Novel Pb(II), Zn(II), and Cd(II) coordination polymers constructed from ferrocenyl-substituted carboxylate and bipyridine-based ligands

Treatment of two kinds of ferrocenyl-substituted carboxylate ligands (3-ferrocenyl-2-crotonic acid, HOOC-CH=(CH(3))CFc (Fc=(eta(5)-C(5)H(5))Fe(eta(5)-C(5)H(4))) or O-ferrocecarbonyl benzoic acid, o-HOOCC(6)H(4)COFc with Pb(OAc)(2).3H(2)O, Zn(OAc)(2).2H(2)O, or Cd(OAc)(2).2H(2)O) resulted in four novel ferrocene-containing coordination polymers [[Pb(mu(2)-eta(2)-OOCCH=(CH(3))CFc)(2)].MeOH](n) (1), [[Zn(o-OOCC(6)H(4)COFc)(2)(4,4'-bipy)(H(2)O)(2)].2MeOH.2H(2)O](n) (4,4'-bipy = 4,4'-bipyridine) (2), [[Cd(o-OOCC(6)H(4)COFc)(2)(bpe)(MeOH)(2)].2H(2)O](n) (bpe = 1,2-bis(4-pyridyl)ethene) (3), and [Pb(o-OOCC(6)H(4)COFc)(eta(2)-o-OOCC(6)H(4)COFc)(bpe)](n)() (4). Their crystal structures have been characterized by single X-ray determinations. In polymer 1, Pb(II) ions are bridged by tridentate FcC(CH(3))=CHCOO(-) anions, forming an infinite chain [Pb(mu(2)-eta(2)-OOC=CH(CH(3))CFc)(2)](n). In polymers 2-4, there are three kinds of components, metal ions, o-FcCOC(6)H(4)COO(-) units, and organic bridging ligands. The bipyridine-based ligands connect metal ions leading to a one-dimensional chain with o-FcCOC(6)H(4)COO(-) units acting as monodentate or chelate ligands in the side chain. Such coordination polymers containing ferrocenyl-substituted carboxylate and bipyridine-based ligands are very rare. The solution-state differential pulse voltammetries of polymers 1-4 were determined. The results indicate that the half-wave potential of the ferrocenyl moieties is influenced by the Pb(II) ions in polymer 1 and strongly influenced by Zn(II), Cd(II), or Pb(II) ions in polymers 2-4. The thermal properties of the four polymers were also investigated.     

Novel one-dimensional polymers generated from p-Ferrocenylbenzoate: syntheses, structures, and magnetic properties

Treatment of p-ferrocenylbenzoate [p-HOOCH4C6Fc, Fc = (eta5-C5H5)Fe(eta5-C5H5)] with Mn(OAc)2 x 2H2O or Cd(OAc)2 x 2H2O afforded one-dimensional linear chain polymer [[Mn(OOCH4C6Fc)2(mu2-OH2)(H2O)2](H2O)]n (1), double-bridge polymer [Mn(mu2-OOCH4C6Fc)2(phen)]n (phen = phenanthroline) (2), and ladderlike framework [[Cd(mu2-OOCH4C6Fc)(eta2-OOCH4C6Fc)(bbp)](CH3OH)]n (bbp = 4,4'-trimethylene-dipyridine) (3). The solution-state cyclic voltammograms indicate that the half-wave potentials of the ferrocenyl moieties in these polymers are all shifted to positive potential compared to that of sodium p-ferrocenylbenzoate. Both 1 and 2 behave as 1D Heisenberg Mn(II) chains with weak intrachain antiferromagnetic interactions between the local high-spin Mn(II) ions, and the exchange coupling parameters J (-5.20 and -3.25 cm(-1) for 1 and 2, respectively) are larger than those of most of the reported di-Mn(II) complexes that contain mu2-aqua and mu2-carboxylato units and one-dimensional Mn(II) carboxylic polymers.     

Controllable assembly of metal-directed coordination polymers under diverse conditions: a case study of the M(II)-H3tma/Bpt mixed-ligand system

A series of new metal-organic polymeric complexes, [[Co(bpt)(Htma)(H2O)3].2.25H2O]n (1), [Co(bpt)(Htma)(H2O)]n (2), [Ni(bpt)(Htma)(H2O)]n (3), [Zn(bpt)2(H2tma)2].6H2O (4), [[Cd(bpt)(Htma)(H2O)].(C2H5OH)(H2O)1.5]n (5), and [[Cd(bpt)(Htma)(H2O)2].5.5H2O]n (6), was prepared from solution reactions of 4-amino-3,5-bis(4-pyridyl)-1,2,4-triazole (bpt) and trimesic acid (H3tma) with different metal salts under diverse conditions. All these compounds were structurally determined by X-ray single-crystal diffraction, and the bulk new materials were further identified by X-ray powder diffraction. Complexes 1 and 6 show 1-D zigzag or linear Htma-bridged polymeric chains, with the terminal bpt ligands as pendants, which are extended to 2-D hydrogen-bonded arrays with 4.8(2) or (6,3) network topology. Coordination polymers 2 and 3, in which the 2-D corrugated metal-organic frameworks make the interdigitated 3-D packing, are isostructural. Complex 4 has a mononuclear structure, and its subunits are hydrogen-bonded to each other to give a 2-D grid-like net. For complex 5, the Cd(II) centers are linked by bpt/Htma ligands to form a 2-D (4,4) coordination layer, and these layers are interdigitated in pairs. Notably, secondary noncovalent forces, such as hydrogen bonds, play an important role in extending and stabilizing these structural topologies. Interestingly, distinct products are obtained for Co(II) (1 and 2) and Cd(II) (5 and 6) under ambient or hydrothermal conditions; however, for Ni(II) and Zn(II), single products, 3 and 4, are generated. The thermal stabilities of 1-6 were studied by thermogravimetric analysis of mass loss. The desorption/adsorption properties of the porous material 5 are also discussed. Solid-state luminescent spectra of the Zn(II) and Cd(II) complexes, 4-6, indicate intense fluorescent emissions at ca. 380 nm.     

