Electrochemical and Photochemical Conversion of [Ru3Ir(μ 3-H)(CO)13] into [Ru3Ir(μ-H)3(CO)12]

Electrochemical and photochemical properties of the tetrahedral cluster [Ru₃Ir( ₃-H)(CO)₁₃] were studied in order to prove whether the previously established thermal conversion of this cluster into the hydrogenated derivative [Ru₃Ir(-H)₃(CO)₁₂] also occurs by means of redox or photochemical activation. Two-electron reduction of [Ru₃Ir( ₃-H)(CO)₁₃] results in the loss of CO and concomitant formation of the dianion [Ru₃Ir( ₃-H)(CO)₁₂]^2–. The latter reduction product is stable in CH₂Cl₂ at low temperatures but becomes partly protonated above 283K into the anion [Ru₃Ir(-H)₂(CO)₁₂]^– by traces of water. The dianion [Ru₃Ir( ₃-H)(CO)₁₂]^2– is also the product of the electrochemical reduction of [Ru₃Ir(-H)₃(CO)₁₂] accompanied by the loss of H₂. Stepwise deprotonation of [Ru₃Ir(-H)₃(CO)₁₂] with Et₄NOH yields [Ru₃Ir(-H)₂(CO)₁₂]^– and [Ru₃Ir( ₃-H)(CO)₁₂]^2–. Reverse protonation of the anionic clusters can be achieved, e.g., with trifluoromethylsulfonic acid. Thus, the electrochemical conversion of [Ru₃Ir( ₃-H)(CO)₁₃] into [Ru₃Ir(-H)₃(CO)₁₂] is feasible, demanding separate two-electron reduction and protonation steps. Irradiation into the visible absorption band of [Ru₃Ir( ₃-H)(CO)₁₃] in hexane does not induce any significant photochemical conversion. Irradiation of this cluster in the presence of CO with _irr>340nm, however, triggers its efficient photofragmentation into reactive unsaturated ruthenium and iridium carbonyl fragments. These fragments are either stabilised by dissolved CO or undergo reclusterification to give homonuclear clusters. Most importantly, in H₂-saturated hexane, [Ru₃Ir( ₃-H)(CO)₁₃] converts selectively into the [Ru₃Ir(-H)₃(CO)₁₂] photoproduct. This conversion is particularly efficient at _irr >340nm.     

Nickel-Ruthenium Mixed-Metal Carbonyl Clusters Syntheses and Solid State Structures of the Two Tetrahedral Clusters [PPh4][NiRu3(μ3 H)(CO)9(μ-CO)3] and [NEt4]2[NiRu3(CO)8(μ-CO)4]

Redox condensation of [Ru₃H(CO)₁₁]- with Ni(CO)₄, in tetrahydrofuran solution, under a nitrogen atmosphere, yields the tetranuclear anion [NiRu_H(CO)₁₁)-. Subsequent deprotonation with Bu'OK in acetonitrile solution leads to the formation of the related dianion. Both anions have been characterized by spectroscopic techniques, elemental analysis and single crystal X-ray diffraction. [PPh₄][NiRu₃H(CO)₁₂] crystallizes in the triclinic space group PI with unit cell dimensionsof a = 11.842(2) Å,b = 12.335(3) Å, c = 13.3080) Å,a = 91.89(2)°, = 93.35(1)°,y = 96.41(2)°, Z = 2, V= 1926.9(7) Å'. The NiRu₃, metal core of the molecule defines a distorted tetrahedron with nine terminal and three edge bridging carbonyl groups. The hydrido ligand was located by difference Fourier techniques and was found to bridge the NiRu₂ basal triangle at a distance of 0.88(6) A from this plane. Selected average distances and angles are: Ru-Ru = 2.839 Å, Ru-Ni = 2.640 Å, Ru-C, = 1.910 A,Ru-C _b = 2.084 Å, Ni-C _b = 2.022 Å, Ru-H = 1.77 Å, C-0, = 1.135 Å, C-O _b = 1.159 Å, M-C-O, = 176.3°,M-C--O _b = 139.3°;other distances are: Ni-C₁ = l.758(7) Å, Ni-H= 1.85(7) Å. [NEt₄]₂[NiRu₃(CO)₁₂] crystallizes in the orthorhombic space group Pnma (no. 62) with unit cell dimensions ofa=20.247(5) Å,b = 15.038(4)Å,c = 12.079(3) Å, Z=4, V=3678(2) A'. The molecule contains a tetrahedral NiRu₃ core with eight terminal and four edge bridging carbon monoxide groups which bridge the three Ni-Ru and one Ru-Ru bond. Average distances and angles are: Ru -Ru =2.3050A Ru-Ni 2.648 Å, Ru-C _t = 1.878 Å, Ru-C _b 2.045 Å, Ni-C _b = 2.055 Å, C-O _t = 1.145 Å, C-01,=1.157 Å, M-C-O,= 176.9°, M-C-O _b = 138.6°; other distance is: Ni-C _t = 1.754(10) Å,t = terminal,b = bridging.     

