Novel Antioxidants Based on Selected 3d Metal Coordination Compounds with 2-Hydroxybenzaldehyde 4,S-Diallylisothiosemicarbazone.

2-Hydroxybenzaldehyde 4,S-diallylisothiosemicarbazone (HL) was synthesized and characterized by 1H, 13C NMR and FTIR spectroscopies. It exists in solution in two isomeric forms: cis (~25%) and trans (~75%). Six stable complexes were obtained by interaction of HL with copper(II), nickel(II), cobalt(III) and iron(III) salts: [Cu(L)Cl] (1), [Cu(L)NO3] (2), [Cu(3,4-Lut)(L)NO3] (3), [Ni(L)OAc] (4), [Co(L)2]Cl (5), [Fe(L)2]NO3 (6). The synthesized complexes have been studied by elemental analysis, FTIR, molar electrical conductivity and single crystal X-ray diffraction (6). For all compounds the antioxidant activity against cation radicals ABTS•+ was studied. All complexes and free ligand are more active than trolox that is used in medicine practice. Complex 4 (IC50=7.20µM) is the most active one. The introduction of heterocyclic amine did not improve the antioxidant activity. The introduction of S-allyl group into isothiosemicarbazone affected the activity of the synthesized substances, and in some cases the resulting complexes exhibit greater activity than complexes with isothiosemicarbazones with other S-radicals.

FeII/III and MnII complexes based on 2,4,6-tris(2-pyridyl)-triazine: synthesis, structures, magnetic and biological properties.

Reaction of the polypyridyl ligand 2,4,6-tris(2-pyridyl)-s-triazine (tpt) with mono- and polynuclear Fe(iii) or Mn(ii) precursors, specifically tri- or hexanuclear Fe(iii) pivalates (piv-), [Mn6O2(piv)10(Hpiv)4] and Mn(ii) isobutyrate (ib-), in various solvents and under various reaction conditions showcase the ligand's surprising coordination characteristics. The reactions result in mononuclear [FeIII(tpt)(tptH)][FeIIICl4]4·2(thf)·0.23(H2O) (1), [FeIII(piv)(tpt)Cl2] (2), [FeII(tpt)Cl2]·2(H2O) (3a), dinuclear [FeIII 2O(tpt)2Cl4] (3), and heptanuclear [FeIII 7O4(piv)12(tpt-O)]·A [A = MeCN (4a) or 4(dioxane) (4b)] and [FeIII 7O4(piv)11(tpt-O)(i-PrO)(i-PrOH)]·0.75(i-PrOH) (5), as well as the mononuclear compounds [MnII(tpt)(NO3)(H2O)2](NO3) (6) and [MnII(tpt)(ib)(Cl)(MeOH)]·MeOH (7). Single-crystal X-ray diffraction analyses identify tpt as a tridentate NNN donor ligand that forms two five-membered metallocycles in 1-3, 6 and 7, whereas in 4 and 5 five tpt N atoms form coordinative bonds accompanied by an unusual metal-induced oxidation of one of the carbon atoms of the central triazine core. Magnetic properties of Fe(iii)-tpt (2-5), Fe(ii)-tpt (3a), and Mn(ii)-tpt (7) compounds show dominant antiferromagnetic coupling for polynuclear coordination cluster compounds. The Mn(ii)-tpt complexes 6 and 7 exhibit efficient catalytic properties in the production of enzymes by microorganisms, which concerns the synthesis of exocellular proteases in Fusarium gibbosum CNMN FD 12 or Trichoderma koningii Oudemans CNMN FD 15 fungi strains. Thus, compounds 6 and 7 can be used for producing proteolytic enzymes with wide applications including in the food, detergents and pharmaceutical industries.

Bis(2-, 3-, 4-carboxyethylpyridinium) hexafluorosilicates as potential caries prophylactic agents.

