Studies on the Reaction Mechanism of Br2 ＋ I2 = 2IBr

1 INTRODUCTION Interhalogen compounds have played an impor- tant role in environment and chemical engineering production. During the course of ozone exhaustion induced by sunlight in polar region, Br2, BrCl and HOBr are all precursors of Br atom[1]. Lately, scien- tists have detected that the content of BrCl in polar region sunlight was 35 ppt, larger than that of Br2 (25 ppt). Previous studies suggested that the con- centration of BrCl and O3 exhibits obvious negative correlation: w…     

Kinetics of O2(a1Deltag) and I(2P1/2) in the photochemistry of N2O/I2 mixtures

The recent demonstration of a discharge-driven oxygen-iodine laser has generated renewed interest in the kinetics of iodine interacting with electronically excited O2 and atomic O. Kinetic measurements that are of relevance to the laser have been carried out using 193 nm pulsed laser photolysis of N2O/I2/CO2 mixtures. Singlet oxygen was generated in this system by the reaction O(1D)+N2O-->O2(a1Deltag, X3Sigma-g)+N2. The fraction of electronically excited O2 produced by this channel was shown to be >0.9. The secondary photochemistry of the N2O/I2/CO2 system was characterized by monitoring the time histories of I(2P1/2), I2, IO, and O2(a). Kinetic modeling of these data was used to determine the rate constant for the deactivation of I(2P1/2) by O(3P) (k=(1.2+/-0.1)x10(-11) cm3 s(-1)). Quenching of I(2P1/2) by O(3P) is suppressed in the discharge-driven laser by using NO2 to scavenge the O atoms. The reaction O(3P)+NO2-->O2+NO is sufficiently exothermic for the production of O2(a), and it has been speculated that this channel may be significant in the laser excitation kinetics. Photolysis of NO2 was used to probe this reaction. O2(a) was not detected, and an upper bound of <0.1 for its production in the reaction of O(3P) or O(1D) with NO2 was established.     

2-Amino-2-thiazoline. V. phenylthioureido and phenylureido derivatives of 2-thiazoline

The reaction of 2-amino-2-thiazoline (I) with phenylisothiocyanate has been reported to give 2-imino-3-phenylthiocarbamoylthiazolidine (II) at low temperatures and l-phenyl-3-(2-thiazolin-2-yl)-2-thiourea (III) at ca. 100°. When performed by us, however, this reaction gave only a single mono-adduct regardless of the temperature. Nmr and chemical evidence indicates that structure III is the correct one. Treatment of I with phenylisocyanate also gave a mono-adduct which was established to be l-phenyl-3-(2-thiazolin-2-yl)urea (V). Compound I does not form a simple di-adduct with excess phenylisothiocyanate but does so with phenylisocyanate to give 2-phenylcarbamoylimino-3-phenylcarbamoylthiazolidine (VI). The reaction of III with phenylisocyanate gives 2-phenylthiocarbamoylimino-3-phenylcarbamoylthiazolidine (VII), however, the corresponding reaction of V with phenylisothiocyanate does not give the anticipated product but a mixture of compounds which includes VI and VII.     

Cl_2 2HI=2HCl I_2反应机理的理论研究

分别在MP2/3-21G!!、CCSD(T)/3-21G!!//MP2/3-21G!!和B3LYP/3-21G!!3种水平上,计算研究了气相反应Cl2 2HI=2HCl I2的机理,求得一系列四中心和三中心的过渡态.通过比较六种反应通道的活化能大小,得到了相同的结论:双分子基元反应Cl2 HI"HCl ICl和ICl HI"I2 HCl的最小活化能小于Cl2、HI和ICl的解离能,从理论上证明了反应Cl2 2HI=2HCl I2将优先以分子与分子作用形式分两步完成.用内禀反应坐标(IRC)验证了MP2/3-21G!!方法计算得到的过渡态.     

