115509-89-2

Upstream product

• 86568-26-5 tetraphenylphosphonium oxopentacyanomolybdate(IV) 
• 80937-33-3 oxygen 

Downstream Products

• 67168-41-6 (PPh₄)4Mo₈O₂₆ 
• 115436-95-8 2P(C₆H₅)4⁽¹⁺⁾*Mo₂O₇^(2-)={P(C₆H₅)4}2{Mo₂O₇} 
• 86568-26-5 tetraphenylphosphonium oxopentacyanomolybdate(IV) 
• 791-28-6 Triphenylphosphine oxide 

Relevant academic research and scientific papers

Crystal structures of mixed-ligand oxocyano complexes of molybdenum(IV) and tungsten(IV) and their reactivity towards molecular oxygen studied by IR spectroscopy

The series of compounds, (PPh4)2[M(CN)4O(L)]·xH2O [M = Mo, W; L = pyrazine (pz), pyridine (py); = phenyl group; x = 0, 2, 3], (PPh4)3[Mo(CN)5O]·7H2O and K(PPh4)2[Mo(CN)5O]·5H2O, which are able to bind molecular oxygen giving peroxo complexes (PPh4)2[M(CN)4O(O2)], have been synthesised. The substrates were characterised by thermogravimetric analysis, vibrational and UV-VIS spectroscopy and the crystal structure determination of (PPh4)2[M(CN)4O(pz)]·3H2O. The latter salts are isomorphous and consist of anions of approximat octahedral geometry, forming a three-dimensional hydrogen-bonded network with channels that enable the penetration of dioxygen. The solid state reactions of all the salts with O2 have been studied by measuring their infrared spectra. The integrated intensities of the O-O, pz or py, MO and C≡N bands change with time according to pseudo-first-order kinetics. The rate constants kobs range from 0.37 × 10-4 to 1.04 × 10-4 s-1 at 323 K. A detailed study of the function of temperature has been undertaken for (PPh4)2[W(CN)4O(pz)]·3H2O. The activation parameters, ΔH# = 68 ± 13 kJ mol-1 and ΔS# = -117 ± 39 J K-1 mol-1, were determined and an associative mechanism of dioxygen uptake was assumed.

Preparation of an oxoperoxocyanomolybdate(VI) complex by dioxygen oxidation of an oxocyanomolybdate(IV) anion. Structure and reactivity toward phosphines and olefins

Potassium oxopentacyanomolybdate(IV), [Mo(O)(CN)5]K3·2H2O, is prepared either through a disproportionation process of the molybdenum(V) cyano intermediate or by controlled hydrolysis of the octacyanomolybdate(IV). The tetraphenylphosphonium salt obtained under phase-transfer conditions reacts readily with dioxygen to give tetraphenylphosphonium oxoperoxotetracyanomolybdate(VI) [Mo(O)(O2)(CN)4][PPh4]2, whose structure is determined by an X-ray analysis. The crystalline compound belongs to triclinic space group P1 with a = 10.951 (2) A?, b = 22.597 (6) A?, c = 10.283 (2) A?, α = 97.66 (2)°, β = 116.24 (2)°, and γ = 84.43 (2)°. The volume of the unit cell is 2260 (2) A°3 with Z = 2. The structure was refined to R = 3.1%. The reactivity of the peroxo complex toward triphenylphosphine is studied and is shown to give 1.5 mol of phosphine oxide/mol of peroxo complex. This unusual stoichiometry is rationalized in terms of a classical oxidation of 1 mol of phosphine by the peroxo moiety followed by an oxo transfer involving 2 mol of the dioxomolybdenum(VI) intermediate. The plausible implications that such a process could have on the catalytic oxidation on metal oxide surfaces is given. The poor reactivity of the oxoperoxomolybdenum dianion toward olefins is dramatically increased in the presence of silver salts. A monoanionic species, stabilized by hexamethylphosphoramide, [Mo(O)(O2)(CN)3·HMPA] [(PhCH2)Ph3P], is isolated and characterized by an X-ray analysis. The crystalline compound belongs to monoclinic space group P21/n with a = 9.801 (2) A?, b = 13.613 (3) A?, c = 27.597 (8) A?, and β = 90.56 (2)°. The volume of the unit cell is 3682 (2) A?3 with Z = 4. The structure was refined to R = 7.12%.