Interaction of 2-, 3-, 4-carboxyethylpyridines (L1, L2, L3) with fluorosilicic acid results in the corresponding bis(pyridinium) hexafluorosilicates I-III, characterized by elemental analysis, IR, 1 H, 19 F nuclear magnetic resonance (NMR), and mass spectrometry, solubility data, and X-ray crystallography. Crystallographic data: Fdd2, Z = 8, a = 28.610(2) Å, b = 18.8378(14) Å, c = 7.3236(5) Å (I); P-1, Z = 1, a = 6.2712(4) Å, b = 7.1706(5) Å, c = 10.9721(7) Å, α = 102.514(6)°, ß = 97.037(5)°, γ = 93.640(6)° (II); P21 /c, Z = 2, a = 10.0345(6) Å, b = 9.8734(5) Å, c = 9.4704(6) Å, ß = 94.347(6)° (III). The dominant intermolecular contacts from the Hirshfeld surface analysis are H… F/F… H, H… H, and H… O/O… H with percentages of 33.3%-34.5%, 26.4%-30.0%, and 16.0%-21.8%. The infrared spectra for I-III exhibit stretching vibrations ν(N+ H) at 3300-3050 cm-1 ; stretching and deformation vibrations ν(SiF) and δ(SiF2 ) for [SiF6 ]2- anions are registered near 740 cm-1 and in the range of 480-440 cm-1 . In the 19 F NMR spectra of aqueous solutions of I-III, strong singlet signals of the [SiF6 ]2- anion were registered at δ(F) = -133.35 ppm (I), -131.43 ppm (II), -129.02 ppm (III) with two satellites due to the spin-spin interaction 29 Si-19 F (J(29 Si-19 F) = 107.5 Hz (II), 107.6 Hz (III)). I-III reveal high solubility in water and dimethyl sulfoxide and very poor solubility in methanol and ethanol. All compounds demonstrate noticeable anticaries activity and absence of hepatotoxic effects, and bis(3-carboxyethylpyridinium) hexafluorosilicate II displays the highest caries-preventive efficacy, which significantly exceeds values for the reference preparations, NaF and (NH4 )2 [SiF6 ].

Synthesis and physical characteristics of narrow bandgap chalcogenide SnZrSe 3.

Background: The development of organic/inorganic metal halide perovskites has seen unprecedent growth since their first recognition for applications in optoelectronic devices. However, their thermodynamic stability and toxicity remains a challenge considering wide-scale deployment in the future. This spurred an interest in search of perovskite-inspired materials which are expected to retain the advantageous material characteristics of halide perovskites, but with high thermodynamic stability and composed of earth-abundant and low toxicity elements. ABX 3 chalcogenides (A, B=metals, X=Se, S) have been identified as potential class of materials meeting the aforementioned criteria. Methods: In this work, we focus on studying tin zirconium selenide (SnZrSe 3) relevant physical properties with an aim to evaluate its prospects for application in optoelectronics. SnZrSe 3 powder and monocrystals were synthesized via solid state reaction in 600 - 800 °C temperature range. Crystalline structure was determined using single crystal and powder X-ray diffraction methods. The bandgap was estimated from diffused reflectance measurements on powder samples and electrical properties of crystals were analysed from temperature dependent I-V measurements. Results: We found that SnZrSe 3 crystals have a needle-like structure (space group - Pnma) with following unit cell parameters: a=9.5862(4) Å, b=3.84427(10) Å, c=14.3959(5) Å. The origin of the low symmetry crystalline structure was associated with stereochemical active electron lone pair of Sn cation. Estimated bandgap was around 1.15 eV which was higher than measured previously and predicted theoretically. Additionally, it was found that resistivity and conductivity type depended on the compound chemical composition. Conclusions: Absorption edge in the infrared region and bipolar dopability makes SnZrSe 3 an interesting material candidate for application in earth-abundant and non-toxic single/multi-junction solar cells or other infrared based optoelectronic devices.

Chromenol Derivatives as Novel Antifungal Agents: Synthesis, In Silico and In Vitro Evaluation.

