Search results for "Cubane"
showing 10 items of 34 documents
Structural Diversity due to Amino Alcohol Ligands Leading to Rare μ4-Hydroxo-Bridged Tetranuclear and “Bicapped Cubane” Cores in Copper(II) Complexes…
2013
The μ4-hydroxo- and alkoxo-bridged tetranuclear copper(II) complexes, [Cu4(μ4-OH)(dmae)4][Ag(NO3)4] (1), [Cu4(μ4-OH)(dmae)4][Na(NO3)4] (2), [Cu4(μ4-OH)(dmae)4][K(NO3)4] (3), and hexanuclear alkoxo-bridged "bicapped cubane" copper(II) complex [Cu6(ae)8(ClO4)2](ClO4)2·MeOH (8) (dmae = N,N-dimethylaminoethanolato and ae = 2-aminoethanolato) were synthesized via self-assembly from chelating amino alcohols and copper(II), silver (1), sodium (2), and potassium (3) nitrates or copper(II) perchlorate (8). The complexes are characterized by elemental analyses, single-crystal X-ray diffraction, and variable temperature magnetic measurements. The crystal structures of complexes 1-3 consist of almost p…
Unraveling the kinetics and molecular mechanism of gas phase pyrolysis of cubane to [8]annulene
2020
The kinetic and electron density flows are studied theoretically for the gas phase pyrolysis of cubane via its cage opening to reach bicyclooctatriene and then thermal rearrangement of bicyclooctatriene to produce [8]annulene which is the experimentally observed major product. The observed kinetic data at the MN15-L/maug-cc-pVTZ level of theory were in good agreement with the experimental results as compared to the CBS-QB3 method. The cage opening and the thermal rearrangement steps at the experimentally employed temperature of 520 K were exergonic and exothermic. The atmospheric rate constants calculated by means of the RRKM theory show that the cage opening is the rate-determining step. T…
A ferromagnetic tetranuclear nickel(II) Schiff-base complex with an asymmetric Ni4O4 cubane core
2014
Abstract The ferromagnetic tetranuclear nickel(II) complex [Ni4(L)4(CH3OH)2]·2MeOH·8H2O (1) has been synthesized by reacting nickel nitrate hexahydrate with the Schiff base ligand H2L (H2L = N-(2-hydroxyphenyl)-3-methoxy-salicylideneamine). Complex 1 was characterized by analytical, thermogravimetric, optical and magnetic techniques. The solid state structure of 1 was established by single crystal X-ray diffraction analysis. Crystal structure determination shows the formation of a distorted Ni4O4 cubane moiety encapsulated by four Schiff base ligands. Compound 1 crystallizes in the triclinic space group P 1 ¯ with a = 12.7624(9) A, b = 15.0477(9) A, c = 16.8589(10) A, α = 94.732(2)°, β = 94…
CCDC 910389: Experimental Crystal Structure Determination
2013
Related Article: Y.Inokuma,S.Yoshioka,J.Ariyoshi,T.Arai,Y.Hitora,K.Takada,S.Matsunaga,K.Rissanen,M.Fujita|2013|Nature (London)|495|461|doi:10.1038/nature11990
Copper(I) Halides (X = Br, I) Coordinated to Bis(arylthio)methane Ligands: Aryl Substitution and Halide Effects on the Dimensionality, Cluster Size a…
2014
Bis(phenylthio)methane (L1) reacts with CuI to yield the 1D-coordination polymer [{Cu4(μ3-I)4}(μ-L1)2]n (1) bearing cubane Cu4I4 clusters as connecting nodes. The crystal structures at 115, 155, 195, and 235 K provided evidence for a phase transition changing from the monoclinic space group C2/c to P21/c. The self-assembly process of CuI with bis(p-tolylthio)methane (L2), bis(4-methoxyphenylthio)methane (L3), and bis(4-bromo-phenylthio)methane (L4) affords the 1D-coordination polymers [{Cu4(μ3-I)4}(μ-Lx)2]n (x = 2, 3, or 4). Compounds 2 and 4 are isostructural with C2/c low temperature polymorph of 1, whereas the inversion centers and 2-fold axes are lost in 3 (space group Cc). The use of b…
