2.2. MOFs with Metal Active Sites 4614 2.2.1. Early Studies 4614 2.2.2. Hydrogenation Reactions 4618 2.2.3. Oxidation of Organic Substrates 4620 2.2.4. CO Oxidation to CO2 4626 2.2.5. Phototocatalysis by MOFs 4627 2.2.6. Carbonyl Cyanosilylation 4630 2.2.7. Hydrodesulfurization 4631 2.2.8. Other Reactions 4632 2.3. MOFs with Reactive Functional Groups 4634 2.4. MOFs as Host Matrices or Nanometric Reaction Cavities 4636

Engineering Metal Organic Frameworks for Heterogeneous Catalysis

ion. The oxidative addition mechanism was originally proposed22i because of the lack of a strong rate dependence on polar factors and on the acidity of the medium. Later, however, the electrophilic substitution mechanism also was proposed. Recently, the oxidative addition mechanism was confirmed by investigations into the decomposition and protonolysis of alkylplatinum complexes, which are the reverse of alkane activation. There are two routes which operate in the decomposition of the dimethylplatinum(IV) complex Cs2Pt(CH3)2Cl4. The first route leads to chloride-induced reductive elimination and produces methyl chloride and methane. The second route leads to the formation of ethane. There is strong kinetic evidence that the ethane is produced by the decomposition of an ethylhydridoplatinum(IV) complex formed from the initial dimethylplatinum(IV) complex. In D2O-DCl, the ethane which is formed contains several D atoms and has practically the same multiple exchange parameter and distribution as does an ethane which has undergone platinum(II)-catalyzed H-D exchange with D2O. Moreover, ethyl chloride is formed competitively with H-D exchange in the presence of platinum(IV). From the principle of microscopic reversibility it follows that the same ethylhydridoplatinum(IV) complex is the intermediate in the reaction of ethane with platinum(II). Important results were obtained by Labinger and Bercaw62c in the investigation of the protonolysis mechanism of several alkylplatinum(II) complexes at low temperatures. These reactions are important because they could model the microscopic reverse of C-H activation by platinum(II) complexes. Alkylhydridoplatinum(IV) complexes were observed as intermediates in certain cases, such as when the complex (tmeda)Pt(CH2Ph)Cl or (tmeda)PtMe2 (tmeda ) N,N,N′,N′-tetramethylenediamine) was treated with HCl in CD2Cl2 or CD3OD, respectively. In some cases H-D exchange took place between the methyl groups on platinum and the, CD3OD prior to methane loss. On the basis of the kinetic results, a common mechanism was proposed to operate in all the reactions: (1) protonation of Pt(II) to generate an alkylhydridoplatinum(IV) intermediate, (2) dissociation of solvent or chloride to generate a cationic, fivecoordinate platinum(IV) species, (3) reductive C-H bond formation, producing a platinum(II) alkane σ-complex, and (4) loss of the alkane either through an associative or dissociative substitution pathway. These results implicate the presence of both alkane σ-complexes and alkylhydridoplatinum(IV) complexes as intermediates in the Pt(II)-induced C-H activation reactions. Thus, the first step in the alkane activation reaction is formation of a σ-complex with the alkane, which then undergoes oxidative addition to produce an alkylhydrido complex. Reversible interconversion of these intermediates, together with reversible deprotonation of the alkylhydridoplatinum(IV) complexes, leads to multiple H-D exchange

Activation of c-h bonds by metal complexes

A series of remarkable crystalline compounds [Cu2(BTC)4/3(H2O)2]6[HnXM12O40]·(C4H12N)2 (X = Si, Ge, P, As; M = W, Mo) were obtained from the simple one-step hydrothermal reaction of copper nitrate, benzentricaboxylate (BTC), and different Keggin polyoxometalates (POMs). In these compounds, the catalytically active Keggin polyanions were alternately arrayed as noncoordinating guests in the cuboctahedral cages of a Cu-BTC-based metal−organic framework (MOF) host matrix. X-ray crystallographic analyses, TG, FT-IR, UV−vis, N2 adsorption studies, and acid−base titration demonstrated their high stability and toleration for thermal and acid−base conditions. No POM leaching or framework decomposition was observed in our study. The representative acid catalytic performance of a compound containing PW12 species was assessed through the hydrolysis of esters in excess water, which showed high catalytic activity and can be used repeatedly without activity loss. Moreover, catalytic selectivity, which is dependent on th...

Highly stable crystalline catalysts based on a microporous metal-organic framework and polyoxometalates.

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Manganese(III)-Based Oxidative Free-Radical Cyclizations

The coordination chemistry of the amidine ligand

Two new copper 2-pyrazinecarboxylate (2-pzc) coordination polymers incorporating [Mo8O26]4- and [V10O28H4]2- anions were synthesized and structurally characterized:  Cu4(2-pzc)4)(H2O)8(Mo8O26)·2H2O (1) and Cu3(2-pzc)4(H2O)2(V10O28H4)·6.5H2O (2). Crystal data:  1, monoclinic, space group P21/n, a = 11.1547(5) A, b = 13.4149(6) A, c = 15.9633(7) A, β = 90.816(1)°; 2, triclinic, space group P1, a = 10.5896(10) A, b = 10.7921(10) A, c = 13.5168(13) A, α = 104.689(2)°, β = 99.103(2)°, γ = 113.419(2)°. Compound 1 contains {Cu(2-pzc)(H2O)2} chains charge-balanced by [Mo8O26]4- anions. In compound 2, layers of {Cu3(2-pzc)4(H2O)2} form cavities that are filled with [V10O28H4]2- anions. The magnetic properties of both compounds are described.