Reactions of carbonyl clusters with potentially tridentate thioethers: Crystal and molecular structures of [Os4(CO) 13([12]aneS3)] and [Ru6(CO)15(μ4-η2- CO)([12]aneS3)] [([12]aneS3) = {(CH2) 3S}3]

The reaction of [Os₃(CO)₁₂ with [12]aneS₃ ([12]aneS₃  {(CH₂)₃S}₃) in octane for 6 h, under reflux, led to isolation of two products [Os₃(CO)₁₁([12]aneS₃)] (1) and [Os₄(CO) ₁₃([12]aneS₃)] (2), while with [Ru₃(CO)₁₂] under similar conditions, in THF, a number of products were obtained, including [Ru₄(CO)₁₁([12]aneS₃)] (3), [Ru₅(CO)₁₃([12]aneS₃)] (4), and [Ru₆(CO)₁₆([12]aneS₃)] (5). An X-ray diffraction study of 2 shows that the macrocycle is coordinated to the ‘wingtips’ of an Os₄ butterfly through the two electron pairs on one sulphur atom, while in 5 all three sulphur atoms of the macrocycle coordinate to two of the Ru atoms in a spiked edge-bridged tetrahedral metal framework.     

[CuCo(CO)4]n的能谱和能带研究

应用EHMO方法计算了[CuCo(CO)4]n低聚物的能谱和无穷链能带.简单分析和具体计算表明,Cu-Co之间以双电子双中心键结合,Cu-Cu之间则成键较弱.对单体的电子结构研究表明,AuCo(CO)4是不稳定的,因Au尚有余价,能与Lewis碱配位体结合或自身多聚.由四聚体[CuCo(CO)4]4的能谱可以得到[CuCo(CO)4]的近似能带,从而可以在统一基础上解释低聚体的能谱与无穷链的能带,为利用低聚物的理论计算和实验结果预言高聚物的物理及化学性质提供近似依据.     

Synthesis and characterisation of novel selenium-containing clusters; crystal structures of [Ru4(μ4-Se)2(CO)8(μ-CO)3] and [Ru3(μ3-Se)2(CO)7(Ph2P(CH2)3PPh2)]

The compound [Ru₄(μ-Se)₂(CO)₈(μ3-CO)₃] (1), has been obtained in good yield by vacuum pyrolysis of [RU₃(CO)₁₂] with [Ph₂Se₂] at 185°C. Reaction of 1 with 1,3-bis(diphenylphosphino)propane at room temperature affords the novel cluster [RU₃(μ₃-Se)₂(CO)₇(Ph₂P(CH₂)₃PPh₂)] (2). The structures of 1 and 2 have been determined by an X-ray diffraction study.     

