Search results for "Oct"
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A short synthesis of dimethyl tricyclo[3.3.0.0 3,7 ]octane‐1,5‐dicarboxylate and its 3,7‐dimethyl derivative. A new route to the tricyclo[3.3.0.0 3,7…
1988
Five-step syntheses of dimethyl tricyclo[3.3.0.03,7]octane-1,5-dicarboxylate (13) and its 3,7-dimethyl derivative 14 from the readily available cis-bicyclo[3.3.0]octane-3,7-diones 1 and 2, respectively, are described. The key-step implies the iodine oxidation of the bis-enolate derived from the corresponding dimethyl cis-bicyclo-[3.3.0]octane-3,7-dicarboxylates 11 and 12, thus being developed a new synthetic entry into the tricyclo[3.3.0.03,7]octane skeleton. Also, some attempts to synthesize diester 13 by using known methodology for the synthesis of compounds containing this tricyclic skeleton are described. Eine kurze Synthese von Tricyclo [3.3.0.03,7]octan-1,5-dicarbonsaure-dimethylester…
Copper(II) Complexes with Derivatives of Barbiturate
1984
Abstract NaCuL2(OH).1,5H2O, KCuP2(OH).1H2O, Na2CuL4 and K2CuP4-8H2O (HL=Phenobarbitone and HP=Methyl Phenobarbitone) were prepared and characterized by elemental analysis, IR and electronic spectral data and magnetic susceptibility measurements. The ESR spectra show and octahedral environment for the Cu(II) ion.
Synthesis, Structure, and Magnetic Properties of a Family of Heterometallic Pentanuclear [Co 4 Ln] (Ln = Gd III , Dy III , Tb III , and Ho III ) Asse…
2013
The reaction of 6-formyl-2-(hydroxymethyl)-4-methylphenol (LH2) with appropriate lanthanide salts followed by reaction with Co(OAc)2·4H2O afforded the pentanuclear heterobimetalllic compounds [Co4Ln(L)4(OAc)2(S)4](NO3)(S) [LnIII = GdIII, S = MeOH (1); LnIII = DyIII, S = H2O (2); LnIII = TbIII, S = MeOH (3); LnIII = HoIII, S = MeOH (4)] in good yields. All the compounds are stable in solution as confirmed by ESI-MS studies. These complexes contain a distorted Co4 tetrahedral core, which encapsulates a central lanthanide ion. The CoII and LnIII ions are in an all-oxygen environments. All the CoII ions possess a distorted octahedral geometry, and the LnIII ions are in a distorted square-antipr…
A rare isostructural series of 3d–4f cyanido-bridged heterometallic squares obtained by assembling [FeIII{HB(pz)3}(CN)3]− and LnIII ions: synthesis, …
2021
A new series of cyanido-bridged {FeIIILnIII}2 neutral molecular squares of general formula [Fe{HB(pz)3}(CN)(μ-CN)2Ln(NO3)2(pyim)(Ph3PO)]2·2CH3CN [Ln = Ce (1), Pr (2), Nd (3), Gd (4), Tb (5), Dy (6) and Er (7); {HB(pz)3}− = hydrotris(pyrazolyl)borate, pyim = 2-(1H-imidazol-2-yl)pyridine and Ph3PO = triphenylphosphine oxide] were obtained by reacting the low-spin [Fe{HB(pz)3}(CN)3]− species with the preformed [LnIII(pyim)(NO3)2(pyim)(Ph3PO)]+ complex anions (generated in situ by mixing the nitrate salt of each Ln(III) ion with pyim and Ph3PO molecules). Single-crystal X-ray diffraction studies show that 1–7 are isostructural compounds that crystallize in the triclinic P space group. Their cry…
Heterometallic Pentanuclear [Ni 4 Ln] (Ln III = Gd, Tb, Dy, Ho) Complexes: Accidental Orthogonality Leading to Ferromagnetic Interactions
2014
The reaction of 6-formyl-2-(hydroxymethyl)-4-methylphenol (LH2) with NiII and LnIII salts afforded a series of heterometallic pentanuclear compounds [Ni4Ln(L)4(OAc)2(MeOH)4](NO3)(MeOH) [LnIII = Gd (1), Dy (2), Tb (3), Ho (4)]. Four dianionic L2– ligands and two acetate anions hold together four NiII and one LnIII ion to form a Ni4Ln core possessing a distorted tetrahedral geometry. All the NiII ions are hexacoordinate (6 O) with a distorted octahedral geometry whereas the LnIII ion is octacoordinate (8 O) with a distorted square-antiprism geometry. All the NiII ions are connected to the central LnIII ion through μ2 bridging of one deprotonated phenolic oxygen and two deprotonated alkoxy oxy…