Herein we report the synthesis of some new 1H-1,2,4-triazole functionalized chromenols (3a-3n) via tandem reactions of 1-(alkyl/aryl)-2-(1H-1,2,4-triazole-1-yl) with salicylic aldehydes and the evaluation of their antifungal activity. In silico prediction of biological activity with computer program PASS indicate that the compounds have a high novelty compared to the known antifungal agents. We did not find any close analog among the over 580,000 pharmaceutical agents in the Cortellis Drug Discovery Intelligence database at the similarity cutoff of 70%. The evaluation of antifungal activity in vitro revealed that the highest activity was exhibited by compound 3k, followed by 3n. Their MIC values for different fungi were 22.1-184.2 and 71.3-199.8 µM, respectively. Twelve from fourteen tested compounds were more active than the reference drugs ketoconazole and bifonazole. The most sensitive fungus appeared to be Trichoderma viride, while Aspergillus fumigatus was the most resistant one. It was found that the presence of the 2-(tert-butyl)-2H-chromen-2-ol substituent on the 4th position of the triazole ring is very beneficial for antifungal activity. Molecular docking studies on C. albicans sterol 14α-demethylase (CYP51) and DNA topoisomerase IV were used to predict the mechanism of antifungal activities. According to the docking results, the inhibition of CYP51 is a putative mechanism of antifungal activity of the novel chromenol derivatives. We also showed that most active compounds have a low cytotoxicity, which allows us to consider them promising antifungal agents for the subsequent testing activity in in vivo assays.

From 1D to 2D Cd(II) and Zn(II) Coordination Networks by Replacing Monocarboxylate with Dicarboxylates in Partnership with Azine Ligands: Synthesis, Crystal Structures, Inclusion, and Emission Properties.

Eight mixed-ligand coordination networks, [Cd(2-aba)(NO3)(4-bphz)3/2]n·n(dmf) (1), [Cd(2-aba)2(4-bphz)]n·0.75n(dmf) (2), [Cd(seb)(4-bphz)]n·n(H2O) (3), [Cd(seb)(4-bpmhz)]n·n(H2O) (4), [Cd(hpa)(3-bphz)]n (5), [Zn(1,3-bdc)(3-bpmhz)]n·n(MeOH) (6), [Cd(1,3-bdc)(3-bpmhz)]n ·0.5n(H2O)·0.5n(EtOH) (7), and [Cd(NO3)2(3-bphz)(bpe)]n·n(3-bphz) (8) were obtained by interplay of cadmium nitrate tetrahydrate or zinc nitrate hexahydrate with 2-aminobenzenecarboxylic acid (H(2-aba)), three dicarboxylic acids, sebacic (decanedioic acid, H2seb), homophthalic (2-(carboxymethyl)benzoic acid, H2hpa), isophthalic (1,3-benzenedicarboxylic acid, H2(1,3-bdc)) acids, bis(4-pyridyl)ethane (bpe) and with four azine ligands, 1,2-bis(pyridin-4-ylmethylene)hydrazine (4-bphz), 1,2-bis(1-(pyridin-4-yl)ethylidene) hydrazine (4-bpmhz), 1,2-bis(pyridin-3-ylmethylene)hydrazine (3-bphz), and 1,2-bis(1-(pyridin-3-yl) ethylidene)hydrazine (3-bpmhz). Compounds 1 and 2 are 1D coordination polymers, while compounds 3-8 are 2D coordination polymers. All compounds were characterized by spectroscopic and X-ray diffraction methods of analysis. The solvent uptakes and stabilities to the guest evacuation were studied and compared for 1D and 2D coordination networks. The de-solvated forms revealed a significant increase of emission in comparison with the as-synthesized crystals.

New vinyl-1,2,4-triazole derivatives as antimicrobial agents: Synthesis, biological evaluation and molecular docking studies.

1,2,4-Triazole is a very important scaffold in medicinal chemistry due to the wide spectrum of biological activities and mainly antifungal activity of 1,2,4-triazole derivatives. The main mechanism of antifungal action of the latter is inhibition of 14-alpha-demethylase enzyme (CYP51). The current study presents synthesis and evaluation of eight triazole derivatives for their antimicrobial activity. Docking studies to elucidate the mechanism of action were also performed. The designed compounds were synthesized using classical methods of organic synthesis. The in vivo evaluation of antimicrobial activity was performed by microdilution method. All tested compounds showed good antibacterial activity with MIC and MBC values ranging from 0.0002 to 0.0069 mM. Compound 2 h appeared to be the most active among all tested with MIC at 0.0002-0.0033 mM and MBC at 0.0004-0.0033 mM followed by compounds 2f and 2g. The most sensitive bacterium appeared to be Xanthomonas campestris while Erwinia amylovora was the most resistant. The evaluation of antifungal activity revealed that all compounds showed good antifungal activity with MIC values ranging from 0.02 mM to 0.52 mM and MFC from 0.03 mM to 0.52 mM better than reference drugs ketoconazole (MIC and MFC values at 0.28-1.88 mM and 0.38 mM to 2.82 mM respectively) and bifonazole (MIC and MFC values at 0.32-0.64 mM and 0.64-0.81 mM). The best antifungal activity is displayed by compound 2 h with MIC at 0.02-0.04 mM and MFC at 0.03-0.06 mM while compound 2a showed the lowest activity. The results showed that these compounds could be lead compounds in search for new potent antimicrobial agents. Docking studies confirmed experimental results.

