Showing papers on "Tetrahedral molecular geometry published in 2014"
TL;DR: In this paper, an azobenzene based iminopyridine ligand was synthesized by a condensation reaction between N,N-dimethyl-4,4′-azodianiline and 2-formylpyridine.
Abstract: An azobenzene based iminopyridine ligand 1 has been synthesized by a condensation reaction between N,N-dimethyl-4,4′-azodianiline and 2-formylpyridine. The complexation of the ligand with ZnCl2 afforded a tetrahedral neutral zinc metal complex (2) formulated as [(Azo-Imino-Py)ZnCl2]. The crystal structure analysis of the complex indicates the formation of a tetracoordinated zinc(II) ion with the expected tetrahedral geometry. In solid state, a 2D supramolecular architecture reinforced by π–π stacking and hydrogen bonding is observed. The UV–visible spectrophotometric titration studies of the ligand, by increasing amount of ZnCl2, confirm the existence of single complex species in solution. The nonlinear optical (NLO) investigations by Z-scan technique of both ligand 1 and complex 2 indicate a dramatic enhancement of the NLO absorption of the ligand upon complexation with ZnCl2. This enhancement is likely to be due to a large dipole moment found for the complex 2 as calculated by DFT/B3LYP methodology.
93 citations
TL;DR: Calculated TDDFT calculations of the electronic CD spectra for the diastereomers Λ-Cu-R-L1 and Δ-Cu/Λ-chiral four-coordinated, non-planar Cu(N^O)2 complexes suggest that the spectra are largely dominated by the configuration at the metal center ( Δ vs. Δ).
Abstract: Bidentate enantiopure Schiff base ligands, (R or S)-N-1-(Ar)ethyl-2-oxo-1-naphthaldiminato-κ2N,O, diastereoselectively yield Δ/Λ-chiral four-coordinated, non-planar Cu(N^O)2 complexes [Ar = C6H5R/S-L1, m-C6H4OMe R-L2, p-C6H4OMe R/S-L3, and p-C6H4Br R/S-L4]. Two N,O-chelate ligands coordinate to the copper(II) atom in distorted square-planar mode, and induce metal-centered Δ/Λ-chirality at the copper atom in the C2-symmetric complexes. In the solid state, the R-L1 (or R-L4) ligand chirality diastereoselectively induces a Λ-Cu configuration in Λ-Cu-R-L1 (or Λ-Cu-R-L4), the S-L1 ligand a Δ-Cu configuration in Δ-Cu-S-L1, forming enantiopure crystals upon crystallization. Conversely, the R-L2 ligand combines both Λ/Δ-Cu-R-L2 as a diastereomeric pair in the crystals. In solution, electronic circular dichroism (CD) spectra show full or partial diastereoselectivity towards Λ-Cu for R ligands and towards Δ-Cu for S ligands. The electronic CD spectra measured on all complexes obtained from R ligands (or S ligands), e.g.Cu-R-L1, Cu-R-L2, Cu-R-L3, and Cu-R-L4 (or Cu-S-L1, Cu-S-L3, and Cu-S-L4), show consistent spectral features. TDDFT calculations of the electronic CD spectra for the diastereomers Λ-Cu-R-L1 and Δ-Cu-R-L1 suggest that the CD spectra are largely dominated by the configuration at the metal center (Λvs.Δ). The experimental CD spectrum of Cu-R-L1 agrees well with the one calculated for the Λ-Cu-R-L1 configuration. Cyclic voltammetry of Cu-R-L1 reveals a quasi-reversible redox wave corresponding to one-electron transfer for the [CuIIL2]0/[CuIL2]−1 couple in acetonitrile. DSC analyses for the complexes show an exothermic peak between 377 and 478 K (ΔH = −12 to −43 kJ mol−1), corresponding to a phase transformation from distorted square-planar/tetrahedral to regular tetrahedral geometry on heating.
62 citations
TL;DR: The temperature dependence of the relaxation rate and the absence of slow dynamics in the Zn(II)-doped sample suggest that neither the simple Orbach mechanism nor Raman or direct processes can account for the relaxation, and collective phenomena have to be invoked for the observed behavior.
