Synthesis,structure characterization and thermal properties of [Zr6(μ3-O)4(μ3-OH)4(OOCCH2Bu)9(μ2-OH)3]2

Oxo/hydoxo zirconium(IV) complex of the general formula [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉(μ₂-OH)₃]₂ has been isolated, when Zr(OⁱPr)₄ reacted with a 2-fold excess of 3,3-dimethylbutyric acid. Single crystal X-ray diffraction data, collected at 103 and 153 K, showed that the studied compound crystallizes in hexagonal system (P6₃/m (no. 176)). Structure consists of dimers composed of [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉] sub-units, linked by six μ₂-OH bridges. Infrared spectroscopic studies proved the presence of hydroxo groups in the structure of studied clusters and formation of different types of oxo/hydroxo bridges. The application of variable temperature infrared spectroscopy and differential scanning calorimetry revealed that the structure of this complex undergoes the phase transitions at 143–183 and 203–293 K. Comparison of spectral and crystallographic data suggests that these phase transitions might be related to changes in the strength of Zr–O bonds of μ₂-OH bridges linking complex sub-units, and change in symmetry of the crystal lattice (from hexagonal to trigonal). Analysis of thermogravimetric data showed that decomposition of [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉(μ₂-OH)₃]₂ proceeds with complete conversion to ZrO₂ (monoclinic form) between 603 and 803 K.     

Synthesis and crystal structure of new one-dimensional copper(II) complex [Cu4(En)2(μ1,1-N3)4(μ1,1,1-N3)2(μ1,3-N3)2]n

A new polymer azido-bridged copper(II) complex [Cu₄(En)₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂(μ_1,3-N₃)₂] _n (I) (En = ethylenediamine) has been synthesized and crystallography characterized. Complex I shows one-dimensional coordination polymeric structure based on a tetranuclear cluster unit [Cu₄(En)₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂(μ_1,3-N₃)₂], in which the azido ions display three different bridging modes.     

Synthesis and structural characterisation of the palladium N-heterocyclic carbene cluster complexes [Pd3(μ-CO)3(NHC)3] and [Pd3(μ-SO2)3(NHC)3]

The reduction of trans-[Pd(NHC)₂Cl₂] (NHC = IMes, 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene; IⁱPr₂ = 1,3-bis-isopropylimidazol-2-ylidene) with potassium graphite under an atmosphere of CO affords the palladium NHC carbonyl clusters [Pd₃(μ-CO)₃(NHC)₃] (NHC = IMes, 1; IⁱPr₂, 3). Treatment of 1 with SO₂ at room temperature yields the bridging SO₂ complex [Pd₃(μ-SO₂)₃(IMes)₃] (4) in quantitative yield. Complexes 1, 3 and 4 have been structurally characterised by X-ray crystallography.     

四核铁配合物[Fe4(NTB)4(μ2-O)2(μ4-Suc)](ClO4)6促进DNA水解

四核铁配合物[Fe₄(NTB)₄(μ₂-O)₂(μ₄-Suc)](ClO₄)₆与DNA具有较强的结合作用，结合常数k_{b达(5.9±0.4)×10⁵ L·mol^-1。该多核铁配合物由水解途径促进DNA断裂，在酸性及低离子浓度条件下的促进作用较为显著。动力学分析表明DNA水解没有明显的序列选择性，质粒DNA从超螺旋转变为切口形式符合饱和酶动力学规律，饱和速率常数ksat=0.014 min^-1。}     

Reaction of the heteronuclear cluster RuOs3(μ-H)2(CO)13 with toluene

The heteronuclear cluster RuOs₃(μ-H)₂(CO)₁₃ (4) reacts with refluxing toluene to form the clusters Ru₂Os₃(μ-H)₂(CO)₁₆ (5) RuOs₃(CO)₉(μ-CO)₂(η⁶-C₆H₅Me) (6) and Ru₂Os₃(CO)₁₂(μ-CO)(η⁶-C₆H₅Me) (7). Cluster 5 exists as a mixture of five isomers. The inter-relationship among the clusters has also been investigated.     

Reactivity of the heteronuclear cluster RuOs3(μ-H)2(CO)13 with indene

The heteronuclear cluster RuOs₃(μ-H)₂(CO)₁₃ (1) reacts with indene under thermal activation to afford the novel clusters RuOs₃(μ-H)(CO)₉(μ-CO)₂(η⁵-C₉H₇) (3), RuOs₃(μ-H)(CO)₉(μ₃,η⁵:η²:η²-C₉H₇) (4) and Ru₂Os₃(μ-H)(CO)₁₁(μ₃,η⁵:η²:η²-C₉H₇) (5), the latter two possessing indenyl ligands in the μ₃,η⁵:η²:η² bonding mode. Cluster 5 exists as a mixture of two isomers. The inter-relationship among the clusters has also been investigated.     

