Development of Catalytic Conversion of Nitrogen Molecule into Ammonia Using Molybdenum Complexes under Ambient Reaction Conditions

Nitrogen fixation using homogeneous transition metal complexes under mild reaction conditions is a challenging topic in the field of chemistry. Several successful examples of the catalytic conversion of nitrogen molecule...

Molybdenum(VI) Complexes with Schiff Base Containing N-Hetero Atom

Parent dioxomolybdenum(VI) complex formation by the reaction of MoO2(acac)2 with Schiff base tetradentate ligand, described in this paper. Schiff base tetradentate ligand [H2NCH2CH2 N=CC4H3S-CC4H3S=NCH2CH2NH2] obtained from the condensation of di-2-thienylethanedione with 1,2-diaminoethane. Macrocyclic molybdenum complexes were obtained from the cyclization of a synthesized complex with different 1,3 – diketones. The general formula of parent molybdenum complex is given as [MoO2( H2NCH2CH2 N=CC4H3S – CC4H3S=N CH2CH2NH2)](acac)2 and for macrocyclic molybdenum complex is [MoO2{(CH2CH2 N=CC4H3S – CC4H3S=N CH2CH2) N=C(R)CH2C(R’)=N}](acac)2. Ligand and all molybdenum complexes were characterized by elemental analyses(EA), molar conductivity(ΛM), ultraviolet(UV-Vis), and infrared (IR) spectral studies. The distorted octahedral geometry of element Mo in the parent as well as in macrocyclic molybdenum complexes is completed by two oxo O-atoms, four N-atoms from derived Schiff ligand.

SUPERCRITICAL FLUID EXTRACTION OF MOLYBDENUM COMPLEXES AND ITS ISOTOPES WITH CARBON DIOXIDE

Separation of molybdenum complexes and its isotopes by supercritical fluid extraction (SFE) with carbon dioxide was experimentally investigated. The type of modifier, which provides increasing the efficiency of the metal and its isotopes separation, was determined. Extraction of molybdenum isotope complexes was carried out in the updated SFE-U unit at a constant value of the initial pressure P = 20 MPa and constant temperatures of the upper (T1 = 35 ⁰C) and bottom (T2 = 45 ⁰C) flanges of the extraction chamber. The exposure time of the extract and the level along the extraction chamber height, from which the eluent was sampled, were set in the experiments. It is shown, that at a certain sampling height and at certain exposure times, change in the natural content of Mo isotopes in the extracts takes place.

Preparation and reactivity of molybdenum complexes bearing pyrrole-based PNP-type pincer ligand

Molybdenum complexes bearing an anionic pyrrole-based PNP-type pincer ligand have been prepared and have been found to work as catalysts for the conversion of N2 into NH3 under ambient conditions.

Influence of the pendant arm in deoxydehydration catalyzed by dioxomolybdenum complexes supported by amine bisphenolate ligands

Molybdenum complexes devoid of a strongly coordinating pendant arm result in enhanced catalytic activity.