Theoretical and Experimental Studies on the Reaction Mechanism of Cl2 ＋ I2- 2ICl

1 INTRODUCTION The reactions between halogen and halogen are basic reactions in chemistry. Especially, in the syn- thesis of iodo-substituted aromatic hydrocarbon, the reaction Cl2 I2 = 2ICl could heighten the usage of iodine atom to 100%. So far, to the best of our know- ledge, the studies about halogen-halogen reaction mechanisms are very few. In detail, only the struc- ture and stability studies of X2Y- (X, Y = Cl, Br and I) ions by calculating reaction potential energy sur- face…     

Absolute rate coefficient determination and reaction mechanism investigation for the reaction of Cl atoms with CH2I2 and the oxidation mechanism of CH2I radicals

The gas-phase reaction of atomic chlorine with diiodomethane was studied over the temperature range 273-363 K with the very low-pressure reactor (VLPR) technique. The reaction takes place in a Knudsen reactor at pressures below 3 mTorr, where the steady-state concentration of both reactants and stable products is continuously measured by electron-impact mass spectrometry. The absolute rate coefficient as a function of temperature was given by k = (4.70 +/- 0.65) x 10-11 exp[-(241 +/- 33)/T] cm3molecule-1s-1, in the low-pressure regime. The quoted uncertainties are given at a 95% level of confidence (2sigma) and include systematic errors. The reaction occurs via two pathways: the abstraction of a hydrogen atom leading to HCl and the abstraction of an iodine atom leading to ICl. The HCl yield was measured to be ca. 55 +/- 10%. The results suggest that the reaction proceeds via the intermediate CH2I2-Cl adduct formation, with a I-Cl bond strength of 51.9 +/- 15 kJ mol-1, calculated at the B3P86/aug-cc-pVTZ-PP level of theory. Furthermore, the oxidation reactions of CHI2 and CH2I radicals were studied by introducing an excess of molecular oxygen in the Knudsen reactor. HCHO and HCOOH were the primary oxidation products indicating that the reactions with O2 proceed via the intermediate peroxy radical formation and the subsequent elimination of either IO radical or I atom. HCHO and HCOOH were also detected by FT-IR, as the reaction products of photolytically generated CH2I radicals with O2 in a static cell, which supports the proposed oxidation mechanism. Since the photolysis of CH2I2 is about 3 orders of magnitude faster than its reactive loss by Cl atoms, the title reaction does not constitute an important tropospheric sink for CH2I2.     

Transient absorption studies and numerical modeling of iodine photoreduction by nanocrystalline TiO2 films

We have used transient absorption spectroscopy to study the reaction between photogenerated electrons in a dye-free nanocrystalline titanium dioxide film and an iodine/iodide redox couple. Recombination kinetics was measured by recording the transient optical signal following band gap excitation by a UV laser pulse. In the presence of a methanol hole scavenger in the electrolyte, a long-lived (0.1-1 s) red/infrared absorbance is observed and assigned to photogenerated electrons forming Ti(3+) species. In the presence of iodine and excess iodide in the electrolyte, the signal decays on a millisecond-microsecond time scale, assigned to reduction of the redox couple by photogenerated electrons in the TiO(2). The electron lifetime decreases inversely with increasing iodine concentration, indicating that the back reaction is first order in [I(2)]. No evidence for I(2)(-) is observed, indicating that the reaction mechanism does not involve the formation of I(2)(-) as an intermediate. The shape of the kinetics evolves from monoexponential at low [I(2)] to stretched-exponential as [I(2)] increases. A Monte Carlo continuous-time random walk model is implemented to simulate the kinetics and its [I(2)] dependence and used to address the order of the recombination reaction with respect to electron density, n. The model incorporates the diffusion of oxidized species from the electrolyte toward the TiO(2) surface as well as electron trapping and transport in the TiO(2). In the limit of low [I(2)], the monoexponential kinetics is explained by the recombination reaction being rate limited by the diffusion of the oxidized species in the electrolyte. The stretched-exponential behavior at high [I(2)] can be explained by the reaction being rate limited by the transport of electrons through a distribution of trap states toward reactive sites at the TiO(2)-electrolyte interface, similar to the mechanism proposed previously for the kinetics of electron-dye cation recombination. Such trap-limited recombination can also explain the superlinear dependence of electron recombination rate on electron density, which has been reported elsewhere, without the need for a reaction mechanism that is second order in n. In contrast, a second-order reaction mechanism in a trap-free medium cannot explain the observed kinetics, although a second-order mechanism incorporating electron trapping cannot be conclusively ruled out by the data. We propose that the most likely reaction scheme, that is first order in both [I(2)] and n, is the dissociative reduction of I(2) onto the metal oxide surface, followed by a second electron reduction of the resulting adsorbed iodine radical, and that empirical second-order behavior of the electron lifetime is most likely explained by electron trapping rather than by a second-order recombination mechanism.     

