-dibromo-2-methyl-8-quinolinol, H-ClMQ = 5,7-dichloro-2-methyl-8-quinolinol) were synthesized and characterized. The Dy(III) ions in complexes BrMQ-Dy and ClMQ-Dy have a pseudo-D4d local symmetry. Magnetic characterizations reveal that complex BrMQ-Dy is a single-ion magnet and complex ClMQ-Dy exhibits field-induced slow magnetic relaxation behaviors. The calculated effective barriers of BrMQ-Dy, BrMQ-Dya, ClMQ-Dy, and ClMQ-Dya are 47.8, 27.3, 96.0, and 65.5 cm-1, respectively (BrMQ-Dya and ClMQ-Dya represent the desolvated samples of BrMQ-Dy and ClMQ-Dy, respectively). Ab initio calculations confirmed that coordination symmetry of the Dy(III) ions, electron-withdrawing ligands, and the guest molecules is a key factor affecting the magnetic dynamics of the two complexes. The IC50 values of BrMQ-Dy and ClMQ-Dy against BEL-7404, HeLa, and Hep-G2 cancer cells were 1.01-22.06 µM. Interestingly, two Dy(III) complexes were less toxic to normal HL-7702 cells. BrMQ-Dy and ClMQ-Dy significantly induced cell arrest at G2 phase and down-regulated the G2 phase-related protein levels. Various experiments suggested that BrMQ-Dy and ClMQ-Dy also caused dysfunction of mitochondrial pathways in HeLa cells. Taken together, the different in vitro anticancer activity of complexes BrMQ-Dy and ClMQ-Dy in the order of 5,7-dichloro substitution > 5,7-dibromo substitution.

Mixed chelating ligands used to regulate the luminescence of Ln(iii) complexes and single-ion magnet behavior in Dy-based analogues.

The organic ligands 5,7-dibromo-2-methyl-8-quinolinol (L1), 1,10-phenanthroline (L2), and 5,7-dichloro-2-methyl-8-quinolinol (L3) were used to react with Dy(NO3)3·6H2O under solvothermal conditions at 80 °C to obtain the complexes [Dy(L1)3(H2O)] (1), [Dy(L2)2(NO3)3] (2), and [Dy(L3)3(H2O)] (3), respectively. The reaction of L1 and L2 with lanthanide(iii) nitrate salts in the presence of triethylamine as a base afforded four mononuclear complexes, namely, [Ln(L1)2(L2)(NO3)] [Ln = Dy (4), Ho (5), Er (6), and Tb (7)]. Complexes 1 and 2 emitted yellow-green and red light under excitation with light of a certain wavelength. Interestingly, 4-7 exhibited a superimposition of the luminescence of 1 and 2. To our knowledge, this is the first example of the use of different organic light-emitting ligands to adjust the fluorescence of Ln(iii) complexes. Moreover, the series of complexes [Ln(L3)2(L2)(NO3)] [Ln = Dy (8), Ho (9), Er (10), and Tb (11)] were also obtained under the same conditions by replacing L1 with L3. In the way that was expected, 8-11 exhibited a superimposition of the luminescence of 2 and 3. Density functional theory (DFT) calculations of electron cloud density showed that the electron cloud densities of complexes 4 and 8 are mainly concentrated in the quinoline rings. Furthermore, analysis of the molecular ion peaks of complexes 4-11 obtained by electrospray mass spectrometry (ESI-MS) showed that only the 1,10-phenanthroline ligand was discovered to dissociate in the solution state. Magnetic measurements of the Dy-containing complexes revealed features of field-induced single-ion magnet behavior.

Diacylhydrazone-assembled {Ln11} nanoclusters featuring a "double-boats conformation" topology: synthesis, structures and magnetism.