Extrinsic Heavy Metal Atom Effect on the Solid-State Room Temperature Phosphorescence of Cyclic Triimidazole.

Four coordination compounds [Zn3 (CH3 COO)6 (H2 O)2 ](TT)2 [Cd(H2 O)6 ](ClO4 )2 (TT)2 , [Cd(H2 O)6 ](BF4 )2 (TT)2 , [Zn(H2 O)6 ](BF4 )2 (TT)2 (1-4) accommodating the crystallization induced emissive triimidazo[1,2-a:1',2'-c:1'',2''-e][1,3,5]triazine (TT) as a guest in their crystal lattice are isolated and fully photophysically and structurally characterized. Their emission properties are compared with those of afterglow TT and interpreted taking into account the heavy atom effect and crystal packing similarities and differences. In the case of 1, due to the closeness of the TT H-aggregates arrangement with that of the phosphor's pure phase, the observed intensification of the phosphorescent emission at the expense of the prompt one is attributed to the extrinsic heavy atom effect of Zn. In 2 and 3, the heavier Cd atom is responsible for a decrease in the lifetimes of the afterglow emission, despite the presence of tightly overlapped H-dimers in the crystal structure. Finally, for 4, isostructural with 3, the Zn atom reveals in RTUP lifetime comparable with that of 1.

Partial in Situ Reduction of Copper(II) Resulting in One-Pot Formation of 2D Neutral and 3D Cationic Copper(I) Iodide-Pyrazine Coordination Polymers: Structure and Emissive Properties.

On the way to copper(I) iodide coordination polymers with specific luminescent properties, the in situ reduction of Cu(II) in the presence of KI and bidentate N-heteroatomic ligand, either pyrazine (pyz) or 4,4'-bipyridine (bpy), resulted in one two-dimensional and two three-dimensional new coordination networks. Starting from Cu(NO3)2·3H2O in the presence of pyz, successive precipitation of known yellow [(CuII)2(pyz)]n, new orange [CuII(pyz)]n, and new dark blue {[CuI(pyz)2]·I5}n polymeric solids was observed. Starting from the same salt in the presence of bpy resulted in the successive precipitation of known yellow [(CuII)2(bpy)]n and new brown {[CuII(NO3)(bpy)2]·I3·(dmf·H2O)}n coordination polymers. By using either Cu(CH3COO)2·H2O or Cu(BF4)2 as starting materials, both known forms, yellow [(CuII)2(bpy)]n and orange [CuII(bpy)]n, precipitated successively. The new solids were characterized by IR spectroscopy and X-ray analysis. [CuII(pyz)]n represents the missing member in the row of two-dimensional coordination networks with general formula [CuIX(pyz)]n (X = Cl, Br, I). Its steady state and time-resolved characterization together with DFT and TDDFT calculations revealed that the emission at room temperature is mainly delayed fluorescence originating from mixed singlet metal-to-ligand charge transfer and halide-to-ligand charge transfer states, while that at 77 K is phosphorescence, associated with the small singlet-triplet energy differences (ΔE = 70 meV).

Tetranuclear {CoII2CoIII2}, Octanuclear {CoII4CoIII4}, and Hexanuclear {CoIII3DyIII3} Pivalate Clusters: Synthesis, Magnetic Characterization, and Theoretical Modeling.

