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A series of Au/FeOx/SBA-15 type materials were prepared by two methods: one conventional and one non-conventional: gold deposition-precipitation on FeOx/SBA-15 and bimetallic carbonyl cluster deposition on SBA-15, respectively. Both chemical physical characterization and catalytic activity tests in the complete combustion of methanol show that the new preparation method of Au/FeOx-supported catalysts leads to the anchoring of the Au by modifying the surface of SBA-15 with FeOx species. This effect results in a considerable improvement in catalyst performance as compared to the classic preparation by deposition-precipitation of Au on SBA-15 and FeOx/SBA-15.

The total oxidation of methanol and toluene, chosen as representative VOCs, was investigated over CeO2-supported Au/FeOx catalysts prepared utilizing the bimetallic carbonyl cluster salt [NEt4][AuFe4(CO)16]. Characterization data showed that the catalysts prepared by the reported method exhibit highly and homogeneously dispersed iron oxide species on the ceria support together with small gold nanoparticles, whose size increases on increasing the amount of gold/iron. Addition of iron oxide species did not substantially increase the methanol combustion activity of ceria, whereas the presence of the mixed gold and FeOx species has been found to strongly enhance the activity towards the total oxidation of methanol. In the case of the toluene combustion the addition of FeOx or FeOx/Au species caused a significant decrease in the activity of the bare CeO2. The above catalytic behavior was rationalized on the basis of different interactions occurring among gold, iron oxide and cerium oxide, which synergically affects both the reactivity of the surface oxygen and the capacity of the support to adsorb the organic reactant.

High yields of the ethoxo-α-aminoacidates of the general formula M(OEt)4[OC(O)CHRNHR'-κO,κN] (M = Nb, R = CH2Ph, R' = H, 2; R = CHMe2, R' = H, 3; R = CH2CHMe2, R' = H, 4; R = H, R' = Me, 5; R = CH2CH2SMe, R' = H, 6; M = Ta, R = CH2Ph, R' = H, 7; R = CH2CH2SMe, R' = H, 8) and M(OEt)4(OC(O)CH(CH2CH2CH2)NH-κO,κN) (M = Nb, 9; Ta, 10) have been obtained by the reaction of the l-enantiopure α-amino acid (or sarcosine) with a slight molar excess of M(OEt)5 (M = Nb, 1a; Ta, 1b) in a dichloromethane solution. The new complexes 2-10 have been fully characterized by spectroscopic and analytical methods and by X-ray diffraction for 2 and 7-9. Such X-ray structures are the first ones ever reported for niobium and tantalum coordination compounds containing an α-aminoacidato ligand. The early-late heterobimetallic derivative Ta(OEt)4[O2CCH(NH2)CH2CH2S(CH3)(AuCl)] (11) has been prepared by the reaction of 8 with a stoichiometric amount of Au(CO)Cl. The bulk polymerization of D,L-lactide initiated by complexes 2 and 7 gave a slightly heterotactic enchainment (Pr = 0.54 and 0.63, respectively), whereas complexes 1a and 1b formed fully atactic polylactide with P(r) ≈ 0.4.

The diiron complex [Fe2{μ-к1(O):η1(C):η3(C)–C(N(Me)(Xyl))C(H) C(Me)C(O)OMe}(μ-CO)(Cp)2] (2) has been obtained from the diiron bridging vinyliminium [Fe2{μ-η1:η3–C(Me) C(H)C N(Me)(Xyl)}(μ-CO)(CO)(Cp)2][SO3CF3] (1; Xyl = 2,5-C6H3Me2) upon treatment with NaH in the presence of CH2 C CMe2, followed by chromatography on alumina with MeOH as eluent. The reaction consists in the incorporation of a methylcarboxylate unit, assembled from CO and MeO−, into the bridging vinyliminium ligand. The resulting complex 2 exhibits a C4 fragment bridging the two iron centres through the carbonyl oxygen atom and the allylidene moiety. The X-ray molecular structure of 2 has been determined.

The total oxidation of methanol and toluene, chosen as representative VOCs, was investigated over CeO2- supported Au/FeOx catalysts prepared utilizing the bimetallic carbonyl cluster salt [NEt4][AuFe4(CO)16]. Characterization data showed that the catalysts prepared by the reported method exhibit highly and homogeneously dispersed iron oxide species on the ceria support together with small gold nanoparticles, whose size increases on increasing the amount of gold/iron. Addition of iron oxide species did not substantially increase the methanol combustion activity of ceria, whereas the presence of the mixed gold and FeOx species has been found to strongly enhance the activity towards the total oxidation of methanol. In the case of the toluene combustion the addition of FeOx or FeOx/Au species caused a significant decrease in the activity of the bare CeO2. The above catalytic behavior was rationalized on the basis of different interactions occurring among gold, iron oxide and cerium oxide, which synergically affects both the reactivity of the surface oxygen and the capacity of the support to adsorb the organic reactant.