Abstract: Three new binuclear helicates, [M2L2]·3DMF (M = Co(II), 1, Zn(II), 3) and [Cu2L2]·DMF·0.4H2O (2), have been assembled using the helicand H2L that results from the 2:1 condensation reaction between o-vanillin and 4,4′-diaminodiphenyl ether. The metal ions within the binuclear helicates are tetracoordinated with a distorted tetrahedral geometry. Direct current magnetic characterization and EPR spectroscopy of the Co(II) derivative point to an easy axis type anisotropy for both Co(II) centers, with a separation of at least 55 K between the two doublets. Dynamic susceptibility measurements evidence slow relaxation of the magnetization in an applied dc field. Since the distance between the cobalt ions is quite large (11.59 A), this is attributed in a first instance to the intrinsic properties of each Co(II) center (single-ion magnet behavior). However, the temperature dependence of the relaxation rate and the absence of slow dynamics in the Zn(II)-doped sample suggest that neither the simple Orbach mechanism n...
57 citations
TL;DR: The sterically encumbered dimer [CpBIGFe(CO)2]2 (1) is able to activate small tetrahedral molecules like P4 and As4 as well as the less reactive cage compounds P4S3 and P4Se3 at room temperature to give the products.
Abstract: The sterically encumbered dimer [CpBIGFe(CO)2]2 (1) (CpBIG = C5(4-nBuC6H4)5) is able to activate small tetrahedral molecules like P4 and As4 as well as the less reactive cage compounds P4S3 and P4Se3 at room temperature to give the products [{CpBIGFe(CO)2}2(μ,η1:1-cage)] (cage = P4 (2a), As4 (2b), P4S3 (2c), P4Se3 (2d)) in a quantitative manner. The reaction proceeds via selective cleavage of one E–E bond (E = P, As) of the starting material. Complex 1 also reacts with CS2 forming the binuclear compound [{CpBIGFe(CO)2}{CpBIGFeCO}(μ,η1:2-CS2)] (3).
55 citations
TL;DR: The heteroleptic complexes 1-4 efficiently initiate the ring-opening polymerization of rac-lactide and α-methyltrimethylene carbonate (α-MeTMC) and the polymerizations are better controlled in the presence of 2-propanol.
Abstract: A series of racemic 2-[(2′-(dimethylamino)biphenyl-2-ylimino)methyl]-4-R2-6-R1-phenols (L1H–L4H) were reacted with {Mg[N(SiMe3)2]2}2 to provide four heteroleptic magnesium complexes (L1–4)MgN(SiMe3)2·(THF)n (1, R1 = tBu, R2 = Me, n = 1; 2, R1 = R2 = CMe2Ph, n = 0; 3, R1 = CPh3, R2 = tBu, n = 1; 4, R1 = Br, R2 = tBu, n = 0), which have been fully characterized. X-ray structural determination shows that complex 1 possesses a monomeric structure, but complex 4 is dimeric with C2-symmetry where the two metal centers are bridged by two phenolate oxygen atoms of the ligands. The coordination geometry around the magnesium center in these complexes can be best described as a distorted tetrahedral geometry. The heteroleptic complexes 1–4 efficiently initiate the ring-opening polymerization of rac-lactide and α-methyltrimethylene carbonate (α-MeTMC) and the polymerizations are better controlled in the presence of 2-propanol. In general, the introduction of a bulky ortho-substituent on the phenoxy unit results in increases of both the catalytic activity and the stereo- or regioselectivity of the corresponding magnesium complex. Microstructure analyses of the resulting PLAs revealed that Pr values range from 0.46 to 0.81, depending on the catalyst and the polymerization conditions. For racemic α-MeTMC, detailed analyses using 1H and 13C NMR spectroscopy indicated the preferential ring-opening of α-MeTMC at the most hindered oxygen–acyl bond (Xreg = 0.65–0.86).