Two gold-ruthenium clusters derived from Ru3(μ-H)3(μ3-CBr)(CO)9

The reaction between AuMe(PPh₃) and Ru₃(μ-H)₃(μ₃-CBr)(CO)₉ (1) affords the novel heptanuclear cluster Au₄Ru₃(μ₃-CMe)(Br)(CO)₉(PPh₃)₃ (2), containing an Au/Ru₃/Au trigonal pyramidal cluster face-capped by two Au(PPh₃) groups and a CMe ligand, together with Au₂Ru₃(μ-H)(μ₃-CMe)(CO)₉(PPh₃)₂ (3), formed by isolobal replacement of two of the three μ-H atoms in 1 by Au(PPh₃) groups. The latter co-crystallises with the analogous μ₃-CH complex, as also shown spectroscopically.     

Ditertiary phosphine derivatives of the heteronuclear cluster RuOs3(μ-H)2(CO)13

The heteronuclear cluster RuOs₃(μ-H)₂(CO)₁₃ (1) reacted readily with a number of ditertiary phosphines under chemical activation with trimethylamine-N-oxide. The solid-state and solution structures of these derivatives have been examined. Six structural types have been characterized crystallographically, including one in which a phenyl group migrates from the ditertiary phosphine ligand to the metal framework. There are many more isomers present in solution, most of which are rapidly inter-converting via hydride migrations.     

Reactivity of [Os3(CO)10(NCMe)2] and [Os3(CO)10(μ-Cl)(μ-AuPPh3)] with 4-mercaptopyridine: X-ray structure of [Os3(CO)10(μ-H)(μ-SC5H4N)] and [Os3(CO)10(μ-AuPPh3)(μ-SC5H4N)]

The compound [Os₃(CO)₁₀(μ-Cl)(μ-AuPPh₃)] (2) was prepared from the reaction between [Os₃(CO)₁₀(NCMe)₂] (1) and [AuClPPh₃] under mild conditions. The reaction of 2 with 4-mercaptopyridine (4-pyS) ligand yielded compounds [Os₃(CO)₁₀(μ-H)(μ-SC₅H₄N)] (4), formed by isolobal replacement of the fragment [AuPPh₃]⁺ by H⁺ and [Os₃(CO)₁₀(μ-AuPPh₃)(μ-SC₅H₄N)] (5). [Os₃(CO)₁₀(μ-H)(μ-SC₅H₄N)] (4) was also obtained by substitution of two acetonitrile ligands in the activated cluster 1 by 4-pyS, at room temperature in dichloromethane. Compounds 2-5 were characterized spectroscopically and the molecular structures of 4 and 5 in the solid state were obtained by single crystal X-ray diffraction studies.     

Formation of the silylene-bridged complex Fe2(CO)6(μ2-SiCl2)3 from cis-Fe(CO)4(SiCl3)2: an experimental and computational study

Abstract  

Thermolysis of cis-Fe(CO)₄(SiCl₃)₂ results in the formation of the novel compound Fe₂(CO)₆(μ₂-SiCl₂)₃, which was characterized by single crystal X-ray diffraction. Density functional theory calculations were carried out to elucidate possible reaction steps leading to the formation of Fe₂(CO)₆(SiCl₂)₃, including CO dissociation and chlorine abstraction by a SiCl₃ radical generated from homolytic Fe–Si bond cleavage involving a singlet–triplet intersystem crossing.     

Stepwise addition of CuBr at [(dtc)2Mo2(S)2(μ-S)2] (dtc=diethyldithiocarbamate): syntheses and crystal structures of two Mo/Cu/S clusters [(dtc)2Mo2(μ3-S)(μ-S)3(CuBr)] and [(dtc)2Mo2(μ3-S)4(CuBr)2]

Reactions of [(dtc)₂Mo₂(S)₂(μ-S)₂] with one or two equivalents of CuBr in CH₂Cl₂ afforded two new heterobimetallic sulfide clusters, [(dtc)₂Mo₂(μ₃-S)(μ-S)₃(CuBr)] (1) and [(dtc)₂Mo₂(μ₃-S)₄(CuBr)₂] (2). Both compounds were characterized by elemental analysis, IR, UV-vis and X-ray analysis. Compound 1 contains a butterfly-shaped Mo₂S₄Cu core in which one CuBr unit is coordinated by one bridging S and two terminal S atoms of the [(dtc)₂Mo₂(S)₂(μ-S)₂] moiety. In the structure of 2, one [(dtc)₂Mo₂(S)₂(μ-S)₂] moiety and two CuBr units are held together by six Cu-μ₃-S bonds, forming a cubane-like Mo₂S₄Cu₂ core.     