Anion-Directed Crystallization of Coordination Polymers: Syntheses and Characterization of Cu4(2-pzc)4(H2O)8(Mo8O26)·2H2O and Cu3(2-pzc)4(H2O)2(V10O28H4)·6.5H2O (2-pzc = 2-Pyrazinecarboxylate)

Photolysis of the manganese half-sandwich complex (η5-C5Me5)Mn(CO)3 (1) in tetrahydrofuran (thf) cleanly yields the solvent complex (η5-C5Me5)Mn(CO)2(thf) (2). Compound 2 is stable as solid at temperatures well below 0°C but undergoes spontaneous elimination of carbon monoxide at ambient temperature with concomitant formation of the novel dinuclear complex (η5-C5Me5)2-Mn2(μ-CO)3 (3). While elemental analysis, infrared and mass spectroscopy as well as the 1H NMR and 13C NMR spectra unequivocally demonstrate this compound to adopt a highly symmetrical triply carbonyl-bridged structure, a single-crystal X-ray diffraction study supports the presence of the first triple bond between manganese atoms (dMn – Mn 217.0(1) pm). An improved synthesis of tricarbonyl(η5-pentamethylclopentadienyl)manganese (1) is also described.



Metallcarbonyl-Synthesen, XVI1). Metall-Metall-Mehrfachbindungen: Synthese, Molekul- und Kristallstruktur von Tri-μ-carbonylbis([η5-pentamethylcyclopentadienyl)mangan](Mn ≡ Mn) – die erste Mangan-Mangan-Dreifachbindung



Photolyse des Halbsandwich-Mangan-Komplexes (η5-C5Me5)Mn(CO)3 (1) in Tetrahydrofuran (THF) fuhrt ohne Nebenreaktionen zum Solvenskomplex (η5-C5Me5)Mn(CO)2(THF) (2). Dieser ist im festen Zustand im deutlich unter 0°C liegenden Temperaturbereich haltbar, erleidet aber spontane CO-Eliminierung bei Raumtemperatur; dabei bildet sich der neue Zweikernkomplex (η5-C5Me5)2Mn2(μ-CO)3 (3). Wahrend Elementaranalyse, Infrarot- und Massenspektren sowie die 1H- und 13C-NMR-Spektren dieser Verbindung eine hochsymmetrische dreifach Carbonylverbruckte Struktur zuweisen, stutzt eine Einkristall-Rontgenstrukturanalyse das Vorliegen der ersten bisher bekannten Mangan-Mangan-Dreifachbindung (dMn – Mn 217.0(1) pm). Eine verbesserte Darstellung von Tricarbonyl(η5-pentamethylcyclopentadienyl)mangan (1) wird beschrieben.

Syntheses of Metal Carbonyls, XVI1). Metal‐Metal Multiple Bonds: Synthesis, Crystal and Molecular Structure of Tri‐μ‐carbonyl‐bis[(η5‐pentamethylcyclopentadienyl)manganese](Mn ≡ Mn) – The First Manganese‐Manganese Triple Bond

Formation of 1,2-dioxacyclohexanes by the reaction of alkenes with tris(2,4-pentanedionato)manganese(III) or with β-ketocarbonyl compounds in the presence of manganese(III) acetate

Crystal structure of trimanganese bis(hexakis(cyano)cobaltate) dodecahydrate and tricadmium bis(hexakis(cyano)cobaltate) dodecahydrate by neutron and x-ray diffraction

The reactions of 1,1-disubstituted ethenes with barbituric acid and its derivatives in the presence of manganese(II) acetate and air yielded 5,5-bis(2-hydroperoxyalkyl)barbituric acids 3aa-ac and 3ba-ja in 62-99% yields. The structure of 3ab was determined by X-ray crystallography. The reaction of 1a and 2a was also effected by manganese(III) acetate (95%) and metallic manganese (92%), but in poor yield by cerium (IV)ammonium nitrate (50%)

James D. Korp

Papers

Anion-Directed Crystallization of Coordination Polymers: Syntheses and Characterization of Cu4(2-pzc)4(H2O)8(Mo8O26)·2H2O and Cu3(2-pzc)4(H2O)2(V10O28H4)·6.5H2O (2-pzc = 2-Pyrazinecarboxylate)

Syntheses of Metal Carbonyls, XVI1). Metal‐Metal Multiple Bonds: Synthesis, Crystal and Molecular Structure of Tri‐μ‐carbonyl‐bis[(η5‐pentamethylcyclopentadienyl)manganese](Mn ≡ Mn) – The First Manganese‐Manganese Triple Bond

Formation of 1,2-dioxacyclohexanes by the reaction of alkenes with tris(2,4-pentanedionato)manganese(III) or with β-ketocarbonyl compounds in the presence of manganese(III) acetate

Crystal structure of trimanganese bis(hexakis(cyano)cobaltate) dodecahydrate and tricadmium bis(hexakis(cyano)cobaltate) dodecahydrate by neutron and x-ray diffraction

Manganese(II) acetate-mediated double 2-hydroperoxyalkylations of barbituric acid and its derivatives