Coordination chemistry of H2 and N2 in aqueous solution. Reactivity and mechanistic studies using trans-FeII(P2)2X2)-type complexes (P2 = a chelating, water-solubilizing phosphine)

The reactions of the trans-Fe(DMeOPrPE)2Cl2 complex (I; DMeOPrPE = 1,2-bis(bis(methoxypropyl)phosphino)ethane) and its derivatives were studied in aqueous and nonaqueous solvents with a particular emphasis on the binding and activation of H2 and N2. The results show there are distinct differences in the reaction pathways between aqueous and nonaqueous solvents. In water, I immediately reacts to form trans-Fe(DMeOPrPE)2(H2O)Cl+. Subsequent reaction with H2 or N2 yields trans-Fe(DMeOPrPE)2(X2)Cl+ (X2=H2 or N2). In the case of H2, further reactivity occurs to ultimately give the trans-Fe(DMeOPrPE)2(H2)H+ product (III). The pathway for the reaction I --> III was spectroscopically examined: following the initial loss of chloride and replacement with H2, heterolysis of the H2 ligand occurs to form Fe(DMeOPrPE)2(H)Cl; substitution of the remaining chloride ligand by another H2 molecule then occurs to produce trans-Fe(DMeOPrPE)2(H2)H+. In the absence of H2 or N2, trans-Fe(DMeOPrPE)2(H2O)Cl+ slowly reacts in water to form Fe(DMeOPrPE)32+, II. Experiments showed that this species forms by reaction of free DMeOPrPE ligand with trans-Fe(DMeOPrPE)2(H2O)Cl+, where the free DMeOPrPE ligand comes from dissociation from the trans-Fe(DMeOPrPE)2(H2O)Cl+ complex. In nonaqueous solvents, the chloride ligand in I is not labile, and a reaction with H2 only occurs if a chloride abstracting reagent is present. Complex III is a useful synthon for the formation of other water-soluble metal hydrides. For example, the trans-[Fe(DMeOPrPE)2H(N2)]+ complex was generated in H2O by substitution of N2 for the H2 ligand in III. The trans-Fe(DHBuPE)2HCl complex (DHBuPE = 1,2-bis(bis(hydroxybutyl)phosphino)ethane, another water-solubilizing phosphine) was shown to be a viable absorbent for the separation of N2 from CH4 in a pressure swing scheme. X-ray crystallographic analysis of II is the first crystal structure report of a homoleptic tris chelate of FeII containing bidentate phosphine ligands. The structure reveals severe steric crowding at the Fe center.     

F~2, F与I~2的化学发光反应

在流动余辉实验装置上,研究了F~2,F与I~2的化学发光反应。首次在F+I~2反应体系中观察到较强的IF(B→X)发射光谱,采用简单碰撞理论对IF(B)的振动驰豫进行估算后,得到了其振动布居,发现与F~2+I~2反应体系有明显的不同,从而推测这两个反应的激发态产物IF(B)是由不同的反应通道形成的。前者由初级反应产物I~2F与F原子进一步作用产生,而后者则由激发态的I(^2p~1~/~2)与基态的F(^2p~3~/~2)碰撞复合产生。     

Br2+2HI=2HBr＋I2应机理的密度泛函理论

用密度泛函理论(DFT)B3LYP方法，取3-21G**基组研究了气相反应Br2＋2HI=2HBr＋I2的机理，求得一系列四中心和三中心的过渡态.双分子基元反应Br2＋HI→HBr＋IBr和IBr＋HI→I2＋HBr的活化能(81.02和121.08 kJ•mol－1)小于Br2、HI和IBr的解离能(249.21、320.16和232.42 kJ•mol－1)，故从理论上证明了标题反应将优先以分子与分子作用形式分两步完成.同时发现I原子与Br2分子反应生成较稳定的IBr2是一个无能垒过程，IBr2分解为IBr和Br原子的能垒为70.88 kJ•mol－1.     