[Zn10(μ4-S)(μ3-S)6(Py)9(SO4)3] as a molecular model of ZnS surfaces: an experimental and theoretical study

Experimental and theoretical results pertaining to [Zn₁₀(μ₄-S)(μ₃-S)₆(Py)₉(SO₄)₃], a possible molecular model of ZnS S-terminated polar surfaces, as well as a potential source of strictly monodispersed ZnS quantum dots, are presented and discussed. The results of density functional theory (DFT) calculations provided a rationale for the peculiar arrangement of [Zn₁₀(μ₄-S)(μ₃-S)₆(Py)₉(SO₄)₃] clusters in the solid state, contemporarily indicating the unsuitability of the isolated species to mimic whatever (polar or non-polar) ZnS surface. Despite the fact that such a failure is further confirmed by time-dependent DFT and UV–Vis diffuse reflectance spectroscopy, the combined use of theoretical outcomes, DRIFT measurements, and literature data pertaining to the surface chemical properties of ZnS (Hertl in Langmuir 4:594, 1988) ultimately testifies that [Zn₁₀(μ₄-S)(μ₃-S)₆(Py)₉(SO₄)₃] is perfectly suited to model the interaction of pyridine molecules with ZnS surface Lewis acid sites. The herein reported theoretical results are expected to be a useful reference for the interpretation of chemisorption experiments of Py-based Lewis bases on single crystal ZnS surfaces.     

Crystal structure of [(C5Me4Et)3Rh3(μ3-Se)2](PF6)2CH3CN and [(C5Me4Et)2Rh2(μ2-Cl)3]PF6

The crystal structure of [(C₅Me₄Et)₃Rh₃(μ₃-Se)₂](PF₆)₂ and [(C₅Me₄Et)₂Rh₂(μ₂-Cl)₃]PF₆, obtained in the reaction of [(C₅Me₄Et)Rh(C₆H₆)](PF₆)₂ with ZnSe in 4M HCl under hydrothermal conditions, is determined. In agreement with the 18VE rule, the triangular cluster contains single metal-metal bonds (Rh-Rh 2.864(1) ?), whereas they are absent in the binuclear complex (Rh ...Rh 3,216(1) ?). Original Russian Text Copyright ? 2009 by P. A. Abramov, M. N. Sokolov, A. V. Virovets, and V. P. Fedin __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 1, pp. 169–172, January–February, 2009.     

Thiolate-bridged heterometallic complexes of manganese and platinum: Synthesis and molecular structures of (CO)4Mn(μ-SPh)Pt(PPh3)2, (CO)3(PPh3)Mn(μ-SPh)Pt(PPh3)(CO), and (CO)3Mn(μ-SPh)Pt(PPh3)(Dppm)

A reaction of the dimer [Mn(CO)₄(SPh)]₂ with (PPh₃)₂Pt(C₂Ph₂) gave the heterometallic complex (CO)₄Mn(μ-SPh)Pt(PPh₃)₂ (I) and its isomer (CO)₃(PPh₃)Mn(μ-SPh)Pt(PPh₃)(CO) (II). A reaction of complex I with a diphosphine ligand (Dppm) yielded the heterometallic complex (CO)₃Mn(μ-SPh)Pt(PPh₃)(Dppm) (III). Complexes I–III were characterized by X-ray diffraction. In complex I, the single Mn-Pt bond (2.6946(3) ?) is supplemented with a thiolate bridge with the shortened Pt-S and Mn-S bonds (2.3129(5) and 2.2900(6) ?, respectively). Unlike complex I, in complex II, one phosphine group at the Pt atom is exchanged for one CO group at the Mn atom. The Mn-Pt bond (2.633(1) ?) and the thiolate bridge (Pt-S, 2.332(2) ?; Mn-S, 2.291(2) ?) are retained. In complex III, the Mn-Pt bond (2.623(1) ?) is supplemented with thiolate (Pt-S, 2.341(2) ?; Mn-S, 2.292(2) 0?) and Dppm bridges (Pt-P, 2.240(1)?; Mn-P, 2.245(2) ?). Apparently, the Pt atom in complexes I–III is attached to the formally double bond , as in Pt complexes with olefins.     