The zwitterionic vinyliminium complex [Fe2{μ-η1:η3-C(R′) C(S)C N(Me)(Xyl)}(μ-CO)(CO)(Cp)2] (2a) (R′ = p-Me-C6H4 (Tol), Xyl = 2,6-Me2C6H3) undergoes electrophilic addition at the S atom by HSO3CF3, MeSO3CF3, SiMe3Cl, BrCH2Ph, ICH2CH CH2 affording the complexes [Fe2{μ-η1:η3-C(Tol) C(SX)C N(Me)(Xyl)}(μ-CO)(CO)(Cp)2][Y] (X = H, Y = SO3CF3, 4a; X = Me, Y = SO3CF3, 4b; X = SiMe3, Y = Cl, 4c; X = CH2Ph, Y = Br, 4d; X = CH2CH CH2, Y = I, 4e). Compound 2a and the corresponding vinyliminium complexes 2b and 2c (R′ = CH2OH, 2b; R′ = Me, 2c) react also with etherated BF3 leading to the formation of the corresponding S-adducts [Fe2{μ-η1:η3-C(R′) C(SBF3)C N(Me)(Xyl)}(μ-CO)(CO)(Cp)2] (R′ = Tol, 5a; R′ = CH2OH, 5b; R′ = Me, 5c). In analogous reactions, the zwitterionic vinyliminium complexes undergo S-metalation upon treatment with in situ generated [Fp]+[SO3CF3]− [Fp = Fe(CO)2(Cp)], leading to the formation of [Fe2{μ-η1:η3-C(R′) C(S–Fp)C N(Me)(Xyl)}(μ-CO)(CO)(Cp)2][SO3CF3](R′ = CH2OH, 6a; R′ = Me, 6b; R′ = Bun, 6c). Similarly, zwitterionic vinyliminium containing Se in the place of S also undergo Se-electrophilic addition. Thus, the complexes [Fe2{μ-η1:η3-C(R′) C(SeX)C N(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R = X = Me, R′ = Tol, 7a; R = Xyl, R′ = Me, X = Fp+, 7b) are obtained upon treatment of the neutral zwitterionic precursors with MeSO3CF3 and [Fp][SO3CF3], respectively. Alkylation at the S or Se atom of the bridging ligand is also accomplished by CH2Cl2, used as solvent, although the reaction is slower compared to more efficient alkylating reagents. The complexes formed by this route are [Fe2{μ-η1:η3-C(R′) C(E-CH2Cl)C N(Me)(R)}(μ-CO)(CO)(Cp)2][X] [E = S, R = Xyl, R′ = Tol, X = Cl, 8a; E = S, R = Xyl, R′ = Me, X = Cl, 8b; E = Se, R = R′ = Me, X = BPh4, 8c]. Finally, treatment of the zwitterionic vinyliminium complexes with I2 results in the oxidative coupling with formation of S–S (disulfide) or Se–Se (diselenide) bond. The reactions, performed in the presence of NaBPh4 afford the tetranuclear complexes [Fe2{μ-η1:η3-C(R′) C(E)C N(Me)(R)}(μ-CO)(CO)(Cp)2]2[BPh4]2 [R = Xyl, R′ = CH2OH, E = S, 9a; R = Xyl, R′ = Me, E = S, 9b; R = Xyl, R′ = Bun, E = S, 9c; R = Xyl, R′ = Me, E = Se, 9d; R = Me, R′ = Bun, E = Se, 9e]. The molecular structures of 4a, 8c and 9e have been determined by X-ray diffraction studies.

The bridging diiron thiocarbyne complex [Fe2{μ-CS(Me)}(μ-CO)(CO)2(Cp)2]ISO 3 CF 3 ] (1) reacts with activated olefins (methyl acrylate, acrylonitrile, styrene, diethyl maleate), in the presence of Me 3 NO and NaH, to give the corresponding μ-allylidene complexes [Fe 2 {μ-η 1 :η 3 -C α (SMe)C β (R')C γ (H)(R")} (μ-CO)(CO)(Cp) 2 ] (R" = CO 2 Me, R'= H, 3a; R" = CN, R'= H, 3b; R" = C 6 H 5 , R'= H, 3c; R" = R' = CO 2 Et, 3d). The coupling reaction of olefin with thiocarbyne is regio- and stereospecific, leading to the formation of only one isomer. C-C bond formation occurs between the less substituted alkene carbon and the thiocarbyne. Moreover, olefinic hydrogens of the bridging ligands are mutually trans. The reactions of 3a-b with MeSO 3 CF 3 result, selectively, in the formation of the cationic μ-sulphonium allylidene complexes [Fe 2 [μ-η 1 :η 3 -C α (SMe 2 )C β (H)C γ (H)(R)}(μ-CO)(CO)(Cp)2][SΟ 3 CF 3 ] (R = CΟ 2 Me, 4a; R = CN, 4b). Compound 4a undergoes displacement of the SMe 2 group by nucleophiles such as NaBH 4 , NBu 4 CN and NaOMe, affording the complexes [Fe 2 ( μ-η 1 :η 3 -C α (R)C β (H)C γ H)(CΟ 2 -Me)}(μ-(CO)(Cp) 2 ] (R = H, 5a; R = CN, 5b; R = OMe, 5c), respectively. The molecular structures of 3a and 5a have been determined by X-ray diffraction studies.

Primary alkynes R′C CH [R′ = Me3Si, Tol, CH2OH, CO2Me, (CH2)4C CH, Me] insert into the metal–carbon bond of diruthenium μ-aminocarbynes [Ru2{μ-CN(Me)(R)}(μ-CO)(CO)(MeCN)(Cp)2][SO3CF3] [R = 2,6-Me2C6H3 (Xyl), 1a; CH2Ph (Bz), 1b; Me, 1c] to give the vinyliminium complexes [Ru2{μ-η1:η3-C(R′) CHC N(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] [R = Xyl, R′ = Me3Si, 2a; R = Bz, R′ = Me3Si, 2b; R = Me, R′ = Me3Si, 2c; R = Xyl, R′ = Tol, 3a; R = Bz, R′ = Tol, 3b; R = Bz, R′ = CH2OH, 4; R = Bz, R′ = CO2Me, 5a; R = Me, R′ = CO2Me, 5b; R = Xyl, R′ = (CH2)4C CH, 6; R = Xyl, R′ = Me, 7a; R = Bz, R′ = Me, 7b; R = Me, R′ = Me, 7c]. The related compound [Ru2{μ-η1:η3-C[C(Me) CH2] CHC N(Me)(Xyl)}(μ-CO)(CO)(Cp)2][SO3CF3], (9) is better prepared by reacting [Ru2{μ-CN(Me)(Xyl)}(μ-CO)(CO)(Cl)(Cp)2] (8) with AgSO3CF3 in the presence of HC CC(Me) CH2 in CH2Cl2 at low temperature.In a similar way, also secondary alkynes can be inserted to give the new complexes [Ru2{μ-η1:η3-C(R′) C(R′)C N(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R = Bz, R′ = CO2Me, 11; R = Xyl, R′ = Et, 12a; R = Bz, R′ = Et, 12b; R = Xyl, R′ = Me, 13). The reactions of 2–7, 9, 11–13 with hydrides (i.e., NaBH4, NaH) have been also studied, affording μ-vinylalkylidene complexes [Ru2{μ-η1:η3-C(R′)C(R″) C(H)N(Me)(R)}(μ-CO)(CO)(Cp)2] (R = Bz, R′ = Me3Si, R″ = H, 14a; R = Me, R′ = Me3Si, R″ = H, 14b; R = Bz, R′ = Tol, R″ = H, 15; R = Bz, R′ = R″ = Et, 16), bis-alkylidene complexes [Ru2{μ-η1:η2-C(R′)C(H)(R″)CN(Me)(Xyl)}(μ-CO)(CO)(Cp)2] (R′ = Me3Si, R″ = H, 17; R′ = R″ = Et, 18), acetylide compounds [Ru2{μ-CN(Me)(R)}(μ-CO)(CO)(C CR′)(Cp)2] (R = Xyl, R′ = Tol, 19; R = Bz, R′ = Me3Si, 20; R = Xyl, R′ = Me, 21) or the tetranuclear species [Ru2{μ-η1:η2-C(Me)CCN(Me)(Bz)}(μ-CO)(CO)(Cp)2]2 (23) depending on the properties of the hydride and the substituents on the complex. Chromatography of 21 on alumina results in its conversion into [Ru2{μ-η3:η1-C[N(Me)(Xyl)]C(H)C CH2}(μ-CO)(CO)(Cp)2] (22). The crystal structures of 2a[CF3SO3] · 0.5CH2Cl2, 12a[CF3SO3] and 22 have been determined by X-ray diffraction studies.