Cubane-Type Mo3CoS4 Molecular Clusters with Three Different Metal Electron Populations: Structure, Reactivity and Their Use in the Synthesis of Hybri…
2004
Heterodimetallic cubane-type complexes coordinated to diphosphanes [Mo(3)CoS(4)(dmpe)(3)Cl(4)](+) ([1](+)) (dmpe=1,2-bis(dimethylphosphanyl)ethane), [Mo(3)CoS(4)(dmpe)(3)Cl(4)] (1) and [Mo(3)CoS(4)(dmpe)(3)Cl(3)(CO)] (2) with 14, 15 and 16 metal electrons, respectively, have been prepared from the [Mo(3)S(4)(dmpe)(3)Cl(3)](+) trinuclear precursor using [Co(2)(CO)(8)] or CoCl(2) as cobalt source. Cluster complexes [1](+) and 1 are easily interconverted chemically and electrochemically. The Co-Cl distance increases upon electron addition and substitution of the chlorine atom coordinated to cobalt with CO only takes place in presence of a reducing agent to give complex 2. Structural changes in…
Assembling Magnetic Blocks: A Strategy to Control the Nuclearity and Magnetic Properties of Polynuclear Complexes
1996
Synthetic strategies dealing with the polymerization of either di-μ-hydroxocopper(II) complexes or 2,2′-bipyrimidine (bpym)-containing first row transition metal ions allow the preparation of polynuclear compounds whose structures and magnetic properties are presented here. The influence of structural and chemical parameters on the magnitude of the singlet-triplet energy gap (J) in di-μ-hydroxocopper(II) complexes [LCu(OH)2CuL]2+ with L = 2,2′-bipyridine (bpy) and bpym is analyzed and discussed. Special attention is devoted to nature of the counterion which allows the preparation of hydroxo-bridge copper(II) cubane and double cubane type complexes where all the intramolecular magnetic inter…
Ferromagnetic coupling in a one-dimensional molecular railroad copper(II) azido compound containing a defective double cubane motif.
2001
The compound [Cu2(bpm)2(N3)4]n (bpm = bis(pyrazol-1−yl)methane) shows three unique coordination modes (μ1,1-, μ1,1,1-, μ1,1,3-N3) and ferromagnetic interaction between the copper(II) ions. The structure of the compound exhibits a one-dimensional railroad polymer made up of repeating defective dicubane-type units linked by μ1,1,3-N3 bridges.
ChemInform Abstract: Cobalt Clusters with Cubane-Type Topologies Based on Trivacant Polyoxometalate Ligands.
2016
Four novel cobalt-substituted polyoxometalates having cobalt cores exhibiting cubane or dicubane topologies have been synthesized and characterized by IR, elemental analysis, electrochemistry, UV–vis spectroscopy, X-ray single-crystal analysis, and magnetic studies. The tetracobalt(II)-substituted polyoxometalate [Co4(OH)3(H2O)6(PW9O34)]4– (1) consists of a trilacunary [B-α-PW9O34]9– unit which accommodates a cubane-like {CoII4O4} core. In the heptacobalt(II,III)-containing polyoxometalates [Co7(OH)6(H2O)6(PW9O34)2]9– (2), [Co7(OH)6(H2O)4(PW9O34)2]n9n– (3), and [Co7(OH)6(H2O)6(P2W15O56)2]15– (4), dicubane-like {CoII6CoIIIO8} cores are encapsulated between two heptadentate [B-α-PW9O34]9– (in…
The Chemistry of the [1,2,3]Triazolo[1,5-a]pyridines: An Update
2010
Publisher Summary This chapter discusses the recent advancement in the chemistry of [1,2,3] triazolo[1,5-a]pyridines. It describes new discoveries in the physical properties and theoretical chemistry, focusing on synthesis of [1,2,3]triazolo[1,5-a]pyridine system, synthesis of novel aryltriazolopyridines, chiral ligands from [1,2,3]triazolo[1,5-a]pyridines, pyridylcarbene formation from triazolopyridines, ring-chain isomerization on [1,2,3]triazolo[1,5-a]pyridines, and novel pyridylcarbonylpyridines. All triazolopyridines have interesting ligand properties to form polynuclear complexes with different metal ions. X-ray single-crystal studies, magnetic, photo-magnetic, and colorimetric measur…