46 citations
TL;DR: A series of novel aluminium complexes containing cyclic β-ketiminato ligands of type Me2Al have been prepared in high yields and revealed that they have a distorted tetrahedral geometry around Al, and both bond distances and bond angles were considerably influenced by the ligand structure.
Abstract: A series of novel aluminium complexes containing cyclic β-ketiminato ligands of type Me2Al{O-[(ArNCHC4H4(C6H4))]} (3a, Ar = 2,6-iPr2C6H3; 3b, Ar = C6H5; 3c, Ar = C6F5) have been prepared in high yields These complexes were identified by 1H, 13C NMR spectroscopy and elemental analysis X-ray structural analyses for 3a–c revealed that these complexes have a distorted tetrahedral geometry around Al, and both bond distances and bond angles were considerably influenced by the ligand structure These complexes were tested as catalyst precursors for ring-opening polymerisation of e-caprolactone (e-CL) and L-lactide (L-LA) in the presence of 2-propanol as an initiator Complex 3a could polymerize e-CL in a controlled manner with high efficiency Based on the living characteristics, the preparation of well-defined block copolymers PCL-b-PLLA via sequential addition of monomers was performed by 3a Note that complex 3c exhibited rather high catalytic activity for the ROP of L-LA with narrow molecular weight distribution The monomer conversion reached completion only in 4 h when the L-LA/Al molar ratio was 100 at 80 °C PLLA-b-PCL copolymers were thus easily produced by 3c
43 citations
TL;DR: In this article, the series of 2-2,6-bis[di(4-fluorophenyl)methyl]-4-chlorophenylimino}-3-aryliminobutane derivatives (L1-L5) and their nickel(II) dibromide complexes (Ni1-Ni5) were synthesized, and all organic compounds were fully characterized by the Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy and by elemental analysis, while the nickel complexes were characterized by FT-IR
Abstract: The series of 2-{2,6-bis[di(4-fluorophenyl)methyl]-4-chlorophenylimino}-3-aryliminobutane derivatives (L1–L5) and their nickel(II) dibromide complexes (Ni1–Ni5) were synthesized, and all organic compounds were fully characterized by the Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy and by elemental analysis, while the nickel complexes were characterized by FT-IR spectroscopy, elemental analysis, as well as by single-crystal X-ray diffraction for two representative examples, namely Ni1 and Ni4. A distorted tetrahedral geometry was observed for these four-coordinate nickel complexes. Upon the activation with either Methylaluminoxane or modified methylaluminoxane as co-catalyst, all nickel complex precatalysts showed very high activity toward ethylene polymerization with activities of up to 107 g(PE)·mol−1(Ni)·h−1, and afforded highly branched polyethylene with a bimodal distribution.
43 citations
TL;DR: The discovery is reported that the natural product pleuromutilin can be used as a structurally complex starting material for the synthesis of a series of bridged cis,cis, cis,c is,c Is-[4.5.7.5]oxafenestranes through a carbocation rearrangement cascade.
Abstract: Fenestranes are an intriguing class of highly strained molecules possessing a quaternary carbon with bonds that deviate from the canonical tetrahedral geometry. Herein we report the discovery that the natural product pleuromutilin can be used as a structurally complex starting material for the synthesis of a series of bridged cis,cis,cis,cis-[4.5.5.5]- and cis,cis,cis,cis-[4.5.7.5]oxafenestranes through a carbocation rearrangement cascade. X-ray crystallographic analysis of several cis,cis,cis,cis-[4.5.5.5]oxafenestranes shows a significant planarization of the central tetracoordinate carbon atom and demonstrates the influence of bridgehead substituents and bridging rings on planarity.
30 citations
TL;DR: In this paper, the structures of metal complexes are elucidated on the basis of elemental analyses, molar conductance, magnetic susceptibility measurements, electronic, ESR, IR and NMR (1H and 13C) spectral studies.
29 citations
TL;DR: In this paper, the location and structure of the framework Ti4+ species in Ti-MWW zeolites were studied by density functional theory (DFT) based on the cluster models mimicking the Ti-Mw zeolite with a Si/Ti ratio of 35.