The vinyliminium complexes [Fe2{μ-η1:η3-C(R′) C(R′)C N(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R = Me, R′ = Et, 1a; R = Me, R′ = Ph, 1b; R = R′ = Me, 1c; R = Xyl, R′ = Me, 1d; R = Xyl, R′ = Et, 1e; R = Xyl, R′ = Ph, 1f; Xyl = 2,6-Me2C6H3), react with MeLi affording the corresponding μ-vinylalkylidene complexes [Fe2{μ-η1:η3-C(R′)C(R′) CHN(Me)(R)}(μ-CO)(CO)(Cp){C5H4(Me)}] (2a–f). The formation of 2a–f is believed to proceed via nucleophilic attack at the Cp ligand, followed by hydrogen migration from the resulting cyclopentadiene to the iminium carbon. Similarly, the complex [Fe2{μ-η1:η3-C(Ph) C(Ph)C N(Me)(Xyl)}(μ-CO)(CO)(Cp)2][SO3CF3] reacts with PhLi to give [Fe2{μ-η1:η3-C(Ph)C(Ph) CHN(Me)(Xyl)}(μ-CO)(CO)(Cp){C5H4(Ph)}] (4). Treatment of 2a with CF3SO3CH3 results in methylation of the nitrogen, yielding the complex [Fe2{μ-η1:η3-C(Et)C(Et)CH(NMe3)}(μ-CO)(CO)(Cp){C5H4(Me)}][CF3SO3] (5). Analogously, the μ-vinylalkylidene complexes [Fe2{μ-η1:η3-C(R′)C(R″) CHN(Me)(R)}(μ-CO)(CO)(Cp)2], (R = Me, R′ = Tol, R″ = H, 3a; R = Me, R′ = SiMe3, R″ = H, 3b; R = Me, R′ = R″ = Et, 3c; R = Me, R′ = R″ = Ph, 3d; R = Bz, R′ = Tol, R″ = H, 3e; R = Bz, R′ = SiMe3, R″ = H, 3f; R = Bz, R′ = COOMe, R″ = H, 3g; R = Bz, R′ = R″ = COOMe, 3h; R = Bz, R′ = R″ = Me, 3i; Bz = CH2Ph), react with CF3SO3CH3 to give the corresponding ammonium-functionalized μ-allylidene complexes [Fe2{μ-η1:η3-C(R′)C(R″)CH(NMe2R)}(μ-CO)(CO)(Cp)2][CF3SO3] (6a–i). The molecular structures of 5 and 6c have been elucidated by X-ray diffraction studies. Finally, protonation of [Fe2{μ-η1:η3-C(Et)C(Et) CH(NMe2)}(μ-CO)(CO)(Cp)2] (3c), with HBF4, affords the complex [Fe2{μ-η1:η3-C(Et)C(Et)CH(NHMe2)}(μ-CO)(CO)(Cp)2]][BF4] (7).

The diiron complexes [Fe(Cp)(CO){μ-η 2 :η 2 -C[N(Me)(R)]N C(C 6 H 3 R′)C CH(Tol)}Fe(Cp)(CO)] (R = Xyl, R′ = H, 3a ; R = Xyl, R′ = Br, 3b ; R = Xyl, R′ = OMe, 3c ; R = Xyl, R′ = CO 2 Me, 3d ; R = Xyl, R′ = CF 3 , 3e ; R = Me, R′ = H, 3f ; R = Me, R′ = CF 3 , 3g ) are obtained in good yields from the reaction of [Fe 2 {μ-CN(Me)(R)}(μ-CO)(CO)( p -NCC 6 H 4 R′)(Cp) 2 ] + (R = Xyl, R′ = H, 2a ; R = Xyl, R′ = Br, 2b ; R = Xyl, R′ = OMe, 2c ; R = Xyl, R′ = CO 2 Me, 2 d; R = Xyl, R′ = CF 3 , 2e ; R = Me, R′ = H, 2f; R = Me, R′ = CF 3 , 2g ) with TolC CLi. The formation of 3 involves addition of the acetylide at the coordinated nitrile and C–N coupling with the bridging aminocarbyne together with orthometallation of the p -substituted aromatic ring and breaking of the Fe–Fe bond. Complexes 3a – e which contain the N(Me)(Xyl) group exist in solution as mixtures of the E - trans and Z - trans isomers, whereas the compounds 3f,g , which posses an exocyclic NMe 2 group, exist only in the Z-cis form. The crystal structures of Z - trans - 3b , E - trans - 3c , Z - trans - 3e and Z - cis - 3g have been determined by X-ray diffraction experiments.

One of the distinct features of metal-tetrazolate complexes is the possibility of performing electrophilic additions onto the imine-type nitrogens of the coordinated five-membered ring. These reactions, in particular, provide a useful tool for varying the main structural and electronic properties of the starting tetrazolate complexes. In this paper, we demonstrate how the use of a simple protonation-deprotonation protocol enables us to reversibly change, to a significant extent, the light-emission output and performance of a series of Re(I)-tetrazolate-based phosphors of the general formulation fac-[Re(N(∧)N)(CO)3L], where N(∧)N denotes diimine-type ligands such as 2,2'-bipyridine (bpy) or 1,10-phenanthroline (phen) and L represents a series of different 5-aryl tetrazolates. Indeed, upon addition of triflic acid to these neutral Re(I) complexes, a consistent blue shift (Δλmax ca. 50 nm) of the emission maximum is observed and the protonated species also display increased quantum yield values (4-13 times greater than the starting compounds) and longer decay lifetimes. This alteration can be reversed to the initial condition by further treating the protonated Re(I) complex with a base such as triethylamine. Interestingly, the reversible modulation of luminescent features by the same protonation-deprotonation mechanism appears as a quite general characteristic of photoactive metal tetrazolate complexes, even for compounds in which the 2-pyridyl tetrazolate ligands coordinate the metal center with a bidentate mode, such as the corresponding Ir(III) cyclometalates [Ir(C(∧)N)2L] and the Ru(II) polypyridyl derivatives [Ru(bpy)2L](+). In these cases, the protonation of the starting materials leads to red-shifted and more intense emissions for the Ir(III) complexes, while almost complete quenching is observed in the case of the Ru(II) analogues.