Functionalization of the cluster [FeCp(μ3–CO)]4

The 33-year-old cluster [FeCp(μ₃-CO)]₄ (1) has been functionalized by reaction with lithium diisopropylamide, followed by CO₂, to give the acid RCO₂H, 2 (R=Fe₄(μ₃–CO)₄Cp₃(C₅H₄–)), recently reported by Rauchfuss. The cluster 2 reacts with (CO)₂Cl₂ to give the new cluster RCOCl (3), which reacts with the disulfide {S(CH₂)₁₁NH₃⁺Cl^–}₂ to give the amido-cluster disulfide [Fe₄(μ₃–CO)₄Cp₃{η⁵′-C₅H₄C(O)NH(CH₂)₁₁S}]₂ (4), with NEt₃ to give the diethylamido cluster [Fe₄Cp₃(η⁵-C₅H₄CONEt₂)(μ₃-CO)₄] (5), and with N-hydroxysuccinimide to give the N-succinimidyl ester cluster 6. © 2000 Académie des sciences / Éditions scientifiques et médicales Elsevier SAScluster functionalization / tetrairon-cylopentadienyl-carbonyl cluster     

The chemistry of hydridocarbonylferrates revisited: syntheses and structures of the new [H2Fe4(CO)12]2- and [HFe5(CO)14]3- anions, and the [Fe(DMF)4][Fe4(CO)12(μ5-η2-CO)(μ-H)]2 adduct containing an unprecedented isocarbonyl

The di-hydride di-anion [H(2)Fe(4)(CO)(12)](2-) has been quantitatively obtained by protonation of the previously reported mono-hydride tri-anion [HFe(4)(CO)(12)](3-) in DMSO and structurally characterised in its [NEt(4)](2)[H(2)Fe(4)(CO)(12)] salt. It shows some subtle but yet significant differences in the stereochemistry of the ligands in comparison to the heavier Ru(4) and Os(4) congeners. The study of the reactivity of these [H(4 -n)Fe(4)(CO)(12)](n-) (n = 2,3) species allowed the serendipitous isolation and structural characterization of the new pentanuclear [HFe(5)(CO)(14)](3-) mono-hydride tri-anion. Attempts to obtain the latter in better yields led to the discovery of intermolecular CO/H(-) mutual exchange reactions and isolation and structural characterization of the [Fe(DMF)(4)][Fe(4)(CO)(12)(μ(5)-η(2)-CO)(μ-H)](2)·0.5CH(2)Cl(2) and [M(+)][Fe(4)(CO)(12)(μ(4)-η(2)-CO)(μ-H)](-) (M = K, Cs) adducts, the former containing an unprecedented isocarbonyl group. The isolation of new tetranuclear and, above all, pentanuclear hydridocarbonylferrates indicates that it is possible to further expand the chemistry of homoleptic Fe carbonyl species.     

New triosmium–iridium clusters: Synthesis and molecular structure of [Os3Ir2(Cp1)2(μ-OH)(μ-CO)2(CO)8Cl] (1), [Os3IrCp1(μ-OH)(CO)10Cl] (2), [Os3IrCp1(μ-H)(μ-Cl)(η3,μ3-C5H2N(NH2)Br)(CO)9] (3) and [Os3IrCp1(μ-Cl)2(η2,μ3-C5H3N(NH)Br)(CO)7] (4)

The trinuclear osmium carbonyl cluster, [Os₃(CO)₁₀(MeCN)₂], is allowed to react with 1 equiv. of [IrCp¹Cl₂]₂ (Cp¹ = pentamethylcyclopentadiene) in refluxing dichloromethane to give two new osmium–iridium mixed-metal clusters, [Os₃Ir₂(Cp¹)₂(μ-OH)(μ-CO)₂(CO)₈Cl] (1) and [Os₃IrCp¹(μ-OH)(CO)₁₀Cl] (2), in moderate yields. In the presence of a pyridyl ligand, [C₅H₃N(NH₂)Br], however, the products isolated are different. Two osmium–iridium clusters with different coordination modes of the pyridyl ligand are afforded, [Os₃IrCp¹(μ-H)(μ-Cl)(η³,μ₃-C₅H₂N(NH₂)Br)(CO)₉] (3) and [Os₃IrCp¹(μ-Cl)₂ (η²,μ₃-C₅H₃N(NH)Br)(CO)₇] (4). All of the new compounds are characterized by conventional spectroscopic methods, and their structures are determined by single-crystal X-ray diffraction analysis.     