A family of novel Ln nanoclusters, namely, [Ln11(ovpho)4(µ-CH3O)2(µ-H2O)2(µ3-OH)6(CH3OH)4(H2O)2(NO3)8](OH)·xH2O·yCH3OH [Ln = Gd (1), x = 1, y = 3; Ln = Tb (2), x = 1, y = 3; Ln = Dy (3), x = 0, y = 3], was obtained via solvothermal reactions of Ln(NO3)3 with a diacylhydrazone ligand N,N'-bis(o-vanillidene)pyridine-2,6-dicarbohydrazide N-oxide (H4ovpho). Their isostructural molecular structures are composed of two crystallographically symmetric {Ln6} rings sharing a Ln3+ ion, and display an unprecedented "double boat conformation" topology that, to our knowledge, has not yet been reported. Ophenol, Oenol and Ooxynitride from ovpho4- ligands, as well as Omethanol, Owater and Ohydroxyl help to bridge the Ln3+ ions. The structural variation between these {Ln11} clusters and a previously reported {Gd18} nanowheel, both of which are assembled by H4ovpho under the same synthetic method and reaction conditions, is caused only by changing the anions of Ln salts. Magnetic investigations revealed a large magnetocaloric effect (MCE) of 1, whose maximum -ΔSm value reaches 30.1 J kg-1 K-1 for ΔH = 50 kOe at 2.0 K. Additionally, it was found that 3 shows single-molecule magnets (SMMs) behavior, with an approximated energy barrier Ueff = 6.13 K and pre-exponential factor τ0 = 1.70 × 10-6 s.

A family of 3d metal clusters based on N-N single bonds bridged quasi-linear trinuclear cores: the Mn analogue displaying single-molecule magnet behavior.

The reactions of the diacylhydrazine ligands N,N'-bisalicyl-2,6-pyridine dicarbohydrazide (H6sphz) and N,N'-bis(3-methoxysalicyl)-2,6-pyridine dicarbohydrazide (H6msphz) with various 3d metal salts, afforded a series of coordination clusters, namely, [MnIII 2MnII(sphz)(acac)2(CH3OH)4] (1, acac- = acetylacetone anions), [NiII 3(msphz)(Py)4] (2, Py = pyridine), [CuII 6(sphz)2(Py)4] (3) and [CuII 6(msphz)2(Py)4]·2DMF·2H2O (4). Cluster 1 and 2 are single ligand assembled quasi-linear trinuclear structures. Both 3 and 4 consist a pair of quasi-linear {Cu3} cores, which are linked together by two crossed ligands. The adjacent 3d metal ions in all trinuclear cores of 1-4 are bridged by N-N single bonds of ligands, which convey ferromagnetic (FM) interactions between 3d metal centers of 1, and antiferromagnetic (AFM) interactions between those of 2-4. In particular, the FM interactions and linear arrangement of mixed-valence Mn centers in 1 result in a large spin ground states value (S T) of 13/2, as well as single-molecule magnet (SMM) behavior of slow relaxation and hysteresis of magnetization.

A single-stranded {Gd18} nanowheel with a symmetric polydentate diacylhydrazone ligand.

An unprecedented {Gd18} nanowheel was solvothermally synthesized with a novel diacylhydrazone ligand. It features a rare single-stranded skeleton just like a Reuleaux triangle with vertices buckled in, represents the highest nuclearity and largest size in lanthanide (Ln) wheels reported so far, and shows a large magnetocaloric effect (MCE).

Experimental and theoretical investigations of four 3d-4f butterfly single-molecule magnets.

The syntheses, structures, and characterization of four 3d-4f butterfly clusters are described. With different polyhydroxy Schiff-base ligands 2-(((2-hydroxy-3-methoxyphenyl)methylene)amino)-2-(hydroxymethyl)-1,3-propanediol (H4L1) and 2-(2,3-dihydroxpropyliminomethyl)-6-methoxyphenol (H3L2), three heterotetranuclear NiLn complexes (NiDy-L1 (1), NiTb-L2 (2), NiDy-L2 (3)) and one heterohexanuclear CoDy complex (4) were obtained. The three heterotetranuclear NiLn complexes display a central planar butterfly topology. The heterohexanuclear complex was built from butterfly CoDy clusters and two Dy(III) ions by the bridging of pivalate. The vertices of the body positions of the butterfly are occupied by transition metal ions in all four complexes. Magnetic analyses indicate that the complexes exhibit typical single-molecule magnet behaviour with anisotropy barriers of 33.7 cm(-1), 60.3 cm(-1), 39.6 cm(-1), and 18.4 cm(-1) for 1-4, respectively. Ab initio calculations were performed on these complexes, and the low lying electronic structure of each Ln(III) (Ln = Dy, Tb) ion and the magnetic interactions were determined. It was found that the two Ln ions may have much more contribution to the total relaxation barrier through the stronger 3d-4f exchange couplings compared to weak Ln-Ln interactions.