28 citations
TL;DR: It is found that the introduction of alkyl moieties into 2,9-positions of 1,10-phenanthroline is highly effective on restricting the geometric relaxation that occurs in excited states, which greatly enhances the photoluminescence (PL) performances, including PL quantum yield improvement, PL decay lifetime increase, and emission blue shift.
TL;DR: A covalently linked B ODIPY-PO2-smaragdyrin dyad is designed and synthesized and efficient energy transfer from the BODIPY unit to the PO2- smaragDyrin unit is demonstrated.
Abstract: The aromatic PO2 complexes of meso-triaryl-25-oxasmaragdyrins were synthesized by treating the free base 25-oxasmaragdyrins with POCl3 in toluene/triethylamine at refluxing temperature. The complexes are stable and characterized by X-ray and different spectroscopic techniques. In these complexes, the phosphorus(V) ion was bound to two pyrrolic nitrogen atoms of the smaragdyrin macrocycle and two oxygen atoms in tetrahedral geometry. The X-ray structure revealed that the smaragdyrin macrocycle showed significant distortion upon insertion of a PO2 unit, and the phosphorus atom lies 1.339 A above the mean plane defined by three meso-carbon atoms of the macrocycle. These complexes absorb strongly in the visible region and are 2.5 times more strongly fluorescent than free base 25-oxasmaragdyrins. The smaragdyrin macrocycle becomes electron-deficient upon complexation with a PO2 unit because these complexes are easier to reduce but difficult to oxidize compared to free base smaragdyrins. We designed and synthes...
TL;DR: The association constant of the ligand and the stability constants of its complexes as well as the thermodynamic parameters were calculated by pH metric measurements at 298, 308 and 318K in 50% dioxane-water mixture, respectively.
TL;DR: A series of three new metal (II) complexes of Schiff base were synthesized from the novel ligand derived from Streptomycin and Amoxicillin in stoichiometric ratio.
Abstract: A series of three new metal (II) complexes of Schiff base were synthesized from the novel ligand derived from Streptomycin and Amoxicillin in stoichiometric ratio They were characterized by elemental analysis and spectral techniques like IR, 1H NMR, electronic spectrum and mass spectrum IR spectral data suggested that the tetradentate ligand has coordination to metal ions through azomethine nitrogen, glycosidic oxygen and two amine nitrogens Electronic spectral measurement indicated square planar geometry of Ni and Zn-complexes and tetrahedral geometry of Cu-complex with diamagnetic behavior Molar conductivity measurements revealed non-electrolyte nature of the complexes where metal ions have coordination through doubly negative charged anions of the Schiff base The thermal behavior (TGA/DTA) of the complexes was studied and kinetic parameters were determined by Coats-Redfern method XRPD technique revealed monoclinic crystal systems for Ni- and Zn-complexes and hexagonal crystal system for Cu-complex The possible geometries of the metal complexes with their bond length were optimized by MM2 calculations using CsChem3D Ultra-11 program package software Antibacterial sensitivity of the ligand and its metal complexes were assayed in vitro against four bacterial pathogens viz E coli, B subtilis, S aureus and K pneumonia by Kirby Bauer paper disc diffusion method and showed moderate to better potency
TL;DR: In this paper, five zinc(II) complexes have been synthesized and characterized by elemental analysis, FT-IR, and multinuclear NMR, and the results have been confirmed by single-crystal X-ray diffraction.
Abstract: Five zinc(II) complexes, [Zn(L1)2] (1), [Zn(L1)2(phen)H2O]·H2O (2), [Zn(L1)2(bipy)] (3), [Zn(L2)2] (4), and [Zn(L2)2(phen)] (5) (where L1 = 4-nitrophenylacetate, L2 = phenylacetate, phen = 1,10-phenanthroline and bipy = 2,2′-bipyridine), have been synthesized and characterized by elemental analysis, FT-IR, and multinuclear NMR. Complexes 2, 3, and 4 have been confirmed by single-crystal X-ray diffraction. In 2 and 3, zinc is bonded monodentate to two carboxylates exhibiting distorted trigonal bipyramidal and tetrahedral geometries, respectively, whereas in 4, the carboxylates are bridging bidentate in distorted tetrahedral geometry. The complexes have been screened for electro- and biological activities, including DNA interaction and enzyme inhibition studies. The effect of concentration of 1–5 on the activity of enzyme, alkaline phosphatase, showed that an increase in concentration of complex decreased the activity of the enzyme. Electrochemical behavior of HL1, 2, and 3 was investigated by cyclic voltam...