d(10) Metal complexes assembled from isomeric benzenedicarboxylates and 3-(2-pyridyl)pyrazole showing 1D chain structures: syntheses, structures and luminescent properties

Seven new d10 metal coordination polymers with isomeric benzenedicarboxylates and 3-(2-pyridyl)pyrazole ligands, [Zn2 L2(1,2-BDC)(H2O)]n ( 1), {[Cd2(H L)2(1,2-BDC)2] x H2O}n ( 2), [Cd(H L)(1,2-BDC)(H2O)]n (3), [Zn(H L)(1,3-BDC)(H2O) x 3H2O]n ( 4), [Cd2 L2(1,3-BDC)(H2O)]n (5), [Zn(H L)2(1,4-BDC)]n ( 6) and [Cd(H L)2(1,4-BDC)]n (7) (BDC = benzenedicarboxylate, H L = 3-(2-pyridyl)pyrazole), have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Single-crystal X-ray analyses reveal that each complex takes a different one-dimensional (1D) chain structure. In 1-7, the BDCs act as bridging ligands, exhibiting rich coordination modes to link metal ions. The three BDC isomers exhibit different coordination modes: micro(1)-eta(1):eta(1)/micro(3)-eta(2):eta(1), micro(3)-eta(1):eta(2)/micro(3)-eta(2):eta(1), micro(2)-eta(1):eta(1)/micro(1)-eta(1):eta(0) and micro(1)-eta(1):eta(1)/micro(1)-eta(1):eta(0) for 1,2-BDC, micro(1)-eta(1):eta(1)/micro(1)-eta(1):eta(0) and micro(1)-eta(1):eta(0)/micro(2)-eta(2):eta(1) for 1,3-BDC, and micro(1)-eta(1):eta(0)/micro(1)-eta(0):eta(1), micro(1)-eta(1):eta(0)/micro(1)-eta(1):eta(0) and micro(1)-eta(1):eta(1)/micro(1)-eta(1):eta(1) for 1,4-BDC, respectively. In these complexes, H acts as a simple bidentate chelate ligand (in 2, 3, 4, 6 and 7), similar to 2,2'-bipyridine, or as a tridentate chelate-bridging ligand (in 1 and 5) via deprotonation of the pyrazolyl NH group and coordination of the pyrazolyl N atom to a second metal ion. The structural differences indicate that the backbone of such dicarboxylate ligands plays an important role in governing the structures of such metal-organic coordination architectures, and the chelating bipyridyl-like ligand H leads to the formation of these coordination polymers with one-dimensional structures by occupying the coordination sites of metal ions. Moreover, the photoluminescent properties of complexes were also studied in the solid-state at room temperature.     

Syntheses, structures, and luminescent and magnetic properties of novel three-dimensional lanthanide complexes with 1,3,5-benzenetriacetate

Five novel lanthanide complexes with the formulas [Nd(bta)(H2O)2.4.35H2O]n(1), [Sm(bta)(H2O)2.4.5H2O]n (2), [Eu(bta)(H2O).1.48H2O]n (3), [Tb(bta)(H2O).1.31H2O]n (4), and [Yb(bta)(H2O).H2O]n (5) (H3bta = 1,3,5-benzenetriacetic acid) have been prepared by using the corresponding lanthanide salt and H3bta. The results of an X-ray crystallographic analysis revealed that all the complexes have three-dimensional channel-like structures, in which the bta3- ligands adopt different coordination modes: monodentate and mu2-eta2:eta1-bridging coordination modes in 1, 2, and 5 and mu2-eta1:eta1-bridging and mu2-eta2:eta1-bridging coordination modes in 3 and 4, respectively. Complexes 1 and 2, as well as 3 and 4, are isostructural, respectively, in which all the Ln(III) (Ln = Nd, Sm, Eu, and Tb) atoms are nine-coordinated, while the Yb(III) atoms in complex 5 are eight-coordinated. Both complexes 3 and 4 showed strong luminescence upon excitation, and their luminescence decay curves fit well with single exponential decays of which the lifetime is 0.45 ms for 3 and 1.0 ms for 4. The magnetic properties of the complexes were investigated in the temperature range of 1.8-300 K.     

