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In the present work, the first data on the catalytic activity of d-metal complexes of petroleum porphyrins obtained via two-stage re-metallization (acid demetallization with subsequent metalation) of high-purity petroleum vanadyl porphyrins are presented. During acid demetallization of petroleum vanadyl porphyrins, the highest yield (49%) and spectral purity of free petroporphyrin bases were achieved with concentrated sulfuric acid and a diluted solution of vanadyl porphyrins in chloroform. In the series of divalent cations of Mn, Fe, Co, Ni, Cu, and Zn, only the last four metals are complexed with demetallated petroporphyrins without significant changes in their component composition, whereas the interaction with Mn and Fe cations causes an evident structural transformation or even full degradation of petroporphyrin macrocycles, respectively. The composition and spectral purity of petroleum porphyrin-containing reactants and products were analyzed by FT-IR, UV-Vis, NMR, and MALDI-TOF mass spectroscopic methods. The obtained petroporphyrin-based d-metal complexes were assayed by the reaction of 2-mercaptoethanol oxidative dimerization, in which the copper porphyrins exhibited the highest catalytic activity.

Routes of white phosphorus activation in the coordination sphere of the nickel complexes with different ligands are shown. The first route is based on the coordination of a P 4 molecule with the metal, resulting in the deformation of the P 4 tetrahedron without destruction. This case is characteristic of the NiX 2 L complexes, which are reduced at higher cathodic potentials (|E red | > 0.9 V) (X = BF 4 , Br, and Cl; L is bpy in DMF, MeCN, and acetone; 2,9 dimethyl 1,10 phenanthroline (phen) and PPh 3 in DMF and acetone). To cleave the P-P bonds in the P 4 molecule, this complex should be reduced on the electrode. The second route is the oxidation of white phosphorus in the coordination sphere of the Ni II complex. It occurs when the complex has a sufficiently high oxidizing ability and is reduced rather easily (|E red | < 0.9 V) (X = BF 4 , L is 1,1,1 tris(diphenylphosphinomethyl)ethane (triphos) in acetone; 1,1´,5,5´ bis[methylenedi(p phenylene)]di(3,7 diphenyl 1,5 diaza 3,7 diphosphacyclooctane) (n 2 p 2 ) in DMF; phen and PPh 3 in MeCN). The P 4 molecule opening is observed to form a new Ni I complex containing the (P 3 ) fragment, for example, [(triphos)Ni(P 3 )Ni(triphos)](BF 4 ) 2 .The electrochemical activation of reagents in processes involving organometallic compounds is very efficient. 1-4 This approach combines advantages of catalysis by metal complexes and activation by means of electrochemical electron transfer. The activation of white phosphorus is a practically important task because of the necessity to search for new routes of direct syntheses of organophos phorus compounds. Numerous reactions of P 4 tetrahedron transformation were described, which resulted in various polyphosphorus structures among which metal complexes with cyclic P 3 , P 5 , and P 6 ligands, 4 as well as the P 4 ligand, 5,6 seem to be most interesting. The P 4 molecule is activated due to the deformation of the P 4 tetrahedron and, as a consequence, the P-P bond length changes. In ultimate cases, these bonds can cleave to form new polyphosphorus structures. Until now, P 4 transformation was studied only by NMR spectroscopy, and very stable compounds were examined. Evidently, the more stable these structures, the more difficult is the preparation of related basis organophosphorus compounds, i.e., the main task of the elemental phosphorus chemistry is the direct transformation of phosphorus into organophosphorus compounds (OPC), excluding traditional steps of its chlo rination. At the same time, metal complexes with poly phosphorus ligands can possess a set of useful properties: semiconductivity, corrosion resistance, and others 7 and act as stable intermediates in various reactions, which are of independent interest.In this work, we attempted to estimate the reactivity of several nickel complexes with σ donor ligands toward white phosphorus using cyclic voltammetry (CV), pre parative electrolysis, and 31 P NMR spectroscopy. The nickel complexes were chosen, because they are catalysts of some reactions of white phosphorus functio...

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The composition of purified vanadyl porphyrins recovered from the resins of heavy oils possessing high and low vanadium contents was investigated. Vanadium content in the resins of the heavy oils under study differs by a factor of ca. 15. To recover and purify vanadyl porphyrins from the resins, extraction by N,N–dimethylformamide (DMF) with subsequent two-stage column chromatography on silica gel and sulfocationite were employed. The change of structural-group composition and content of vanadyl porphyrins in the products obtained at each stage was evaluated using Fourier IR and UV-Vis spectroscopy. Analysis of the purified vanadyl porphyrins using MALDI mass spectrometry determined distribution of their most abundant types (etio- and DPEP) and identified C27–C39 homologs for the resins possessing high vanadium content and C28–C39 homologs for the resins with low vanadium content.

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