TL;DR: Among these compounds, the ligand and Zn(2+) complex, exhibited the potent ABTS (2,2'-azino-bis(3-ethyl benzthiazoline-6-sulfonic acid) radical scavenging activity, comparable to that of vitamin C.
TL;DR: A series of complexes of N-(3-imidazol-1-yl-propyl)-1,8-naphthalimide (L) with divalent ions of manganese, cobalt, zinc, cadmium and mercury are structurally characterized in this article.
Abstract: A series of complexes of N-(3-imidazol-1-yl-propyl)-1,8-naphthalimide (L) with divalent ions of manganese, cobalt, zinc, cadmium and mercury are structurally characterized. The metal complexes [ML2Cl2] {M = Zn (1), Cd (2), Hg (3)} are isomorphous and have a distorted tetrahedral geometry with a bend conformation of L. The thiocyanate complex [ZnL2(SCN)2] has a distorted tetrahedral geometry with L in bent conformation but with a different geometry from that in the structure of complex 1. The manganese and cobalt thiocyanate complexes [ML4(SCN)2]·2CH3CN (M = Mn, Co) are isomorphous and have a distorted octahedral geometry with the thiocyanate ligands occupying the axial positions. The cadmium complex [CdL3(SCN)2DMF]·DMF has a distorted octahedral geometry with thiocyanate ligands in the axial positions. The tetrahedral complexes [ML2Cl2] {M = Zn (1), Cd (2)} in the solid state show emission at shorter wavelengths than the single emission peak observed from the ligand, whereas the fluorescence emission of [ML2(SCN)2] {M = Zn (1), Cd (2)} occurred at longer wavelengths than L. On the other hand, [HgL2Cl2] (3) showed a single emission peak with higher intensity but at 31 nm shorter wavelength than the emission peak of the parent ligand. Two types of bend orientations of the ligand L, namely parallel arrangement of imidazole with the 1,8-naphthalimide ring and non-parallel arrangement in the tetrahedral complexes are observed. The former case favors intra-molecular charge transfer to show shorter wavelength emission, whereas the non-parallel arrangement facilitates exciplex leading to emission at longer wavelengths.
TL;DR: The results show that the geometry and halogen and ligand types have a strong effect on the catalytic properties of the complexes, and either mono- or binuclear intramolecular O-H···X hydrogen bonds enhance the stability of the structures.
Abstract: The reaction of copper(I) halides with 2-thiouracil (TUC), 6-methyl-2-thiouacil (MTUC), and 4-methyl-2-mercaptopyrimidine (MPMTH) in the presence of triphenylphosphine (tpp) in a 1:1:2 molar ratio results in a mixed-ligand copper(I) complex with the formulas [Cu2(tpp)4(TUC)Cl] (1), [Cu2(tpp)4(MTUC)Cl] (2), [Cu(tpp)2(MPMTH)Cl]·(1)/2CH3OH (3), [Cu(tpp)2(MTUC)Br] (4), and [Cu(tpp)2(MTUC)I]·(1)/2CH3CN (5). The complexes have been characterized by FT-IR, (1)H NMR, and UV-vis spectroscopic techniques and single-crystal X-ray crystallography. Complexes 1 and 2 are binuclear copper(I) complexes. Two phosphorus atoms from tpp ligands are coordinated to the copper(I) ions, forming two units that are linked to each other by a deprotonated TUC or MTUC chelating ligand through a sulfur bridge. A linear Cu-S-Cu moiety is formed. The tetrahedral geometry around the metal centers is completed by the nitrogen-donor atom from the TUC or MTUC ligand for the one unit, while for the other one, it is completed by the chloride anion. Two phosphorus atoms from two tpp ligands, one sulfur atom from MPMTH or MTUC ligand, and one halide anion (Cl, Br, and I) form a tetrahedron around the copper ion in 3-5 and two polymorphic forms of 4 (4a and 4b). In all of the complexes, either mono- or binuclear intramolecular O-H···X hydrogen bonds enhance the stability of the structures. On the other hand, in almost all cases of mononuclear complexes (with the exception of a symmetry-independent molecule in 4a), intermolecular NH···O hydrogen-bonding interactions lead to dimerization. Complexes 1-5 were studied for their catalytic activity for the intermolecular cycloaddition of iodonium ylides toward dihydrofuran formation by HPLC, (1)H NMR, and LC-HRMS spectroscopic techniques. The results show that the geometry and halogen and ligand types have a strong effect on the catalytic properties of the complexes. The highest yield of dihydrofurans was obtained when "linear" complexes 1 and 2 were used as the catalysts. The activity of the metal complexes on the copper(I)-catalyzed and uncatalyzed intramolecular cycloaddition of iodonium ylide is rationalized through electronic structure calculation methods, and the results are compared with the experimental ones.