Crystal engineering of a versatile building block toward the design of novel inorganic-organic coordination architectures

Six novel inorganic-organic coordination supramolecular networks based on a versatile linking unit 4-pyridylthioacetate (pyta) and inorganic Co(II), Cu(II), Ag(I), Zn(II), Mn(II) and Pb(II) salts have been prepared in water medium and structurally characterized by single-crystal X-ray diffraction analysis. Reaction of CoCl(2).6H(2)O with Hpyta afforded a neutral mononuclear complex [Co(pyta)(2)(H(2)O)(4)](1), which exhibits a two-dimensional (2-D) layered architecture through intermolecular O-HO interactions. Reaction of CuCl(2.2H(2)O with Hpyta yielded a neutral one-dimensional (1-D) coordination polymer [[Cu(pyta)(2)(H(2)O].0.5H(2)O](n)(2) consisting of rectangle molecular square units, which show a three-dimensional (3-D) supramolecular network through S...S and O-H...O weak interactions. However, when AgNO(3), Zn(OAc)(2).2H(2)O or MnCl(2).4H(2)O salts were used in the above self-assembled processes, the neutral 2-D coordination polymers [Ag(pyta)](n)(3), [[Zn(pyta)(2)].4H(2)O](n)(4) or [[Mn(pyta)(2)(H(2)O)]](n)(5) with different topologies were obtained, respectively. While substituting the transition metal ions used in 1-5 with Pb(OAc)(2).3H(2)O, a one-dimensional coordination polymer [Pb(pyta)(2)](n)(6), which shows a novel 2-fold interpenetrating 2-D supramolecular architecture through weak SS interactions, was isolated. It is interesting to note that the building block pyta anion exhibits different configurations and coordination modes in the solid structures of complexes 1-6. These results indicate that the versatile nature of this flexible ligand, together with the coordination preferences of the metal centers, play a critical role in construction of these novel coordination polymers or supramolecules. The spectral and thermal properties of these new materials have also been investigated.     

An unusual ligand in copper chemistry: coordination oligomers and polymers containing the [[CpMo(CO)2]2(mu,eta2-Sb2)] cluster

The coordination behavior of [[CpMo(CO)(2)}(2)(mu,eta(2)-Sb(2))] (1; Cp = cyclopentadiene) toward Cu(I) was investigated. Its reaction with CuX (X = Br, Cl, and I) produced oligomers or polymers of the general formula [[CpMo(CO)(2)](2)(mu,eta(2)-Sb(2))(mu-CuX)](n). While 2 (X = Cl, n = 2) and 3 (X = Br, n = 2) proved to be halogen-bridged dimers in both solution and solid state, the molecules of 4 (X = I, n = infinity) self-assembled in the crystal forming a linear polymer with a Cu-I skeleton supported by Sb-Cu bonds. The reaction of 1 with Cu[GaCl(4)] resulted in the formation of the ionic complex [[CpMo(CO)(2)](2)(mu,eta(2)-Sb(2))](4)Cu(2)[GaCl(4)](2) (5). Its dication contains four [[CpMo(CO)(2)](2)(mu,eta(2)-Sb(2))] ligands arranged around a Cu-Cu dumbbell. All new compounds were characterized using IR, electrospray ionization mass spectrometry, (1)H NMR, elemental analysis, and single-crystal X-ray diffraction. The ligand was oxidized by both silver(I) and copper(II), and a cyclovoltammetric study revealed that 1 suffered irreversible reduction and oxidation in a dichloromethane solution at -2.04 and 0.10 V, respectively, versus ferrocene.     

Bismuth-ferrocene carboxylates: synthesis and structure

The reaction of ferrocenedicarboxylic acid with triphenylbismuth in a 1?:?1 ratio under solvothermal conditions afforded the 1D coordination polymer [Bi(2)(μ(2)-η(2)-OOCFcCOO-μ(2)-η(2))(η(2)-OOCFcCOO-η(2))(μ(2)-η(2)-OOCFcCOO-η(2))](n) (1). In this polymer two types of bismuth centers (hepta- and octacoordinate) are present and are interconnected by the bridging coordination of ferrocene dicarboxylate ligands. The reaction of ferrocenecarboxylic acid with triphenylbismuth in a 1?:?3 ratio, in toluene, under refluxing conditions, afforded the 1D coordination polymer [Bi(μ(2)-η(2)-FcCOO)(η(2)-FcCOO)(2)](n) (2). In the solid state, 2 exists as a helical polymer, where the inner bismuth chain is enclosed by an external sheath of ferrocene carboxylate ligands. In solution, however, 2 decomposes into the monomeric repeat unit [Bi(FcCOO)(3)] which is indicated by ESI-MS as well as cyclic voltammetric studies. Thus, a single, quasi-reversible redox event is seen for 2 in solution. The reaction of triphenylbismuth with ferrocenecarboxylic acid in a 1?:?1 stoichiometry afforded the molecular dimer [Bi(2)(μ(2)-η(2)-FcCOO)(2)(η(2)-FcCOO)(4)(H(2)O)(4)]·(2FcCOOH) (3). Compounds 1-3 reveal rich supramolecular architectures in the solid state as a result of the presence of C-HO, C-Hπ and ππ interactions.     

