Tetra­carbonyl­bis(η5-cyclo­penta­dienyl)bis[(dec-9-en-1-yl)diphenyl­phosphine]dimolybdenum(0)(Mo—Mo) tetra­hydro­furan disolvate

The asymmetric unit of the title compound, [Mo2(η5-C5H5)2(C22H29P)2(CO)4]·2C4H8O, contains two half-mol­ecules of the organometallic species and two solvent mol­ecules. Both organometallic mol­ecules are completed by crystallographic inversion symmetry, yielding dimeric units with Mo—Mo single-bond lengths of 3.2703 (6) and 3.2548 (6) Å. Each Mo atom is also coordinated by an η5-cyclo­pentdienyl ligand, two carbonyl ligands, and a (dec-9-en-1-yl)diphenyl­phosphine ligand

trans-Bis{1,2-bis­[bis­(2-methoxy­ethyl)phosphino]ethane}dichloridoiron(II)

The Fe atom in the title compound, [FeCl2(C14H32O4P2)2], has a distorted octa­hedral coordination with four P atoms in equatorial positions and two Cl atoms in apical positions

Bis{1,2-bis­[bis­(3-hydroxy­prop­yl)phosphino]ethane}dichloridoiron(II)

In the title compound, [FeCl2(C14H32O4P2)2], the FeII atom (site symmetry ) adopts a distorted trans-FeCl2P4 octa­hedral geometry with two P,P′-bidentate ligands in the equatorial positions and two chloride ions in the axial positions. In the crystal, mol­ecules are linked by O—H⋯O and O—H⋯Cl hydrogen bonds, generating a three-dimensional network

Synthesis of Unsymmetrical Bis(phosphine) Oxides and Their Phosphines via Secondary Phosphine Oxide Precursors

The unsymmetrical bidentate phosphine ligands (Me)2PCH2CH2CH2P(Et)2 (14), (Me)2PCH2CH2CH2P(iPr)2 (15), (Me)2PCH2CH2CH2P(Cy)2 (16), and (Me)2PCH2CH2CH2P(Ph)2 (17) were synthesized using air–stable phosphine oxide intermediates. In the first step, sodium phosphinites formed by deprotonation of (Me)2P(O)H, (Et)2P(O)H, and (iPr)2P(O)H were alkylated by 1-bromo-3-chloropropane. The different substitution rates of the chloride and bromide groups allowed the isolation of the intermediates (Me)2P(O)CH2CH2CH2Cl (2), (Et)2P(O)CH2CH2CH2Cl (3), and (iPr)2P(O)CH2CH2CH2Cl (4). Subsequent reaction of (Me)2P(O)CH2CH2CH2Cl (2) with the sodium phosphinites generated from (Et)2P(O)H, (iPr)2P(O)H, (tBu)2P(O)H, (Cy)2P(O)H, or (Ph)2P(O)H gave unsymmetrical bidentate phosphine oxides; reduction of these oxides yielded the unsymmetrical phosphines. The unsymmetrical bidentate phosphines react with metal salts to form complexes. X-ray crystal structures of cis-Pt((Me)2P(CH2CH2CH2)P(iPr)2)Cl2 (20) and racemic [CuI((Me)2P(CH2CH2CH2)P(Ph)2)]Cl (21) were obtained. The kinetics and scope of the synthetic route were also explored. Experiments showed that the rate of substitution of the alkyl chloride group in (R)2P(O)CH2CH2CH2Cl-type oxides increases relative to unsubstituted alkyl chlorides due to the presence of the phosphonyl group on one end of the molecule. The scope of the reaction involving 1,2-dihaloalkanes was also investigated, and it was found that the reaction mixture of sodium dimethylphosphinite and 1,2-dihaloalkanes formed tetramethylbis(phosphine) monoxide (22), which decomposes on work-up to give complex reaction mixtures

Predicting dynamic formation pressure using artificial intelligence methods

Determining formation pressure in the well extraction zones is a key task in monitoring the development of hydrocarbon fields. Direct measurements of formation pressure require prolonged well shutdowns, resulting in underproduction and the possibility of technical problems with the subsequent start-up of wells. The impossibility of simultaneous shutdown of all wells of the pool makes it difficult to assess the real energy state of the deposit. This article presents research aimed at developing an indirect method for determining the formation pressure without shutting down the wells for investigation, which enables to determine its value at any time. As a mathematical basis, two artificial intelligence methods are used – multidimensional regression analysis and a neural network. The technique based on the construction of multiple regression equations shows sufficient performance, but high sensitivity to the input data. This technique enables to study the process of formation pressure establishment during different periods of deposit development. Its application is expedient in case of regular actual determinations of indicators used as input data. The technique based on the artificial neural network enables to reliably determine formation pressure even with a minimal set of input data and is implemented as a specially designed software product. The relevant task of continuing the research is to evaluate promising prognostic features of artificial intelligence methods for assessing the energy state of deposits in hydrocarbon extraction zones