TL;DR: The chiral compound (2-Me2NCH2C6H4)PhSbCl (1) was obtained from 2-NHCH2c6H5]-PdCl3{SbCL(Ph(Ph)(C 6H4CH2NMe2-2)-Sb}]− (3) and [PdCL2{Mes2SbMes 2(C6h4CH 2NMe 2-2]-N,Sb] (4) in 1:2 molar ratio as discussed by the authors
Abstract: The chiral compound (2-Me2NCH2C6H4)PhSbCl (1) was obtained from (2-Me2NCH2C6H4)Li and PhSbCl2 in 1:1 molar ratio, while (2-Me2NCH2C6H4)Mes2Sb (2) was prepared from (2-Me2NCH2C6H4)SbCl2 and MesMgBr in 1:2 molar ratio. The compounds 1 and 2 were used to obtain the Pd(II)/stibine complexes: [Me2NHCH2C6H5]+[PdCl3{SbCl(Ph)(C6H4CH2NMe2-2)-Sb}]− (3) and [PdCl2{SbMes2(C6H4CH2NMe2-2)-N,Sb}] (4). All the compounds were characterized by multinuclear NMR spectroscopy in solution, elemental analysis, mass spectrometry and single-crystal X-ray diffraction studies. In compounds 1–3 the coordination geometry around the antimony atom is pseudo-trigonal bipyramidal, while in compound 4 a tetrahedral geometry around the antimony atom is observed. Theoretical calculations at the DFT level on compounds 1–4 were used in order to gain insight into the nature of the coordinative bonds.
TL;DR: In this paper, two Schiff base ligands (HL1 and HL2) were synthesized by a condensation reaction of halogenated salicylaldehyde and amantadine.
Abstract: By a condensation reaction of halogenated salicylaldehyde and amantadine, two new Schiff base ligands (HL1 and HL2) were synthesized, respectively. A followed mixture of the ligands and zinc(II) chloride in the presence of NaOH in an alcoholic medium brought out two novel complexes (ZnL21) (I) and (ZnL22 (II). These two complexes were characterized by the means of melting point, elemental analysis, IR, UV-Vis, 1H NMR, molar conductance and single-crystal X-ray diffraction analysis. X-ray diffraction analysis reveals that I crystallizes in monoclinic system, P21/c space group, a = 9.7812(5), b = 25.6198(12), c = 27.7381(18) A, β = 105.881(4), F(000) = 1416, R1 = 0.0731, wR2 = 0.1147; II crystallizes in orthorhombic system, Pbca space group, a = 11.1717(10), b = 20.5888(15), c = 27.7381(18) A, F(000) = 2976, R1 = 0.1341, wR2 = 0.1410. Both in I and II, the central zinc(II) atom is four-coordinated via two nitrogen atoms and two oxygen atoms from the corresponding Schiff base ligands, forming a distorted tetrahedral geometry.