2 + 2] cross coupling of benzene and tropylium ligands in reductively activated piano stool complexes of Mn,Cr, and W

We have established cation/anion coupling reactions between the tropylium ligand in [M(eta7-C7H7)(CO)3]+ (M = Cr, W) and the reductively activated eta4-benzene ligand in [Mn(eta4-C6H6)(CO)3]- (3-) to form [M(CO)3(mu2-eta6:eta5-C7H7-C6H6)Mn(CO)3]; [Cr(CO)3(mu2-eta6:eta5-C7H7-C6H6)Mn(CO)3] can be further reduced to [Cr(CO)3(mu2-eta5:eta4-C7H7-C6H6)Mn(CO)3]2-, in which the tropylium and benzene ligands have undergone a [2 + 2] cross coupling reaction.     

Transfer hydrogenation processes to mu(3)-alkylidyne groups on the organotitanium oxide [Ti(3)Cp*O(3)

The photochemical treatment of mu(3)-alkylidyne complexes [[TiCp*(mu-O)](3)(mu(3)-CR)] (R=H (1), Me (2), Cp*=eta(5)-C(5)Me(5)) with the amines (2,6-Me(2)C(6)H(3))NH(2), Et(2)NH, and Ph(2)NH and the imine Ph(2)C=NH leads to the partial hydrogenation of the alkylidyne moiety that is supported on the organometallic oxide, [Ti(3)Cp*O(3)], and the formation of new oxoderivatives [[TiCp*(3)(mu-CHR)(R'NR")] (R"=2,6-Me(2)C(6)H(3), R'=H, R=H (3), Me (4); R'=R"=Et, R=H (5), Me (6); R'=R"=Ph, R=H (7), Me (8)) and [[TiCp*(mu-O)](3)(mu-CHR)(N=CPh(2))] (R=H (9), R=Me (10)), respectively. A sequential transfer hydrogenation process occurs when complex 1 is treated with tBuNH(2), which initially gives the mu-methylene [[TiCp*(mu-O)](3)(mu-CH(2))(HNtBu)] (11) complex and finally, the alkyl derivative [[TiCp*(mu-O)](3)(mu-NtBu)Me] (12). Furthermore, irradiation of solutions of the mu(3)-alkylidyne complexes 1 or 2 in the presence of diamines o-C(6)H(4)(NH(2))(2) and H(2)NCH(2)CH(2)NH(2) (en) affords [[TiCp*(mu-O)](3)(mu(3)-eta(2)-NC(6)H(4)NH)] (13) and [[TiCp*(mu-O)](3)(mu(3)-eta(2)-NC(2)H(4)NH)] (14) by either methane or ethane elimination, respectively. In the reaction of 1 with en, an intermediate complex [[TiCp*(mu-O)](3)(mu-CH(2))(NHCH(2)CH(2)NH(2))] (15) is detected by (1)H NMR spectroscopy. Thermal treatment of the complexes 4-10 quantitatively regenerates the starting mu(3)-alkylidyne compounds and the amine R'(2)NH or the imine Ph(2)C=NH; however, heating of solutions of 3 or 4 in [D(6)]benzene or a equimolecular mixture of both at 170 degrees C produces methane, ethane, or both, and the complex [[TiCp*(mu-O)](3)[mu(3)-eta(2)-NC(6)H(3)(Me)CH(2)]] (16). The molecular structure of 8 has been established by single-crystal X-ray analysis.     

Cadmium(II) and copper(II) complexes with imidazole-containing tripodal polyamine ligands: pH and anion effects on carbon dioxide fixation and assembling

A new Cd(II) complex [Cd3(L)3(mu3-CO3)](ClO4)4.2CH3CN (1) with two-dimensional (2D) network structure was obtained by reaction of an imidazole-containing tripodal polyamine ligand N1-(2-aminoethyl)-N1-(2-imidazolethyl)-ethane-1,2-diamine (L) with Cd(ClO4)2.6H2O at pH 9.0 in air. The carbonate anions (CO3(2-)) are from the hydration of the atmospheric carbon dioxide, which is the same as in the previously reported Cu(II) complex [Cu3(L)3(mu3-CO3)](ClO4)4.3CH3CN (2). However, the coordination mode of CO3(2-) in 1 is mu3-eta2:eta2:eta2 while the one in 2 is mu3-eta1:eta1:eta1. One-dimensional (1D) chain Cd(II) and Cu(II) complexes [Cd(L)Cl]ClO4.H2O (3) and [Cu(L)(H2O)](ClO4)2 (4) without CO3(2-) were prepared by a similar method as that for 1 and 2 except for the different reaction pH, namely, 3 and 4 were obtained at pH 7 while 1 and 2 were obtained at pH 9. In addition, when Cu(NO3)2 was used to react with L at pH 9, a unique 1D double-stranded helical chain complex [Cu(L)Cl]NO3.1.25H2O (5) was obtained. The results revealed that the reaction pH and the counteranion have great impact on the carbon dioxide absorption and hydration as well as on the assembling and structure of the complexes. The magnetic property of complex 2 was investigated in the temperature range of 1.8-300 K, and weak ferromagnetic coupling among the mu3-eta1:eta1:eta1-CO3(2-) bridged Cu(II) atoms was observed.     