N,N-Diethylcarbamates [NbE(O2CNEt2)3] (E = O, S) have been prepared in high yields by treating NbOCl3 or [NbSCl3(CH3CN)2] with CO2/NHEt2 in toluene at approximately -10 degrees C. The products were characterized by spectroscopic techniques, elemental analysis and X-ray diffractometry in the case of [NbO(O2CNEt2)3]. The molecular structure of the latter consists of a niobium centre coordinated to the oxido moiety and six O atoms belonging to bridging and bidentate carbamates, in a slightly distorted pentagonal-bipyramidal arrangement. The structures of both [NbE(O2CNEt2)3] compounds were reproduced by DFT calculations, which show substantial similarity despite the different nature of the chalcogen atoms.

WCl6, 1, reacted with two equivalents of HC(O)NR2 (R = Me, Et) in CH2Cl2 to afford the W((VI)) oxo-derivatives WOCl4(OCHNR2) (R = Me, 2a; R = Et, 2b) as main products. The hexachlorotungstate(V) salts [{O-C-N(Me)CH2CH2CH2}(2)(mu-H)][WCl6], 3, and [PhNHC(Me)N(Ph)C(O)Me][WCl6], 4, were isolated in moderate yields from the 1 : 2 molar reactions of 1 with N-methyl-2-pyrrolidone (in CH2Cl2) and acetanilide (in CDCl3), respectively. The additions of two equivalents of ketones/aldehydes to 1/CH2Cl2 yielded the complexes WOCl4[OC(R)(R')] (R = Me, R' = Ph, 5a; R = R' = Ph, 5b; R = R' = Me, 5c; R = R' = Et, 5d; R = H, R' = 2-Me-C6H4, 5e) and equimolar amounts of C(R)(R')Cl-2. Analogously, WOCl3[kappa(2)-{1,2-C6H4(O)(CHO)}], 5f, and 1,2-C6H4(OH)(CHCl2) were obtained from 1 and salicylaldehyde. The 1 : 1 reaction of 1 with acetone in CH2Cl2 resulted in the clean formation of WOCl4 and 2,2-dichloropropane. Compounds 5a, b, f were isolated as crystalline solids, whereas 5c, d, e could be detected by solution NMR only. The interaction of 1/CH2Cl2 with isatin, in a 1 : 1 molar ratio, revealed to be a new, convenient route for the synthesis of 3,3-dichloro-2,3-dihydro-1H-indol-2-one, 6. The 1 : 1 reactions of 1 with R'OCH(R)CO2Me (R = H, R' = Me; R = Me, R' = H) in a chlorinated solvent afforded the tungsten(V) adducts WCl4[kappa(2)-OCH(R)(COMe)-Me-2] (R = H, 7a; R = Me, 7b). 1/CH2Cl2 reacted sluggishly with equimolar quantities of trans-(CO2Et)CH=CH(CO2Et) and CH2(CO2Me)(2) to give, respectively, the W(IV) derivatives WCl4[kappa(2)-CH2(CO2Me)(2)], 8a, and [WCl4-kappa(2)-{trans-(CO2Et)CH-CH (CO2Et)}](n), 8b, in about 70% yields. The molecular structures of 2a, 3, 4, 5a, 5f, 7a and 7b were ascertained by X-ray diffraction studies.

The complex [Fe2Cp2(CO)(µ-CO){µ-η1:η3-C(H)=C(C(CH3)CH2)C(=O)}] (2) underwent addition of a series of electrophiles to afford the -allenyl [Fe2Cp2(CO)2(-CO)-1:2,-CH=C=C(CH3)(CH2E)}][X] (E = CPh3, X = BF4, [3][BF4]; E = SiMe3, X = Cl, [4][Cl]; E = H, X = BF4, [1][BF4]), in high yields. The new compounds [3][BF4] and [4][Cl] were characterized by analytical, spectroscopic and electrochemical methods, moreover the molecular structure of [3][BF4] was elucidated by X-ray diffraction. DFT calculations were carried out on [3]+ and [4]+: in both cases, the structure bearing the C-methyl substituent pointing to the FeFe axis is more stable than the structure with opposite configuration of the C-substituents (U = 7 Kcal mol1 for [3]+ and U = 1 Kcal mol1 for [4]+). These computer outcomes are in agreement with the X-ray structure of [3][BF4] and with NMR evidences. The protonation of 2 was investigated by DFT calculations, thus the C carbon resulted the most favorable site of H+ attack in 2 on theoretical grounds: the formation of the allenyl complex [1]+ rather than the vinyl isomer [Fe2Cp2(CO)2(µ-CO){µ-η1:η2-CH=CHC(Me)=CH2}]+ ([7]+) is thermodinamically more favoured by … Kcal mol1. Attempts to convert [1]+ into ([7]+) by high temperature reaction resulted in fragmentation of the diiron frame. The reaction of [1]+ with NHEt2 in the presence of PhSSPh resulted in prevalent formation of [FeCp(CO)2SPh] (8).

none 3 Published: 21 December 2011 A novel preparation method was developed for the preparation of gold/iron oxide supported catalysts using the bimetallic carbonyl cluster salts [NEt4]4[Au4Fe4(CO)16] and [NEt4][AuFe4(CO)16] as precursors of highly dispersed nanoparticles over different supports. A series of catalysts with different metal loadings were prepared and tested in the complete oxidation of dichlorobenzene, toluene, methanol and in the preferential oxidation of CO in the presence of H2 (PROX) as model reactions. The characterization by BET, XRD, TEM, H2-TPR, ICP-AES and XPS point out the way the nature of the precursors and the thermal treatment conditions affected the dispersion of the active phase and their catalytic activity in the studied reactions R. Bonelli; S. Zacchini; S.Albonetti R. Bonelli; S. Zacchini; S.Albonetti