A series of 3D metal organic frameworks based on [24-MC-6] metallacrown clusters: structure, magnetic and luminescence properties.

Four isostructural metal organic frameworks (MOFs), namely [Co6(HipO)6]·6H2O (1), [Mn6(HipO)6]·6H2O (2), [Cd6(HipO)6]·6H2O (3) and [Zn6(HipO)6]·7H2O (4) (H3ipO = 2-hydroxyisophthalic acid), were synthesized and structurally characterized. They have a 3D (4,6)-connected framework based on [24-MC-6] metallacrown clusters ([24-MC-6]-based MOFs). The arrangements of the 24-MC-6 metallacrown SBUs show a regular change indicated by the orientation of their symmetry axes, resulting in a special dense packing mode different from other [24-MC-6]-based MOFs. The analysis of SQUID measurements reveal that compound 1 displays the dominant antiferromagnetic exchanges in 300-10 K between the adjacent Co(II) ions and a ferromagnetic-like behavior at lower temperatures, whereas compound 2 shows an antiferromagnetic interaction between the adjacent Mn(II) ions. Compound 1 exhibits a magnetocaloric effect (MCE) with the resulting entropy change (-ΔS(m)) of 15.20 J kg(-1) K(-1) for ΔH = 50 kG at 6 K, which is the highest value among the cobalt-based MOFs with MCE reported so far. The luminescence properties of compounds 3 and 4 were studied, both of them exhibit photoluminescence in the solid state at room temperature which can be ascribed to intraligand π→π* transitions.

Series of edge-sharing bi-triangle Ln4 clusters with a µ4-NO3- bridge: syntheses, structures, luminescence, and the SMM behavior of the Dy4 analogue.

A series of Ln4 clusters, [Ln4L2(µ3-OH)2(µ4-NO3)(NO3)4(OCH3)(H2O)]·xMeCN·yMeOH (Ln = Gd (1), Tb (2), Dy (3), Ho (4), Er (5), Yb (6), L = 2-{[2-(2-hydroxy-ethoxy)-ethylimino]-methyl}-6-methoxyphenol), have been synthesized by the reaction of Ln(NO)3 and a Schiff-base ligand formed in situ. The six complexes display similar structures, with an overall metal core comprising two edge-sharing triangular Ln3 units linked by a µ4-NO3(-) bridge. The luminescence spectrum of complex 2 shows the characteristic emission of the Tb(III) ions. The magnetic susceptibility studies reveal that the Ln(III) ions are very weakly interacting in all six compounds. Frequency dependence of the ac-susceptibility was found for 3, suggesting a typical single-molecule magnet (SMM) behavior with an anisotropic barrier of 28 K.

Poly[mu(8)-4,4'-bipyridine-2,2',6,6'-tetracarboxylato-dilead(II)].

The Pb(II) cation in the title compound, [Pb(2)(C(14)H(4)N(2)O(8))](n), is seven-coordinated by one N atom and six O atoms from four 4,4'-bipyridine-2,2',6,6'-tetracarboxylate (BPTCA(4-)) ligands. The geometric centre of the BPTCA(4-) anion lies on an inversion centre. Each pyridine-2,6-dicarboxylate moiety of the BPTCA(4-) ligand links four Pb(II) cations via its pyridyl N atom and two carboxylate groups to form two-dimensional sheets. The centrosymmetric BPTCA(4-) ligand then acts as a linker between the sheets, which results in a three-dimensional metal-organic framework.

Three-dimensional metal azide coordination polymers with amino carboxylate coligands: synthesis, structure, and magnetic properties.