Ammonolysis of mono(pentamethylcyclopentadienyl) titanium(IV) derivatives

Ammonolyses of mono(pentamethylcyclopentadienyl) titanium(IV) derivatives [Ti(eta5-C5Me5)X3] (X = NMe2, Me, Cl) have been carried out in solution to give polynuclear nitrido complexes. Reaction of the tris(dimethylamido) derivative [Ti(eta5-C5Me5)(NMe2)3] with excess of ammonia at 80-100 degrees C gives the cubane complex [[Ti(eta5-C5Me5)]4(mu3-N)4] (1). Treatment of the trimethyl derivative [Ti(eta5-C5Me5)Me3] with NH3 at room temperature leads to the trinuclear imido-nitrido complex [[Ti(eta/5-CsMes)(mu-NH)]3(mu3-N)] (2) via the intermediate [[Ti(eta5-C5Me5)Me]2(mu-NH)2] (3). The analogous reaction of [Ti(eta5-C5Me5)Me3] with 2,4,6-trimethylaniline (ArNH2) gives the dinuclear imido complex [[Ti(eta5-C5Me5)Me])2(mu-NAr)2] (4) which reacts with ammonia to afford [[Ti(eta5-C5Me5)(NH2)]2(mu-NAr)2] (5). Complex 2 has been used, by treatments with the tris(dimethylamido) derivatives [Ti(eta5-C5H5-nRn)(NMe2)3], as precursor of the cubane nitrido systems [[Ti4(eta5-C5Me5)3(eta5-C5H5-nRn)](mu3-N)4] [R = Me n = 5 (1), R = H n = 0 (6), R = SiMe3 n = 1 (7), R = Me n = 1 (8)] via dimethylamine elimination. Reaction of [Ti(eta5-C5Me5)Cl3] or [Ti(eta5-C5Me5)(NMe2)Cl2] with excess of ammonia at room temperature gives the dinuclear complex [[Ti2(eta5-C5Me5)2Cl3(NH3)](mu-N)] (9) where an intramolecular hydrogen bonding and a nonlineal nitrido ligand bridge the "Ti(eta5-C5Me5)Cl(NH3)" and "Ti(eta5-C5Me5)Cl2" moieties. The molecular structures of [[Ti(eta5-C5Me5)Me]2 (mu-NAr)2] (4) and [[Ti2(eta5-C5Me5)2Cl3(NH3)](mu-N)] (9) have been determined by X-ray crystallographic studies. Density functional theory calculations also have been conducted on complex 9 to confirm the existence of an intramolecular N-H...Cl hydrogen bond and to evaluate different aspects of its molecular disposition.     

Interplay of cubic building blocks in (et6-arene)ruthenium-containing tungsten and molybdenum oxides

A series of molybdenum and tungsten organometallic oxides containing [Ru(arene)]2+ units (arene =p-cymene, C6Me6) was obtained by condensation of [[Ru(arene)Cl2]2] with oxomolybdates and oxotungstates in aqueous or nonaqueous solvents. The crystal structures of [[Ru(eta6-C6Me6]]4W4O16], [[Ru(eta6-p-MeC6H4iPr]]4W2O10], [[[Ru-(eta6-p-MeC6H4iPr)]2(mu-OH)3]2][[Ru(eta6-p-MeC6H4iPr)]2W8O28(OH)2[Ru(eta6-p-MeC6H4iPr)(H2O)]2], and [[Ru(eta6-C6Me6)]2M5O18[Ru(eta6-C6Me6)(H2O)]] (M = Mo, W) have been determined. While the windmill-type clusters [[Ru(eta6-arene)]4(MO3)4(mu3-O)4] (M = Mo, W; arene =p-MeC6H4iPr, C6Me6), the face-sharing double cubane-type cluster [[Ru(eta6-p-MeC6H4iPr)]4(WO2)2(mu3-O)4(mu4-O)2], and the dimeric cluster [[Ru(eta6-p-MeC6H4iPr)(WO3)3(mu3-O)3(mu3-OH)Ru(eta6-pMeC6H4iPr)(H2O)]2(mu-WO2)2]2- are based on cubane-like units, [(Ru(eta6-C6Me6)]2M5O18[Ru(eta6-C6Me6)(H2O)]] (M = Mo, W) are more properly described as lacunary Lindqvist-type polyoxoanions supporting three ruthenium centers. Precubane clusters [[Ru(eta6-arene)](MO3)2(mu-O)3(mu3-O)]6- are possible intermediates in the formation of these clusters. The cluster structures are retained in solution, except for [[Ru(eta6-p-MeC6H4iPr)]4Mo4O16], which isomerizes to the triple-cubane form.     