Di-μ3-oxido-di-μ2-oxido-tetra­oxido­bis­(1,1,2,2-tetra­methyl­ethylenedicyclo­penta­dien­yl)­dimolyb­denum(IV)­dimolybdenum(VI) hexa­hydrate

The title compound, [Mo4(C16H20)2O8]·6H2O, is a centrosymmetric ansa-molybdocene complex in which two dinuclear [C2Me4(η5-C5H4)2]Mo(μ2-O)2MoO2 units dimerize by forming two μ3-O bridges between three Mo atoms. The ansa-molybdocene [C2Me4(η5-C5H4)2]Mo unit has a typical bent-sandwich metallocene structure with an inter-ring angle of 127.98 (8)°. The Mo atom in the bridging (μ2-O)(μ3-O)2MoO2 group has a distorted trigonal–bipyramidal coordination. The Mo—(μ3-O) and Mo—(μ2-O) bond distances inside the units [2.0869 (14) and 2.1014 (15) Å, respectively] are slightly longer than the Mo(−x + 1, −y + 1, −z)—(μ3-O) bond distance between the units [1.9986 (14) Å]. The solvent water mol­ecules together with complex O atoms form a network of O—H⋯O hydrogen bonds

Bis{1,2-bis­[bis­(3-meth­oxy­prop­yl)phosphan­yl]ethane-κ2 P,P′}dichlorido­osmium(II)

In the centrosymmetric title compound, [OsCl2(C18H40O4P2)2], the OsII atom adopts a trans-OsCl2P4 geometry, arising from its coordination by two chelating diphosphane ligands and two chloride ions. One of the meth­oxy side chains of the ligand is disordered over two orientations in a 0.700 (6):0.300 (6) ratio

Triammonium hexa­hydroxidoocta­deca­oxidohexa­molybdogallate(III) hepta­hydrate

The title compound, (NH4)3[GaMo6(OH)6O18]·7H2O, contains two centrosymmetric GaMo6 B-type Anderson cluster units consisting of central GaO6 octa­hedra surrounded by a hexa­gonal assembly of MoO6 edge-sharing octa­hedra. Like other B-type Anderson clusters, where the central Mo atom is substituted with a di- or trivalent metal ion, the central six μ3-oxido bridges are protonated. The average Ga—O bond length is 1.97 (1) Å, whereas the average Mo—O distances are 2.29 (2), 1.94 (1) and 1.709 (5) Å, respectively, for Mo—(μ3-OH), Mo—(μ2-O) and Mo=O bonds. In the crystal structure, the Ga(μ3-OH)6Mo6O18 3− polyanionic clusters are surrounded by NH4 + cations and solvent water mol­ecules, forming an extended network of hydrogen bonds

Solid-State Dynamics of Uranyl Polyoxometalates

Understanding fundamental uranyl polyoxometalate (POM) chemistry in solution and the solid state is the first step to defining its future role in the development of new actinide materials and separation processes that are vital to every step of the nuclear fuel cycle. Many solid-state geometries of uranyl POMs have been described, but we are only beginning to understand their chemical behavior, which thus far includes the role of templates in their self-assembly, and the dynamics of encapsulated species in solution. This study provides unprecedented detail into the exchange dynamics of the encapsulated species in the solid state through Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) spectroscopy. Although it was previously recognized that capsule-like molybdate and uranyl POMs exchange encapsulated species when dissolved in water, analogous exchange in the solid state has not been documented, or even considered. Here, we observe the extremely high rate of transport of Li⁺ and aqua species across the uranyl shell in the solid state, a process that is affected by both temperature and pore blocking by larger species. These results highlight the untapped potential of emergent f-block element materials and vesicle-like POMs.Keywords: polyoxometalate, solid-state NMR, uranyl, proton MAS NMR, ion-exchang

Tetracarbon­ylbis(η5-cyclo­penta­dien­yl)bis(diphenyl­phosphine)dimolybdenum(Mo—Mo) hexane solvate

The title compound, [Mo2(C5H5)2(C12H11P)2(CO)4]·C6H14, is a centrosymmetric Mo complex in which two Mo atoms are connected by an Mo—Mo bond [3.2072 (12) Å]. Each Mo atom is coordinated by an η5-cyclo­penta­dienyl ligand, two carbonyl ligands and a diphenyl­phosphine ligand in a piano-stool fashion