The zwitterionic bridging vinyliminium complex [Fe2{μ-η1:η3-C(Tol) C(CS2)C N(Me)2}(μ-CO)(CO)(Cp)2] (5a) undergoes the addition of two equivalents of MeO2C–C C–CO2Me affording the bridging bis-alkylidene complex [Fe2{μ-η1:η3-C(Me)C{C(CO2Me)C(CO2Me)CSC(CO2Me)C(CO2Me)S}CNMe2}(μ-CO)(CO)(Cp)2] (6). One alkyne unit inserts into a C–CS2 bond of the bridging ligand, with consequent rearrangement that leads to the formation of a diene. The reaction shows analogies with the enyne metathesis. The second alkyne is incorporated into the bridging frame via cycloaddition at the thiocarboxylate function, affording a 1,3-dithiolene. The complexes [Fe2{μ-η1:η3-C(R′) C(CS2)C N(Me)(R)}(μ-CO)(CO)(Cp)2] (R = Xyl, R′ = Tol, 5b; R = p-C6H4OMe, R′ = Me, 5c; Xyl = 2,6-Me2C6H3), treated with MeO2C–C C–CO2Me and then with HBF4, undergo the cycloaddition of the alkyne with the dithiocarboxylate group and protonation of the dithiocarboxylate carbon, affording the complexes [Fe2{μ-η1:η3-C(R′) C{C(H)SC(CO2Me)C(CO2Me)S}C N(Me)(R)}(μ-CO)(CO)(Cp)2][BF4] (R = Xyl, R′ = Tol, 7a; R = p-C6H4OMe, R′ = Me, 7b), respectively. The X-ray molecular structure of 6 has been determined.

The room temperature reactions of a series of 1,2-dialkoxyalkanes ROCH2CH(R′)OR′′ with MX5 (M = Nb, Ta; X = Br, I) in 1:1 ratio result in single C–O bond cleavage and high-yield formation of the halo-alkoxides MBr4[κ2-OCH2CH(R′)OR′′] or [NbI4{κ1-OCH2CH(R′)OR′′}]2, and equimolar amounts of the corresponding alkyl halides RX. The reaction of NbBr5 with 1,2-dimethoxyethane, dme, proceeds with preliminary formation of the ionic species [NbBr4(κ2-dme)(κ1-dme)][NbBr6], 3b, which has been identified by solution NMR at low temperature and conductivity analyses. The gas-phase structure of 3b has been optimized by DFT calculations, confirming that the dme ligands adopt bidentate and monodentate coordination, respectively. Although the formation of NbOBr3(dme), 4b, 1,4-dioxane and MeBr from NbBr5/dme (ratio 1:2) is an exoergonic process (calculated Δ G r ° = −115.96 kcal mol−1), it is inhibited at room temperature. High temperature conditions enhance the production of 1,4-dioxane at the expense of selectivity. The dinuclear species NbOBr3(dme)NbBr5 (Nb–O–Nb), 5b, (X-ray) has been isolated in modest yield as byproduct of the room temperature reaction of NbBr5 with dme. In general, the 1:2 molar reactions of NbX5 (X = Br, I) with ROCH2CH(R′)OR′′ occur with the exclusion of nearly one equivalent of organic reactant.

The salts [S(NMe2)3][MF6] (M = Nb, 2a; M = Ta, 2b) and [S(NMe2)3][M2F11] (M = Nb, 2c; M = Ta, 2d) have been prepared by reacting MF5 (M = Nb, 1a; M = Ta, 1b) with [S(NMe2)3][SiMe3F2] (TASF reagent) in the appropriate molar ratio. The solid state structure of 2b has been ascertained by X-ray diffraction. The 1:1 molar ratio reactions of 1a with a variety of organic compounds (L) give the neutral adducts NbF5L [L = Me2CO, 3a; L = MeCHO, 3b; L = Ph2CO, 3c; L = tetrahydrofuran (thf), 3d; L = MeOH, 3e; L = EtOH, 3f; L = HOCH2CH2OMe, 3g; L = Ph3PO, 3h; L = NCMe, 3i] in good yields. The complexes MF5L [M = Nb, L = HCONMe2, 3j; M = Nb, L = (NMe2)2CO, 3k; M = Ta, L = (NMe2)2CO, 3l; M = Nb, L = OC(Me)CH CMe2, 3m] have been detected in solution in admixture with other unidentified products, upon 2:1 molar reaction of 1 with the appropriate reagent L. The ionic complexes [NbF4(tht)2][NbF6], 4a, and [NbF4(tht)2][Nb2F11], 4b, have been obtained by combination of tetrahydrothiophene (tht) and 1a, in 1:1 and 2:3 molar ratios, respectively. The treatment of 1 with a two-fold excess of L leads to the species [MF4L4][MF6] [M = Nb, L = HCONMe2, 5a; M = Ta, L = HCONMe2, 5b; M = Nb, L = thf, 5c; M = Ta, L = thf, 5d; M = Nb, L = OEt2, 5e]. The new complexes have been fully characterised by NMR spectroscopy. Moreover, the revised 19F NMR features of the known compounds MF5L [M = Ta, L = Me2CO, 3n; M = Ta, L = Ph2CO, 3o; M = Ta, L = MePhCO, 3p; M = Ta, L = thf, 3q; M = Nb, L = CH3CO2H, 3r; M = Nb, L = CH2ClCO2H, 3s; M = Ta, L = CH2ClCO2H, 3t], TaF4(acac), TaF4(Me-acac) and [TaF(Me-acac)3][TaF6] (Me-acac = methylacetylacetonato anion) are reported.

A novel preparation method was developed for the preparation of gold/iron supported catalysts on TiO2 and CeO2 by employing bi-metallic carbonyl cluster salts. All prepared catalysts were fully characterized and tested in toluene and methanol total oxidation and in PROX reaction. The novel preparation method resulted in small gold metallic nanoparticles surrounded by highly dispersed amorphous iron oxide species on the supports. Results confirmed that FeOx species stabilize small Au particles. Partial encapsulation of gold atoms by iron species was also observed together with a strong interaction between gold and oxide species (both iron oxide and reducible supports). The presence of gold has been found to enhance the activity of iron oxide towards both the complete oxidation of toluene and methanol to CO2 and the PROX reaction. The extent of this positive effect resulted to be dependent on the adsorption properties of the organic molecule (toluene vs methanol), the support used and the interaction degree between FeOx and Au species. Moreover, CO preferential oxidation was found to strongly depend on Au particle size and surface oxygen reducibility, being related to the different oxide species which can be formed using different thermal treatment conditions or iron loadings over the support. The use of carbonyl clusters to synthesize bimetallic catalysts is a promising way to obtain iron stabilized gold nanoparticles and could find application even on support on which stabilization of gold is usually very difficult. In this way catalysts with highly dispersed active phase and an enhanced catalytic activity were obtained.