Synthesis, characterisation, crystal structures, reactivity, and electrochemistry of ruthenium-nitrido, ruthenium-cobalt-imido and ruthenapyrrolidone carbonyl clusters containing alkyne ligands

Thermolysis of [Ru3(CO)9(mu3-NOMe)(mu3-eta2-PhC2Ph)] (1) with two equivalents of [Cp*Co(CO)2] in THF afforded four new clusters, brown [Ru5(CO)8(mu-CO)3(eta5-C5Me5)(mu5-N)(mu4-eta2-PhC2Ph)] (2), green [Ru3Co2(CO)7(mu3-CO)(eta5-C5Me5)2(mu3-NH)[mu4-eta8-C6H4-C(H)C(Ph)]] (3), orange [Ru3(CO)7(mu-eta6-C5Me4CH2)[mu-eta3-PhC2(Ph)C(O)N(OMe)]] (4) and pale yellow [Ru2(CO)6[mu-eta3-PhC2(Ph)C(O)N(OMe)]] (5). Cluster 2 is a pentaruthenium mu5-nitrido complex, in which the five metal atoms are arranged in a novel "spiked" square-planar metal skeleton with a quadruply bridging alkyne ligand. The mu5-nitrido N atom exhibits an unusually low frequency chemical shift in its 15N NMR spectrum. Cluster 3 contains a triangular Ru2Co-imido moiety linked to a ruthenium-cobaltocene through the mu4-eta8-C6H4C(H)C(Ph) ligand. Clusters 4 and 5 are both metallapyrrolidone complexes, in which interaction of diphenylacetylene with CO and the NOMe nitrene moiety were observed. In 4, one methyl group of the Cp* ring is activated and interacts with a ruthenium atom. The "distorted" Ru3Co butterfly nitrido complex [Ru3Co(CO)5(eta5-C5Me5)(mu4-N)(mu3-eta2-PhC2Ph)(mu-I)2I] (6) was isolated from the reaction of 1 with [Cp*Co(CO)I2] heated under reflux in THF, in which a Ru-Ru wing edge is missing. Two bridging and one terminal iodides were found to be placed along the two Ru-Ru wing edges and at a hinge Ru atom, respectively. The redox properties of the selected compounds in this study were investigated by using cyclic voltammetry and controlled potential coulometry. 15N magnetic resonance spectroscopy studies were also performed on these clusters.     

Rhodium/iridium-titanium azaheterometallocubanes

Treatment of [[Ti(eta5-C5Me5)(mu-NH)]3(mu3-N)] (1) with the diolefin complexes [[MCl(cod)]2] (M = Rh, Ir; cod = 1,5-cyclooctadiene) in toluene afforded the ionic complexes [M-(cod)(mu3-NH)3Ti3(eta5-C5Me5)3(mu3-N)]Cl [M = Rh (2), Ir (3)]. Reaction of complexes 2 and 3 with [Ag(BPh4)] in dichloromethane leads to anion metathesis and formation of the analogous ionic derivatives [M(cod)(mu3-NH)3Ti3-(eta5-C5Me5)3(mu3-N)][BPh4] [M = Rh (4), Ir (5)]. An X-ray crystal structure determination for 5 reveals a cube-type core [IrTi3N4] for the cationic fragment, in which 1 coordinates in a tripodal fashion to the iridium atom. Reaction of the diolefin complexes [[MCl(cod))2] (M = Rh, Ir) and [[RhCl(C2H4)2]2] with the lithium derivative [[Li(mu3-NH)2(mu3-N)-Ti3(eta5-C5Me5)3(mu3-N)]2] x C7H8 (6 C7H8) in toluene gave the neutral cube-type complexes [M(cod)(mu-NH)2(mu3-N)Ti3-(eta5-C5Me5)3(mu3-N)] [M = Rh (7), Ir (8)] and [Rh(C2H4)2(mu3-NH)2(mu3-N)Ti3(eta5-C5Me5)3(mu3-N)] (9), respectively. Density functional theory calculations have been carried out on the ionic and neutral azaheterometallocubane complexes to understand their electronic structures.     

Synthetic, electrochemical, and theoretical studies of tetrairidium clusters bearing mono- and bis[60]fullerene ligands