New tetranuclear and octanuclear mixed-valent cobalt(II/III) pivalate clusters, namely, [NaCo4(O2CCMe3)6(HO2CCMe3)2(teaH)2(N3)]·2H2O (in two polymorphic modifications, 1 and 1a) and [Co8(O2CCMe3)10(teaH)4(N3)](Me3CCO2)·MeCN·H2O (2) have been synthesized by ultrasonic treatment of a dinuclear cobalt(II) pivalate precursor with sodium azide and triethanolamine (teaH3) ligand in acetonitrile. The use of Dy(NO3)3·6H2O in a similar reaction led to the precipitation of a tetranuclear [NaCo4(O2CCMe3)4(teaH)2(N3)(NO3)2(H2O)2]·H2O (3) cluster and a heterometallic hexanuclear [Co3Dy3(OH)4(O2CCMe3)6(teaH)3(H2O)3](NO3)2·H2O (4) cluster. Single-crystal X-ray analysis showed that 1 (1a) and 3 consist of a tetranuclear pivalate/teaH3 mixed-ligand cluster [CoII2CoIII2(O2CCMe3)4(teaH)2(N3)]+ decorated with sodium pivalates [Na(O2CCMe3)2(HO2CCMe3)2]- (1 or 1a) or sodium nitrates [Na(NO3)2]- (3) to form a square-pyramidal assembly. In 2, the cationic [Co8(O2CCMe3)10(teaH)4(N3)]+ cluster comprises a mixed-valent {CoII4CoIII4} core encapsulated by an azide, 4 teaH2- alcoholamine ligands, and 10 bridging pivalates. Remarkably, in this core, the µ4-N3- ligand joins all four CoII atoms. The heterometallic hexanuclear compound 4 consists of a cationic [CoIII3DyIII3(OH)4(O2CCMe3)6(teaH)3(H2O)3]2+ cluster, two NO3- anions, and a crystallization water molecule. The arrangement of metal atoms in 4 can be approximated as the assembly of a smaller equilateral triangle defined by three Dy sites with a Dy···Dy distance of 3.9 Å and a larger triangle formed by Co sites [Co···Co, 6.1-6.2 Å]. The interpretation of the magnetic properties of clusters 2-4 was performed in the framework of theoretical models, taking into account the structural peculiarities of clusters and their energy spectra. The behavior of clusters 2 and 3 containing CoII ions with orbitally nondegenerate ground states is determined by the zero-field splitting of these states and Heisenberg exchange interaction between the ions. To get a good understanding of the observed magnetic behavior of cluster 4, we take into consideration the crystal fields acting on the DyIII ions, the ferromagnetic coupling of neighboring DyIII ions, and the intercluster antiferromagnetic exchange. For all examined clusters, the developed models describe well the observed temperature dependence of the magnetic susceptibility and the field dependence of magnetization. The computational results apparently show that in cluster 4 two DyIII ions with similar nearest surroundings demonstrate single-molecule-magnet (SMM) behavior, while the strong rhombicity of the ligand surrounding hinders the SMM behavior of the third DyIII ion.

Ultralarge 3d/4f Coordination Wheels: From Carboxylate/Amino Alcohol-Supported {Fe4Ln2} to {Fe18Ln6} Rings.