Unconventional nanofabrication is attractive for organic electronics because of its potential impact in manufacturing low-cost electronics starting from soluble precursors that can be processed and patterned via a sustainable technology. So far, the major endeavor aimed at the development of organicbased devices has been through the design of new materials, novel synthetic procedures and purification methods, optimized conditions for thin film growth, and original methods for nanofabrication. In particular, a strong effort was devoted to the technological control of organic semiconductors in transistors. Yet, only a limited number of studies have focused on new approaches for low cost fabrication of electrodes and their integration with the organic materials. Successful examples of unconventional electrode manufacturing include stencil printing of Au nanoparticles, inkjet printing, Ag electroless plating followed by microcontact patterning, lamination, microtransfer printing of Ag nanoparticles, metal transfer printing, and soft lithography. Although inkjet printing is probably the most straightforward example of an additive process where both the electrodes and the active layers can be realized on the same platform, the fabrication of the electrodes and the active layers often relies on different processes, specifications, and platforms. Precisely, standard microfabrication approaches consisting of photolithography and/or electron-beam lithography followed by vacuum metallization are generally used for the source and drain definition, while wet methods (spin-coating, layer-by

The Group 5 pentahalides MX5 (M = Nb, Ta; X = Cl, Br), 1, react with a variety of epoxides (1,2-epoxybutane, styrene oxide, 2,3-dimethyl-2,3-epoxybutane, epoxycyclohexane, ethylene oxide) in a 1:3 molar ratio to afford the dinuclear dihalide-tris(2-haloalcoholato) complexes [MX2(OR)2(μ-OR)]2 [M = Nb, X = Cl, R = –CH(Et)CH2Cl, 2a; M = Nb, X = Cl, R = –CH2CH(Ph)Cl, 2b; M = Nb, X = Cl, R = –C(Me)2C(Me)2Cl, 2c; M = Nb, X = Br, R = –CH2CH(Ph)Br, 2d; M = Nb, X = Br, R = –C(Me)2C(Me)2Br, 2e; M = Ta, X = Cl, R = –CH(Et)CH2Cl, 2f; M = Ta, X = Cl, , 2g; M = Ta, X = Br, R = –CH2CH2Br, 2h], in moderate to good yields. The products, 2a–h, result from multiple epoxide insertion into metal–halide bonds, and the reactions involving 1,2-epoxybutane and styrene oxide proceed with high regioselectivity. The molecular structure of 2h has been elucidated by X-ray diffraction. Differently, NbF5 adds one equivalent of 2,3-dimethyl-2,3-epoxybutane to give the monomer NbF5[O C(Me)(But)], 3, in high yield, as a result of epoxide to ketone isomerization. The reactions of MF5 (M = Nb, Ta) with other epoxides proceed non-selectively according to various pathways, including formation of C–O and C–F bonds and C–C and C–H cleavages.

Niobium and tantalum pentahalides, MX5 (1), react with acetic acid and halo-substituted acetic acids, in 1:1 ratio, to give the dinuclear complexes [MX4(μ-OOCMe)]2 [M = Nb, X = Cl, 2a; M = Ta, X = Cl, 2b; Br, 2c] and [MCl4(μ-OOCR)]2 [M = Nb, R = CH2Cl, 4a; CHCl2, 4c; CCl3, 4e; CF3, 4g; CHBr2, 4i; CH2I, 4j; M = Ta, R = CH2Cl, 4b; CHCl2, 4d; CCl3, 4f; CF3, 4h]. The solid state structures of 2b and 4e have been ascertained by X-ray diffraction studies. The reactions of 1 with acetic anhydride and halo-substituted acetic anhydrides result in C–O bond activation and afford 2 and 4, respectively, with concomitant formation of acetyl halides. Moreover, the complexes MCl5[OC(Cl)Me] [M = Nb, 3a; M = Ta, 3b] have been detected in significant amounts within the mixtures of the reactions of MCl5 with acetic anhydride. TaI5 is unreactive, at room temperature, towards both MeCOOH and (MeCO)2O. MF5 react with RCOOH (R = Me, CH2Cl) in 1:1 molar ratio, to afford the ionic compounds [MF4(RCOOH)2][MF6], 5a–d, in high yields. The additions of (RCO)2O (R = Me, CH2Cl) to MF5 give 5, suggesting that anhydride C–H and C–O bonds activation is operative during the course of these reactions.

The SPh functionalized vinyliminium complexes [Fe 2 {μ-η 1 :η 3 -C γ (R')=C β (SPh)C α =N(Me)(R)}(μ-CO)(CO)(Cp) 2 ][SΟ 3 CF 3 ] [R=Xyl, R' = Me, 2a; R=Me, R' = Me, 2b; R = 4-C 6 H 4 ΟMe, R'=Me, 2c; R=Xyl, R' CH 2 OH, 2d; R = Me, R' CH 2 OH, 2e; Xyl = 2,6-Me 2 C 6 H 3 ) are generated in high yields by treatment of the corresponding vinyliminium complexes [Fe 2 {μ-η 1 : η 3 -C γ (R')=C β (H)C α =N(Me)(R)}(μ-CO)(CO)(Cp) 2 ][SO 3 CF 3 ] (la-e) with NaH in the presence of PhSSPh. Likewise, the diruthenium complex [Ru 2 {μ-η 1 :η 3 -C γ (Me)=C β (SPh)C α =N(Me)(Xyl)}(μ-CO)(CO)(Cp) 2 ][SO 3 CF 3 ] (2f) was obtained from the corresponding vinyliminium complex [Ru2{μ-η 1 :η 3 -C γ (Me)=C β (H)C α =N(Me)(Xyl)}(μ-CO)(CO)(Cp )2] (1f). The synthesis of 2c is accompanied by the formation, in comparable amounts, of the aminocarbyne complex [Fe 2 {μ-CN (Me)(4-C6H40Me))(SPh)(μ-CO )(CO)(Cp)2] (3). The molecular structures of 2d, 2e and 3 have been determined by X-ray diffraction studies.