TL;DR: Two cobalt metal-organic frameworks constructed from 1,2,4,5-benzenetetracarboxylic acid and flexible bis(5,6-dimethylbenzimidazole) ligands, namely {[Co1.5(Hbtec)(L1)1]·(H2O)}, have been hydrothermally synthesized by physicochemical and spectroscopic methods and by single-crystal X-ray diffraction.
Abstract: Two cobalt(II) metal–organic frameworks constructed from 1,2,4,5-benzenetetracarboxylic acid and flexible bis(5,6-dimethylbenzimidazole) ligands, namely {[Co1.5(Hbtec)(L1)1.5(H2O)2]·(H2O)}
n
and {[Co(H2btec)(L2)]·(L2)0.5(H2O)2}
n
[L1 = 1,4-bis(5,6-dimethylbenzimidazole-1-ylmethyl)benzene, H4btec = 1,2,4,5-benzenetetracarboxylic acid, L2 = 1,4-bis(5,6-dimethylbenzimidazole)butane], have been hydrothermally synthesized and characterized by physicochemical and spectroscopic methods and by single-crystal X-ray diffraction. The cobalt atoms present different coordination environments, with trigonal-bipyramidal and octahedral geometries in 1, and a tetrahedral geometry in 2. Complex 1 has a 2D (6,3) wave like layer structure, which is further linked by hydrogen bonding to generate a 3D supramolecular architecture. It is a trinodal (4,4,4)-connected topology with a point symbol of {42·6·83}2{42·62·82}{43·63}2. Complex 2 is a 2D (6,3) honeycomb net, further linked into a 3D supramolecular network via two modes of π–π stacking interactions. The degradation of methyl orange in a Fenton-like process using complexes 1 and 2 as catalysts has been investigated.
TL;DR: On the basis of spectral studies, octahedral or tetrahedral geometry has been assigned to the metal complexes and these complexes have been tested invitro against tumor cells and number of microorganisms in order to assess their antitumor and antimicrobial properties.
TL;DR: In this paper, a trinuclear complex of N′-benzoyl hydrazine carboperthioate (bhcp) and 5-phenyl-1,3,4-oxadiazole-2-thione has been characterized by elemental analyses, m.p, IR, NMR and single crystal X-ray data.
TL;DR: In this article, the tetracarboxylate acid ligands, 5,5′-(1,2,3-triazole-1,4-diyl)diisophthalic acid (H4TADIP), 5-(bis(4-carboxybenzyl)amino)isophalic acid(H4BCBAIP), and 5-(3,5-dicarboxy benzyloxy)-isophanolic acid, (H 4DBIP) have been reacted with Mn(II), Co(
Abstract: Three tetracarboxylate acid ligands, 5,5′-(1H-1,2,3-triazole-1,4-diyl)diisophthalic acid (H4TADIP), 5-(bis(4-carboxybenzyl)amino)isophthalic acid (H4BCBAIP), and 5-(3,5-dicarboxybenzyloxy)isophthalic acid (H4DBIP) have been reacted with Mn(II), Co(II) and In(III) salts to construct four new metal–organic frameworks, [Mn2(TADIP)(DMF)3]·2DMF·3H2O (1), [Co2(TADIP)(DEF)3]·0.5DEF (2), [Mn2(BCBAIP)(DMF)3]·7.5DMF (3), and (Me2NH2)[In(DBIP)]·3DMF·7H2O (4) under solvothermal conditions. Due to the rotation ability of these ligands that exhibit a quadrangle or tetrahedral geometry, these compounds show diverse three-dimensional four-connected topologies. Compound 1 is composed of binuclear Mn(II) units and quadrangle type ligand H4TADIP with pts topology, while compound 2 possesses a zeolitic abw topology constructed from the 4-connected tetrahedral type ligand H4TADIP and binuclear Co(II) units. Compound 3 is a 3D structure possessing a zeolitic sod topology from the coordination of binuclear Mn(II) units with the tetrahedral type ligand H4BCBAIP. Compound 4 is an anionic framework constructed from tetrahedral type ligand H4DBIP and In(III) ions that has a topology of unc. Variable temperature magnetic susceptibility measurements show that compound 1 exhibits antiferromagnetic behavior. The selective dye-adsorption and luminescent properties of compound 4 have been studied in detail.