A family of wheel-shaped charge-neutral heterometallic {FeIII4LnIII2}- and {FeIII18MIII6}-type coordination clusters demonstrates the intricate interplay of solvent effects and structure-directing roles of semiflexible bridging ligands. The {Fe4Ln2}-type compounds [Fe4Ln2(O2CCMe3)6(N3)4(Htea)4]·2(EtOH), Ln = Dy (1a), Er (1b), Ho (1c); [Fe4Tb2(O2CCMe3)6(N3)4(Htea)4] (1d); [Fe4Ln2(O2CCMe3)6(N3)4(Htea)4]·2(CH2Cl2), Ln = Dy (2a), Er (2b); [Fe4Ln2(O2CCMe3)4(N3)6(Htea)4]·2(EtOH)·2(CH2Cl2), Ln = Dy (3a), Er (3b) and the {Fe18M6}-type compounds [Fe18M6(O2CCHMe2)12(Htea)18(tea)6(N3)6]·n(solvent), M = Dy (4, 4a), Gd (5), Tb (6), Ho (7), Sm (8), Eu (9), and Y (10) form in ca. 20-40% yields in direct reaction of trinuclear FeIII pivalate or isobutyrate clusters, lanthanide/yttrium nitrates, and bridging triethanolamine (H3tea) and azide ligands in different solvents: EtOH for the smaller {Fe4Ln2} wheels and MeOH/MeCN or MeOH/EtOH for the larger {Fe18M6} wheels. Single-crystal X-ray diffraction analyses revealed that 1-3 consist of planar centrosymmetric hexanuclear clusters built from FeIII and LnIII ions linked by an array of bridging carboxylate, azide, and aminopolyalcoholato-based ligands into a cyclic structure with a cavity, and with distinct sets of crystal solvents (2 EtOH per formula unit in 1a-c, 2 CH2Cl2 in 2, and 2 EtOH and 2 CH2Cl2 in 3). In 4-10, the largest 3d/4f wheels currently known, nearly linear Fe3 fragments are joined via mononuclear Ln/Y units by a set of isobutyrates and amino alcohol ligands into virtually planar rings. The magnetic properties of 1-10 reveal slow magnetization relaxation for {Fe4Tb2} (1d) and slow relaxation for {Fe4Ho2} (1c), {Fe18Dy6} (4), and {Fe18Tb6} (6).

Synthesis, biological evaluation and molecular docking studies of 2-piperazin-1-yl-quinazolines as platelet aggregation inhibitors and ligands of integrin αIIbß3.

A series of 2-piperazin-1-yl-quinazolines were synthesized and evaluated for their antiaggregative activity. The synthesized small molecule compounds have potently inhibited platelet aggregation in vitro and blocked FITC-Fg binding to αIIbß3 integrin in a suspension of washed human platelets. The key αIIbß3 protein-ligand interactions were determined in docking experiments and some correlations have been observed between values of the affinity and docking scores.

Iron(III) carboxylate/aminoalcohol coordination clusters with propeller-shaped Fe8 cores: approaching reasonable exchange energies.

A series of new octanuclear propeller-like aminoalcohol-supported Fe(III) oxocarboxylate coordination clusters, [Fe8O3(O2CCHMe2)9(tea)(teaH)3]·MeCN·2(H2O) (1), [Fe8O3(O2CCHMe2)6(N3)3(tea)(teaH)3] (2), [Fe8O3(O2CCMe3)6(N3)3(tea)(teaH)3]·0.5(EtOH) (3), and [Fe8O3(O2CCHMe2)6(N3)3(mdea)3(MeO)3] (4) (where teaH3 = triethanolamine; mdeaH2 = N-methyldiethanolamine) has been isolated and magnetochemically analyzed combining the programs wxJFinder and CONDON in an approach to avoid overparameterization issues that are common to larger spin polytopes. Dominant antiferromagnetic exchange interactions exist in all clusters along the edges of the propellers, while moderate ferromagnetic interactions are found along the propeller axes in their {Fe8O3} metallic cores.

Halogen impact into new oxonium benzo-crown ether complexes with tetrachloro- and tetrabromoaurates(III).

Five oxonium tetrahalogenaurate(III) (Hal = Cl, Br) benzo-crown ether (BCE) complexes are prepared and reported. The new compounds are [(H3O)(B18C6)(0.58)(4'-Cl-B18C6)0.42][AuCl4] 1, [(H3O)(B18C6)][AuCl4] 2, [(H3O)(4'-Br-B18C6)][AuCl4] 3, [(H3O)(4'-Br-B18C6)][AuBr4] 4, and [(H3O)(B18C6)][AuBr4] 5. The reaction medium, distinctive from the previously used aqua regia, allowed avoiding the unwanted nitration of initial macrocycles. The compositions and structures for 1, 3, 4, and 5 were proved by single crystal X-ray crystallography. The complete conversion of tetrachloroaurate(III) to the tetrabromoaurate(III) salts resulted in complex 4 isomorphous and isostructural to 3. All compounds form the laminated structures with alternation of cationic and anionic layers. The robustness of the anionic sheets is sustained by the halogen-halogen interactions and makes crucial impact on extraction of stoichiometric products in the case of tetrabromoaurate(III) salts.