Conductive wires of sub-micrometer width made from platinum-carbonyl clusters have been fabricated by solution-infilling of microchannels as in microinject molding in capillaries (MIMIC). The process is driven by the liquid surface tension within the micrometric channels followed by the precipitation of the solute. Orientation of supramolecular crystalline domains is imparted by the solution confinement combined with unidirectional flow. The wires exhibit ohmic conductivity with a value of 0.2 S/cm that increases, after thermal decomposition of the platinum-carbonyl cluster precursor to Pt, to 35 S/cm.

The chemistry of cyclopentadienyl ligands with functionalized pendant arms is still largely studied [1]. Herein we describe the totally diastereoselective formation of new air stable and water soluble Iridium (I) (Ko/w 0.9) and (III) complexes, by utilizing the recently synthesized, [2] multi-substituted and overcrowded, propeller-like ligand CpOOO, rac-1,2,4[C5H2R3; R = CH(CH2)3CHOH]. The latter reacts with [Ir(COD)Cl]2 giving quantitatively [Ir(COD)CpOOO] 1. Iodide addition to dichloromethane solution of 1 causes prompt displacement of the coordinated olefin, yielding dinuclear Iridium(III) [Ir(η5-CpOOO)I(µ-I)]2 2, which has been isolated as a red powder [3]. In agreement with the proposed structure, 1H NMR spectra of species 2 exhibit high-shifted double set of signals for the Cp groups. Reactions of 2 with phosphines (PR3: R = Me, Ph) or pyrazole (C3H4N2) ligands form quantitatively Ir(η5-CpOOO)I2L (L = PR3, R = Me 3, Ph 4; pzH 5), by iodide bridge breaking. All the complexes, isolated as dark yellow solids, have been spectroscopically characterized. To get new insights on oxidative addition mechanism paths, [4] further reactivity of 1 with CH3I is currently under investigation.

The diiron aminocarbyne complexes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO)(NCMe)(Cp)2][SO3CF3] (R = Xy1, 1a; R = Me, 1b; R = CH2Ph, 1c; Xy1 = 2,6-Me2C6H3) undergo replacement of the coordinated nitrile by halides, diethyldithiocarbamate, and dicyanomethanide to give [Fe2{μ-CN(Me) (R)}(μ-CO)(CO)(X)(Cp)2] complexes (R = Me, X = Br, 4a; R = Me, X = I, 4b; R = CH2Ph, X = Cl, 4c; R = CH2Ph, X = Br, 4d; R = CH2Ph, X = I, 4e; R = Xy1, X = SC(S)NEt2, 5a; R = Me, X = SC(S)NEt2, 5b; R = Xy1, X = CH(CN)2, 7), in good yields. The molecular structure of 5a shows an unusual η1 coordination mode of the dithiocarbamate ligand. Similarly, treatment of [M2{μ-CN(Me) (R)}(μ-CO)(CO)(NCMe)(Cp)2][SO3CF3] (M = Fe, R = Xy1, 1a; M = Fe, R = Me, 1b; M = Ru, R = Xy1, 2a; M = Ru, R = Me, 2b) with a series of phosphanes generates the cationic complexes [M2{μ- CN(Me)(R)}(μ-CO)(CO)(P)(Cp)2][SO3CF3] (M = Fe, R = Xy1, P = PPh2H, 6a; M = Fe, R = Xy1, P = PPh3, 6b; M = Fe, R = Xy1, P = PMe3, 6c; M = Fe, R = Me, P = PMe2Ph, 6d; M = Fe, R = Me, P = PPh3, 6e; M = Fe, R = Me, P = PMePh2, 6f; M = Ru, R = Xy1, P = PPh2H, 6g; M = Ru, R = Me, P = PPh2H, 6h), in high yields. The molecular structure of 6a has been elucidated by an X-ray diffraction study. The reactions of [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO)(NCR′)(Cp)2][SO3CF3] [R′ = Me, 1a; R′ = tBu, 3] with PhLi and PPh2Li yield [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO)(Ph)(Cp)2] (8) and [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO)(PPh2)(Cp)2] (9), respectively. The molecular structure of 8 has been ascertained by X-ray diffraction. Conversely, the reaction of 1a with MeLi generates the aminoalkylidene compound [Fe2{C(Me)N(Me)(Xy1)}(μ-CO)2(CO)(Cp)2] (10). Finally, the acetone complex [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO)(OCMe2)(Cp)2][SO3CF3] (12) reacts with lithium acetylides to give complexes [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO)(C≡CR)(Cp)2] (R = p-C6H4Me, 11a; R = Ph, 11b; R = SiMe3, 11c), in high yields. Filtration through alumina of a solution of 11a in CH2Cl2 results in hydration of the acetylide group and C-Si bond cleavage, affording [Fe2{μ-CN(Me)(Xy1)}(μ-CO)(CO){C(O)Me}(Cp)2] (12).

In this contribution, we report the synthesis, the chemical and photophysical characterization, and the study of the reactivity toward electrophiles of two mononuclear complexes of the type [Ru(bpy)2L]+ (bpy is 2,2'-bipyridyl), in which L is represented by the deprotonated form of 2-(1,H-tetrazol-5-yl)pyridine (L1) or 2-(1,H-tetrazol-5-yl)pyrazine (L2). The 1H and 13C NMR experiments that were performed on complexes RuL1 and RuL2 allowed us to establish that the tetrazolate moiety is bonded to the metal center via the N-1 nitrogen, while the coplanar arrangement adopted by the coordinated ligand upon coordination and the consequent interannular conjugation effect accounts for the unexpectedly low field resonance of the tetrazole carbon. The 13C NMR spectroscopy is also of fundamental importance to determine the chemo- and regioselectivity of the addition of a methyl group to RuL1 and RuL2, which takes place at the N-3 nitrogen of the five-membered ring. All these features were confirmed by the X-ray diffraction structures of RuL1 and of the methylated compounds RuL1Me and RuL2Me. Relative to these latter complexes, the presence of a methyl moiety does not cause any distortion from coplanarity of the coordinated tetrazolates. The redox properties of the complexes were investigated by cyclic voltammetry and indicated a quite different behavior between the pyrazinyl-tetrazolate and the pyridyl-tetrazolate complexes as the consequence of the higher electron-withdrawing character of the pyrazine ring. The study of the photophysical properties of the complexes also shows a significant diversity between the luminescent RuL1 and the rather poorly emissive RuL2. Interestingly, the methylated compounds RuL1Me and RuL2Me display radiative excited-state decays with longer lifetimes than their precursors; this feature indicates that methylation is a useful reaction for the tuning of the light emission performances of similar tetrazolate complexes. The synthesis and the characterization of a novel dinuclear complex of type [(bpy)2Ru-L3-Ru(bpy)2]2+, Ru(L3)Ru, where L3 is the bis-anion derived from bis-2,3-(1,H-tetrazol-5-yl)pyrazine, is also reported.

