Stabilization of tautomeric forms P(OH)3 and HP(OH)2 and their derivatives by coordination to palladium and nickel atoms in heterometallic clusters with the Mo3MQ4 4+ core (M = Ni, Pd; Q = S, Se)

Abstract

The cluster aqua complexes [Mo 3 (MCl)Q 4 (H 2 O) 9 ] 3+ (M = Pd or Ni) in hydrochloric acid solutions induce isomerization of the hydrophosphoryl compounds (HO) 2 P(O)H, (HO)P(O)H 2 , PhP(O)(OH)H, and Ph 2 P(O)H into the hydroxo tautomers P(OH) 3 , HP(OH) 2 , PhP(OH) 2 , and Ph 2 P(OH), which are stabilized by coordination of the phosphorus atom to the Pd or Ni atoms. The reactions were studied by 31 P NMR and UV Vis spectroscopy. The kinetics of the reactions of phosphorous acid with [Mo 3 (PdCl)Q 4 (H 2 O) 9 ] 3+ was investigated by spectropho tometry. The [Mo 3 (Pd(PhP(OH) 2 ))S 4 (H 2 O) 2 Cl 7 ] 3-complex was isolated as a supramolecular adduct with cucurbit[8]uril, and the [Mo 3 (Ni(P(OH) 3 ))S 4 (H 2 O) 8 Cl] 3+ complex was isolated as an adduct with cucurbit[6]uril. The structures of both compounds were established by X ray diffraction analysis.

Unprecedented Solvent‐Assisted Reactivity of Hydrido W3CuS4 Cubane Clusters: The Non‐Innocent Behaviour of the Cluster‐Core Unit

“…[1][2][3][4] In the last 20 years, the reactivity and kinetics of ligand-exchange [5][6][7][8][9] and isomerisation reactions [10][11][12] at the M' centres in cuboidal M 3 M'S 4 clusters (M = Mo, W; M' = Fe, Ru, Co, Ni, Pd, Pt, Cu) have been intensely studied. The M 3 M'S 4 units remain intact in all cases, thus indicating the robustness of these units.…”

Combined kinetic and DFT studies on the stabilization of the pyramidal form of H3PO2 at the heterometal site of [Mo3M′S4(H2O)10]4+ clusters (M′ = Pd, Ni)

“…The related Ni complex (1Ni) shows similar kinetics, although the second step occurs under conditions of reversible equilibrium, in agreement with the reported lower reactivity of 1Ni. 12 The values of the rate constants for 1Ni are k 1 = (2.38 ± 0.05) ¥ 10 -2 mol -1 dm 3 s -1 , k 2forw = (1.00 ± 0.06) ¥ 10 -4 mol -1 dm 3 s -1 and k 2rev = (1.76 ± 0.05) ¥ 10 -5 s -1 . Fig.…”

“…10 Nowadays it is known that the unstable pyr-H 3 PO 2 tautomer can be stabilized via coordination to a soft metal center and, as a matter of fact, there are several well-characterized metal complexes containing the pyr forms of H 3 PO 2 and related acids in low oxidation states. 3,[11][12][13][14][15][16][17] At this point it is important to note the relevant role that M 3 M¢Q 4 cuboidal clusters (M = Mo, W; Q = S, Se; M¢ = Ni, Pd…) have played in this field. [12][13][14][15][16][17] Scheme 1…”

“…3,[11][12][13][14][15][16][17] At this point it is important to note the relevant role that M 3 M¢Q 4 cuboidal clusters (M = Mo, W; Q = S, Se; M¢ = Ni, Pd…) have played in this field. [12][13][14][15][16][17] Scheme 1…”

Contribuição à química das Cucurbit[n]urilas

“…Até meados de 2010 pouco havia sido feito com relação à coordenação de íons de transição atuando como ácidos duros aos opérculos das CBs. Varios trabalhos no entanto reportavam a caracterização estrutural de adutos poliméricos envolvendo alguns íons de transição, que eram obtidos ao acaso, por secagem de soluções contendo seus precursores 153,[156][157][158][159][160][161][162][163][164]166,168,[199][200][201][202][203][204][205][206][207][208][209][210][211][212][213][214][215][216][217][218] . Eram e são até hoje raros os trabalhos na literatura que se propoem a construir um complexo metálico com uma estrutura particular, visando uma aplicação em específico.…”