Heating a mixture of Ir(4)(CO)(9)(PPh(3))(3) (1) and 2 equiv of C(60) in refluxing chlorobenzene (CB) affords a "butterfly" tetrairidium-C(60) complex Ir(4)(CO)(6){mu(3)-kappa(3)-PPh(2)(o-C(6)H(4))P(o-C(6)H(4))PPh(eta(1)-o-C(6)H(4))}(mu(3)-eta(2):eta(2):eta(2)-C(60)) (3, 36%). Brief thermolysis of 1 in refluxing chlorobenzene (CB) gives a "butterfly" complex Ir(4)(CO)(8){mu-k(2)-PPh(2)(o-C(6)H(4))PPh}{mu(3)-PPh(2)(eta(1):eta(2)-o-C(6)H(4))} (2, 64%) that is both ortho-phosphorylated and ortho-metalated. Interestingly, reaction of 2 with 2 equiv of C(60) in refluxing CB produces 3 (41%) by C(60)-assisted ortho-phosphorylation, indicating that 2 is the reaction intermediate for the final product 3. On the other hand, reaction of Ir(4)(CO)(8)(PMe(3))(4) (4) with excess (4 equiv) C(60) in refluxing 1,2-dichlorobenzene, followed by treatment with CNCH(2)Ph at 70 degrees C, affords a square-planar complex with two C(60) ligands and a face-capping methylidyne ligand, Ir(4)(CO)(3)(mu(4)-CH)(PMe(3))(2)(mu-PMe(2))(CNCH(2)Ph)(mu-eta(2):eta(2)-C(60))(mu(4)-eta(1):eta(1):eta(2):eta(2)-C(60)) (5, 13%) as the major product. Compounds 2, 3, and 5 have been characterized by spectroscopic and microanalytical methods, as well as by single-crystal X-ray diffraction studies. Cyclic voltammetry has been used to examine the electrochemical properties of 2, 3, 5, and a related known "butterfly" complex Ir(4)(CO)(6)(mu-CO){mu(3)-k(2)-PPh(2)(o-C(6)H(4))P(eta(1)-o-C(6)H(4))}(mu(3)-eta(2):eta(2):eta(2)-C(60)) (6). These cyclic voltammetry data suggest that a C(60)-mediated electron transfer to the iridium cluster center takes place for the species 3(3)(-) and 6(2)(-) in compounds 3 and 6. The cyclic voltammogram of 5 exhibits six well-separated reversible, one-electron redox waves due to the strong electronic communication between two C(60) cages through a tetrairidium metal cluster spacer. The electrochemical properties of 3, 5, and 6 have been rationalized by molecular orbital calculations using density functional theory and by charge distribution studies employing the Mulliken and Hirshfeld population analyses.     

Construction of [(eta5-C5Me5)MoS3Cu3]-based supramolecular assemblies from the [(eta5-C5Me5)MoS3(CuNCS)3]- cluster anion and multitopic ligands with different symmetries

The assembly of a new family of [(eta5-C5Me5)MoS3Cu3]-supported supramolecular compounds from a preformed cluster [PPh4][(eta5-C5Me5)MoS3(CuNCS)3].DMF (1.DMF) with four multitopic ligands with different symmetries is described. Reactions of 1 with 1,2-bis(4-pyridyl)ethane (bpe) (Cs symmetry) or 1,4-pyrazine (1,4-pyz) (D2h symmetry) in aniline gave rise to two polymeric clusters {[{(eta5-C5Me5)MoS3Cu3}2(NCS)3(mu-NCS)(bpe)3].3aniline}n (2) and [(eta5-C5Me5)MoS3Cu3(1,4-pyz)(mu-NCS)2]n (3). On the other hand, solid-state reactions of 1 with 2,4,6-tri(4-pyridyl)-1,3,5-triazine (tpt) (D3h symmetry) or 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphyrin (H2tpyp) (D4h symmetry if 21H and 23H of the H2tpyp are omitted) at 100 degrees C for 12 h followed by extraction with aniline yielded another two polymeric clusters {[(eta5-C5Me5)MoS3Cu3(tpt)(aniline)(NCS)2].0.75aniline. 0.5H2O}n (4) and {[(eta5-C5Me5)MoS3Cu3(NCS)(mu-NCS)(H2tpyp)0.4(Cu-tpyp)0.1].2aniline.2.5benzene}n (5). These compounds were characterized by elemental analysis, IR spectra, UV-vis spectra, 1H NMR, and X-ray analysis. Compound 2 consists of a 2D (6,3) network in which [(eta5-C5Me5)MoS3Cu3] cores serve both a T-shaped three-connecting node and an angular two-connecting node to interconnect other equivalent units through single bpe bridges, double bpe bridges, and mu-NCS bridges. Compound 3 has a 3D diamondlike framework in which each [(eta5-C5Me5)MoS3Cu3] core, acting as a tetrahedral connecting node, links four other neighboring units by 1,4-pyz bridges and mu-NCS bridges. Compound 4 contains a honeycomb 2D (6,3)core(6,3)tpt network in which each cluster core, serving a trigonal-planar three-connecting node, links three pairs of equivalent cluster cores via three tpt lignads. Compound 5 has a rare scalelike 2D (4,62)core(42,62)ligand network in which each cluster core acts as a T-shaped three-connecting node to link with other equivalent ones through mu-NCS bridges and H2tpyp (or Cu-tpyp) ligands. The results showed that the formation of the four different multidimensional topological structures was evidently affected by the symmetry of the ligands used. In addition, the third-order nonlinear optical properties of 1-5 in aniline were also investigated by using Z-scan techniques at 532 nm.     