Silver(I)-dithiolate chemistry: Syntheses and characterizations of three new Ag1 cluster anions containingi-MNT [i-MNT= S2CC(CN) in2 su2− ] ligands-[Ag4(i-MNT)4]4−, [Ag8(i-MNT)6(PPh3)4]4−, and [Ag9(i-MNT)6(PPh3)6]3−

The reaction of AgNO₃ with [(“Bu₄N₂ i-MNT)]³ in CH₃CN produces a new silver cluster anion [Ag₄(i-MNT)₄]^4? ,3, a species having a tetrahedral arrangement of silver atoms bridged by fouri-MNT ligands which has been isolated and characterized by X-ray crystallography as [Bu₄N]₂[(PPh₃)₂]₂ [Ag₄(i-MNT)₄],4. The reaction of two or three equivalents of Ag(PPh₃)₂NO₃ with [BzEt₃N]₆[Ag₆(i-MNT)₆] in CH₃CN produces two new clusters, [BzEt₃N]₄[Ag₈(i-MNT)₆(PPh₃)₄],6, and [BzEt₃N]₃[Ag₄(i-MNT)₆(PPh₃)₆], 7, having the common structural feature of an octahedral Ag₆S₁₂ core. The octanuclear Ag₈ cluster also can be synthesized from the reaction of 4 and PPh₃ in CH₂Ck₂ and compound 5 has been structurally characterized as [Bu₄N]₂[(PPh₃)₂N]₂[Ag₈(i-MNT)₆(PPh₃)₄]. The³¹P{¹H} NMR spectrum of 6 in CD₃CN at ?43° shows two sets of two doublets. The corresponding chemical shift and coupling constant of each species is 9.32 ppm (354, 408.8 Hz) and 9.45 ppm (346.7, 401.7 Hz), respectively. Pertinent crystallographic data are as follows: Compound 4 crystallizes in the orthorhombic space group Cc2a, witha=18.668(3)A,b=36.793(4) A,c=17.836(3)A, Z=4, andV= 12250(3)A³. Compound 5 crystallizes in the triclinic space group P1, witha=16.506(3)A,b=17.280(3)A,c=19.144(4) A,x=98.485(14)°, β= 105.44(2)°.y=94.63(2),Z= 1, andV = 5164(2)A³. Compound6 crystallizes in the monoclinic space group C2/m, witha= 25.341(9)A,b= 25.289(9)A,c= 15.076(7)A, β= 107.19(5)°,Z=2, and V=9230(6)A³. Compound7 crystallizes in the monoclinic space group C2/c, witha=25.872(6)A,b=21.288(4) A,c=35,928(5), β=100.98(1)°,Z-4, andV=19426(6)A³.     

Thermal, solution and structural studies of a 3D Ag(I) coordination polymer with various Ag-Ag bonds, [Ag3(μ-Hbtc)(μ-H2btc)]n

[Ag₃(μ-Hbtc)(μ-H₂btc)]_n (H₃btc = 1,3,5-benzenetricarboxylic acid) (1), a new rarely reported Ag(I) three-dimensional coordination polymer with several Ag-Ag bonds, has been synthesized, characterized by elemental analysis and IR spectroscopy and its structure determined by single-crystal X-ray diffraction. The thermal stability of compound 1 was studied by thermal gravimetric and differential thermal analyses. The single crystal X-ray analysis of compound 1 shows that the complex consists of [Ag₃(μ-Hbtc)(μ-H₂btc)] subunits containing four different Ag environments. The results of studies of the stoichiometry and complex formation in methanol solution supported their solid state stoichiometry.     

Crystal structure of [Pd3(μ-OH)(μ-CH3COO)5]

The crystals of the [Pd₃(μ-OH)(μ-CH₃COO)₅] complex are obtained and characterized using powder and single crystal X-ray diffraction and IR spectroscopy. The crystal structure (a = 15.6942(6) Å, b = 11.7190(3) Å, c = 9.7871(3) Å, V = 1800.05(10) ų, space group Pna2₁, Z = 4) is formed from neutral trinuclear cyclic molecules of [Pd₃(μ-OH)(μ-CH₃COO)₅], in which the OH^? group, together with five CH₃COO^? anions, is a bridge ligand.     

