13320-71-3Relevant articles and documents
Snythesis, characterization and thermal dissociation of cobalt(II) complexes of the photoproducts of octacyanomolybdate(IV) and -tungstate(IV) with ethylenediamine
Ali,Majid, Kowsar
, p. 141 - 149 (1998)
Photosubstituted mixed ligand complexes of Co(II) with irradiated solutions of Mo(CN)84- and W(CN)84- with ethylenediamine have been synthesized. The complexes have been isolated and characterized by their elemental analysis and IR spectroscopy. The assigned formulae are Co2[Mo(CN)2(C2H8N2) 2(OH)2]Cl4.2H2O I and Co[W(CN)2(C2H8N2) 2(OH)2]Cl2.2H2O II for Mo(IV) and W(IV) complexes, respectively. The IR peaks observed for both the complexes show N-H stretching, H-N-H bending and stretching vibrations of the C-N and C-C bonds. Depending on the nature of the absorption bands, complex I is assigned as -trans and complex II as -cis configuration. The thermal decomposition of these complexes has been studied by TG and DSC techniques. The reaction scheme for decomposition of each complex has been proposed. The activation energy (Ea), pre-exponential factor (A) and entropy of activation (ΔS#) have been calculated by employing the integral methods like Arrhenius, Coats-Redfern and Doyle. Enthalpy (ΔH) values for each transition are obtained from DSC data.
Thermal, spectroscopic and kinetic characterization of reaction products of copper(II) chloride with photoproducts of octacyanocomplexes of Molybdenum(IV) and Tungsten(IV) with ethylenediamine
Ali,Majid, Kowsar
, p. 173 - 181 (1998)
The thermal dissociation of complexes formed by copper(II) chloride with photoproducts of M(CN)4-8 [where M=Mo or W] and ethylenediamine has been studied by thermogravimetry (TG), differential scanning calorimetry (DSC) and IR spectroscopy. The observed IR bands for different groups support the assigned composition. Both Mo(IV) and W(IV) show the same stoichiometric behaviour towards complex formation but a different decomposition behaviour. In case of Mo(IV) decomposition takes place in four steps with cyanide and oxide of copper and tetrachloro molybdenum(IV) as residue, while in case of W(IV) the decomposition occurs only in three steps up to 298°C. The copper cyanide along with tetrachloro tungstate(IV) is found as residue. DSC for Mo complex displays four transitions, two exothermic and two endothermic. In case of W, DSC displays three endothermic transitions corresponding to three decomposition steps with three different ΔH values. On the basis of TG and DSC, mechanism for decomposition of each complex has been proposed. Kinetic parameters like activation energy (Ea), frequency factor (A), entropy of activation (ΔS#) for each step has been calculated involving differential methods like Doyle, Coats and Redfern and Arrhenius. The heat of the reaction is obtained from DSC curves.
Size-dependent spectroscopy of MoS2 nanoclusters
Chikan,Kelley
, p. 3794 - 3804 (2002)
The synthesis and characterization of 3.5, 4.5, and 8 nm diameter MoS2 nanoclusters are described. Each size is characterized by TEM images, electron diffraction, and optical spectroscopy. These nanoclusters can be synthesized directly or may be synthesized from samples of polydisperse nanoclusters. Obtaining larger or smaller discrete sizes from polydisperse samples indicates that these nanocluster sizes are thermodynamically favored, that is, these sizes correspond to free-energy minima. Electron diffraction and static spectroscopic results indicate that the particles are three atoms thick, specifically, single S-Mo-S trilayer disks. Static and time-resolved absorption and emission spectroscopy were used to determine the polarizations of the lowest energy allowed transitions in each case. We find that the 8 nm particles have a lowest energy absorption maximum at 473 nm that has mixed x - y and z polarizations, 4.5 nm particles have absorption maxima at 400 and 440 nm that are x - y and z polarized, respectively, and 3.5 nm particles have an absorption maximum at 362 nm that is z polarized. These results indicate that the polarization of the lowest observed transition is size-dependent and that the ordering of the lowest excited states changes as the particle size decreases.
Novel benzyl-substituted molybdocene anticancer drugs
Gleeson, Brendan,Claffey, James,Deally, Anthony,Hogan, Megan,Méndez, Luis Miguel Menéndez,Müller-Bunz, Helge,Patil, Siddappa,Tacke, Matthias
, p. 1831 - 1836 (2010/09/04)
From the reaction of 6-(p-methoxyphenyl) fulvene (1a), 6-(3,4-dimethoxyphenyl) fulvene (1b) and 6-(3,4,5-trimethoxyphenyl) fulvene (1c) with LiBEt3H, lithiated cyclopentadienide intermediates (2a-c) were synthesised. These intermediates were then transmetallated to molybdocene using MoCl4 (synthesized in situ) to yield the benzyl-substituted molybdocenes bis-[(p-methoxybenzyl)cyclopentadienyl] molybdenum (IV) dichloride (3a), bis-[(3,4-dimethoxybenzyl)cyclopentadienyl] molybdenum (IV) dichloride (3b), and bis-[(3,4,5-trimethoxybenzyl)cyclopentadienyl] molybdenum (IV) dichloride (3c). The molybdocene 3a was characterised by single crystal X-ray diffraction. All three molybdocenes had their cytotoxicity investigated through MTT based preliminary in vitro testing on the human renal cell line Caki-1 in order to determine their IC50 values and compare them with the corresponding titanocene and vanadocene dichloride derivatives. Molybdocenes 3b-c were found to have the same IC50 values of 290 μM, while 3a yielded a value of 84 μM, respectively.