The Polynuclear Complexes of Iron(II,III) and Copper(II) with Cyanide as Bridging Ligand

1996 ◽  
Vol 26 (9) ◽  
pp. 1537-1549 ◽  
Author(s):  
Zdeněk Smékal ◽  
František Březina ◽  
Zdeněk Šindelář ◽  
Roman Klička ◽  
Dagmar Krausová ◽  
...  
2008 ◽  
Vol 2 (2) ◽  
pp. 122-139
Author(s):  
Takashi Komiyama ◽  
Satoshi Igarashi ◽  
Yasuhiko Yukawa

1994 ◽  
Vol 33 (3) ◽  
pp. 484-489 ◽  
Author(s):  
Joan Ribas ◽  
Montserrat Monfort ◽  
Carmen Diaz ◽  
Carles Bastos ◽  
Xavier Solans

2007 ◽  
Vol 829 (1-3) ◽  
pp. 57-64 ◽  
Author(s):  
Sixto Domínguez ◽  
Julia Torres ◽  
Florencia Peluffo ◽  
Alfredo Mederos ◽  
Javier González-Platas ◽  
...  

2008 ◽  
Vol 2 (2) ◽  
pp. 122-139 ◽  
Author(s):  
Takashi Komiyama ◽  
Satoshi Igarashi ◽  
Yasuhiko Yukawa

2006 ◽  
Vol 45 (1) ◽  
pp. 127-136 ◽  
Author(s):  
Mauricio Cattaneo ◽  
Florencia Fagalde ◽  
Néstor E. Katz ◽  
Ana María Leiva ◽  
Russell Schmehl

1996 ◽  
Vol 51 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Martin Hilbers ◽  
Margita Meiwald ◽  
Rainer Mattes

Abstract Aqueous or methanolic solutions containing vanadium(IV), molybdenum(V) and molyb-denum(VI) oxo species and fluoride ions react with squaric acid to give the oligonuclear complexes [C(NH2)3]4[V2O2F4(C4O4)2]·4H2O (1), Cs4[V3O3F4(C4O4)3]·5H2O (2a), [nBu4N]4[V3O3F4(C4O4)3]·2H2O (2b), [Et4N]4[Mo4O10F6(C4O4)] (3a), [Et4N]4[Mo4O10Cl6(C4O4)] (3b), [Et4N]3[Mo3O8F(C4O4)2] (4) and [Et4N]3[Mo2O3Cl3(C4O4)2] (5). The structures of compounds 1, 2a, 2b, 3a, 4 and 5 have been determined by single crystal X-ray diffraction. The [V2O2F4(C4O4)2]4- ion in 1 consists of the planar V2O2F4 core with the vanadium sites bridged by two ,μ-1,2-squarato ligands. The unique cone-shaped [V3O3F4(C4O4)3]4- ion in 2a and 2b contains a central defect and severely distorted V3F4 cubane unit. Each vanadium atom bears a terminal oxo ligand; pairs of vanadium atoms are bridged by μ-1,2-squarato ligands. The [Mo4O10F6(C4O4)]4- ion in 3a consists of a squarate ion, which is coordinated to four metal centers. Pairs of metal atoms are bridged by μ(O)μ(F)-bridges. Two terminal oxo ligands and one terminal fluoro ligand complete the metal coordination. Oxo and fluoro ligands are partly disordered. The structure of the [Mo3O8F(C4O4)2]3- ion in 4 is related to the structure of [V3O3F4(C4O4)3]4- It consists of a defect Mo3(O3F) cubane unit. Two pairs of molybdenum atoms are bridged by μ-1,2-squarato ligands. Terminal oxo and dioxo groups complete the molybdenum coordination. The [Mo2O3Cl3(C4O4)2]3- ion in 5 exhibits a unique structure with a planar OClMo(μ-O)(μ-Cl)MoOCl core and a cis, cis-orientation of the oxygen ligands. Two, μ-1,2-squarato ligands bridge the molybdenum centers above and below the Mo2O3Cl3 plane.