Dual graphs realized in the compounds di-μ3-4-mercaptopyridine catena-di-μ2-iodo-di-μ3-iodo-μ4-iodo penta copper(I) and di-μ3-4-mercaptopyridine-di-catena-iodo-di-μ3-iodo tri copper(I)

Two compounds, [Cu5I5](SNC5H4)2 [i] and [Cu3I3](SNC5H4)2 [ii], were synthesized under hydrothermal conditions and the crystal structures were solved. Both compounds crystallized in space group I41/a. The iodide and the sulphur from mercaptopyridine are connected to copper atom, giving the copper atoms tetrahedral coordination geometry. The pyridine end of the organic moiety is non-bonding and fills the empty space around the tetrahedra formed from copper, sulphur and iodide.     

Synthesis and characterization of the cluster complexes containing tetrahedral FeCrCo(μ3-S) cluster cores generated by isolobal displacement reactions. Crystal structures of (η-RC5H4)FeCrCo(μ3-S)(CO)8 (R=H, CO2Et) and FeCo2(μ3-S)2(CO)9

The monoanions (η⁵-RC₅H₄)(CO)₃Cr⁻ (1, R=H; 2, R=Me; 3, R=CO₂Et) reacted with tetrahedral cluster FeCo₂(μ₃-S)(CO)₉ to give single isolobal displacement products (η⁵-RC₅H₄)FeCrCo(μ₃-S)(CO)₈ (4, R=H; 5, R=Me; 6, R=CO₂Et) in 86-89% yields, whereas monoanion (η⁵-RC₅H₄)(CO)₃Cr⁻ (7, R=C(O)Me) reacted with FeCo₂(μ₃-S)(CO)₉ to afford the expected single isolobal displacement product (η⁵-RC₅H₄)FeCrCo(μ₃-S)(CO)₈ (8, R=C(O)Me) in 5% yield and an unexpected square pyramidal cluster FeCo₂(μ₃-S)₂(CO)₉ (9) in 45% yield. Similarly, the dianions [η⁵-C₅H₄CH₂(CH₂OCH₂)_nCH₂C₅H₄-η⁵][(CO)₃Cr⁻]₂ (10, n=1; 11, n=2; 12, n=3) reacted with two molecules of FeCo₂(μ₃-S)(CO)₉ to produce double isolobal displacement products [η⁵-C₅H₄CH₂(CH₂OCH₂)_nCH₂C₅H₄-η⁵][FeCrCo(μ₃-S)(CO)₈]₂ (13, n=1; 14, n=2; 15, n=3) in 32-36% yields, while treatment of dianion [η⁵-C₅H₄C(O)CH₂]₂[(CO)₃Cr⁻]₂ (16) with two molecules of FeCo₂(μ₃-S)(CO)₉ gave the unexpected square pyramidal cluster FeCo₂(μ₃-S)₂(CO)₉ (9) in 42% yield and the corresponding double isolobal displacement product [η⁵-C₅H₄C(O)CH₂]₂[FeCrCo(μ₃-S)(CO)₈]₂ (17) in 8% yield. Products 4-6, 8, 9, 13-15 and 17 were characterized by elemental analyses, IR and ¹H NMR spectroscopy, as well as for 4, 6 and 9 by X-ray diffraction techniques.     

Synthesis and molecular structures of the Co3(μ-OOCPh)4(μ,η2-OOCPh)2[OC(Ph)OHNEt3]2 and Co(Hdmpz)2(OOCPh)2 complexes (Hdmpz = 3,5-dimethylpyrazole)

The product of the thermal reaction between cobalt acetate hydrate and benzoic acid reacts with a triethylamine excess to form the trinuclear complex Co₃(μ-OOCPh)₄(μ,η²-OOCPh)₂[OC(Ph)OHNEt₃]₂, and its reaction with 3,5-dimethylpyrazole yields the mononuclear complex Co(Hdmpz)₂(OOCPh)₂. The compound structures are discussed on the basis of X-ray crystallographic data.     

Reactions of the titanium-carbide species CpTi(μ-Me)(μ-NPi-Pr3)(μ-C)(AlMe2)3

The reaction of CpTi(μ²-Me)(μ²-NPi-Pr₃)(μ⁴-C)(AlMe₂)₃ with ClSnMe₃ and MeO₃SCF₃ affords the species CpTi(μ²-Cl)(μ²-NPi-Pr₃)(μ⁴-C)(μ²-Cl)(AlMe)(AlMe₂)₂1 and CpTi(μ²-Me)(μ²-NPi-Pr₃)(μ⁴-C)(μ²-O₃SCF₃)(AlMe)(AlMe₂)₂2, respectively. Both 1 and 2 have been structurally characterized.