The diiron vinyliminium complexes [Fe2{μ-η1:η3-C(R′) C(H)C N(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Me, R′ = SiMe3 (1a); R = Me, R′ = CH2OH (1b); R = CH2Ph, R′ = Tol (1c), Tol = 4-MeC6H4; R = CH2Ph, R′ = COOMe (1d); R = CH2Ph, R′ = SiMe3 (1e)) undergo regio- and stereo-selective addition by cyanide ion (from NBu 4 n CN ), affording the corresponding bridging cyano-functionalized allylidene compounds [Fe2{μ-η1:η3-C(R′)C(H)C(CN)N(Me)(R)}(μ-CO)(CO)(Cp)2] (3a–e), in good yields. Similarly, the diiron vinyliminium complexes [Fe2{μ-η1:η3-C(R′) C(R′)C N(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R = R′ = Me (2a); R = Me, R′ = Ph (2b); R = CH2Ph, R′ = Me (2c); R = CH2Ph, R′ = COOMe (2d)) react with cyanide and yield [Fe2{μ-η1:η3-C(R′)C(R′)C(CN)N(Me)(R)}(μ-CO)(CO)(Cp)2] (9a–d). The reactions of the vinyliminium complex [Fe2{μ-η1:η3-C(Tol) CHC N(Me)(4-C6H4CF3)}(μ-CO)(CO)(Cp)2][SO3CF3] (4) with NaBH4 and NBu 4 n CN afford the allylidene [Fe2{μ-C(Tol)C(H) C(H)N(Me)(C6H4CF3)}(μ-CO)(CO)(Cp)2] (5) and the cyanoallylidene [Fe2{μ-C(Tol)C(H) C(CN)N(Me)(C6H4CF3)}(μ-CO)(CO)(Cp)2] (6), respectively. Analogously, the diruthenium vinyliminium complex [Ru2{μ-η1:η3-C(SiMe3) CHC N(Me)(CH2Ph)}(μ-CO)(CO)(Cp)2][SO3CF3] (7) reacts with NBu 4 n CN to give [Ru2{μ-η1:η3-C(SiMe3)CHC(CN)N(Me)(CH2Ph)}(μ-CO)(CO)(Cp)2] (8). Finally, cyanide addition to [Fe2{μ-η1:η3-C(COOMe) C(COOMe)C N(Me)(Xyl)}(μ-CO)(CO)(Cp)2][SO3CF3] (2e) (Xyl = 2,6-Me2C6H3), yields the cyano-functionalized bis-alkylidene complex [Fe2{μ-η1:η2-C(COOMe)C(COOMe)(CN)CN(Me)(Xyl)}(μ-CO)(CO)(Cp)2] (10). The molecular structures of 3a and 9a have been elucidated by X-ray diffraction.

Terminal alkynes (HCCR′) (R′=COOMe, CH2OH) insert into the metal–carbyne bond of the diiron complexes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO)(NCMe)(Cp)2][SO3CF3] (R=Xyl, 1a; CH2Ph, 1b; Me, 1c; Xyl=2,6-Me2C6H3), affording the corresponding μ-vinyliminium complexes [Fe2{μ-σ:η3-C(R′)CHCN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Xyl, R′=COOMe, 2; R=CH2Ph, R′=COOMe, 3; R=Me, R′=COOMe, 4; R=Xyl, R′=CH2OH, 5; R=Me, R′=CH2OH, 6). The insertion is regiospecific and C–C bond formation selectively occurs between the carbyne carbon and the CH moiety of the alkyne. Disubstituted alkynes (R′CCR′) also insert into the metal–carbyne bond leading to the formation of [Fe2{μ-σ:η3-C(R′)C(R′)CN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R′=Me, R=Xyl, 8; R′=Et, R=Xyl, 9; R′=COOMe, R=Xyl, 10; R′=COOMe, R=CH2Ph, 11; R′=COOMe, R=Me, 12). Complexes 2, 3, 5, 8, 9 and 11, in which the iminium nitrogen is unsymmetrically substituted, give rise to E and/or Z isomers. When iminium substituents are Me and Xyl, the NMR and structural investigations (X-ray structure analysis of 2 and 8) indicate that complexes obtained from terminal alkynes preferentially adopt the E configuration, whereas those derived from internal alkynes are exclusively Z. In complexes 8 and 9, trans and cis isomers have been observed, by NMR spectroscopy, and the structures of trans-8 and cis-8 have been determined by X-ray diffraction studies. Trans to cis isomerization occurs upon heating in THF at reflux temperature. In contrast to the case of HCCR′, the insertion of 2-hexyne is not regiospecific: both [Fe2{μ-σ:η3-C(CH2CH2CH3)C(Me)CN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Xyl, 13; R=Me, 15) and [Fe2{μ-σ:η3-C(Me)C(CH2CH2CH3)CN(Me)(R)}(μ-CO)(CO)(Cp)2][SO3CF3] (R=Xyl, 14, R=Me, 16) are obtained and these compounds are present in solution as a mixture of cis and trans isomers, with predominance of the former.

The iron complex [Fp][OTf] (Fp+L[Fe(CO)2(Cp)]+, OTf2LSO3CF32) was found to act as efficient catalyst for the dehydrative etherification of ferrocenylmethanol [HOCH2–Fc] with a variety of alcohols (ROH), providing a valuable route for the formation of ferrocenylmethanol-ethers [ROCH2–Fc]. The complex [Fp][OTf] also catalyzes etherification of propargyl alcohols with other alcohols. The advantages of the method are associated with the use of a non toxic and easily available transition metal as catalyst, and the dehydrative synthetic approach, which produces water as the only by-product.