Preparation and structural characterization of the isomorphous compounds: [Bu4N][Mo3(μ3-O)(μ-X)3(μ-OAc)3 X 3]·(CH3)2CO,X=Cl,Br

The reaction of MoCl₃(H₂O)₃ with a mixture of acetic acid and acetic anhydride in the presence of [N(C₄H₉)₄][BF₄] followed by crystallization from acetone/hexane gives a 77% yield of dark purple [NBu₄][Mo₃OCl₆(OAc)₃]·Me₂CO (1). A similar reaction employing MoBr₃(H₂O)₃ gives purple [NBu₄][Mo₃OBr₆(OAc)₃]·Me₂CO (2) in 50% yield. Also produced in this reaction in low (10–20%) yields are [NBu₄]₂[Mo₄OBr₁₂] · 0.5Me₂CO and [NBu₄]₂[Mo₃OBr₆(OAc)₃] · Me₂CO which will be discussed elsewhere Compounds (1) and (2) are isomorphous, space groupP2₁/n,Z=4 with the following unit cell dimensions, where the values for (1) and (2) are given in that order for each one:a=13.406(4), 13.726(5) Å;b=15.701(4), 15.839(5) Å;c=19.250(5), 19.831(6) Å; =101.61(2), 102.92(3)°. Both (1) and (2) are eight-electron species in which the mean Mo-Mo distances are 2.578(1) Å and 2.597(1) Å, respectively.     

Synthesis and Crystal Structure of[Co3(CO)9(μ3-C)C(O)OCH2]2

The title compound [Co3(CO)9(μ3-C)C(O)OCH2]2 was synthesized by the reaction of [Cl3CC(O)OCH2]2 with Co2(CO)8 at 40～50 ℃. Crystal data: C24H4O22Co6, Mr=997.88, monoclinic, space group P21/n(#14), a=9.330(2), b=15.197(4), c=11.783(4), β=91.16(2)°, V=1670.4(7) 3, Z=2, Dc=1.984 g/cm3, μ(MoKα)=30.01 cm-1, F(000)=972.00, T=293K, final R=0.045, Rw=0.051 for 1936 observed reflections with I＞2σ(I). The structure contains two centrosymmetric dimeric molecules in a unit cell, each of which has two tetrahedral skeletons (CCo3) connected through a C(O)OCH3CH2OC(O) bridge.     

The chemical identity of “[Ag(py)2]MnO4” organic solvent soluble oxidizing agent and new synthetic routes for the preparation of [Ag(py)n]XO4 (X = Mn,Cl, and Re,n = 2–4) complexes

Abstract

A widely used oxidizing agent in organic chemistry with an assumed structure of “[Ag(py)₂]MnO₄” and its perchlorate and perrhenate analogues are studied. Their synthesis in pure form is challenging. In order to clarify the chemical nature of the known compounds and find routes to new derivatives, a systematic study is presented for the synthesis of [Ag(py)_n]XO₄ (X?=?Mn, Cl, and Re, n?=?2–4) complexes. Ten complexes including four new derivatives, [Ag(py)₄]MnO₄, [Ag(py)₄]MnO₄·4[Ag(py)₂]MnO₄, [Ag(py)₂]ClO₄·0.5 py, and [Ag(py)₂]ReO₄, are synthesized and characterized. The chemical identity of “Ag(py)₂MnO₄” is also clarified. A novel route to prepare [Ag(py)₂]MnO₄ is developed. The reaction of AgXO₄ salts with neat pyridine followed by various crystallization techniques is used to prepare [Ag(py)₂]XO₄, [Ag(py)₄]XO₄, [Ag(py)₄]XO₄·4[Ag(py)₂]XO₄, and [Ag(py)₂]XO₄·0.5py (X?=?Cl, Mn) complexes. The solid phase structure of [Ag(py)₂]MnO₄·0.5py is determined (a?=?19.410 Å, b?=?7.788 Å, c?=?21.177 Å, β?=?104.20°, C2/c (15), Z?=?4 (3a)). [Ag(py)₂]⁺ cations in the crystal form dimeric units where silver ions are connected by oxygen atoms of two MnO₄^– anions. The Ag…Ag distance is indicative of argentophilic interactions. The pyridine ring π…π interactions contribute to the stability of the crystal lattice.     