Modification by fluoride,bromide, iodide,thiocyanate and nitrite anions of reaction of a myeloperoxidase-H2O2-Cl- system with nucleosides

The influence of fluoride (F(-)), bromide (Br(-)), iodide (I(-)), thiocyanate (SCN(-)) and nitrite (NO(2)(-)) on the reaction of a myeloperoxidase-H(2)O(2)-Cl(-) system with a nucleoside mixture was studied. The reaction was carried out under mildly acidic conditions and terminated by N-acetylcysteine. Without the additional anions, quantity of nucleosides consumed fell in the following order: 2'-deoxyguanosine>2'-deoxycytidine>2'-deoxythymidine>2'-deoxyadenosine asymptotically equal to 0. F(-) did not affect the reaction. Br(-) increased the consumption of 2'-deoxycytidine and 2'-deoxythymidine, but decreased that of 2'-deoxyguanosine. I(-), SCN(-) and NO(2)(-) suppressed the reaction. These results suggest that Br(-) has a unique effect in relation to nucleoside damage caused by myeloperoxidase.     

Kinetics of the reactions of CH2Br and CH2I radicals with molecular oxygen at atmospheric temperatures

The kinetics of the reactions of CH2Br and CH2I radicals with O2 have been studied in direct measurements using a tubular flow reactor coupled to a photoionization mass spectrometer. The radicals have been homogeneously generated by pulsed laser photolysis of appropriate precursors at 193 or 248 nm. Decays of radical concentrations have been monitored in time-resolved measurements to obtain the reaction rate coefficients under pseudo-first-order conditions with the amount of O2 being in large excess over radical concentrations. No buffer gas density dependence was observed for the CH2I + O2 reaction in the range 0.2-15 x 10(17) cm(-3) of He at 298 K. In this same density range the CH2Br + O2 reaction was obtained to be in the third-body and fall-off area. Measured bimolecular rate coefficient of the CH2I + O2 reaction is found to depend on temperature as k(CH2I + O2)=(1.39 +/- 0.01)x 10(-12)(T/300 K)(-1.55 +/- 0.06) cm3 s(-1)(220-450 K). Obtained primary products of this reaction are I atom and IO radical and the yield of I-atom is significant. The rate coefficient and temperature dependence of the CH2Br + O2 reaction in the third-body region is k(CH2Br + O2+ He)=(1.2 +/- 0.2)x 10(-30)(T/300 K)(-4.8 +/- 0.3) cm6 s(-1)(241-363 K), which was obtained by fitting the complete data set simultaneously to a Troe expression with the F(cent) value of 0.4. Estimated overall uncertainties in the measured reaction rate coefficients are about +/-25%.     

Crystal structures and pressure-induced redox reaction of Cs2PdI4.I2 to Cs2PdI6

Two iodopalladates of the same empirical formula with palladium in different oxidation states were synthesized from aqueous HI solution. Their crystal structures were characterized by single-crystal X-ray analysis, and the effect of hydrostatic pressure on the structural properties has been investigated. Dicesium hexaiodopalladate(IV), Cs2PdI6, crystallizes in a cubic system, space group Fm3m, with a = 11.332(1) A and Z = 4, and is isotypic to K2PtCl6. The second compound, dicesium tetraiodopalladate(II) diiodine, Cs2PdI4.I2, shows tetragonal symmetry with space group I4/mmm, a = 8.987(1) A, c = 9.240(1) A, and Z = 2. The crystal structure can be described in resemblance to the Cs2Au(I)Au(III)Cl6 type. Structural relationships and chemical and structural transformation between both compounds will be discussed. DTA measurements at ambient pressure showed liberation of I2 and decomposition of the compounds. Cs2PdI4.I2 represents an excellent example for studying a solid-state electron-transfer reaction. The redox reaction to Cs2PdI6 can be demonstrated by performing pressure-dependent X-ray studies.     