Structural studies of N,N'-di(ortho-fluorophenyl)formamidine group 1 metallation

The treatment of N,N'-di(ortho-fluorophenyl)formamidine (HFPhF) in tetrahydrofuran with equimolar amounts of n-butyllithium, sodium bis(trimethylsilyl)amide or potassium bis(trimethylsilyl)amide affords the colourless crystalline formamidinate complexes [Li(FPhF)(thf)] (1), [Na(FPhF)(thf)] (2) and [K(FPhF)] (5). Low-temperature preparation of 2 in diethyl ether yields the Et(2)O adduct [Na(FPhF)(Et(2)O)] (3). At ambient temperature the sodium fluoride inclusion complex [Na(3)(FPhF)(3)(Et(2)O)(NaF)] (4) is also formed. Spectroscopic ((1)H, (13)C and (19)F((1)H) NMR) data for 1-5, microanalytical analyses for compounds 1, 2 and 5 and X-ray structure determinations for 1, 3-5 confirm the formulae of these species. In the solid-state, 1 and 3 possess a dimeric nature in which the formamidinate ligands coordinate through mu(2):eta(2):eta(1) (1) and mu(2):eta(2):eta(2) (3) binding modes. These are enabled by partial ortho-fluoro donation. Compound 4, which is also dimeric, contains two trisodium tris(formamidinate) units that comprise mu(2):eta(2):eta(2)-FPhF ligands, a bridging diethyl ether moiety and an unprecedented mu(3):eta(2):eta(2):eta(2)-formamidinate donor. Together, these trinuclear units encapsulate two sodium fluoride units by eta(2)-N,N-formamidinate chelation of the sodium cations (thereby creating further mu(3):eta(2):eta(2):eta(2)-bound formamidinates) and fluoride-sodium interactions. Compound 5 extends the coordinative versatility of FPhF to mu(2):eta(4):eta(3) coordination by the generation of K(2)(mu(2):eta(4):eta(3)-FPhF)(2) units that exhibit eta(2)-arene interactions. Macromolecularly, the overlaying of these units affords a polymeric solvent-free structure that incites coordination of the FPhF ligands to metal atoms above and below the K(2)(FPhF)(2) plane. Overall, this generates a remarkable mu(4):eta(4):eta(3):eta(2):eta(1)-amidinate binding mode that incorporates both bridging and terminal fluorine donors. Compounds 1-5 are the first non-chromium complexes of N,N'-di(ortho-fluorophenyl)formamidinate.     

Synthesis, structural diversity and fluorescent characterisation of a series of d10 metal-organic frameworks (MOFs): reaction conditions, secondary ligand and metal effects

Along with our recent investigation on the flexible ligand of H(2)ADA (1,3-adamantanediacetic acid), a series of Zn(II) and Cd(II) metal-organic frameworks, namely, [Zn(3)(ADA)(3)(H(2)O)(2)](n)·5nH(2)O (1), [Zn(ADA)(4,4'-bipy)(0.5)](n) (2), [Zn(2)(ADA)(2)(bpa)](n) (3), [Zn(2)(ADA)(2)(bpa)](n) (4), [Zn(2)(ADA)(2)(bpp)](n) (5), [Cd(HADA)(2)((4,4'-bipy)](n) (6), [Cd(3)(ADA)(3)(bpa)(2)(CH(3)OH)(H(2)O)](n) (7), and [Cd(2)(ADA)(2)(bpp)(2)](n)·7nH(2)O (8) have been synthesized and structurally characterized (where 4,4'-bipy = 4,4'-dipyridine, bpa = 1,2-bis(4-pyridyl)ethane and bpp = 1,3-bis(4-pyridyl)propane). Due to various coordination modes and conformations of the flexible dicarboxylate ligand and the different pyridyl-containing coligands, these complexes exhibit structural and dimensional diversity. Complex 1 exhibits a three-dimensional (3D) framework containing one-dimensional (1D) Zn(II)-O-C-O-Zn(II) clusters. Complex 2 exhibits a 2D structure constructed by 1D double chains based on [Zn(2)ADA(2)] units and a 4,4'-bipy pillar. Complexes 3 and 4 possess isomorphic 2D layer structures, resulting from the different coordination modes of carboxylate group of ADA ligands. Complex 5 features a 2D 4(4) layer in which ADA ligands and Zn(II) atoms construct a 1D looped chain and the chains are further connected by bpp ligands. Complex 6 is composed of 1D zig-zag chains that are entangled through hydrogen-bonding interactions to generate a 2D network. Complex 7 is a rare (3,5)-connected network. Complex 8 possesses a 3D microporous framework with lots of water molecules encapsulated in the channels. The structural diversity of the complexes perhaps mainly results from using diverse secondary ligands and different metal centre ions, and means the assistant ligand and metal centre play important roles in the design and synthesis of target metal-organic frameworks. This finding revealed that ADA could be used as an effective bridging ligand to construct MOFs and change coordination modes and conformational geometries in these complexes. The thermogravimetric analyses, X-ray powder diffraction and solid-state luminescent properties of the complexes have also been investigated.     

The first fullerene-metal sandwich complex: an unusually strong electronic communication between two C(60) cages

Reaction of Rh(6)(CO)(9)(dppm)(2)(mu(3)-eta(2),eta(2),eta(2)-C(60)) (1) with C(60) in refluxing chlorobenzene followed by treatment with CNR (R = CH(2)C(6)H(5)) at room temperature affords the first fullerene-metal sandwich complex Rh(6)(CO)(5)(dppm)(2)(CNR)(mu(3)-eta(2),eta(2),eta(2)-C(60))(2) (2). Compound 2 has been characterized by an X-ray diffraction study. Electrochemical study of 2 reveals six well-separated reversible redox couples localized at C(60) cages due to a strong electronic communication between the two C(60) centers via the Rh(6) cluster spacer.