2013 ◽  
Vol 394 ◽  
pp. 196-202 ◽  
Author(s):  
Julia Torres ◽  
Javier González-Platas ◽  
Joaquín Sanchíz ◽  
Jorge Castiglioni ◽  
Sixto Domínguez ◽  
...  

2008 ◽  
Vol 80 (6) ◽  
pp. 1303-1316 ◽  
Author(s):  
Julia Torres ◽  
Carlos Kremer ◽  
Sixto Domínguez

Polynuclear complexes are widely regarded as potential materials in separation, catalysis, gas storage, and molecular recognition. Those complexes including lanthanide (Ln) ions in the heterobimetallic assembly enhance the structural flexibility and increase the thermodynamic stability. Up to now, the studies on these heteropolynuclear complexes have been mostly focused on lanthanide-copper compounds in the solid state. We have expanded the studies to solution chemistry, to know if such polynuclear species can also exist in aqueous solution. In this work, potentiometric titrations (25.0 °C, and I = 0.50 M Me4NCl) were carried out for systems containing a Ln ion (La, Ce, Sm), a bridging ligand (oda or ida), and a second metal ion. We found that polynuclear units can be formed with MII (Mn, Fe, Co, Ni, Cu, Zn, Cd, and VO2+) and MIII (Fe, Al) ions, and can be predominant in aqueous solution. Species like [Ln2M3L6] or [Ln2M3L6(OH)n]n- (n = 3, 6) can exist in solution, representing the same 2:3:6 stoichiometry found in the solid state. The presence of an amino group in the ida ligand makes the mononuclear complexes with 3d metal ions more stable, preventing to some extent the formation of polynuclear complexes.


2021 ◽  
Vol 60 (3) ◽  
pp. 1806-1813
Author(s):  
Husain N. Kagalwala ◽  
Mahesh S. Deshmukh ◽  
Elamparuthi Ramasamy ◽  
Neelima Nair ◽  
Rongwei Zhou ◽  
...  

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 186
Author(s):  
Georgiy B. Shul’pin ◽  
Lidia S. Shul’pina

The review describes articles that provide data on the synthesis and study of the properties of catalysts for the oxidation of alkanes, olefins, and alcohols. These catalysts are polynuclear complexes of iron, copper, osmium, nickel, manganese, cobalt, vanadium. Such complexes for example are: [Fe2(HPTB)(m-OH)(NO3)2](NO3)2·CH3OH·2H2O, where HPTB-¼N,N,N0,N0-tetrakis(2-benzimidazolylmethyl)-2-hydroxo-1,3-diaminopropane; complex [(PhSiO1,5)6]2[CuO]4[NaO0.5]4[dppmO2]2, where dppm-1,1-bis(diphenylphosphino)methane; (2,3-η-1,4-diphenylbut-2-en-1,4-dione)undecacarbonyl triangulotriosmium; phenylsilsesquioxane [(PhSiO1.5)10(CoO)5(NaOH)]; bi- and tri-nuclear oxidovanadium(V) complexes [{VO(OEt)(EtOH)}2(L2)] and [{VO(OMe)(H2O)}3(L3)]·2H2O (L2 = bis(2-hydroxybenzylidene)terephthalohydrazide and L3 = tris(2-hydroxybenzylidene)benzene-1,3,5-tricarbohydrazide); [Mn2L2O3][PF6]2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane). For comparison, articles are introduced describing catalysts for the oxidation of alkanes and alcohols with peroxides, which are simple metal salts or mononuclear metal complexes. In many cases, polynuclear complexes exhibit higher activity compared to mononuclear complexes and exhibit increased regioselectivity, for example, in the oxidation of linear alkanes. The review contains a description of some of the mechanisms of catalytic reactions. Additionally presented are articles comparing the rates of oxidation of solvents and substrates under oxidizing conditions for various catalyst structures, which allows researchers to conclude about the nature of the oxidizing species. This review is focused on recent works, as well as review articles and own original studies of the authors.


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