TL;DR: InFeO3(ZnO)m series of oxides are found to give unprecedented H2 evolution from water-methanol mixtures without using any cocatalysts and local structure characterization reveals that Zn coordination changes from pentacoordinated to tetrahedral geometry across the series, whereas Fe geometry remains trigonal bipyramidal in all the compounds.
Abstract: InFeO3(ZnO)m series of oxides are found to give unprecedented H2 evolution from water–methanol mixtures without using any cocatalysts. This family of compounds has an anisotropically layered structure in which Zn/FeOn polyhedra are sandwiched between InO6 octahedral layers. Local structure characterization by X-ray absorption spectroscopy reveals that Zn coordination changes from pentacoordinated to tetrahedral geometry across the series, whereas Fe geometry remains trigonal bipyramidal in all the compounds. This peculiar structure is conducive for a spatial separation of photogenerated charges reducing recombination losses. Band gap energies calculated from absorption spectra indicate potential visible light activity, and this may be due to the orbital mixing of Fe 3d and O 2p as revealed by pre-edge features of X-ray absorption spectra. Band positions are also advantageously placed for a visible light H2 generation and is indeed found to be the case in methanol-assisted water splitting with standardized...
TL;DR: Two novel pendant-armed dialdehydes were prepared by a one-step reaction between 5-chloro-3-(chloromethyl)-2-hydroxybenzaldehyde and cyclohexylamine involving two nucleophilic substitutions, and they were used to react with 1,3-propanediamine to prepare Schiff-base macrocyclic complexes in the presence of ZnX2 salts.
Abstract: Two novel pendant-armed dialdehydes (1a and 1b) were prepared by a one-step reaction between 5-chloro-3-(chloromethyl)-2-hydroxybenzaldehyde/5-methyl-3-(chloromethyl)-2-hydroxybenzaldehyde and cyclohexylamine involving two nucleophilic substitutions, and they were used to react with 1,3-propanediamine to prepare Schiff-base macrocyclic complexes in the presence of ZnX2 salts (X = Cl, Br, and I). As a result, five dinuclear (2a, 2b, 3b, 4a, and 4b) and one mononuclear (3a) [1 + 1] flexible macrocyclic Zn(II) complexes have been structurally and spectrally characterized. The zinc centers in three pairs of macrocyclic complexes have the common four-coordinate tetrahedral geometry with one or two coordinated halide ions, where the template Zn(II) cations and the auxiliary halide anions with different sizes and coordination abilities are believed to play important roles in forming the resulting macrocyclic complexes. In addition, subtle alterations of electron-withdrawing and electron-donating substituted groups (Cl versus CH3) in the macrocyclic backbone result in different 1H NMR and UV-vis spectra.
TL;DR: In this paper, the copper dithiocarbamate and xanthate complexes were synthesized by metathesis reactions of the precursor complex [Cu(PPh3)2NO3] and potassium salts of the ligands (KL) in an equimolar ratio.
TL;DR: The single crystal X-ray structure of [Zn(SMeaaiNEt)2I2] has been characterized by different spectroscopic studies as discussed by the authors, which shows distorted tetrahedral geometry of ZnN 2I2 coordination sphere of two imidazolyl-N from two SMEANEt and two iodides.
TL;DR: A series of neutral bis-dithiocarbamate complexes, [M(1,1-ditiolato)2] {1, 1dithiolato ǫ = 3-DithIocarbamato coumarin; Mǫ= mn(2) 1, Co(II) 2, Zn(III) 3, Cd(III), Cdǫ) 4, and Cc(III)) were synthesized in a single pot reaction as mentioned in this paper.
TL;DR: In this paper, it was shown that the far-infrared region can be used as a diagnostic probe in recognizing triiodides in the presence of a triiodide in the P-1 space group.