Coupling vs surface-etching reactions of alkyl halides on GaAs(100). 2. CH2I2 reactions

Surface reactions of CH2I2 on gallium-rich GaAs(100)-(4 x 1), studied by temperature programmed desorption and X-ray photoelectron spectroscopy (XPS), show CH2I2 adsorbs dissociatively at liquid nitrogen temperatures to form surface chemisorbed CH2(ads) and I(ads) species. Controlled hydrogenation of a fraction of the CH2(ads) species in the chemisorbed layer by the background hydrogen radicals results in a surface layer comprising both CH3(ads) and CH2(ads) species. This hydrogenation step initiates a plethora of further surface reactions involving these two species and I(ads). Thermal activation leads to three sequential methylene insertions (CH2(ads)) into the CH3-surface bond to form three higher alkyl (ethyl (C2), propyl (C3), and butyl (C4)) species, which undergo beta-hydride elimination to evolve the respective higher alkene (ethene, propene, and butene). In competition with beta-hydride elimination, reductive elimination of the ethyl and propyl species with I(ads) occurs to liberate the respective alkyl iodide. Beta-hydride elimination in the alkyls, in the temperature range 420-520 K, is the more dominant pathway, and it is also the rate-limiting step for further chain propagation. The evolution of the alkyl iodides represents the only pathway for the removal of surface iodines in this study and is different from previous investigations where gallium and arsenic iodide etch products (GaI(x), AsI(x) (x = 1-3)) formed instead. The desorption of methane and methyl iodide, formed from surface CH3(ads) species at high temperatures by the reaction between surface methylenes and hydrogens eliminated from the surface C2-C4 alkyls, terminates the chain propagation. We discuss the reaction mechanisms by which the observed reaction products form and postulate reasons for the reaction pathways adopted by the surface species.     

A density functional theory investigation of the Simmons-Smith cyclopropanation reaction: examination of the insertion reaction of zinc into the C-I bond of CH(2)I(2) and subsequent cyclopropanation reactions.

The insertion reaction of zinc into the C-I bond of CH(2)I(2) and subsequent cyclopropanation reactions with CH(2)CH(2) have been investigated using B3LYP level density functional theory calculations. The Simmons-Smith cyclopropanation reaction of olefins does not proceed easily due to the relatively large barriers on the insertion and cyclopropanation pathways. The computed results indicate that the IZnCH(2)I molecule is the active reagent in the Simmons-Smith reaction. This is consistent with the IZnCH(2)I reactive species being generated from diiodomethane and a Zn-Cu couple as proposed by several other research groups. The Simmons-Smith IZnCH(2)I carbenoid and CH(2)I-I carbenoid cyclopropanation reactions with olefins are compared. The reactions of olefins with the radicals from the decomposition of the IZnCH(2)I and CH(2)I-I species were also compared. We found that the chemical reactivity of the carbenoid species is dependent on its electrophilic behavior, steric effects, the leaving group character and the mechanism of the cyclopropanation reactions.     

Synthesis,Structure and Reaction of a New Bitungsten Compound:(Et_4N)_2W_2S_4 (tdt)_2

1INTRODUCTION'TheclusterscontainingMo--SorW--Shavebeenstudiedextensivelyfortheirimportantapplicationsinmanyfieldsll~43.Alongwith.thedevelopmentofrationaldesignedsynthesissuchasthe"UnitConstruction"utilizingwell-definedactivecom-poundsasbuildingblocks,binuclearsulfidecompoundsusedtodesignnewclustershavebeenpaidattentiontots'6itandalotofcompoundscontainingiM,S.O.--.J' (M=MoorW)coreshavebeenprepared['i.Inthispaper,thefirstexamplpofbitung-stencompoundwithtdtZ--ligands(Et.N),W,S.(tdt),,…     

2D-3D transformation of layered perovskites through metathesis: synthesis of new quadruple perovskites A2La2CuTi3O12 (A = Sr, Ca)