The crystal structure and magnetic properties of 3-pyridinecarboxylate-bridged Re(ii)M(ii) complexes (M = Cu, Ni, Co and Mn)
2015
The novel Re(II) complex NBu4[Re(NO)Br4(Hnic)] (1) and the heterodinuclear compounds [Re(NO)Br4(μ-nic)Ni(dmphen)2]·½CH3CN (2), [Re(NO)Br4(μ-nic)Co(dmphen)2]·½MeOH (3), [Re(NO)Br4(μ-nic)Mn(dmphen)(H2O)2]·dmphen (4), [Re(NO)Br4(μ-nic)Cu(bipy)2] (5) [Re(NO)Br4(μ-nic)Cu(dmphen)2] (5') (NBu4(+) = tetra-n-butylammonium cation, Hnic = 3-pyridinecarboxylic acid, dmphen = 2,9-dimethyl-1,10-phenanthroline, bipy = 2,2'-bipyridine) have been prepared and the structures of 1-5 determined using single crystal X-ray diffraction. The structure of 1 consists of [Re(NO)Br4(Hnic)](-) anions and NBu4(+) cations. Each Re(II) is six-coordinate with four bromide ligands, a linear nitrosyl group and a nitrogen ato…
Magnetic Polyoxometalates: Anisotropic Antiferro- and Ferromagnetic Exchange Interactions in the Pentameric Cobalt(II) Cluster [Co3W(D2O)2(CoW9O34)2…
2001
The ground-state properties of the pentameric Co(II) cluster [Co(3)W(D(2)O)(2)(CoW(9)O(34))(2)](12-) were investigated by combining magnetic susceptibility and low-temperature magnetization measurements with a detailed inelastic neutron scattering (INS) study on a fully deuterated polycrystalline sample of Na(12)[Co(3)W(D(2)O)(2)(CoW(9)O(34))(2)].46D(2)O. The encapsulated magnetic Co(5) unit consists of three octahedral and two tetrahedral oxo-coordinated Co(II) ions. Thus, two different types of exchange interactions are present within this cluster: a ferromagnetic interaction between the octahedral Co(II) ions and an antiferromagnetic interaction between the octahedral and the tetrahedral…
Field-induced single molecule magnet behavior of a dinuclear cobalt(II) complex: a combined experimental and theoretical study.
2020
Two dinuclear cobalt(ii) complexes, [(dmso)CoIIL1(μ-(m-NO2)C6H4COO)CoII(NCS)] (1) and [(dmso)CoIIL2(μ-(m-NO2)C6H4COO)CoII(NCS)] (2) [dmso = dimethylsulfoxide, H2L1 = (2,2-dimethyl-1,3-propanediyl)bis(iminomethylene)bis(6-methoxyphenol) and H2L2 = (2,2-dimethyl-1,3-propanediyl)bis(iminomethylene)bis(6-ethoxyphenol)] have been synthesized and structurally characterized by single-crystal X-ray diffraction, magnetic-susceptibility measurements and various spectroscopic techniques. Each complex contains a cobalt(ii) center with a slightly distorted octahedral geometry and a second cobalt(ii) center with a distorted trigonal prismatic one. To obtain insight into the physical nature of weak non-co…
Synthesis, crystal structure, EXAFS, and magnetic properties of catena [mu-tris(1,2-bis(tetrazol-1-yl)propane-N1,N1')iron(II)] bis(perchlorate). Firs…
2000
[Fe(btzp)3](ClO4)2 (btzp = 1,2-bis(tetrazol-1-yl)propane) represents the first structurally characterized Fe(II) linear chain compound exhibiting thermal spin crossover. It shows a very gradual spin transition (T1/2 = 130 K) which has been followed by magnetic susceptibility measurements and 57Fe Mössbauer spectroscopy. The structure has been solved at 200 and 100 K by single-crystal X-ray analysis. It crystallizes in the trigonal space group P3c1 with Z = 2 Fe(II) units at both temperatures. The molecular structure consists of chains running along the c axis in which the Fe(II) ions are linked by three N4,N4' coordinating bis(tetrazole) ligands. The main difference between the two forms ap…
Copper(I) pseudorotaxane monolayers assembled on gold electrodes.
2003
Two new copper (I) pseudorotaxanes bearing a thioctic acid appended unit have been prepared and deposited onto a gold electrode surface, leading to surface-attached electroactive pseudorotaxanes.