Structural study and Raman scattering analysis of Cu2ZnSiTe4 bulk crystals.

Bulk crystals of Cu(2)ZnSiTe(4) (CZSiTe) have been prepared by modified Bridgman method and have been investigated by single crystal X-ray method, Energy Dispersive X-Ray analysis and Raman scattering techniques. The structural studies revealed that the CZSiTe compounds crystallizes in the tetragonal space group I4¯2m, with a = b = 5.9612(1) Å and c = 11.7887(4) Å at 293 K. The Raman spectrum characteristic of the crystals exhibits nine peaks, with two dominant peaks at approximately 134 cm(-1) and 151 cm(-1) that can be used as fingerprint peaks for the identification of this compound. The Raman peaks were analyzed on the basis of the derived irreducible representation for the zone center phonons and by comparison with experimental and theoretical data from close related semiconductors as Cu(2)FeSnS(4) and Cu(2)ZnSnSe(4).

Synthesis, biological evaluation, X-ray molecular structure and molecular docking studies of RGD mimetics containing 6-amino-2,3-dihydroisoindolin-1-one fragment as ligands of integrin αIIbß3.

A series of novel RGD mimetics containing phthalimidine fragment was designed and synthesized. Their antiaggregative activity determined by Born's method was shown to be due to inhibition of fibrinogen binding to αIIbß3. Molecular docking of RGD mimetics to αIIbß3 receptor showed the key interactions in this complex, and also some correlations have been observed between values of biological activity and docking scores. The single crystal X-ray data were obtained for five mimetics.

Cluster-based networks: 1D and 2D coordination polymers based on {MnFe2(µ3-O)}-type clusters.

A straightforward approach to heterometallic Mn-Fe cluster-based coordination polymers is presented. By employing a mixed-valent µ(3)-oxo trinuclear manganese(II/III) pivalate cluster, isolated as [Mn(II)Mn(III)(2)O(O(2)CCMe(3))(6)(hmta)(3)]·(solvent) (hmta = hexamethylenetetramine; solvent = n-propanol (1), toluene (2)) in the reaction with a µ(3)-oxo trinuclear iron(III) pivalate cluster compound, [Fe(3)O(O(2)CCMe(3))(6)(H(2)O)(3)]O(2)CCMe(3)·2Me(3)CCO(2)H, three new heterometallic {Mn(II)Fe(III)(2)} cluster-based coordination polymers were obtained: the one-dimensional polymer chain compounds {[MnFe(2)O(O(2)CCMe(3))(6)(hmta)(2)]·0.5MeCN}(n) (3) and {[MnFe(2)O(O(2)CCMe(3))(6)(hmta)(2)]·Me(3)CCO(2)H·(n-hexane)}(n) (4) and the two-dimensional layer compound {[MnFe(2)O(O(2)CCMe(3))(6)(hmta)(1.5)]·(toluene)}(n) (5). Single-crystal X-ray diffraction analysis reveals a µ(3)-oxo trinuclear pivalate cluster building block as the main constituent in all polymer compounds. Different M:hmta ratios in 1-5 are related to the different structural functions of the N-containing ligand. In clusters 1 and 2, three hmta ligands are monodentate, whereas in chains 3 and 4 two hmta ligands act as bridging ligands and one is a monodentate ligand; in 5, all hmta molecules act as bidentate bridges. Magnetic studies indicate dominant antiferromagnetic interactions between the metal centers in both homometallic {Mn(3)}-type clusters 1 and 2 and heterometallic {MnFe(2)}-type coordination polymers 3-5. Modeling of the magnetic susceptibility data to a isotropic model Hamiltonian yields least-squares fits for the following parameters: J(1)(Mn(II)-Mn(III)) = -6.6 cm(-1) and J(2)(Mn(III)-Mn(III)) = -5.4 cm(-1) for 1; J(1) = -5.5 cm(-1) and J(2)(Mn(III)-Mn(III)) = -3.9 cm(-1) for 2; J(1)(Mn(II)-Fe(III)) = -17.1 cm(-1) and J(2)(Fe(III)-Fe(III)) = -43.7 cm(-1) for 3; J(1) = -23.8 cm(-1) and J(2) = -53.4 cm(-1) for 4; J(1) = -13.3 cm(-1) and J(2) = -35.4 cm(-1) for 5. Intercluster coupling plays a significant role in all compounds 1-5.