The reaction of [Ru10C(CO)24][ppn]2 with carbon monoxide to yield [Ru3(CO)12] and [Ru6C(CO)16]2−

The dianion [Ru₁₀C(CO)₂₄]²⁻ in CH₂Cl₂ reacts with CO under ambient conditions to produce quantitative amounts of the species [Ru₃(CO)₁₂] and [Ru₆C(CO)₁₆]²⁻; the hydrido-anion [HRu₁₀C(CO)₂₄]⁻ reacts similarly to form [Ru₆C(CO)₁₆]⁻.     

Synthesis,structures, and properties of the niobium and tantalum telluride cubane clusters [M4(μ4-O)(μ3-Te)4(CN)12]6– (M = Nb or Ta)

The new cubane cluster complex K₆[Ta₄(₄-O)(₃-Te)₄(CN)₁₂]·KOH·4H₂O was prepared from a mixture of TaTe₄ and KCN by the high-temperature synthesis followed by crystallization from aqueous solutions. The compound was characterized by cyclic voltammetry, X-ray diffraction analysis, and IR, Raman, and electronic spectroscopy. A comparative study of the clusters [M₄(₄-O)(₃-Te)(CN)₁₂]^6– (M = Nb or Ta) containing the ₄-O ligands was carried out. These clusters are the first molecular chalcogenide cubane complexes of Group V metals.     

Experimental and theoretical Mössbauer study of an extended family of [Fe8(μ4-O)4(μ-4-R-px)12X4] clusters

Six [Fe(8)(μ(4)-O)(4)(μ-4-R-pyrazolato)(12)X(4)] complexes containing an identical Fe(8)(μ(4)-O)(4) core have been structurally characterized and studied by M?ssbauer spectroscopy. In each case, an inner μ(4)-O bridged Fe(III) cubane core is surrounded by four trigonal bipyramidal iron centers, the two distinct sites occurring in a 1:1 ratio. The M?ssbauer spectrum of each of the clusters consists of two quadrupole doublets, which, with one exception (X = NCS, R = H), overlap to give three absorption lines. The systematic variation of X and R causes significant changes in the M?ssbauer spectra. A comparison with values for the same clusters computed using density functional theory allows us to establish an unequivocal assignment of these peaks in terms of a nested model for the overlapping doublets. The changes in M?ssbauer parameters (both experimental and computed) for the 1-electron reduced species [Fe(8)(μ(4)-O)(4)(μ-4-Cl-pyrazolato)(12)Cl(4)](-) are consistent with a redox event that is localized within the cubane core.     

Cu Doping-Induced Transformation from [Ag62S12(SBut)32]2+ to [Ag62−xCuxS12(SBut)32]4+ Nanocluster

The change in the valence state of nanocluster can induce remarkable changes in the properties and structure. However, achieving the valence state changes in nanoclusters is still a challenge. In this work, we use Cu²⁺ as dopant to “oxidize” [Ag₆₂S₁₂(SBu^t)₃₂]²⁺ (4 free electrons) to obtain the new nanocluster: [Ag_62−xCu_xS₁₂(SBu^t)₃₂]⁴⁺ with 2 free electrons. As revealed by its structure, the [Ag_62−xCu_xS₁₂(SBu^t)₃₂]⁴⁺ (x=10∼21) has a similar structure to that of [Ag₆₂S₁₂(SBu^t)₃₂]²⁺ precursor and all the Cu atoms occupy the surface site of nanocluster. It′s worth noting that with the Cu atoms doping, the [Ag_62−xCu_xS₁₂(SBu^t)₃₂]⁴⁺ nanocluster is more stable than [Ag₆₂S₁₂(SBu^t)₃₂]²⁺ at higher temperature and in electrochemical cycle. This result has laid a foundation for the subsequent application and exploration. Overall, this work reveals crystals structure of a new Ag−Cu nanocluster and offers a new insight into the electron reduction/oxidation of nanocluster.