The reaction of M(II) ions with azido ligands in the presence of different amino carboxylic acids gave four three-dimensional metal-azido coordination polymers, [Mn(3,5-daba)(N(3))](n) (1), [Cd(3,5-daba)(N(3))](n) (2; 3,5-daba = 3,5-diaminobenzoate), [Mn(4-aba)(N(3))](n) (3; 4-aba = 4-aminobenzoate), and [Cu(2)(gly)(2)(N(3))(2)](n) (4; gly = glycinate), which display different topological structures. Polymers 1 and 2 present 4,6-connected 3D networks with different Schlafli symbols. However, 3 and 4 feature an unprecedented trinodal 3,6-connected network with the Schlafli symbol (4(2).6)(4.6(2))(4(3).6(6).8(6)) and an unusual 4-connected 3D net with the Lonsdaleite (hexagonal diamond) topology, respectively. Magnetic susceptibility measurements revealed dominant antiferromagnetic couplings for 1 and 3 and an overall dominant ferromagnetic coupling for 4, which presents metamagnetic behavior with a magnetic phase transition at a critical temperature of 6 K and a transition field of ca. 6030 Oe. The results demonstrate that the EE azido and syn-anti carboxylato bridges in our cases induce an antiferomagnetic interaction, and the anti-anti carboxylato bridge in 4 mediates a ferromagnetic interaction. The magnetic interaction through the EO azido bridge in 3 and 4 has a dependence on the value of the M-N-M bond angle.

(Z)-Isobutyl 2-benzamido-3-(4-chloro-phen-yl)acrylate.

The title compound, C(20)H(20)ClNO(3), is a α-amino acid derivative which displays a Z configuration about the C=C double bond. The dihedral angle betwen the aromatic rings is 87.75 (12)°. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯N hydrogen bond. In the crystal structure, centrosymmetrically related mol-ecules inter-act through inter-molecular C-H⋯O hydrogen-bond inter-actions, forming dimers. The dimers are further linked into chains parallel to the a axis by N-H⋯O hydrogen bonds. The methyl groups of the isopropyl group are disordered over two positions with occupancy factors of 0.5.

A novel three-dimensional coordination polymer: poly[di-mu3-acetato-di-mu2-acetato-di-mu3-hydroxido-octa-mu3-triazolato-heptamanganese(II)].

The title compound, [Mn7(C2H2N3)8(C2H3O2)4(OH)2]n, is composed of centrosymmetric heptanuclear building units with the central Mn atom on an inversion center. In the building block, three Mn(II) ions are held together by one mu3-hydroxide group, two mu2-triazolate (trz) ligands and two mu2-acetate groups, forming an Mn3 cluster. Two Mn3 clusters are bridged by an Mn atom via two mu2-trz ligands and two mu2-O atoms from two acetate ions to construct a heptanuclear building block. The heptanuclear building units, lying parallel to each other along the b direction, form one-dimensional ladder-like chains and are further interlinked, resulting in a three-dimensional framework through Mn-N(trz) bonds.

(6-Oxido-2-oxo-1,2-dihydropyrimidine-5-carboxylato-κO,O)(4-oxido-2-oxo-1,2-dihydropyrimidin-3-ium-5-carboxyl-ato-κO,O)bis(1,10-phenanthroline-κN,N')erbium(III) dihydrate.

The erbium(III) atom in the title compound, [Er(C(5)H(2)N(2)O(4))(C(5)H(3)N(2)O(4))(C(12)H(8)N(2))(2)]·2H(2)O, is located on a twofold rotation axis and chelated by two 1,10-phenanthroline heterocycles as well as by a 2,4-dihydroxy-pyrimidine-5-car-box-yl-ate monoanion and a 2,4-dihydroxy-pyrimidine-5-car-box-yl-ate dianion in a square-anti-prismatic coordination geometry.

(µ-6-Oxido-4-oxo-1,2-dihydro-pyrimidine-5-carboxyl-ato-κO,O:O,N)bis-[aquabis-(4-oxido-2-oxo-1,2-dihydro-pyrimidin-3-ium-5-carboxyl-ato-κO,O)-(1,10-phenanthroline-κN,N')neodymium(III)] hexa-hydrate.

The water-coordinated neodymium(III) atom in the centrosymmetric title compound, [Nd(2)(C(5)H(2)N(2)O(4))(C(5)H(3)N(2)O(4))(4)(C(12)H(8)N(2))(2)(H(2)O)(2)]·6H(2)O is chelated by a 1,10-phenanthroline heterocycle and two 2,4-dihydroxy-pyrimidine-5-carboxyl-ate dianions. Two tris-chelated water-coordinated units are bridged by a 2,4-dihydroxy-pyrimidine-5-carboxyl-ate dianion, which is disordered about a center of inversion. The metal center has a monocapped square-anti-prismatic coordination.