The next chapter in MOF pillaring strategies: trigonal heterofunctional ligands to access targeted high-connected three dimensional nets, isoreticular platforms.

A new pillaring strategy, based on a ligand-to-axial approach that combines the two previous common techniques, axial-to-axial and ligand-to-ligand, and permits design, access, and construction of higher dimensional MOFs, is introduced and validated. Trigonal heterofunctional ligands, in this case isophthalic acid cores functionalized at the 5-position with N-donor (e.g., pyridyl- or triazolyl-type) moieties, are designed and utilized to pillar pretargeted two-dimensional layers (supermolecular building layers, SBLs). These SBLs, based on edge transitive Kagomé and square lattices, are cross-linked into predicted three-dimensional MOFs with tunable large cavities, resulting in isoreticular platforms.

One-dimensional coordination polymers from hexanuclear manganese carboxylate clusters featuring a {Mn(II)4Mn(III)2(mu4-O)2} core and spacer linkers.

The bridging of hexanuclear mixed-valent carboxylate coordination clusters of the type [Mn(6)O(2)(O(2)CR)(10)] (R = CMe(3); CHMe(2)) featuring a {Mn(II)(4)Mn(III)(2)(mu(4)-O)(2)} core by geometrically rigid as well as flexible spacer ligands such as pyrazine (pyz), nicotinamide (na), or 1,2-bis(4-pyridyl)ethane (bpe) results exclusively in one-dimensional (1D) coordination polymers. The formation of {[Mn(6)O(2)(O(2)CCMe(3))(10)(Me(3)CCO(2)H)(EtOH)(na)] x EtOH x H(2)O}(n) (1), {[Mn(6)O(2)(O(2)CCHMe(2))(10)(pyz)(3)] x H(2)O}(n) (2), and {[Mn(6)O(2)(O(2)CCHMe(2))(10)(Me(2)CHCO(2)H)(EtOH)(bpe)] x Me(2)CHCO(2)H}(n) (3) illustrates a surprising preference of the interlinked {Mn(6)} units toward 1D coordination chains. In the solid-state, the observed chain propagation axes are either colinear (1 and 3) or perpendicular (2), whereby crystal packing is further influenced by solvent molecules. Magnetic properties of these network compounds can be rationalized based on that the magnetism of discrete [Mn(6)O(2)(O(2)CR)(10)]-type coordination clusters with all-antiferromagnetic intramolecular exchange and weak antiferromagnetic intercluster coupling in 1, 2, and 3 follows the expected exchange coupling strength of the employed spacer linkers.

A missing high-spin molecule in the family of cyanido-bridged heptanuclear heterometal complexes, [(LCu(II))6Fe(III)(CN)6]3+, and its Co(III) and Cr(III) analogues, accompanied in the crystal by a novel octameric water cluster.

Three isostructural cyanido-bridged heptanuclear complexes, [{Cu(II)(saldmen)(H2O)}6{M(III)(CN)6}]-(ClO4)3·8H2O (M= Fe(III) 2; Co(III), 3; Cr(III) 4), have been obtained by reacting the dinuclear copper(II) complex, [Cu2(saldmen)2(µ-H2O)(H2O)2](ClO4)2·2H2O 1, with K3[Co(CN)6], K4[Fe(CN)6], and K3[Cr(CN)6], respectively (Hsaldmen is the Schiff base resulting from the condensation of salicylaldehyde with N,N-dimethylethylenediamine). A unique octameric water cluster, with bicyclo[2,2,2]octane-like structure, is sandwiched between the heptanuclear cations in 2, 3 and 4. The cryomagnetic investigations of compounds 2 and 4 reveal ferromagnetic couplings of the central Fe(III) or Cr(III) ions with the Cu(II) ions (J(CuFe) = +0.87 cm⁻¹, J(CuCr) = +30.4 cm⁻¹). The intramolecular Cu···Cu exchange interaction in 3, across the diamagnetic cobalt(III) ion, is -0.3 cm⁻¹. The solid-state ¹H-NMR spectra of compounds 2 and 3 have been investigated.