We describe the synthesis of two new quadruple perovskites, Sr(2)La(2)CuTi(3)O(12) (I) and Ca(2)La(2)CuTi(3)O(12) (II), by solid-state metathesis reaction between K(2)La(2)Ti(3)O(10) and A(2)CuO(2)Cl(2) (A = Sr, Ca). I is formed at 920 degrees C/12 h, and II, at 750 degrees C/24 h. Both the oxides crystallize in a tetragonal (P4/mmm) quadruple perovskite structure (a = 3.9098(2) and c = 15.794(1) A for I; a = 3.8729(5) and c = 15.689(2) A for II). We have determined the structures of I and II by Rietveld refinement of powder XRD data. The structure consists of perovskite-like octahedral CuO(4/2)O(2/2) sheets alternating with triple octahedral Ti(3)O(18/2) sheets along the c-direction. The refinement shows La/A disorder but no Cu/Ti disorder in the structure. The new cuprates show low magnetization (0.0065 micro(B) for I and 0.0033 micro(B) for II) suggesting that the Cu(II) spins are in an antiferromagnetically ordered state. Both I and II transform at high temperatures to 3D perovskites where La/Sr and Cu/Ti are disordered, suggesting that I and II are metastable phases having been formed in the low-temperature metathesis reaction. Interestingly, the reaction between K(2)La(2)Ti(3)O(10) and Ca(2)CuO(2)Cl(2) follows a different route at 650 degrees C, K(2)La(2)Ti(3)O(10) + Ca(2)CuO(2)Cl(2) --> CaLa(2)Ti(3)O(10) + CaCuO(2) + 2KCl, revealing multiple reaction pathways for metathesis reactions.     

I(+1) transfer from diiodomalonic acid to malonic acid and a complete inhibition of the CO and CO2 evolution in the Briggs-Rauscher reaction by resorcinol

A recent report on an intense CO 2 and CO evolution in the Briggs-Rauscher (BR) reaction revealed that iodination of malonic acid (MA) is not the only important organic reaction in the classical BR oscillator. To disclose the source of the gas evolution, iodomalonic (IMA) and diiodomalonic (I2MA) acids were prepared by iodinating MA with nascent iodine in a semibatch reactor. The nascent iodine was generated by an iodide inflow into the reactor, which contained a mixture of MA and acidic iodate. Some CO2 and a minor CO production was observed during these iodinations. It was found that in an aqueous acidic medium the produced I2MA is not stable but decomposes slowly to diiodoacetic acid and CO2. The first-order rate constant of the I 2MA decarboxylation at 20 degrees C was found to be k1 = 9 x 10(-5) s(-1), which is rather close to the rate constant of the analogous decarboxylation of dibromomalonic acid under similar conditions (7 x 10(-5)s(-1)). From the rate of the CO2 evolution, the I2MA concentration can be calculated in a MA-IMA-I2MA mixture as only I2MA decarboxylates spontaneously but MA and IMA are stable. Following CO2 evolution rates, it was proven that I2MA can react with MA in the reversible reaction I2MA + MA <--> 2 IMA. The equilibrium constant of this reaction was calculated as K = 380 together with the rate constants of the forward k 2 = 6.2 x 10 (-2) M (-1)s(-1) and backward k-2 = 1.6 x 10(-4) M(-1)s(-1) reactions. The probable mechanism of the reaction is I(+1) transfer from I2MA to MA. The presence of I(+1) in a I2MA solution is demonstrated by its reduction with ascorbic acid. To estimate the fraction of CO2 coming from the decarboxylation of I2MA in an oscillatory BR reaction, the oscillations were inhibited by resorcinol. Unexpectedly, all CO2 and CO evolution was interrupted for more than one hour after injecting a small amount of resorcinol (10(-5) M initial concentration in the reactor). Finally, some implications of the newly found I(+1) transfer reactions and the surprisingly effective inhibition by resorcinol regarding the mechanism of the oscillatory BR reaction are discussed. The latter is explained by the ability of resorcinol to scavenge free radicals including iodine atoms without producing iodide ions.     

New synthesis of 2-amino-3-cyano-4,5-tetramethylenethiophene

We have shown that 2-amino-3-cyano-4,5-tetramethylenethiophene (IV) is formed in the reaction of cyclohexanethione (I) with malononitrile (II) and sulfur in the presence of triethylamine. The reaction proceeds through a step involving the formation of cyclohexylidenemalononitrile (III) and occurs via attack by the malononitrile anion on the sulfur atom of the thiocarbonyl group of I. Δ^2,α-Bornanylmalononitrile (V) was similarly obtained from thiocamphor and II; the latter reaction cannot be realized with camphor because of the steric hindrance of the carbonyl carbon atom.     

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.